Antenna polarization may be one of the least understood properties of a wireless signal. If you are installing many antennas in one location, like on a tower, polarization is an important piece of the puzzle that you’ll need to take into consideration. Here we give you a quick overview on antenna polarization.
Polarization is determined by the way an antenna is mounted, usually horizontally or vertically. To ensure optimal network performance only like-polarized antennas should be used in point-to-point wireless applications. It is possible to establish a wireless link using antennas with different polarities but network performance and connectivity will suffer.
The big advantage of using different antenna polarization schemes is to reduce interference. For example when mounting several antennas on a tower, it is best to stagger vertically and horizontally polarized antennas to reduce interference.
If horizontal or vertical polarization won’t work for your wireless application there are dual-polarized, cross-polarized and circular-polarized antenna options to explore.
Antenna Polarization Options
Dual-polarized antennas feature two antenna elements in a single physical package (radome), one that is vertically polarized and one that is horizontally polarized. When properly installed, dual polarized antennas can communicate with both vertically and horizontally polarized antennas. An advantage of dual polarity antenna is that you get basically two antennas in one package, this saves space and money. These types of antennas are often used with MIMO (multiple-in/multiple-out) wireless access points and CPE devices.
Cross-polarized antennas sometimes referred to as X-Pol antennas, feature two elements in one package. One element is +45° polarized and the other is -45° polarized. The two opposing 45° angle of the elements produces a cross or X orientation. Using a cross polarized antenna with vertically and horizontally polarized antennas further reduces interference.
Circular-polarized antennas have equal response to either horizontal or vertical polarized antennas. These antennas are designed to either support right hand or left hand polarization to suit varied wireless connectivity applications. Using a circular-polarized antenna on a fixed access point can be beneficial if the linear-polarized remote links are constantly moving.
Republished with permission and courtesy of L-com Global Connectivity.
As many of you know, I am an avid APRS operator. I am proud to have had a fulltime, RF-driven Ham Radio APRS Weather Station on the air from my home continuously for over twenty years.
I am also heartened by several new RF-driven APRS Weather Stations that have popped up on the air in the last few months. Kudos to KM4LTG and K4DKK to name a couple of relatively new Hams who have not only taken the plunge into APRS but are “brapping” live weather data into the RF network. These stations are proverbial “points of light” for the National Weather Service and Ham Radio as they track our sometimes abundant rainfall and wind activity from thunderstorms rolling through our area. This is one more way Amateur Radio continues to be a “relevant” force in the 21st century!
APRS is an acronym for Automatic Position Reporting System, an invention of Bob Bruninga of the U.S. Naval Academy. It has been around since the early 1990s and was originally created to track moving objects using GPS and Ham Radio. In fact, it provides Bruninga a means of tracking his Midshipmen while they were out on the water at Annapolis.
A few years later, identical twins Keith-WU2Z and Mark-KB2ICI Sproul, developers of the WinAPRS and MacAPRS software expanded their apps to include support for transmitting live weather data. Other APRS developers soon followed. And to collect all this data for analysis by the National Weather Service, APRS was married to the Internet through the APRS-IS network. Along the way, another Florida Ham, Steve Dimse-K4HG, created the findu.com website, a portal for literally everyone to view the data collected from thousands of Amateur Radio APRS Weather Stations nationwide.
Here’s a fun factoid about the real-time application of APRS Weather Station data. In 2004, the APRS Weather Station network in central Florida was used by National Weather Service meteorologists to track the path of Hurricane Frances as it came across the peninsula.
The West Central Florida Group has supported APRS for many years. The NI4CE digipeaters at Verna and Riverview are hubs for the APRS network in the Greater TampaBay area and gateways for APRS weather data to the Internet. We have just upgraded the NI4CE-11 Weather Digi at Riverview and will soon be adding APRS Weather Stations at our Holiday and Lake Placid repeater sites. Polk County Emergency Management operates an extensive network of APRS Weather Stations (WC4PEM) in their county. Data collected by these stations is used daily by Polk County firefighters to aid their efforts assessing fire danger and battling wild fires.
If you would like to know more about APRS, APRS Weather Stations and how you can get on the air, just send an email to email@example.com.
Before I close, a word about Internet-only Weather Stations operated by a number of area Hams. We are grateful for the weather data you are collecting and sharing with us. But it really isn’t Ham Radio and APRS unless you add a radio and send it over the air on 144.390 MHz. Put your callsign and your weather data on the APRS map. Go all the way!
-May 27, 2019
When you are growing up (or at least when I was growing up), you are taught that sharing is a good thing. Of course, there is a limitation to that. For instance, you really don’t want to share the flu or a head cold with someone else. But we routinely will share radios, pizza, tools and lots of other things with family and friends.
As Amateur Radio operators, we share some of the spectrum we are assigned and use regularly. Our 70 cm (UHF) frequencies are shared with the Federal Government, primarily the Department of Defense. Our 902-928 MHz allocation overlays the ISM (Industrial, Scientific, and Medical) band. Over 1 GHz, there is all kinds of frequency sharing (e.g. 2.4 GHz Wi-Fi, 5.8 GHz Wi-Fi, 5.9 GHz ITS, etc.). There are also a couple of instances of Deep Space SETI cut-outs in the 3.3 GHz band. There is nothing wrong with spectrum sharing as long as you and those entities you are sharing with can peacefully co-exist with each other.
But Spectrum Sharing does have its limits. Some recent attempts to overlay Wi-Fi on some bands with existing Satellite users are proving to be not such a good idea. Signals from orbiting satellites are very, very weak by the time they arrive from space. Drop some Wi-Fi emissions into the mix and at best they will raise the noise floor, at worst, they will cause harmful interference. Such is the case with the effort to allow Wi-Fi in and near the C-band satellite spectrum.
There is a new proposal now before the FCC to allow a private 5G Cellular provider to operate on the spectrum that has been in use for decades by NOAA to download satellite weather imagery and other climate-related data. The frequencies being looked at are 1675-1680 MHz.
Frequencies between 1670-1675 MHz are already allocated for commercial wireless use. The petitioner wants to use the 1670-1675 MHz spectrum plus the 1675-1680 MHz segment to provide wider band, high speed, 5G services than they would otherwise be able to do.
NOAA’s fleet of weather satellites and the imagery they provide are critical tools for forecast severe weather, particularly hurricanes and other tropical disturbances. Anything that potentially blinds us to that critical information this time of year is not a good idea.
Groups like the American Meteorological Society (AMS), National Weather Association (NWA) and the American Geophysical Union have already come out against this proposal. You, too, can weigh in and let the FCC know what you think (for or against) by using the following web link: FCC link
-June 29, 2019
For those of you who were fans of the old “Six Million Dollar Man” TV series you will recall how the show opened every week with the proclamation “We have the technology”. Then, along came Star Trek and the Borg. It was the Six Million Dollar Man mass produced and on steroids.
So with all the technology we now possess in 2017, with the extreme miniaturization of circuits that is now found in everything electronic and with our collective ability to control almost everything with software, why is it two-way radio transceivers do not have something as basic as a VU meter to monitor and display the audio quality of what is being transmitted?
When I first started my broadcasting career it was drilled into my psyche that the VU Meter was not only your friend but the single best tool at your toolbox to monitor the level and quality of your audio. You lived and died by what the VU meter on your console, on your air monitor on anything that enabled you to control the audio quality of your signal told you. Without a VU meter to monitor your audio output, you may as well have been trying to drive a car at night wearing a blindfold. You lived and died by your VU meter if you wanted consistent (and properly modulated) audio levels.
When I ventured into Amateur Radio in 1995, I was absolutely shocked to find few if any Amateur Radio transmitters with some means (other than your ears) of assuring proper modulation and audio quality. And today twenty-two years later, the only devices I have found that are outfitted with something approaching a VU meter are very high-end HF rigs that only a handful of Hams have in their shack. Why is that you might ask? I wish I had the answer.
Just turn on NI4CE any evening during one of the many Nets are conducted each week. You will hear stations that are LOUD, some painfully so. You will hear stations whose audio sounds about right. And you will hear stations (if you turn the speaker volume to the MAX) with low audio, some averaging no more than ten to fifteen percent modulation. It’s all over the road! And with a simple addition of a VU meter or some means of monitoring the transmitted audio volume of the transceiver, these all-over-the-road audio levels are preventable.
Of course, unless someone (FCC) were to require some means of real-time audio level monitoring, it probably won’t happen. Adding an Automatic Gain Control (AGC) circuit to every radio would help. But good luck getting being able to buy any transceiver for thirty dollars after an AGC circuit is added. I am afraid we may have to add this one to the list “obvious problems to fix” (right next to building utility lines through trees).
As we continue to pick up the pieces from this year’s spate of intense and destructive tropical cyclones, there are questions about what worked (and why) and what did not work (and hopefully, why). Were our expectations high enough? Was our vision broad enough? Did we individually and collectively have a realistic view of how to prepare, how to respond and, so to speak, weather the storm? But maybe the most important question that needs to be asked (and answered) is “Can We Make It Better?”.
When the concept of the NI4CE Repeater System was first conceived in 1999, the purpose was to fill a perceived need. Our region did not have a single point, “go to” Amateur Radio communications system where Hams who were SKYWARN spotters could report severe weather information. Before the NI4CE system was built, Net operations were strictly county-based. That meant a Net Control operator located at the National Weather Service in Ruskin spent most of the time “spinning the dial”, going from one repeater to another, trying to collect information. The opportunity for a county-based Net Control operator to have clear visibility of what was coming at them from the next county over was minimal.
When the “Big Stick” repeaters at Verna went on the air, it was the start of connecting a lot of dots. No more “spin the dial”, no more “flying blind”, a network started being built. In 2004, the repeaters at Verna and St Petersburg helps a lot of people “weather the storm” and aided disaster responders like the Salvation Army and Red Cross with their relief efforts.
“Big Stick” was never envisioned as a “Be All, End All” solution. And after the 2004 experience, we were able to expand the system with repeaters at Pebbledale (now Bartow) and Riverview. This accomplished two important improvements: better coverage, particularly for indoor portable radio operation and repeater redundancy. Still, that did not get us where we wanted to be. In 2011, the Holiday site came online to provide better redundancy over the TampaBay Metro area and to expand coverage over counties to the North. And in 2015, a long talked about repeater in Lake Placid was added to cover Highlands County.
Of course, all this has taken a lot of money and a lot of time to build and maintain. Having some great partners, particularly our Broadcast partners Cox Media Group, iHeart Media, ION Networks, Hearst Broadcasting, American Tower Corporation, and Insite Tower has been a big, no, HUGE plus. And the support we receive from the Amateur Radio community has allowed the NI4CE system to serve West Central Florida. To all, we say “Thank You”!
If you have not seen Dave Rockwell’s article titled ‘Disaster Traffic” that was posted on the NI4CE website last week, please take a few minutes to read it and digest it. Disaster response communications don’t just happen. It takes a lot of vision and planning. And, hopefully, our experiences this year will enable us to better plan for the next disaster.
The advent of cellular communications has done more to put mobile, interactive communications devices in the hands of every American than anything else in history. There are now an estimated three hundred thirty million cell phones or cellular enabled devices (e.g. tablets, computers, etc.,) in domestic use. WOW! I wish we had even one percent of that in Amateur Radio.
One thing most cellular enabled devices also have onboard is Wi-Fi. There are currently two main Wi-Fi bands that operate in the U.S., 2.4 GHz (sometimes referred to as 802.11b,g) and 5 GHz (sometimes referred to as 802.11a). Two newer IEEE protocols, 802.11n and 802.11ac with higher data throughput them their predecessors, are also prevalent on both bands. And in case you haven’t noticed it, most Wi-Fi enabled phones will work just fine with data apps even if your cellular LTE service is down or disconnected (Airplane mode when you are flying).
Almost all Wi-Fi operates with requiring a FCC license of any kind. This is because most (but not all) Wi-Fi devices transmit with no more than one hundred milliwatts (or 0.1 watts). That is the threshold for licensed versus unlicensed domestic radio transmitter operation. One exception to this is (wait for it) AMATEUR RADIO. Yessiree Bob, Hams can operate with more than 0.1 watts on Channels 1 through 6 in the 2.4 GHz band and on frequencies between 5.65 GHz and 5.925 GHz in the 5 GHz band. Of course, Ham can also operate on all Wi-Fi frequencies within the boundaries of the Part 15 rules because, after all, we’re just plain folks, too.
I mention all this because we are about to head into yet another Hurricane and Tropical Storm Season when the Amateur Radio community may be called on to provide emergency communications for our neighbors. One of the “lessons learned” from recent hurricanes is Americans of all shapes, sizes, genders and backgrounds are addicted to their Wi-Fi (and LTE) enabled communications devices. So, when you want to get information into the hands of those in a community impacted by a storm or some other emergency, where are us “just plain folks” likely to look first for that information. If you answered the above question with “Their Wi-Fi / LTE device”, give yourself a gold star!
That does present a real challenge for Emergency Managers and others who are trying to put critical information into the hands of those in the emergency / disaster zone. If the Cellular Networks are out in the area, you have a really big hurdle to overcome. One way to overcome this speedbump is with Wi-Fi hotspots mounted on easy to move pushup poles.
Most Wi-Fi is used indoors in our homes and businesses. Put four walls around a transmitter operating with 0.1 watts inside a well-constructed building and you will limit the propagation of the signal. But put that same 0.1 watt output on a push-up pole thirty to fifty feet above ground level and you will be surprised at just how far that signal will travel. In a densely populated area or an urban sprawl (like the TampaBay area), you will need lots of these Wi-Fi hotspots. But this is a technology every community should consider using in an emergency. And this is a technology every Ham operator should consider putting up at their home base to help their neighbors out.
Wi-Fi, all by itself, is not necessarily the “Silver Bullet”. But when you are looking at what you and your neighbors have in common, Wi-Fi may be close to the top of the list.
-May 12, 2019
Comparing radios with one another is what a “Shootout” is all about. It is a time tested method for evaluating the various offerings in the marketplace where apples are apples (so to speak), not oranges, apricots or grapefruit.
The advent and miniaturization of silicon components have allowed several manufacturers to cram so many features into very small physical packages. Sometimes we lose sight of what is really important – voice and speech quality. The ultimate test for any two-way radio should be how well it actually sounds. All the fancy features don’t mean a hoot if the radio sounds like something that was just dragged through a swamp.
The ability of the radio to reproduce clear, intelligible audio is a by-product of the technology inside the chassis. But that is not the only factor. The operating mode of your radio (analog versus digital), the modulation schema of the radio (AM, FM, SSB, FDMA, TDMA, etc.) and the signal strength of both the transmitted carrier and the received carrier all factor into the clarity and understandability of what you hear. One other really important factor is the quality of the speaker or headset you are using to reproduce what has been transmitted.
Amateur Radio operators have been very slow adopting digital voice radios. I am sure price has had something to do with it, particularly given the number of cheap (and I am not just talking about price) radios that have flooded the market. Digital voice radios require a chip, a vocoder, that converts speech to zeros and one for transmission and, conversely, takes the received zeroes and ones and re-creates human speech. A vocoder or any kind of DSP (digital speech processing) adds to the cost of these radios. But take it from someone who values clear speech without all the bleeps, chirps, snap, crackle and static crashes, the cost of the vocoder and what it brings to the table is well worth the expense.
The downside with digital voice radios is the lack of compatibility. Even though most digital voice radios are built around the same vocoder chip, there is no one single set of standards the manufacturers have adopted for these radios. Two-way digital voice radio is unlike digital broadcast radio and digital television where all manufacturers have built their transmitters and receiving equipment to a universal standard. This lack of a single standard has scared off Hams from entering the digital realm for the lack of interoperability. Analog radios may not sound as clear and readable as their digital counterparts. But at least they all work together, well, sort of.
The FCC laid out a roadmap and their vision for narrowband digital voice radio in 2004. Two Japanese radio manufacturers, ICOM and Kenwood, took on the challenge and created NXDN. Their products are interoperable in conventional (non-trunking) mode. And the radios produce clear, easy to understand audio that is shaped to the human ear. Oddly enough, it was an American company, now among others, who begged, pleaded and lobbied for an exception to what the FCC laid out. Why? Because their narrowband digital voice radios took a different path.
Had the FCC stood its ground fifteen years ago to ensure compatibility and interoperability, narrowband digital voice radio would not be the Beta vs VHS free-for-all it has turned out to be. Two likely outcomes would be better, less expensive radios for all to use and enjoy and advanced technological innovation.
The TampaBay area is a leader in Amateur Radio NXDN digital voice radio. Come visit the NI4CE Booth at the TampaBay Hamfest December 13 and 14 to hear just how good NXDN radios sound.
-October 29, 2019
If you read my posts on a regular basis, you know most are focused on using communications technology to help make our lives better. And because these posts appear here on a website devoted to Amateur Radio, special attention is paid to our wonderful hobby.
I am going to broaden the scope of this post, however, not only because there is a potential direct impact to Amateur Radio but to everyone in of society. And my comments are going to be directed toward a particular segment of our Florida population: our elected politicians in Tallahassee.
Once again, lawmakers are headed down another rat hole trying to fix the problem of distracted driving. As well intentioned as their effort might be, once again, they have it all wrong. You are not going to stop distracted anything, crawling, walking, driving, skateboarding, roller blading, wind surfing or any other endeavor involving cell phones and motion unless you force a common sense change to the technology. As long as the display on these devices can remain active while the device is in motion, it is only human nature that some will want to and continue to use their smart phone to text, email, or play with some other app inappropriately.
Distracted driving is a huge problem. Lives are being lost. Many other people, through no fault of their own, are being injured. But this stupidity is not limited to people operating motor vehicles. The distraction of using portables devices is also a problem with pedestrian traffic as well. A person texting while walking is a hazard to other pedestrians around them and to themselves (particularly if they step off the curb and walk out in front of a moving vehicle).
The only way you are going to curb this serious problem is to use the onboard technology now built into all smart phones to disable the device’s display when the smart phone is in motion, period! If you can’t see the message, you can’t read it or write a response to it. With text to speech technology also included on many of these devices, it may also be necessary to disable this capability as well to control this problem and human behavior.
Of course, there will be some people who will scream bloody murder claiming their rights are being infringed by such a law. Too bad! Operating a digital information device while in motion is not a right granted in anyone’s Constitution. And the last time I looked, driving a motor vehicle is a “privilege” not a “right”.
Common sense would go a long way toward solving the problem of distracted people in motion and all that can result. But we all know that common sense is not very common. So, in its absence, other action is required. If our politicians really want to curb “digital distraction”, they need to effectively limit the use of the technology, not just slap another band-aid on the open wound and hope it cures the patient. Senate bill S76 and House bill HB 107 are not the answer.
-March 8, 2019
If you live in Florida, anywhere in Florida, the last week has been extraordinary. For many, life is getting back to “normal”, if you define “normal” as electricity from a power utility, air conditioning, a hot shower and most if not all the other conveniences of life prior to Hurricane Irma. For many others, however, “normal” is still an elusive target. And Hurricane Season still has a long way to go.
The last time Florida experienced a storm that ran up the center of the state and affected so many people was Hurricane Donna, exactly sixty-seven years ago. I wasn’t living in Florida at the time. But those who experienced Donna first-hand did not have the satellite imagery, the Tropical Cyclone forecasting, and the other technology now in place to prepare them for what was about to change their lives. A couple Donna survivors I have talked with have told me the impact of Irma was much worse. I wonder if the all the pre-storm anxiety, the long lines at gas stations, food stores, Home Depot, Lowes and other stores wasn’t part of their assessment.
Floridians in 1960 did not have the vast communications resources and networks we have today, either There were no cell phones, Facebook, Twitter and the like to share the experience with others. Heck, Ham Radio and SKYWARN had barely met in 1960 to provide real-time information on the storm, where it was going and who would be impacted the most. Of course, there were a lot fewer people in Florida in 1960 than today. It was a simpler time and place.
We are not going to know the full extent of just how bad Irma was for a few months. For those of us who lost our utilities and were inconvenienced for a few days, the impact will be far more fleeting than those whose homes are flooded or otherwise severely damaged. I can only hope that whatever Irma’s impact was on your neighborhood, you took the opportunity to get to know your neighbors a little better and help them out if you could. And I hope everyone will take this experience and acknowledge what worked, what needs improvement and be better prepared for the next storm that will barge into our lives.
I want to take a moment to acknowledge some extraordinary efforts that helped keep people informed before, during and after the storm. A tip of the hat to Evans Mitchell-KD4EFM and Jason Triolo-KD4ACG for their efforts both collecting and disseminating information about Irma on NI4CE. They kept the SKYWARN Net running under very tough circumstances. Another tip of the hat to our partners at Cox Media Group, iHeart Radio, American Tower Corp. and Polk Co Emergency Management for keeping the generators running, allowing the NI4CE system to remain on the air and available for the Ham Radio community. Downed trees and power lines at the Holiday site made re-fueling the generators there a real exercise in “adapt, improvise and overcome”. And a big thumbs up for the Hams who manned shelters and are aiding in the recovery effort.
Hurricanes like Harvey, Irma and Jose and all those that preceded them serve a necessary purpose, that is, to evacuate an extraordinary amount of heat and energy from the surface of our planet. Hurricanes have been doing this long time, long before all the chatter about climate change. It is part of Mother Nature’s grand schema to keep out eco-system in balance. It is unfortunate so many lives must be disrupted in the process.
I have written before about Digital Two-Way Radio, the several flavors of digital radio that are currently available. I have also discussed what some of the differences between these Common Air Interfaces (CAI) are and why the West Central Florida Group, Inc. made NXDN as its choice for the digital repeaters we operate.
One thing I have not gotten into is WHY digital two-way radio for VHF and UHF is important to the Amateur Radio community here in West Central Florida and for that matter, to Hams everywhere. Once you understand that, I think you will agree it is something we all need to take seriously.
Hams have not been mandated by the FCC (or any other body yet) to go Narrowband on VHF and UHF. We have been allowed to continue operating with 25 KHz, wideband FM (WBFM) signals on these two important bands, unlike commercial, Land Mobile Radio operators. But don’t believe for a minute that 12.5 KHz Narrowband FM (NBFM) operations will never come. Many newer “Ham” radio products will operate in NBFM mode. It is not a matter of “if” but rather a matter of “when” this will occur.
What is narrowbanding all about? It is simple: Doing More With Less. Narrowband FM operations can enable up to twice as many radio channels for both repeater and simplex operations. But there are some significant drawbacks with Narrowbanding many Ham have yet to discover. One big drawback is the loss of coverage. Narrowband repeaters generally experience a twenty-five percent or more loss of their coverage footprint versus their current WBFM operation. That’s HUGE! This loss of coverage will cause more instances of weak signal reception and loss of reception altogether. Another downside is the impact of more repeaters on the air. More repeaters can increase the probability of Intermod when two or more signals from different sources mix to create a spurious signal.
So WHY is digital so important? And WHY should Hams start paying more attention to DIGITAL? Again it’s all about “doing more with less”.
NI4CE selected NXDN as the digital mode we would support for several reasons. NXDN radios operate with 6.25 KHz channel bandwidth. But instead of suffering a loss of coverage, NXDN actually provides a ten percent or more increase in coverage when compared with a WBFM signal. NXDN voice is clear, no static, no “snap-crackle-pop” even when the received signal strength in analog would be noisy and unreadable. NXDN radios can also be used to deliver text messaging and GPS location data. And the process of connecting NXDN repeaters over IP / Internet to form a repeater network is very simple and straightforward.
End-user NXDN radios are readily available and feature-rich, There is more than one manufacturer producing NXDN radios. And support for the development of applications for the Ham community is also available.
To help Hams in West Central Florida know more about NXDN, we have set up the NI4CE-NXDN email group. You can join the discussion by sending an email to firstname.lastname@example.org. We will be happy to add you to the list. And watch the NI4CE.org website for news about an NXDN Net on the NI4CE NXDN Repeaters coming soon.
As we, once again, celebrate the Fourth of July and the freedoms we enjoy here in the United States, it is easy to be reminded that freedom (and all good things for that matter) is something we cannot become complacent about. Freedom is a precious commodity something we must work at every day. It does not just happen all by itself.
Ham radio and the freedom to communicate freely is the same way. No one, to the best of my knowledge, was born with the knowledge and skills needed to use technology, any technology, to convey ideas, solve problems or just “shoot the breeze”. Using wireless technology, including Ham Radio equipment, is a learned process. If you don’t believe me just tune in to any repeater system and witness the number of key-ups or “kerchunks” followed by dead silence. Those of us who are Volunteer Examiners were called on to administer Morse Code tests to evaluate the ability of Ham Radio license candidates to operate with Morse Code. I sometimes think we need some sort of Phone Proficiency exam as part of the testing process to make sure that operators actually know what to do once they have pressed the Push-To-Talk button.
But back to the topic of “complacency”. It has been thirteen years since those of us on the West Coast of Florida experienced a major disaster. Someone said to me the other day we need a good hurricane or some other type of disaster event to shake everyone out of their complacency and not take everything for granted. By nature, humans, including those of us with an Amateur Radio license, tend to get into a “comfort zone” and stay there because it is the easy thing to do. We avoid taking on challenges or thinking outside the box unless it is something we are really motivated to do.
Unfortunately, we live in a world where the challenges are growing in scope and in number. There are the natural threats (like severe weather and hurricanes) that we can get some prior warning about. And then there are the manmade threats for which we will receive almost no prior warning.
One threat we need to take seriously is EMP – Electro Magnetic Pulse. EMP can occur naturally, the result of sunspot solar flare activity and lightning. EMP can also be manmade on a scale that can range from something very localized to a catastrophic, existential event. The loss of the electric power grid and most electronic communications (including Ham Radio) that we rely on daily could have an enormous impact.
There are several actions you can take to mitigate the threat from EMP. First, protect your radio equipment with EMP-rated devices, like PolyPhasor Lightning Protectors. The West Central Florida Group, Inc. has been using EMP-rated lightning protection for over a decade at our several NI4CE repeater sites. Second, build a Faraday Cage and place one or more radios into it for safe keeping. Third, think about all the things you need electricity for and what you would do if the lights went out. You will find this goes well beyond communications. Finally, raise your voice with your elected representatives and electric power provider about the work that needs to be done to shore up the Electric Power Grid in the United States. Several studies conducted over the last two decades have concluded the electric grid is at significant risk from an EMP event. One of these studies has determined the power grid can be strengthened and made more secure at a cost of around $2 billion. Complacency about this problem and its potential impact, however, has led to inaction. Not good enough!
Take stock of the freedoms we enjoy this Independence Day Week. And if you will be cooking some burgers on the grill, I’ll take mine medium rare!
Lots of hams on NI4CE wanted to help during Hurricanes Harvey, Irma, and Maria. After all, many of us became radio amateurs to become public service operators in the Amateur Radio Emergency Services (ARES). There were questions every night on Eagle Net about how to get health and welfare (H&W) traffic into first Texas, then the Caribbean, and, after Maria, into Puerto Rico. Folks with family in the impacted areas reached out to amateurs here in our coverage area to get messages to friends and loved ones. Many amateurs were frustrated when their H&W traffic requests were turned back. So, let me see if I can put this situation in perspective.
First, let’s look at the situation where we, the local amateurs, are in the impact zone of the hurricane (works for earthquakes, volcanoes, blizzards, and manmade disasters). Depending on the severity of damage, we may only have a small number of radio stations that can operate. Since the power will be out, the stations will likely be on generator or battery power. These operators may have suffered damage and trauma from the storm. Bottom line: If these operators can operate at all, it is for a short period of time. Remember our rule in ARES is “family first”. Make sure you and your family are safe before jumping on the radio.
If the impact area is large, there will be thousands of people displaced by the event. We need an efficient means for folks in the impact zone to pass messages to friends and loved ones. ARES usually works with non-government organizations (NGOs as we call them in Emergency Management) like the Red Cross or Salvation Army (and other faith-based groups). These organizations have proven techniques for collecting health and welfare information. In the impacted area, the NGOs set up reception tables and may have representatives in major shelters and medical facilities. These reps collect names and status of people and destination information for the H&W message. These are assembled into book traffic destined for regions. This makes very efficient use of the scarce radio time.
Now let’s look at what should happen outside the impact area. The natural tendency for most people who know a ham operator is to ask him or her to send a radiogram to the relative or friend. This isn’t bad for a small local event, but the number of such requests soon overwhelms the National Traffic System and the Radio Relay International nets. So, once again, we rely on our partner NGOs, like the Red Cross and Salvation Army to collect requests, assemble them into book traffic, and pass them to affiliated amateur stations.
With our modern, network-based, communications such as the Internet and cellular phone service, amateur radio nets are becoming the last resort channel. If the network infrastructure is partially intact in the impacted areas, the local, state, or regional emergency management team may establish online resources for folks to post H&W queries and reports. Some of the social media services, like Facebook, have services where folks can report their status to friends and loved ones. If the networks are running, these should be the first way. Local governments or NGOs in the impacted areas may establish kiosks where those impacted can post their status. Don’t forget cellphone text messaging. Many times, text messages can make it through the system when voice cannot. The messages take very little bandwidth.
In general, for amateur radio nets during disasters, we give priority to outbound traffic. Inbound H&W queries may be rejected or cached. We want to give precedence to actual H&W traffic, like ARRL ONE (“Everyone safe here. Please don’t worry.”) from a specific person going to a specific destination. Remember, we probably have limited time windows based on the fuel in the generator and propagation, to get that message delivered. Clogging the system with hundreds or thousands of queries doesn’t help. Some of the NGOs set up bulletin boards for incoming queries. These might be online or actual physical signboards. It can be different for each location and disaster.
Now, what do we need to do? First, we need to educate our fellow amateurs in how H&W information is passed. Consider making it a topic at your next ham club meeting. Reach out to your local NGOs and build a working relationship and develop processes to handle H&W traffic. Make sure your agreements and practice sessions with the NGO include the scenarios of being in the disaster zone and serving folks who are outside the zone. Also, tell your family, friends, social groups, and others how the process works. They should know to contact the Red Cross to find out about someone’s status in the impact zone. Ensure everyone knows that it may take days or weeks to get an answer to the query. It’s not unusual for the person in the impacted area to call the relative long before a reply from the amateur radio H&W messages makes it.
In times of emergency like the recent hurricanes, we need to remember that we are communications experts first and radio operators second. We need to advise folks on the most likely channels to get their message through or the query answered. When that channel is amateur radio, then we need to apply our best traffic handling skills and make sure the message gets through as quickly and accurately as possible. Remember, these skills come with practice. If you haven’t sent and received messages in the last six months, you are probably rusty. Join one of the traffic nets and take traffic.
73 de W4PXE
Dave Rockwell-W4PXE is Manager of the Eagle Traffic Net conducted nightly at 8:30 PM. Dave is also a West Central Florida Group Inc. Board Member.
For those of you who may have missed the Tech Net last Thursday evening on the NI4CE Repeater System, I thought I would share some comments I made concerning an equipment heating issue we recently solved.
The problem first showed its ugly head several months ago when we installed a new RF power amplifier at the Verna Repeater Site. The new amp boosts the output power of the 145.430 MHz VHF repeater there. To achieve the rated power output of the amplifier, we needed to feed it with two watts from the repeater. Sounds simple enough, just dial back the power output and all is good.
Shortly after the amplifier went into service, problems began cropping up. During a Net where both the repeater and the amplifier were in transmit mode for an extended period of time, the output power dropped to almost zero. The symptoms suggested an overheating problem. Was it the repeater or the amplifier? Since the repeater had been in service for an extended period of time and without incident, it was logical to suspect the amp. A fan was placed in front of the heat sink to provide additional heat dissipation. That seemed to work for a while.
But alas after a few weeks, the problem showed up again. And this time, it persisted.
Troubleshooting the repeater got a lot easier with the development of a Windows app and direct IP connectivity that allowed us to monitor the repeater’s core temperature in real time. It did not take long to conclude the repeater, in fact, was where the heat issue resided. The temperature inside the repeater chassis rose quickly during Nets and other periods of extended transmit operations.
To provide better heat dissipation, one of the WCFG Board members (and a retired engineer) Paul Knupke-N4PK, resurrected a desire that has been in place for several years at the NI4CE Riverview site. He modified a rackmount shelf and attached two high volume four inch fans that would blow air across the heat sink and chassis of the VHF and its companion UHF repeater. We tested the impact of the additional air flow in a controlled environment similar to the Verna Communications Room. The data collected confirmed this design worked keeping both repeaters within their published operating temperature. Since this modification has been installed, both repeaters are operating within normal parameters, even during extended transmit periods.
The important take away from this experience is the importance of gathering empirical data to support your troubleshooting hypothesis. In this instance, the problem was excessive heat generation. But the initial culprit, the external power amplifier, was not the culprit. It was the repeater, a piece of equipment that operates within its rated one hundred percent duty cycle power output. Had we not been able to measure the internal core temperature of the repeater, we might still be chasing the problem.
Let us know what you think by sending email to email@example.com or on our Facebook page.
If it seems like we have been down this road before, it’s because we have been. Ham Radio operators know all too well what happens when the members of the “Aesthetics Brigade” mobilize in a neighborhood or development near you.
“Those towers and antennas that are near and dear to our hearts are ‘ugly eyesores’”, these do-gooders will shout at the top of their lungs. “They are a blight and immoral, an obscene violation of our sensibilities and cannot be allowed”.
Despite Federal laws like PRB-1, most residential developments built in the last fifteen years are not only absent of anything that remotely resembles a Ham Radio antenna, the Aesthetics Brigade has also been successful at running off satellite dishes and Over-the-Air TV/FM antennas from their midst, PRB-1 notwithstanding. And now, the Aesthetics Brigades have a new target to take aim at: 5G Wireless!
Battles are already being waged in what will be a nationwide war. Brigade members in one California community near San Francisco are trying to banish 5G antenna from atop neighborhood light poles using that “ugly” argument, again. Unlike 4G cellular, which relies on those “ugly” but not necessarily in our backyard towers and monopole structures, 5G service will need to be far more localized, embedded in each neighborhood. 5G signals at 28.5 GHz and 39 GHz, require antennas mounted on the tops of light poles to be effective. Of course, this not only fuels the “ugly” argument but also gives rise to “RF Radiation and Safety” concerns. Of course, Ham operators know you have to be within a few feet of “non-ionizing RF radiation” for it to be harmful. But the members of the Aesthetics Brigade have never let the facts get in the way of their scare tactics.
One thing the cellular providers have that Hams and others who have fought the “Ugly” wars in the past have not had if their own brigade of lawyers and the money to pay them. That may help level the playing field with City Hall and the HOAs this time around. Of course, another event that would level the playing field is a Federal Law (this time with teeth in it) that “wireless radiators regardless of their origin are permitted in all neighborhoods in the United States so long as they are in the public interest”.
Now, let me refer you to the verbiage contained in CFR47, FCC Part 97.1:
“The rules and regulations in this part are designed to provide an amateur radio service having a fundamental purpose as expressed in the following principles:
(a) Recognition and enhancement of the value of the amateur service to the public as a voluntary noncommercial communication service, particularly with respect to providing emergency communications.”
Maybe 5G and Ham Radio do have something in common.
-June 6, 2019
Having worked professionally in both the Commercial Broadcast and the Land Mobile Radio industries, I have seen more than a few changes. One of the biggest changes is the sheer amount of RF spectrum that is now energized. And knowing just how much electro-magnetic energy is now being emitted up and down the band, you have to wonder if there is something we should be concerned about.
Think about it. If you are over forty years old, there was a time when television signals were mostly on VHF frequencies. What UHF stations that were on the air were relatively low power and scattered over four hundred megahertz of spectrum. And while the migration to digital TV signaling has capped the power output of UHF signals at one megawatt or lower, there are a lot more stations on the air and the average duty cycle on a digital signal is much higher than on the analog signals we grew up with. And the four hundred megahertz of spectrum once allocated to UHF TV has shrunk dramatically to just over one hundred megahertz concentrating all that energy and eliminating near all of the emission-free “white space”.
Commercial broadcast radio was AM, operating on a small size of spectrum around 1 MHz. There were (and still are) a number of AM stations operating with fifty thousand watts signals. The vast majority of AM stations are on the air with far less power. FM stations started appearing in the 1960s but were usually low power. Today, many of those FM stations operate with an effective radiated power of one hundred thousand watts. If they are usually circularly polarized antennas, the effective power is closer to two hundred thousand watts. Large markets like Tampa are also seeing lower power “translator stations” filling in the gaps adding to the overall power signature ns saturation of the FM band (88-108 MHz).
White space (no RF emissions) used to be abundant between 600 MHz and 900 MHz. Not anymore. Literally, tens of thousands of Cellular and Public Safety radio transmitters now fill the airwaves with high duty cycle digital voice and data transmissions.
And the RF spectrum above 1 GHz is almost as crowded with all kinds of emissions: cellular, satellite, high power radar, terrestrial microwave links, Wi-Fi and a lot more. Coming soon to light poles in your neighborhood, new RF antennae that will emit signals on 28 GHz and 39 GHz (5G cellular), spectrum that previously was pristine.
The good news is RF energy is non-ionizing and dissipates rather rapidly once you put some distance between you and the transmit antenna. Still, RF Safety is enough of a concern that those who work around RF transmitters, including all Amateur Radio operators, are required to know and work within the guidelines for RF Safety published by the Federal government.
I’m sure somebody, somewhere has looked at all these emissions on a “one-off” basis and is convinced there is nothing to worry about. And even cumulatively, the sum of all these new emissions, scattered throughout the RF spectrum probably pales by comparison to the energy emitted by the sun. But do we REALLY know for sure our new technological age has not opened a new Pandora’s Box on us? I’m just asking.
One thing we do know is the electricity needed to run all these transmitters, network and other supporting equipment and the air conditioning needed to keep the technology cool is soaring. We can talk about solar, wind and other potential sources of non-fossil fuel energy sources to produce the power needed. But solar and wind are only viable when the sun is shining and the wind is blowing.
-March 24, 2019
Every year around this time, the great migration of the North American Snowbird starts in earnest. When I first moved to Florida almost twenty years ago, I was fully aware of the migration of Canadian Geese (the ones that fly in V formation) and the elegant, oversized Sand Crane to habitats along the Gulf of Mexico. Being a Wisconsin native, I can’t blame any living being for leaving the Arctic cold and snow in Dodgeville, or Nekoosa or Eagle River (all places I have been in Winter) for Bradenton, Port Charlotte or Lake Placid (FL not NY).
If you have come to West Central Florida to spend some time with us this Winter, we welcome you and hope you enjoy yourself. Our little corner of Paradise has a lot to offer when a CAT 3 or CAT 4 hurricane (also known as a Bad Hair Day) isn’t blowing through. And we have a lot to offer Ham Radio operators who have come to escape the cold.
If you are new to the area or have not previously discovered the NI4CE Repeater Systems before, we have a lot to offer. The five-site Analog repeater system is open to all licensed operators (including our friend from VE-land). You will need to program any or all of our analog repeater frequencies with a PL or CTCSS tone of 100.0 Hz. To find the repeater nearest you, visit the Repeater Page on the NI4CE.org webpage.
The NI4CE Analog System features at least one Net every night at 8:30 with multiple Nets on Monday, Tuesday and Thursday evenings. The NI4CE Digital System will soon have an NXDN Net on Wednesday nights at 8:00 PM where we will be discussing all things digital. One other Net that will pop up as conditions require is the Regional SKYWARN Severe Weather Net. We take severe weather very seriously!
Just in time for Snowbird Season, we have just added a third NXDN Digital Repeater to our network to complement the Riverview (444.425) and Verna (444.3125) repeaters. NXDN is now loud and clear in Northern Pinellas, Northwest Hillsborough, Pasco and Western Hernando Counties on 442.650. All three repeaters use RAN 1 and support Talkgroups 1200 (Local) and 65000 (NXDN-Worldwide). If you are from New England, you may also want to use TG 9000.
Of course, both NI4CE systems are available for friendly QSOs anytime there isn’t a Net scheduled. You will find a pretty diverse group to rag chew with. Please try to limit your use of four-letter words like COLD, SNOW and WORK. We try to be “family friendly”. We also ask that you keep any kerchunking to a minimum We ask that of everyone, although a couple people think squeezing their PTT button is good hand exercise and a stress reliever.
So, welcome, snowbirds, to West Central Florida and NI4CE-land. Ham Radio Lives Here!
“For every action, there is an equal and opposite reaction”. That is Newton’s Third Law, something I was first exposed to a long time ago in High School. I am not sure if those in high school today are still being taught about Newton and his several laws but they should be. You see, nothing is ever static. And as the population expands, as the political winds shift and as technology exerts its influence on how we live, we are seeing the ripples all this change causes.
There was a time (in my lifetime) when walking around with a portable radio on your hip was reserved to Ham Radio operators. Then, in the 1980s, along came cellular phone technology. Today, nearly everyone is walking around with a radio (cell phone) by their side. Radio spectrum that used to be reserved for Broadcast Television, Military or other Government use and, yes, Amateur Radio, is being re-purposed or shared to accommodate the changing needs of the many.
Recently, I wrote about a proposal in front of the FCC to “share” some spectrum currently used exclusively for downloading satellite weather imagery. The proposal comes from the successor of a company that proposed “sharing” spectrum with GPS satellites that failed miserably. This latest proposal (in my humble opinion) is equally flawed. But it is not the only one out there that regulators are considering.
Now, there is a proposal backed by the government of France to re-allocate several pieces of radio spectrum for use by the Aviation industry. After all, there are more planes in the air than ever before, flying both passengers and cargo. More planes mean more pressure on the existing radio resources needed to communicate and control those aircraft.
Now, here is where you need to pay attention if you are a licensed Amateur Radio operator. The French proposal seeks to re-allocate the 144-168 MHz portion of the Two Meter Amateur Radio Band to Aviation, worldwide! Say it isn’t so. But it is. In fact, the proposal is right now on track to be brought before the ITU World Radio Meetings in 2023 for action.
At first glance, this proposal doesn’t seem to make a lot of sense. The frequencies being looked at are not adjacent to any current Aviation band. Aviation uses AM modulation. FM signals populate most of the 144-146 MHz band now. So the opportunity to “share” this spectrum with Aviation users seems remote. Maybe this is just some trial balloon bring floated as a bargaining chip to get the ITU to re-allocate some other spectrum. But it has to be taken seriously.
Some early pronouncements I have seen from the ARRL suggest a “wait and see” attitude toward this proposal. A lot can change in four years. And threatening the Two Meter Band may also just be a bargaining chip.
No matter what, the hand writing is on the wall. There is nothing sacred about Ham Radio’s access to spectrum. If we want to maintain our ability to maintain our presence on the airwaves, we are going to have to be willing to do more with less. Those Hams who are using digital modes like NXDN and DMR have discovered you can do a lot with less. The days of the Wide Band FM are numbered, particularly since the vast majority of the population seems to think all you need is a 4G or 5G cell phone.
-July 13, 2019
After I wrote my last article about yet another potential threat to Amateur Radio’s assigned RF spectrum, a friend of mine sent me a link to an article posted on the IEEE’s Spectrum website. IEEE is the Institute of Electrical and Electronic Engineers. The article, by Julianne Pepitone, delved into a petition filed with the FCC by Ron Kolarik of Lincoln, NE seeking some significant changes in Part 97 dealing primarily with digital communications.
The basis for Kolarik’s petition is his contention the airwaves are now filled with too many digital signals that cannot be easily deciphered. If adopted by the FCC, RM-11831, a Notice of Proposed Rulemaking with seek to make all digital communications in the Amateur Radio Service more transparent in an effort to reduce interference.
We wrote about RM-11831 earlier this year and urged you to weigh in on it during the FCC’s Public Comment period. Many Hams, both for and against the proposition, did. Now, we are waiting for the Commission to announce their decision on this matter.
Many who support the NPRM contend digital signals generated by software, including WinLink, step over the line between “hobby” and, well, something that could be considered “productive and useful”. Let’s not forget WinLink was created by Hams for Hams to pass textual messages and information and is now widely used by disaster responders to do just that. The creators have automated part of that process to make it efficient. And it works!
What I believe is the real issue here is an age-old “generational battle”: The Last Generation of Technology and Operators versus the Next Generation of both. The “last generation” relied heavily on Morse Code, skilled operators, and a manual process. The “next generation” has moved on to newer, more sophisticated technology, operators who are focused on moving real information in a timely manner and who have to introduce a modicum of automation into the process.
The IEEE article put forth the question “Is Ham Radio a hobby, a utility or both?”. Maybe it is both. Maybe it is neither. At the time the Amateur Radio Service was created, it served as a hot bed of experimentation, activities that have led to many of the communications tools we have today. The only digital communication was Morse Code. And in many parts of the country (and the world for that matter), the telephone was only a dream. All that has changed. Cell phones, the Internet, satellites, software now make global communication instantaneous and available to almost everyone, including Hams.
In spite of this, there still is a place and a need for Amateur Radio. Our “one-to-many” voice communications capabilities are not easily duplicated in the cellular world. Disaster response communications rely on simplex radio operation. Cell phones cannot be used in that manner. And the Amateur Radio Service provides a pool of non-commercial frequencies and operators available on a moment’s notice when cell networks and the Internet are imploding on themselves.
My great fear is Mr. Kolarik’s quest to eavesdrop on every signal his radio can receive may actually doom Amateur Radio to oblivion. The proposed rules changes could make it impossible to further embrace 21st Century technology along with all the new possibilities for learning and innovation “digital” brings to the table. It could mean an unceremonious end to the public service and disaster response activities Hams are noted for. Maybe Mr. Kolarik and others who support him are ready to take their place in a museum somewhere. But I am not. There is a place for “digital” Amateur Radio. You just have to be willing to embrace it and grow with it.
-July 24, 2019
During a recent discussion on Facebook, I was asked for some tips on NXDN radios. The person asking was a fellow Ham I know who wants to become active on the NXDN digital repeaters here in the Tampa Bay area.
After giving it some thought and knowing a little bit about what this Ham was interested in, I posted my thoughts for him to consider. Shortly thereafter, another person posted a comment which I thought was somewhat telling. The comment stated in part, “But you can’t buy any of those radios at a Ham Radio store.” At face value, that is a true statement. NXDN radios are considered Land Mobile Radio products by both ICOM and Kenwood. As such, you will need to visit a local Land Mobile Radio dealer in person or on the web if you want to purchase a new NXDN radio.
However, let’s look at this statement in a slightly broader sense. There are a lot of Hams, rightly or wrongly, who believe equipment used in Ham Radio MUST be purchased from a Ham Radio vendor or it just isn’t “Ham Radio”. Let me give you a couple examples.
Many vendors produce ANTENNAS that are cut to work specifically in the VHF, 222 MHZ and UHF “Ham” bands. You will generally find these products sold at Ham Radio stores. But you will also find a wealth of omnidirectional antennas, Yagis, mobile antennas and replacement portable antennas on websites and at retail locations that are not “Ham Stores”. Many repeaters use commercial grade antennas because Ham-grade antennas would not hold up to the environmental conditions several hundred feet off the ground. Commercial grade antennas are generally built to withstand more punishment.
Ham Radio has always been a haven for equipment built for Land Mobile Radio. Many WBFM analog repeaters are refurbished Motorola and General Electric radios that started their service with Public Safety agencies or other commercial users. Now that digital two-way radio is here, NXDN, DMR, and P25 repeaters and end-user gear come almost exclusively from the Land Mobile Radio marketplace. D-Star and Fusion are the exceptions. That should not be a surprise since repeaters, whether they are operating on “Ham Radio” or Land Mobile Radio frequencies, must be able to co-exist with each other in high RF environments. That means tighter filtering and better adjacent channel and harmonic rejection.
Ham Radio RF equipment must pass the technical standards established by the FCC for Part 97 operation. Land Mobile Radio equipped must navigate a tighter, more strenuous set of technical standards to be Type Accepted for Part 90 Land Mobile Radio. When you are talking RF, the better the specs, the better the radio. That does not necessarily make these radios more expensive!
Hams who want to use Land Mobile Radio equipment for their Ham Radio activities do face one challenge. Most Part 90 radios cannot be programmed on the fly. You must use software to put a frequency, a PL tone or RAN code into the radio or activate other features. “Ham Radio” equipment does allow you the freedom to put a new frequency or parameter in from the front panel. Many “Ham Radio” portables and mobiles will also allow you to operate on more than one band. There are some newer Part 90 radios that operate on more than a single band. But you have to have really, really deep pockets to afford them.
My advice to all my fellow Ham operators is simple: Don’t be afraid to expand your horizons. And don’t discount a radio, an antenna or any other equipment just because it doesn’t say “Ham Radio” on it.
I am sure I am going to take some flak for what I am about to say. And I am sure some people are going to think I am just an “old fuddy-duddy”. But I need to get this off my chest!
Ham Radio has been something special, something worth taking the time to earn an FCC license for. It has enabled license holders to experiment, communicate with other Hams, even help out during emergencies on RF spectrum reserved for us. All we needed to do was come up with the necessary radio equipment and the time.
But there has been an increasing trend by Hams to abandon our Ham Radio roots and spectrum in favor of unlicensed Part 15 frequencies (which anybody can use), piggybacking on licensed, pay-to-play spectrum and the Internet. What gives?
Digital two-way radio is not exactly a new technology. And there are lots of flavors to choose from NXDN, DMR, P25, TETRA, not to mention Vo IP and LTE just to name a few. These commercial modes are finally starting to attract some attention in the Ham world but not in a way that you might expect. In the analog world, you either operated simplex (radio-to-radio) or through a repeater. Hams today seem fixated on using “Hot Spots” to connect with non-Ham Radio spectrum and the Internet. Yes, Hams are putting digital mode repeaters on the air. But the inability of the Ham community to embrace any single digital operating mode coupled with the desire to operate “everywhere” has caused the “hot spot” to become the new “gotta have” device in Ham Radio.
I am excited that Hams want to learn more about digital communications. Since the Ham community is somewhat dependent these days on the commercial marketplace, there will come a time when today’s aging analog repeaters and radios will disappear. But the use of “hot spots” and dependence on the several commercial cellular networks as a transport is, I believe, a train wreck waiting to happen. We have already seen numerous examples of what happens when major disasters or terrorism events occur. Without robust, digital repeater systems, Amateur Radio communications efforts will be negatively impacted. And your digital Ham Radio transceiver will become a useless appliance, just like your cell phone.
We can lament how Ham Radio is virtually invisible to most Americans. But we have done it to ourselves. Instead of building a robust and independent communications capability using Ham Radio spectrum and resources, we have copped out, instead of throwing our $$$$ at Verizon, AT&T, T-Mobile and the dozens of Internet Service Providers that dot the landscape. Instead of a fifty-watt mobile/base station radio, we are content settling for a four or five-watt portable radio and a “hot spot”, kidding ourselves into believing they are all we will ever need. Sorry, but that’s not the Ham Radio I signed up for.
Every profession, every hobby seems to come with its own set of litmus tests as a means of measuring a person’s commitment to and competence with the endeavor. Ham Radio has had a number of these “qualifiers” over the years, some which newly licensed Hams probably never experienced.
There was a time when you could not earn a U.S. Amateur Radio license without passing a Morse Code test. Even an entry-level Technician Class licensee had to pass a five word per minute proficiency test to get on the air. If you wanted to upgrade to a General Class license, the requirement was the success with a thirteen word Morse Code exam. And Amateur Extra candidates had to score a passing grade on a twenty word per minute code test to earn the top ticket.
Some old time Hams maintained these Morse Code requirements kept CBers from getting into the ranks of Ham Radio and trashing up the airwaves with their use of “10 codes” and “Roger Good Buddy” lingo. I have heard worse language, much worse, from Hams who passed the Morse Code litmus test, once again demonstrating the fallacy of that filter as a benchmark.
Another litmus test was a Ham’s ability to build a radio from scratch, or at least from a kit you could purchase from the local Ham Radio Store. There are some radio kits still available if you want to make the effort. But it is less of a litmus test and/or rite of passage in today’s microprocessor-based world.
I would suggest a better measure of a Ham Radio operator is their command of the radio(s) they are using, their technical ability to construct a station that operates efficiently and enables clear communication and their grasp of written and verbal communications skills. Unfortunately, none of these qualities are incorporated into any of the FCC exams. And unlike Marshall McLuhan, who put forth the position “the medium is the message”, I would maintain it is how you use your Ham Radio technology that is much more important. “The message IS the message” even if all it is is “You’re 5-9, West Central Florida. Good luck in the contest”.
Know the basics. You wouldn’t use #18 wire for a twenty amp electrical circuit in your shack. Check the specs on your coax and use an appropriately sized cable when building your antenna system. Check your forward and reflected power. If the SWR is greater than 2:1, some adjustments are required.
If all you have is a portable radio (particularly one of the “cheap” portables), don’t expect to hit a repeater forty miles away with a clear signal, not even NI4CE. Concrete, metal, and distance attenuate radio signals.
Know what you want to say before you press the PTT button on your mic or radio. The goal is to convey information, clearly, concisely and conversationally. Find a mentor to help you. At the very least, take the advice of an Air Force MARS Training Officer I know, “Listen, listen and learn”.
It has been eighteen years since the NI4CE Repeater System began serving the Amateur Radio community of West Central Florida. February 24, 2001 to be exact. Back in the day, the two repeaters (145.430 and 442.950) at Verna were known as “Big Stick”, in part, because they operated from the tallest commercial broadcast tower on this side of the state. Only the Channel 6 tower in Homestead and what will soon be the Channel 14 tower in Osceola County are taller.
Many of the Hams who helped put the original “Big Stick” repeaters, either through generous financial support or what we call “sweat equity” are still with us and are still active on the repeater system. Others, sadly, have become Silent Keys. But their contributions to the success of the NI4CE system live on.
The equipment that made up the first repeaters at Verna has been retired and replaced (twice) with newer hardware. The Verna site also serves as home for one of three NXDN digital repeaters that are part of a separate, parallel “next generation” Amateur Radio repeater system. This NXDN digital system covers a major portion of the NI4CE analog system’s footprint. And like the NI4CE analog repeaters, the NXDN digital repeaters are linked full time to each other. In addition, you will hear Hams from as far away as Europe and Australia providing West Central Florida Hams with one more Window on the World.
When the repeater system went on the air, there were two primary objectives / purposes for NI4CE. One was to provide the newly created ARRL West Central Florida Section a dynamic, multi-county communications conduit to conduct Nets, provide emergency communications support and to help with Ham Radio education. Today, the Section still conducts a weekly Information Net, the nightly Eagle NTS Traffic Net and the Tech Net every Thursday evening to help get Hams answers to their technical questions.
The second objective was to provide trained Ham Radio SKYWARN severe weather spotters a one-stop communications link to report severe weather to the National Weather Service and to receive guidance and warning information from the NWS. NI4CE has been there for every major severe weather event. And as the NI4CE expanded, the objective was to build out a “mission critical” communications system that offered Hams in the Greater TampaBay area with multiple ways of getting into the system.
In the end, the NI4CE system is all about YOU, the Hams of West Central Florida who use the system occasionally or every day exercising the operating privileges that come with your Amateur Radio license. Whether you are experimenting with a new radio, trying to have a little fun, whether you are catching up some of with your Ham Radio friends or are part of an emergency communications response effort, the NI4CE systems are the glue that brings it all together. On behalf of the West Central Florida Group, Inc., thanks for your continuing support and for making NI4CE part of your Ham Radio life.
-Feb. 21, 2019
Well, I figured there would be some reaction to my last article on the use of HotSpots to support Amateur Radio Digital Communications activity. But by some of the reaction I received, you would have thought I was suggesting the abolition of Amateur Radio.
“How dare you criticize my use of a HotSpot?” wrote one commenter. Another commented “If I want to build and use a HotSpot, I am going to do it. After all, this is Ham Radio where experimentation is perfectly OK.”
As a short-term “means to an end” solution, using a HotSpot will enable operators to use their NXDN, DMR, and P25 radios almost everywhere. Aside from a reliance on “commercial, pay-to-play” network services, both wired and wireless, it is a way to allow Hams to use these modes. But to grow the digital modes, to really make them part of the mainstream rather than just another Ham Radio sideshow, the Ham community needs to make a commitment, a long-term commitment to building out the digital repeater infrastructure needed in their area. Relying on commercial cellular carriers for the transport of a Ham Radio signal is not in the hobby’s best interest.
The FCC holds the future of analog VHF and UHF radio in its hand. We are still waiting for the other shoe to drop as the Commission moves towards its quest to squeeze more use out of the existing VHF and UHF spectrum. Their stated goal is to enable four “conversations” in the same bandwidth that used to support one conversation. The 2013 implementation of Narrowbanding-Part One has achieved half that goal. The other half remains in abeyance in part, because the Commission allowed Public Safety to use P25 Phase One emissions on VHF and UHF channels. P25 Phase One uses a 12.5 KHz emission making the “Ultra-Narrowbanding” of these bands to the stated goal of 6.25 KHz channels, at least on some level, impossible. But when analog emissions are finally phased out, Hams will be hard-pressed to continue analog operations for very long.
That is why it is in Ham Radio’s long-term interest to build and operate a digital infrastructure. Yes, the food fight going on in the industry between NXDN, DMR, Fusion, and D-Star make that more difficult. But remember, the FCC has already stated the ultimate goal is 6.25 KHz channelization for Land Mobile Radio. Ham Radio would do well to take its lead from that pronouncement and embrace the technology that gets us there.
Of course, HotSpots enable the use of low power, digital portable radios almost everywhere. But that’s because the cellular industry can afford to build out its massive infrastructure. Ham Radio, collectively, does not have that kind of money. Ham operators will better serve their interests by mixing portable radios with higher output mobile/base radios. This will reduce the cost of the infrastructure needed and reduce the dependence on non-Ham Radio infrastructure to have fun and serve the community.
It has been fifteen years since the FCC proposed a fundamental makeover of the VHF and UHF Land Mobile Radio (commercial) bands. For those of you who may not be familiar with Land Mobile Radio, it is the part of the spectrum right above our Two Meter and Seventy Centimeter bands used by Private and Public Sector commercial users. The makeover proposed slicing and dicing the available spectrum to enable more users in both bands. The first step, implemented in 2013, saw all Land Mobile users migrated to either Narrowband Analog or some digital mode (e.g. NXDN, DMR, P25, etc.). All LMR users that used to have a 25 KHz channel now has half the bandwidth they used to have.
Those that chose to continue operating in Narrowband Analog mode, NBFM, quickly came to realize they got the short end of the deal. NBFM had some distinct downsides, not the least of which is a significant and noticeable reduction in RF coverage. In reality, most who chose NBFM gave up about thirty percent of their coverage footprint. In simple terms, if their 25 KHz signal was weak, their NBFM signal was probably non-existent. And areas, where coverage was OK, may now be marginal.
Narrowbanding has been proposed (but not mandated yet) for Amateur Radio VHF and UHF operations. At a time where repeater frequencies are hard to come by in many places, you might view Narrowbanding as a positive move. Narrower channels mean more frequencies will be available. More frequencies means more repeaters, right? Maybe, but at what cost.
Narrowbanding reduces channel bandwidth to 12.5 KHz. Two Meter channels between 145.00 MHz and 145.50 MHz are 20 KHz wide. Channels above 146 KHz are only 15 KHz wide. Unless you completely re-order the VHF band, the net gain in channels from Narrowbanding is ZERO!
In the UHF-seventy centimeter band, where channels are 25 KHz wide, Narrowbanding could result in some additional repeater frequencies becoming available. But not without a price in coverage. Remember, most Land Mobile users saw a thirty percent reduction in their coverage footprint when they went from WBFM (25 KHz) to NBFM (12.5 KHz). Now think about what that would mean if the repeaters you currently use lost their percent of their coverage. I guarantee you there will be a lot of Hams who primarily use portable radios who will be left out in the cold.
Most Ham Radio transceivers, portable and mobile, built in the last ten years will operate in Narrowband FM mode. But it is usually an “all or nothing” proposition. All your memory channels will operate in NBFM mode like it or not. Repeater operators would take the biggest hit if narrowband operation is mandated. Most legacy repeaters, particularly all those converted mobile radios, cannot be narrowbanded. Then, there is the coverage loss. If you were in the outer thirty percent of the repeater’s coverage footprint, well, you are now in the land of “white noise”. Remember, indoor coverage takes about a 30 dbm hit versus outdoor coverage.
And then, there is the reality of the marketplace. Repeaters are, for the most part, Land Mobile Radio products. Many commercial repeaters can be made to operate in WBFM mode with special firmware. But for how long? Now, factor in the economics of Narrowbanding. How many repeater operators will be willing to spend the money on new equipment? Narrowband Amateur Radio is not the answer. But what is?
More on this topic in my next post immediately below.
-July 28, 2019
Narrowbanding Ham Radio in the VHF and UHF bands in not a practical solution for a lot of reasons. Narrowband FM comes at an enormous cost for both the repeater operators and the repeater users in the need for new radio equipment and loss of coverage. And unless there is a major re-ordering of the Two Meter (VHF) band, there are no new channels to be gained.
We can lament the inevitable loss of Wide Band FM (WBFM). But that train has already left the station. So, what’s next? Is there a future for Ham Radio on the Two Meter (VHF) and Seventy Centimeter (UHF) bands?
The answer is MAYBE. I say that because of the driving force behind most things Ham Radio is the commercial communications marketplace. The introduction of cellular and smartphone technology has sucked up most of the oxygen in the room. Simply put, the marketplace and the technology is passing us by.
There has been a lot of experimentation in the Ham community with the several digital modes available. The West Central Florida Group began digital operations in 2007. Our first entrée was with ICOM’s D-Star platform, a technology of, by and for Hams. We stuck with it for about a year and walked away from it because of all its shortcomings.
We then migrated to NXDN, a mode created jointly in ICOM and Kenwood. We were attracted to NXDN because we felt it had the most to offer. The audio quality was really good, better than DMR. RF coverage was comparable to wideband FM. Unlike D-Star, it is easy to network. And the price for repeaters and end-user radio equipment was reasonable (unlike P25). Moreover, the underlying technology was exactly what the FCC was looking to have implemented in the Land Mobile Radio spectrum.
Unfortunately, Digital Ham Radio has not taken off, in part because of the continuing “Food Fight” that persists in the marketplace, the incompatibilities that exist between the several digital modes on the air and the unwillingness of government regulators (FCC) to stick to the roadmap they laid out for the two-way radio industry in 2004. None of the major radio manufacturers are actively pursuing the Ham Radio market with their LMR Digital offerings. ICOM is still promoting D-Star. Yaseu now has Fusion, or should I say “confusion” to muddy up the digital waters even more. And the influx of cheap Chinese imports, analog and digital (mostly DMR), further dilutes the market.
Ham Radio operators have created products like the MMDVM interface and NXCore networking software has demonstrated some creativity and ingenuity to address some of the “food fight” issues. Unfortunately, MMDVM relies heavily on leveraging commercial technologies (Internet and LTE) to make connections. That dependence detracts from the need to build a parallel, independent Ham Radio infrastructure. There is still development needed to make NXCore a complete product. It lacks the ability to support text messaging and individual calling.
There still is a need for “one to many” push-to-talk communications that does not rely on the “ginormous” commercial LTE, 5G and wired networks. I believe there is a need for portable and mobile radio products that will allow simplex and repeated signaling that enables digital voice and text messaging with a user interface similar to what is now available on most cellular smartphones. And I think enough Hams worldwide will buy into this technology if it is offered at a reasonable price point.
In the meantime, come join us on Wednesday evenings at 8:00 PM for our weekly TampaBay NXDN Net. There are six NXDN repeaters in Hillsborough, Manatee, Pasco, Pinellas and Polk Counties waiting to help you discover Digital Ham Radio.
-August 9, 2019
We all want to have the best technology at our fingertips, be it in the form of a computer or tablet, a cell phone, an efficient, well-outfitted vehicle, 4K or the new 8K LED television set, even the radios we use on the Ham bands. I could go on and on and on. But then there is the reality check that seems to creep in and cause us all to take a second look: How much does it cost.
Early in 2018, tech giant Apple discovered the battery technology that powers its many products was causing many of its customers to complain about the poor performance of their iPhones. Some customers and groups even suggested Apple was throttling the performance of their devices as part of a much larger scheme to sell new phones.
Yes, the iOS Operating System that runs the iPhone has code that monitors available battery power so as to keep the high powered processors in the iPhone from going into a figurative meltdown. Yes, performance takes a hit. But better to have something working most of the day even if it is at less than one hundred percent of when the phone (and battery) were brand new. After significant research, Apple’s engineers concluded the problem was not their software but the batteries powering their phones. Even as good as Lithium-ion batteries are, they can only sustain maximum performance for a finite number of charge cycles.
Apple offered customers of two and three-year-old phone the opportunity to purchase a new battery at a substantial discount. Some customers took advantage of the offer and discovered new life in their older phones. But most just limped along waiting for the new iPhone to come to market.
When the latest iPhone made its debut, Apple, of course, heralded it as the “Next Big Thing”. But then reality showed up in the form of a change in how the cell carriers promoted and subsidized the latest cell phone offerings from Apple and most other carriers. Instead of these new phones costing the consumer a couple hundred out of pocket dollars, users were now looking at out of pockets costs that eclipsed a thousand dollars for some models. “Whoa! Hold the phone”, said many of those potential buyers. And at the same time, many of them remembered (or were reminded of) Apple’s Replacement Battery offer good through the end of 2018. Twenty-five dollars versus One Thousand dollars. You don’t have to be a rocket scientist to figure out what caused Apple’s projected new phone sales to come up short.
Your portable Ham Radio may be underperforming because the battery powering it is coming up short. While Lithium-ion batteries don’t develop show-stopping memory issues like earlier Ni-Cad did, they do have a finite number of charging cycles before their ability to hold a full charge wanes. Keeping your radio’s battery in the charger when you are not using it can also shorten its useful life. Sometimes, all it takes is a brand new battery to bring your radio back from the dead.
– Jan. 21, 2019
I fielded a question from a new Ham recently about the sustainability of the NI4CE Repeater System in an emergency. He wanted to know if there was a scenario where the NI4CE system would no longer be able to operate.
The simple answer to this inquiry is YES. No matter how much redundancy you put into the design, no matter how many contingencies you plan for, no matter how many backups you have to your backups, the simplest of failures can take out one or more repeaters. And if that happens, no matter what the cause, your best hope is you can get the site operational with a minimum of effort and lost time.
No matter how much you plan to avoid failure, Murphy is always lurking right around the corner. After all, we live in Florida where a myriad of hazards is always on the table. Impacts from severe weather are what a lot of people focus on because they go with our geo-location. Tornadoes and severe thunderstorms can (and do) disrupt commercial power, take down trees, cause buildings to collapse and in a worst case scenario, topple communications towers. That’s during the “quiet” months. Every June through November sees the threat level rise immensely with the onslaught of tropical weather systems. Storms like Andrew, Charlie, Ivan, Dennis, Irma, and Michael are game changers.
Weather is not the only potentially catastrophic hazard we face. And it is important to recognize and acknowledge this. The power blackouts occurring right now in Venezuela can turn life upside down and bring life to a screeching halt. We have so come to rely on electricity and all the gadgets it powers. Pull the plug and are we really prepared to live in the dark, even for a short period of time? Couple this with the sophistication of nearly all twenty-first century, silicon-based systems. Everything is a “network” with thousands of moving parts. Cause the wrong one of those parts or some combination of parts to fail and the network implodes.
Back to the original question. How resilient is the NI4CE system? From time to time, pieces of it can and will fail. The most recent interruption of service of the Holiday repeater was caused by a broken jumper cable that connects the antenna at eleven hundred feet above ground to the main transmission cable. What caused the failure? One theory is stress from high winds. The good news was the rest of the system remained on the air.
The location and coverage footprints of the repeaters afford us overlapping coverage. That doesn’t mean someone won’t be left out in the cold from a failure. But Hams in the TampaBay Metro area usually can reach more than one repeater. These sites are also on long term, generator-based backup power, thanks to our site partners. Those backup generators will usually keep NI4CE powered for at least seven days before needing the fuel supply replenished.
The NI4CE analog repeaters are RF linked, less fragile and usually more reliable than the Internet which the NXDN repeaters rely on.
In short, we have tried to build and maintain NI4CE with more than just casual resiliency. And with your continued support, we will do our best to keep our old friend Murphy at bay.
-March 17, 2019
During one of our recent SKYWARN severe weather nets, an operator came up on frequency asking if the NI4CE System had an Echolink node. It seemed he was going to be moving to a location (inside a building) where the signal from the nearest NI4CE repeater was weak. I informed him we had taken down both the Echolink node we used to operate as well as the IRLP mode. A couple of moments later, another Ham came up on frequency and suggested that operator use his computer to log in to a website called Broadcastify.com. NI4CE and everything transmitted on NI4CE can be heard there. Well, this raised my antenna and got my attention because as President of the West Central Florida Group, Inc., the owner and operator of the NI4CE system, this Broadcastify thing was all news to me. I also checked with our System Trustee. He, too, knew nothing about this Broadcastify thing. So, what is Broadcastify and how does it work? A little research shows Broadcastify.com was created to stream audio products, primarily Public Safety Radio (Police, Fire, EMS) traffic. Consumers of these audio streams include Broadcast News Departments, Newspapers, “Scanner Heads” and others who are fascinated with the daily events going on in their communities. Because these digital audio streams can be accessed from anywhere there is an Internet connection, consumers are no longer restricted to accessing this information with a Bearcat or similar Police Scanner receiver. Gee, what a concept. Now you can use your computer or smartphone to eavesdrop on your local “Cop Shop” and Fire Department no matter where you are and all without having to invest in a Police Scanner or be within the coverage footprint of these radio systems. And, as an extra added bonus, you can also monitor the NI4CE Amateur Radio Repeater System without having to have a radio, too. In fact, when you go to the Broadcastify website’s NI4CE page, it looks just some something you would find here on our NI4Ce.org website. But the disclaimer at the bottom of this page contains the important “fine print” you should not ignore. NI4CE on Broadcastify is NOT AUTHORIZED by the West Central Florida Group, Inc. In fact, one could make the case their actions constitute a theft of “intellectual property”. No one from Broadcastify has ever contacted us to ask our permission to re-transmit the voice transmissions heard on NI4CE. As such, the “who, what, where and how” of their effort to obtain the audio from the NI4CE system is something of a mystery. The West Central Florida Group, Inc. has gone to great lengths over the eighteen years we have been in operation to make the NI4CE system “mission critical” reliable. The repeaters and other electronics are on battery and generator backup power. The antennas at each site are sturdy “professional grade” quality. Our grounding and lightning protection is engineered to take a pounding so we can remain in service and on the air even through major hurricanes. We have no idea to what lengths, if any, Broadcastify has gone to insure the viability of their audio streaming product. One other point that needs to be made. Even though NI4CE analog radio transmissions are “in the clear” and open for eavesdropping by other Hams and non-Hams, Broadcastify has taken that potential eavesdropping to a significantly higher level. We want you to be aware of this not only for what you say but how you say it. Now, you really can have no idea who may be listening. It might be gratifying to know that someone thinks what we do on NI4CE is worth sharing with the rest of the world, literally. But I have serious ethical issues with what Broadcastify and any accomplices they may have are doing. Just because you can doesn’t mean you should!
NXDN (Almost) Everywhere: Increase coverage with Hotspots
Part One: Introduction and Brief History
By Jason Triolo, KD4ACG
Several years ago, as digital modes were becoming more popular on Amateur Radio airwaves, we started to see a small number of Internet-connected devices arrive on the market. These devices were typically a USB stick, designed to connect to a Windows PC. They enabled a user to access a D-Star network, even if a D-Star repeater was not available in his/her area.
Over the years, much has changed. When these “dongles” first arrived on the scene, D-Star was still the predominant digital mode in Amateur Radio. Now, these devices have evolved to support virtually every digital mode that’s present in our hobby. These include not only amateur-only modes like D-Star and Fusion, but also modes adapted from the commercial realm, such as DMR, P25, and most recently, NXDN.
While their capability has improved, so has their portability. Thanks to miniature computers, such as the wildly popular Raspberry Pi, coupled with an inexpensive USB battery pack, and the nearly universal access to Internet/Wi-Fi, these hotspots now allow users to take their favorite digital modes almost anywhere. Digital users are no longer limited strictly to the coverage footprint of a repeater.
This means, you no longer have to leave the NXDN radio at home, just because you’re leaving the NI4CE coverage area. Now, you have a way to take NXDN with you, virtually anywhere you go.
(Pictured Left: Hotspot based on Pi 3, Right: Hotspot based on Pi Zero. Both have a .96-inch OLED display mounted to them, and are in clear cases purchased online. Part Two of this article will provide more detail.)
While we believe in the importance of full-power terrestrial repeaters, the reality is that not every digital mode has blanket repeater coverage in every part of the country, or in every building within a coverage area. Thanks to hotspots, all digital modes are now more accessible to more people in more places and can extend a user’s digital footprint when he/she travels. They are certainly a handy supplement to your digital communications toolbox.
In Parts Two and Three respectively, we’ll discuss the hardware and software that comprises a hotspot.
-November 4, 2019
NXDN (Almost) Everywhere: Increase coverage with Hotspots
Part Two: The Hardware
By Jason Triolo, KD4ACG
Now that you have a brief background on the concept of a digital hotspot, you may wonder what it takes to get started?
Of course, you’ll need a digital radio, which you probably already own. Ideally, the radio should operate in the digital mode that you plan to use. (In a future article, we’ll discuss this in more detail.)
The foundation for virtually all hotspots is a Raspberry Pi. Almost any model will work, from the ultra-compact Pi Zero to the more powerful Pi-3 or newer Pi-4 models. Although any model provides the same audio quality and on-air performance, those who prefer to have both wired Ethernet and Wi-Fi capability should opt for the Pi 3 or 4, as the Pi Zero only has Wi-Fi built-in. You’ll also need a microSD card for the Pi, which will hold the operating system and software for the device. The hotspot doesn’t need a lot of storage, so that old 8GB card that you probably already have lying around somewhere, can be put to good use here. For this application, it’s far more than you’ll ever need
Once you have the computer, it’s time to add the digital interface. There are many models available, from the commercially-made ZumSpot (named for the callsign of its creator, KI6ZUM), to imports and competitors like Jumbospot and Nex-Gen, to name a few. If you’re really skilled and adventurous, you can even build your own. Be sure to choose your device carefully, as some older devices (namely, the DVMEGA) do not support all modes, particularly NXDN. Further, the OpenSpot, which is not based on Raspberry Pi, doesn’t properly link to NXDN repeaters, just other hotspots. So, read the specs on any device before clicking the “Buy” button, to make sure it supports the modes you intend to use.
Assembly of the components is easy. The digital board simply attaches to the Pi, by way of the 40-pin GPIO connector.
As far as hardware is concerned, that’s all you’ll need. However, you’ll probably want to consider a couple of extras, such as a case (the standard Pi cases aren’t tall enough and lack a cutout for the antenna, but custom models and 3D printer templates are available online), or an external display. Displays can be as compact as a .96-inch monochrome OLED display, or as large as a full-color Nextion LCD display, which ranges from 2.3-inch to 4.0-inch.
If you’d rather not purchase and assemble the parts yourself, fear not. Many pre-assembled kits are available online (but where’s the fun in that?).
How much does it cost? Depending on the Raspberry Pi model you choose, the manufacturer of the board, and the accessories (display) you select, an entry-level hotspot starts at approximately $100. Even for a fully-loaded device, it’s hard to spend more than $250 for a complete package.
Now that you have the hardware, we’ll tackle the software in the next installment.
-November 10, 2019
The invention of high-resolution cameras, high capacity storage devices and networked transports that can carry large amounts of data from one place to another has enabled a whole new discussion about PRIVACY. This discussion, in many ways, has manifested itself in the framework of “Do the Good Guys have an inherent right to be safe and secure in their person and their property” versus “Do people who do not respect laws and any semblance of moral character have an overriding right to infringe on the safety and security of others in the guise of privacy”.
Questions about privacy are not new. Think back to the days when the telephone in your parent’s house was connected to a “Party Line”. When y folks moved to a rural area in Wisconsin in the mid-1950s, the only telephone service that was available was on a “party line” they shared with twenty-five other neighbors. An expectation of privacy – only in your dreams. The ole “party line” was Gossip Central!
Ham Radio communications have always been “open” and in the clear. When you key-up a mic, you know there will be other people lurking in the weeds (and sometimes they aren’t other Hams) listening to your every word. If there was any security, it was only by the obscurity of the frequency being used. And to reinforce the concept of communications in the open, the ITU, the world governing body of all RF communications, prohibited Hams early on from using any form of encryption, in part out of fear European Hams would compete against the government bodies there that controlled telephony and broadcasting.
Digital technology has made it a lot easier for coding and obscuring content transmitted via wired or wireless media. Satellite TV providers routinely encrypt their transmissions to prevent intellectual property theft. Many law enforcement agencies are now encrypting their transmissions to maintain the security of their transmissions. Wi-Fi users are routinely encouraged to encrypt their transmissions to prevent theft on several different levels. This has created conflict since many unlicensed Part 15 users use the same RF spectrum that is licensed to Amateur Radio which is not allowed to employ encryption. This is something the FCC needs to address, hopefully with whatever rulemaking falls out of the RM-11831 process.
There is, however, a huge difference between transmitting content converted to zeroes and ones and actually “encrypting” that digital stream. The digitizing process does not change the meaning of the content. It merely allows the user to send the content as some collection of zeroes and ones. It is no different than an operator sending a message using Morse Code. What some people get hung up on is where the intelligence to code and decode the content resides. Digital voice and messaging rely on silicon-based intelligence rather than some learned ability by an operator to decipher dits and dahs at some speed.
I could easily make a case for allowing true encryption on Amateur Radio bands above 1 GHz, particularly on bands we share with unlicensed Part 15 users. It’s the only way we can keep those unlicensed users from using our equipment. I could also make a case for allowing the encryption of emergency communications on any band, particularly content that is governed by HIIPA and other legislated privacy mandates.
Do we all have a right to be safe and secure? You bet we do. But we also have a personal responsibility to protect our privacy. If you don’t want the world to know your secrets, don’t put them out there in plain sight. Conversely, when it comes to the rights of others, keepa ya fingers off. Just because you can doesn’t mean you should.
-October 13, 2019
One of the questions I am asked most frequently is “Why can’t I get into the repeater system with my handheld radio inside my house? I can hear it just fine.” So, let’s talked about that for a moment.
Ham Radio signals are just another like any other RF emission. The strength of the transmitted signal at any location is dependent on the power output of the repeater, the gain (or lack thereof) of the antenna, the height above ground of the antenna, the quality (and loss) of the filtering (duplexer), cable loss and your surroundings. Each one of the preceding items has a number associated with it. The transmitter and antenna are usually positive values, the antenna height governs just how large a coverage footprint the repeater will have. Everything else, while necessary, has a negative value in the equation.
The same holds true for the receiver side of the repeater. Antenna height and gain are positives while cable length and its loss characteristics and filtering put a drag on just how much signal gets to the receiver. One optional mitigating item some repeater systems (including NI4CE) incorporate is a Receiver Pre-amplifier which introduces some positive signal gain. Pre-amps mitigate cable and filtering losses and help equalize the signal differential that exists when the repeater is transmitting 100 watts but the radio being used in the field is only putting out four or five watts. That signal strength differential can often be 20 dBm or greater.
All this assumes you are operating in free space with nothing to obstruct or inhibit the RF signals between you and the repeater. But this is Florida, not Colorado, Texas or some other locale that has mountains, open plains and unobstructed RF signal paths. Florida has trees, lots of trees and many different varieties. Some pine trees, for example, have needles that approximate the length of a UHF (70 cm) signal. That can be a real show stopper. Ever notice how much better radio signals are in January and February before the new leaf growth emerges. Trees love to eat RF.
Then there are buildings that inhibit RF signals. Commercial buildings can introduce a 30 dBm to 40 dBm signal loss without breaking a sweat. Most residential construction (your house) in the Sunshine State is rated at a 20 dBm to 30 dBm signal inhibitor. Things like protective Hurricane Film on your windows also block radio signals. And yes, weather conditions can inhibit radio coverage. A recent hail storm in our area caused some serious, short term attenuation to signals going to and coming from the repeaters.
The coverage footprints for the several NI4CE analog and NXDN digital repeaters represent what is known in radio circles as “mobile coverage” and assumes you are using an external antenna. If you are operating your radio with the antenna inside your vehicle, immediately subtract 20 dBm both transmit and receive. Even with our high gain antennas and outstanding antenna height, receiver pre-amps and some good engineering, using your portable radio inside your house forty miles from the site is probably a non-starter. For reliable, in-building, portable radio coverage, even on UHF, we would need more repeaters, a lot more.
Two-way radio is a NUMBERS game. Sometimes the numbers add up in your favor. Sometimes, it’s just hard to get there.
-July 5, 2019
There is no doubt distracted drivers are a HUGE problem in Florida. People who think they can text and drive are as much of a menace to our safety and those driving under the influence of alcohol and drugs. But as sure as I am that drivers who cannot seem to put their cell phone down when they are behind the wheel are a problem, I am just as sure Florida State Senate Bill SB-76 is not the solution!
SB-76 seeks to make the use of all wireless communications devices by drivers a “primary offense”. That means if you are observed by law enforcement texting and driving, you can be pulled over for solely that infraction. Nothing wrong with that.
However, that’s where SB-76 goes off the rails. This bill arbitrarily lumps all wireless devices, including cell phones, computers and two-way radios into the same basket and requires a completely “hands-free” operation. The only exemption currently in the bill as written is for “law enforcement”. Let’s think about that wording for a moment.
There is a lot of Public Safety personnel we rely on daily who would not be exempted from this hands-free operation” language. Firefighters and EMS technicians are “Public Safety” not “Law Enforcement” What about School Bus Drivers and Public Transit Drivers who we rely on to us from where we are to where we need to be? And, to admittedly be a little selfish, what about Ham Radio operators who safely operate two-way radios while driving, often in the Public Interest? As this bill is currently written, only law enforcement personnel are exempted from the “hands-free operation” provision in SB76.
Come on, let’s be realistic. The current Distracted Driver Law that prohibits texting while driving has been a colossal failure. It assumes, falsely, that just because you write a law people will change their behavior. I am sure some have. But many, many others have not. This update to the existing law now treats the use of two-way radios, which are half-duplex voice devices in the same manner as cell phones, which are full-duplex voice and interactive text messaging devices. There is a HUGE difference in the human interaction required to operate a two-way radio versus a cell phone. In many ways, human passengers riding with a vehicle driver can be as much of a distraction as using a cell phone. What are our enlightened legislators going to come up with next: prohibiting passengers in a moving motor vehicle? Good luck with that one!
If you can’t change how humans behave with the technology, change the technology. Cell phones all have onboard GPS capability. That means they have the capability to know when the device is in motion. If humans cannot act responsibly with the technology in their possession, mandate all text display and authoring capability be DISABLED when the device is traveling more than 8 miles per hour. Now, I know vehicle passengers will howl at the prospect of not being able to text while in motion. To that I say, too bad! The way society as a whole has behaved with these devices must be changed.
Lumping two-way radio use in with the use of cell phones is a huge and potentially costly mistake. The human interaction required with the device is radically different because of how two-way radio works. The cost of replacing the two-way radios in Fire and EMS vehicles, School Buses and Public Transit vehicles will be a budget buster. Yes, the technology exists. But is it really required? I don’t think so.
Unless someone can show me data proving Ham Radio operations are detrimental to public safety, let’s not throw the baby out with the bath water. Think about all the Hams that have responded during the many disasters we have seen in Florida. Take away the core tool they need and use and you have taken away their reason for responding.
If you think SB 76 needs some changes, contact your State Senator and State Representative today. You will find a list at https://www.flsenate.gov/Senators/.
-April 27, 2019
If you read my posts with any regularity, you know I have made no secret of my advocacy of digital radio. I am particularly fond of the NXDN digital operating protocol, in part, because it is the only digital voice protocol that fully complies with the FCC’s 2004 Record and Order for VHF and UHF Narrowbanding. I also happen to think it offers superior voice quality and fidelity to the other modes currently vying for market share in the “digital radio food fight”.
Like it or not, digital radio and other digital operating modes are here to stay on our precious RF spectrum. And Amateur Radio, the birthplace of experimentation and innovation, should reflect this reality.
So why is it the FCC is even considering this Petition for Rulemaking, RM11381, that would severely restrict, if not downright prohibit, the use of digital modes on Amateur Radio frequencies? The petition, filed by Ron Kolarik-K0IDT, a Ham from Nebraska, seems like a knee-jerk reaction to the growing presence of digital signals on the air. More to the point, it seems like a heaping bunch of sour grapes!
If adopted, changes to 97.221(2) would mandate that all transmissions on Amateur Radio frequencies remain open for over-the-air eavesdropping of station identification, message content, and capable of being fully decoded with publicly available methods as required by Part 97.113(a)(4). Translation: Digital radio is not the one-size-fits-all method that plain, ole, analog radio signaling is. As such, it requires both technology and skills that Hams should not be required to possess to listen in on any given transmission.
The second part of the petition deals with digital emissions, primarily on HF frequencies from Automatic Control Data Stations (ACDS) which generally use an assigned channel or frequency. As digital stations proliferate and start showing up on additional frequencies, the petitioner contents these signals must be easily identifiable. And as the digital protocols being used also expand, the new modes must be easily decodable so as to be considered “in the open”.
One of the arguments being given weight in this matter is Amateur Radio’s so-called “self-policing” tradition. As a Ham who has had to deal with interference issues, the argument about “self-policing” is an empty suit. If there is an infraction of the rules, the FCC must first makes its’ own case on the merits of the situation and, if an infraction of Part 97 rules is verified, only the FCC is empowered to take action against the offender(s) in the matter.
Yes, life was simpler when everything on the air was “plain vanilla analog mode”. The proliferation of digital operating modes has injected a level of complexity the FCC never anticipated when Part 97 was written to govern the Amateur Radio Service. But instead of throwing the baby out with the bathwater, a better solution can be had by using some plain ole common sense. If you want to transmit “zeroes and ones”, the protocol you are using must be published and publicly available. If there is a need to partition a portion of spectrum for over-the-air experimentation, change the rules to address the need.
The FCC’s document also suggests there is some underlying heartburn with the use of hardware, modulation schemas and protocols that are in use in Land Mobile, Aviation, Marine and other radio services. Aside from encryption (which has never been allowed in Amateur Radio by International Treaty), I have no problem whatsoever with allowing the operation an FCC Type Accepted Radio on Ham frequencies. Yes, a Part 90 Type Accepted radio may cost a little more. But you get what you pay for as we have all seen with the Bao-feng debacle.
You can weigh in on this matter. Go to https://www.fcc.gov/ecfs/filings/express and file your comments on RM-11381 for the FCC to consider. I have already done so.
Now, if the FCC really wants to bring clarity to “digital radio”, particularly digital two-way voice emissions, it should go back to its own 2004 Report and Order for Land Mobile Radio. It clearly spelled out what it wanted to see used: 6.25 KHz channel bandwidth, FDMA modulation and a data rate of 4800 baud. Clean up the dog pile you have allowed for Part 90 VHF and UHF and some real clarity on digital signaling for both Land Mobile Radio and Amateur Radio will start.
-April 26, 2019
I was reminded of the importance of building around “standards” recently when I was trying to pull up to the gasoline pump. If the Automobile Industry built all the vehicles to a single standard for the location of the Fuel Intake, the chaos I was experiencing could have been avoided. But, NO, some vehicles have to have the Fuel Intake on the LEFT side while others have it on the RIGHT side. You will also find some vehicles with the Fuel Intake at the REAR of the vehicle (hidden by the fold down license plate frame). Yeesh! It’s a wonder there isn’t road rage at the pumps!
The same thing holds true for the electronics industry. Yes, there are quite a few IEEE and EIA standards that spell out how a radio or television should perform. These standards govern any number of operating parameters, from spurious emissions to selectivity to receiver sensitivity. Yes, there is a single broadcast standard for FM HD signaling, for digital television (currently ATSC 1.0 but coming soon ATSC 3.0). But even within the standards, there are now a number of variants that ingesting an over-the-air television signal REQUIRES TV receives to be capable of digesting 720p, 1080i, 4K and now 8K. In other words, thirty years later, we are still waging the Beta vs VHS battle with no end in sight.
The battle consuming both Land Mobile Radio and VHF-UHF Amateur Radio is sheer and utter nonsense. In December 2004, the FCC issued a Report and Order spelling out the technical parameters their Engineering folks wanted to see adopted for the migration to narrow-band channel operation in VHF and UHF. The three defining items were Channel Width (6.25 KHz), Modulation Method (FDMA) and Data Rate (4800 baud). Now that doesn’t seem too complicated or difficult to understand, does it? Problem is, those defining parameters were released AFTER the APCO25 Phase One standard for Public Safety was already being sold and after a number of consumers already had Motorola’s MotoTRBO TDMA radios in their hands. So, instead of sticking to their principles (and standards), the FCC wimped out and wrote exemptions For P25 Phase 1 and MotoTRBO (DMR), both requiring 12.5 KHz channels into the Report and Order. As a result, we are no closer to realizing the goal the FCC set today than we were in 2004!
Cellular communications are just as chaotic with four different modulation schemas currently on the air and 5G on the way.
There is even a food fight being waged in the implementation of analog communications. The implementation of Land Mobile Radio Narrowbanding in 2013 has resulted in a 12.5 KHz channel standard for LMR while Amateur Radio remains (for the most part) at 25 KHz.
Yes, I get it. As technology enables us to do more with less, it is only natural to want to embrace the newest technology. But let’s bring some sanity (and common sense) to the process. Create a technical standard for each application (i.e. Land Mobile Radio, Broadcast AM and FM digital radio, Amateur Radio, Marine and Aviation Radio, etc.), adopt it and move on. Let the manufacturers compete on quality, features and price point.
I started this post looking at the positioning of the Fuel Intake on vehicles. Manufacturers — take your pick: Left, Right or Center and be consistent. Same holds true for the height the headlights and turn signals are mounted at no matter whether it is a passenger car, SUV, pickup truck or other-the-road Big Rig.
-April 7, 2019
Someone asked me the other day if I knew what the median age of the Amateur Radio operators in the U.S. was. I guess he must have thought my name was “Google”, or “Bing” or one of those Internet search engines.
If you take a look around at most Ham Radio clubs or at a Hamfest or two, you rapidly come to the conclusion the median age is probably something North of sixty-five. And if you believe the Internet, the median age of licensed U.S. Amateur Radio operators is eighty (80) years. Well, that makes me feel like a youngster (I think).
That begets asking the question, “Where is the next generation of Ham operators, RF Explorers to carry on our mission?” Maybe the question that could/should be asked is “Where are the next generation and their parents?”. I pose the question in that way because even though I had always had an interest in Ham Radio as a youth, my earlier years were spent in commercial broadcasting. It wasn’t until I was forty-five years old before I got my license.
A lot has changed since I was in High School. Back then, we barely had satellites for any communications application. We didn’t have personal computers, cell phones, video games, and all the other electronic gadgets, contraptions and the distractions that go with them. If you wanted to talk with someone half a world away or even half a county away, you got your Amateur Radio license and a “rig”. Nationwide calling, texting, and video using a handheld device wasn’t even a pipedream. But today, you can do all those things and more. And you don’t have to have a license…just Mom and Dad’s deep pockets.
No, Ham Radio may not have all the “magic” it once had. But there still are a lot of discoveries to be made and a lot of new applications for RF-based technology to be developed.
The last big influx of youth into Ham Radio was post World War II. Back then, you had a large group of young military radio operators who have developed a skill they wanted to continue using: Morse Code. What better place to tap out those dits and dahs than Ham Radio?
I think there is another group of the “Next Generation” primed and ready to jump into the RF pool. Getting them licensed and on the air may be a bit more challenging because, first, they have to know there still IS a Ham Radio available to turn them loose to explore.
Many schools, starting at the Middle School level, are now actively seeking out members of the “Next Generation” to engage in S-T-E-M programs and curricula. S-T-E-M is short for Science – Technology- Engineering – Math. Gee, this sounds like all the stuff Ham Radio is made of. And, it is. What better place for sons, daughters and in many cases, grandsons and granddaughters to learn while they explore and explore while they learn. Many of us think of Ham Radio as a “hobby”. But Ham Radio can also be home for scientific learning and a great way to develop verbal and non-verbal communications skills. And if we can attract a large enough pool of young people into Amateur Radio, they can also discover its worth (as many did fifty years ago) as a great “social media”.
Our greatest legacy may be our ability to find the “Next Generation” of Amateur Radio operators and enthusiasts and turn them on to what Ham Radio has to offer.
-September 6, 2019
Recently, on one of our Wednesday night TampaBay Area NXDN Nets, we talked about using your portable and mobile Ham Radios indoors. By the way, if you don’t have a NXDN digital radio, you need to get one and join us every Wednesday evening at 8:00 PM on the growing six-repeater TampaBay Area NXDN Network, Talkgroup 1200.
Back to the topic at hand, INDOOR COMMUNICATIONS. Using a radio inside your well-built, hurricane standard home or business can be a challenge. Reliable VHF communications are particularly challenging because of the band’s longer wavelength. But even on UHF, the four or five watts your radio transmits with can push the radio and repeater you are using to their respective limits. The materials your home is constructed with act as a giant RF attenuator. Concrete block walls will easily inhibit incoming and outgoing signals by 20 dB. Some hurricane-rated windows can offer some relief unless they incorporate transparent film which not only stops flying objects but RF signals as well. Older windows that have had Hurricane Film added act like a mirror to a radio signal. Metal blinds on your windows will also add another layer of difficulty for RF.
Then, there is your roof. Metal roofs are sturdy, durable and do a great job reflecting sunlight and heat. They also stop radio waves dead in their tracks. Shingle roofing material is a lot friendly to RF and easier to penetrate.
Some homes and commercial buildings are now using steel studs instead of traditional wood Two-By-Fours. If the dwelling you are in uses steel, there is yet another speed bump to overcome.
With hurricane season upon us, figuring out how to use your Ham Radio portable or base station inside your dwelling takes on new importance. Here are a couple of tips that can pay big dividends.
- INDOOR ANTENNA Most residential buildings have some vertical and horizontal space to house an antenna. You may be limited to a “mobile antenna” mounted on a circular ground plane and attached to a joist for stability. But this will buy you some extra height and allow your antenna to transmit and receive through roofing material which is generally less of an inhibitor than concrete and stucco. If you have a metal roof, try to locate the antenna near a dormer or vertical wall not covered in metal.
- LOW PROFILE ANTENNA If the vertical clearance in your attic is minimal, you may be limited to a quarter-wave vertical antenna. Another possible solution is one of the MP Antenna Multi-polarized mobile antennas. The 08-ANT0863 “Classic” supports VHF, 222 MHz and UHF. If you are really jammed up for vertical space, the 08-ANT0864 UHF antenna is a real performer. If you do not have vertical space for the lower ground radials, use the top portion of these antennas along with a circular flat metal ground plane.
- LOW LOSS COAX Use a low loss cable, like LMR-400, Belden 9913 or Eupen EC1-50 to minimize loss. Try to avoid using RG-58U. The loss factor is just too high.
- SPARE BATTERIES Have at least one spare, fully charged battery for each of your portable radios. As you drain your battery, your radio’s transmit output power will also drop. Consider purchasing a high capacity UPS to recharge your radio batteries or run your mobile radio from. A deep cycle Gel Cell Battery can be very useful to power your station.
Finally, if you have a generator to help you through any extended loss of commercial power, consider adding a Line Conditioner, like the Tripplite LC1800 or LC2400 to run your electronics on. Even a small deviation in frequency (something other than true 60 Hz) may cause problems keeping your radio on frequency or even re-charging a UPS.
While standing next to a window will usually provide the least RF resistance, it is not a place you want to be during stormy weather. A few precautions now when the sun is shining can pay dividends.
-August 15, 2019
One of the things that does not get a lot of discussion or visibility in Amateur Radio is the cost of this hobby. While most Hams eventually find out what new radios, coax cable, antennas and other components cost, most have little or no idea what the costs are associated with putting a repeater on the air and maintaining one (or more). Well, let’s shed a little sunlight on this topic.
But first, an analogy. When you first got your license and could start using your privileges on VHF and UHF, you quickly learned about how to operate and communicate with your fellow Hams on a repeater. Most QSOs were like talking on a telephone, except only one of you could talk at a time. If your QSO was with a group of people, you quickly learned that if two or more in your group tried talking at the same time, there was this annoying and ear piercing racket that came through your radio’s speaker.
When you graduated to a license that allowed you to operate on HF, you quickly realized you had to learn a whole new set of skills, technical and otherwise. Operating here was in a completely different realm that didn’t seem to have a lot in common with VHF/UHF.
Most Hams get over whatever “Mic Fright” they may have and quickly become proficient operating through a repeater with their portable or mobile radio. But few really get to know much about the repeater itself. If it is a Club repeater they are using, they just know that Joe or Tom or Larry is the “repeater guy”. They are usually shielded from the details of what this magic box is, how it works and how much it costs. It is time to change that because every repeater “user” needs to know these details.
First, repeaters are NOT like your ordinary Ham Radio transceiver. They are usually “commercial grade” devices you will not find at your favorite Ham Radio store or website. While most Ham radios have a Twenty Percent Duty Cycle, that is, for every minute the radio is transmitting, it is receiving (and cooling off) four more minutes. Repeaters, on the other hand, need to have a One Hundred Percent Duty Cycle, that is, they need to be built to withstand continuous duty, no time outs. That means better components, better construction, and better cooling,
Most repeaters usually require a “Controller”, another piece of electronics that controls how the repeater operates, including the transmission of its FCC ID every ten minutes. Most repeaters also require a “Duplexer”, a filtering device that must be tuned to the frequencies (input and output) the repeater operates on. Many repeaters also use an external Power Amplifier and an external Receiver Pre-amp to enable the use of low power end user portable radios. There is also the Power Supply, the coax cable (usually not the LMR400 most Hams use at their Home station), a commercial grade antenna built to withstand the rigors of the environment they operate it and of course, a high-quality Lightning Arrestor to keep Mother Nature from blowing everything up.
Whoa! That’s a lot of stuff. It is! And the cost of all that stuff can be, collectively, ten or twenty times (or more) the cost of your Home station!
But that is just the starting point. Most repeaters are located on tall buildings or commercial towers. While many repeater owners have been successful in getting a monthly tower or building space fee waived, the cost of Liability Insurance, tower climbing fees, electricity and Internet service adds up quickly. For example, one trip up a commercial tower to mount an antenna or install coax cable can cost thousands of dollars. Many tower owners and building owners now require insurance that goes well beyond your homeowner’s or vehicle insurance coverage.
In my next article, we are going to discuss why every Ham has a stake in keeping your local repeater(s) on the air and what you can do to ensure your favorite repeater is there when you want to use it.
In my last post, I mentioned that most Hams have little or no knowledge about all the things that go into the operation of a Ham Radio repeater. They just know if they want to use one, they
need to program the transmit and receive frequencies into their radio (along with the Offset, CTCSS tone or RAN code) and press the Push-To-Talk button.
No matter WHO owns and operates the repeater, every USER of that repeater has a financial stake in keeping it on the air. REPEATERS ARE NOT FREE!!!
Here in Florida (and most places), there are three groups of repeater owners. The first group is the LOCAL Repeater Club. Depending on where the club is located (rural versus urban) and how many members are in the Club, the repeater system may be a single VHF or UHF repeater, a VHF and a UHF repeater at a single site or a multi-site repeater system that may include multiple repeaters. Most Club repeaters cover a very specific (and limited) geographic area. Most Clubs charge an Annual Membership Dues or fee, much of which is used to cover the costs I talked about in my last post. If a repeater, antenna or some other component needs to be replaced, the Treasurer may need to “pass the hat” to cover the costs involved.
The second group of repeater owners is Government. Many local Emergency Management agencies operate one or more repeaters for use by their local RACES, ARES or ACS groups. When there is no emergency in progress, the repeater(s) are usually available for all Hams to use. In this case, your property taxes are paying for the repeater(s).
Finally, the third group consists of private individuals or non-Club operators. The repeater(s) may or may not be OPEN for all to use or may cater to a specific group of operators.
The West Central Florida Group, Inc. falls into this third category. The NI4CE system was conceived in 2000 as an OPEN repeater system to enable Hams in a multi-county region to communicate with each other using portable and mobile VHF and UHF equipment. NI4CE is a one-stop point of contact during major severe weather events. It enables a daily regional NTS Traffic Net, a regional Technical Net and provides regional Ham Radio support for organizations and events that would otherwise require a “spin the dial” approach to communicate.
It costs around $3,600.00 a year to operate and maintain NI4CE. That’s around $300.00 per month. If we had to cover the cost of tower space in real dollars, multiply that figure by 10! We don’t talk about this on the air because Part 97 of the FCC rules prohibits us from doing so.
By comparison, some commercial SMR repeater systems with similar coverage charge $35.00 to $50.00 per month to use their repeaters. But NI4CE is Ham Radio and, by law, we are prohibited from doing that, too.
What we can do is ASK (NI4CEly) here for your support. If we all pitch in just a little bit every month to underwrite the cost of this one of a kind community and regional Ham Radio resource, we, the NI4CE users, can continue to enjoy something most areas of the country do not have on the air and available 24/7/365. Do your part. Click on one of the PayPal buttons you will find on the NI4CE Home Page right now.
Most Hams, particularly those operators new to Ham Radio, use one or more VHF or UHF repeaters to communicate with their local Ham Radio friends. The repeater is that magic box that enables you to communicate more than a mile or two, particularly if you are using a portable radio.
So what is a repeater? How does it work? Why do some repeaters cover more territory than others?
First, let’s talk about the radio side of the repeater. Most portable and mobile radios operate in half-duplex mode. That is, they transmit and receive but not simultaneously. That’s called Half Duplex mode operation and is the “norm” for two-way radio. Repeaters, on the other hand, receive an incoming signal (uplink) and then immediately re-transmit that signal (downlink) on a different frequency. In the VHF band, the uplink signal is usually 600 KHz above or below the downlink signal. In the UHF band, there is usually a 5 MHz difference between the uplink (mobile and portable user) and the downlink (repeater output).
A repeater can use one antenna to receive the uplink signal and a separate antenna to transmit the downlink (repeater output). The antennas usually require some amount of vertical separation, usually 20 feet for UHF, 30 feet or more for VHF. If that vertical separation cannot be achieved, a single antenna can be used to receive the uplink signal and transmit the downlink repeater output. In order to keep the local transmit signal from causing interference and feedback into the repeater’s receiver, a set of RF filters, called a duplexer, is now part of the repeater system.
Duplexers come in various shapes sizes and configurations. The filters are tuned to pass the specific frequency that is being received or transmitted, nothing more, nothing less. Most duplexers consist of four filters, two for receive and two for transmit. As you increase the power output of the transmitted signal, more RF filtering is usually required on both the receive and transmit side of the equation.
A repeater system can incorporate a receive Pre-amp. This boosts the strength of the incoming uplink signal by 15 dB or more. To boost the strength of the repeater’s output (downlink), an external Power Amplifier can be used.
Many Ham repeaters use an external Repeater Controller to enable Station IDs, announcements and connections with link radios or other audio sources like a Weather Alert radio.
All of the active components (e.g. repeater, controller, receiver pre-amp, RF power amplifier) all require electrical power to operate. That’s where a 13.8 VDC Power Supply (sometimes with a Battery Backup) comes into the picture.
Finally, there is the transmission line and Lightning Protection. If the repeater is on a building top, like an apartment or condo building, a hospital or a tall office building, your cable can be relatively short. However, if your antenna is mounted in a tower, your cable can be quite long and lose a lot of signal along the way.
We’ll discuss the challenges of operating a repeater in our next post.
Go to facebook.com/NI4CE now and tell us what you think. Or send an email to info@NI4CE.org
In our last post, we detailed the several different components that make up a typical Ham Radio repeater. If you were not aware of how many working parts there are in most repeaters, don’t feel bad. Most Hams just think of a repeater as a “black box” and never get into the intimate details to appreciate the complexity.
One of the questions we posed in our last post was what determines the geographic area a repeater covers. The downlink transmit power of a repeater is one determining factor. Another factor is the efficiency of the coax cable and antenna. What determines the Effective Radiated Power (ERP) or a repeater is a complex equation: Transmitter Power Output – (Duplexer Loss + Coax Cable Loss) + Antenna Gain. For example, if your repeater output is 50 watts, Duplexer Loss=3 dB plus Coax Loss=3 dB, with an Antenna Gain of 3dBd, your Effective Radiated Power will be 25 watts.
The biggest determining factor of just how far a repeater will be able to receive and transmit is Antenna Height. An antenna located one hundred feet above ground level (AGL) will have a line-of-sight horizon line of 11.89 miles. By comparison, a repeater antenna located at 1,000 feet (AGL) will have a line-of-sight horizon line of 37.60 miles, quite a difference. The formula for determining the horizon line for a repeater is SQRT(1.414*Ant Ht (in feet)). Because radio waves can go beyond the line-of-sight horizon, the formula for determining the Radio Horizon is SQRT(1.414*Ant HT)*1.333.
The NI4CE system is much more than a collection of stand-alone repeaters. Our five sites are strategically located and constructed to optimize coverage. But more importantly, by linking the five sites together, many parts of West Central Florida’s most densely populated counties enjoy overlapping coverage from two or more sites. This design is not by accident and affords many operators the ability to access the system from more than one site.
Building and maintaining a repeater system, whether it is a one site system or the five site system that is NI4CE, is a challenging and costly endeavor. But without repeaters, like NI4CE, Ham Radio’s ability to use of the 2 meter (VHF) and 70 cm (UHF) bands would be severely limited. Now that you know what goes into a repeater system, we think you will have a much better appreciation of all the repeaters that are on the air here in West Central Florida and the role they play in your Ham Radio life.
I was reminded of just how far we have come when a note from a Ham Radio friend of mine. He sent me a quick email commemorating the 71st anniversary of the first photo of our planet taken from outer space. That first image was from a camera onboard a V-2 rocket launched in October 1946. WOW!
Today, we would be hard-pressed to predict major storms like Hurricanes Harvey, Irma, and Maria. Our manned space program (when we had one) enabled the astronauts to maintain constant contact with flight controllers through the TDRS satellites that hovered thousands of miles above them. That dish antenna at your neighborhood gas station connects that card reader you just swiped your credit card through with a satellite to a processing center. And despite their name, CNN (Cable News Network) would likely be nowhere without the satellites they use to distribute their product. Let’s face it; life in the 21st Century would be a lot different without all the satellites that now orbit our planet.
I guess that is why I found another recent announcement fascinating. This week, the several MARS organizations that still function will be working with the Departments of Defense and Homeland Security on a terrestrial-based communications readiness exercise. According to an Information Release from the ARRL, this drill will be used to gather information from official and unofficial sources in the wake of a “Very Bad Day”. Ham Radio operators who are not affiliated with MARS can participate through reports offered up on local VHF and UHF repeaters. The information that is gathered will then is relayed via HF radio to Command Posts on the East Coast and in Arizona. By the way, if you were around on 9/11/2001, all this may sound eerily familiar.
If you have an HF radio or shortwave receiver in your shack, this Interoperability Exercise will kick off Tuesday, October 31 at 0300 UTC with a high power broadcast on 5330.5 KHz (Channel 1 in the 60-meter band). MARS operators will be looking for signal reports to find out just how many locales were able to hear the voice transmission.
Now, “why is this so important?” you might ask. This almost seems like one of those “busy work”, Back to the Future drills to justify your existence. After all, everyone has a cell phone. What do we need with 60-meter voice broadcasts, Ham Radio and MARS? The answer can be found in Newton’s Third Law (for those of you who remember High School Physics): “For every action, there is an equal and opposite reaction.”
Imagine, if you will, what life would be like without cell phones, satellites, the Internet and all the other communications devices and services we now rely on daily. I think that would likely qualify as a “very bad day”. And just as Newton told us centuries ago, there is a counter-balance we cannot and should not ignore. It could be an event, like the devastation Puerto Rico is now experiencing from Hurricane Maria or something much worse that will isolate us and turn our world upside down. The inconvenience of a few days without power could pale by comparison.
Take advantage of this Interoperability Exercise this week. And let’s hope we never have to experience a “very bad day” for real.
Ham Radio is sometimes more about the technology than applying available technology to solve a problem or a need. It has also been, over the years, a proving ground for many of the communications technologies we now use in everyday life. This article is about a Ham Radio technology that is a very practical solution that benefits everyone.
We know this technology by its four-letter acronym, APRS. That’s short for Automatic Position Reporting System. APRS is a mix of GPS technology, mapping software, and Ham Radio. Its roots date back to the early 1990s at the U.S. Naval Academy in Annapolis MD where Professor Bob Bruninga was looking for a low-cost method for tracking Midshipmen as they conducted maneuvers on the water.
Today, in the commercial world, the practical application of APRS allows transportation companies to track their fleets, provides firefighters and other in Public Safety situational awareness at events large and small and pizza drivers the needed information to get you your pie while it is still hot.
But APRS has turned into much more. In 1997, twin identical brothers, Keith (WU2Z) and Mark (KB2ICI) Sproul, teamed up with another Ham Radio operator who was heavily involved with the National Weather Service SKYWARN program in New Jersey to expand APRS’ mission. They were the first to bring the transmission of live weather telemetry to APRS as a practical transport. Hundreds of Amateur Radio weather stations beacon temperature, wind, barometric pressure and rainfall data in real time to enhance the SKYWARN program. The data from these weather stations also supplement data from NOAA sensors to help forecasters plot tomorrow’s forecast.
APRS weather station data can provide accurate, real-time information on rainfall and wind speed and direction to trigger severe weather warnings. That data is also used to tell forecasters whether radar estimates of precipitation are accurate. And sometimes, that data can be used to track a storm. Such was the case in 2004 when APRS weather stations here in West Central Florida provided a means of tracking Hurricane Francis when other instrument data was offline because of the storm.
The West Central Florida Group operates a number of APRS Weather Stations and Digipeaters to support the network here. Other Hams, including Dave-KG4YZY in Pasco County, Polk County Emergency Management and Highlands Co. Emergency Management have joined the effort. And so can you. All you need is a weather instrument sensor package (some of the most popular are from Peet Brothers in St. Cloud, FL and Davis Instruments), a two-meter radio to operate on 144.390 MHz, a TNC, like the Kantronics KPC-3+ or the new WX3in! controller and an antenna system. Once your station is on the air, you will want to register it with the National Weather Service’s Community Weather Observer Program (CWOP). You can do so online at www.wxqa.com/SIGN-UP.html
If you are a licensed Ham and are operating a weather station on the Internet only, exercise your operating privileges and put your station on the air.
If you are a Star Trek fan, like I and many other Hams I know are, you will recall one of the last movies the original Star Trek cast was center stage in, The Undiscovered Country. It was all about our inherent fear of the unknown and the reluctance of many beings, Humans, Klingons and many more to venture into territory and relationships we just don’t feel comfortable with.
Amateur Radio has traditionally been all about exploring the “Undiscovered Country” of RF right from its inception. Without those early explorers like Marconi, Bell (yes, Alexander Graham Bell was not solely into wired inventions), Sarnoff and hundreds more, we would not have most of the communications technologies we enjoy today. Amateur Radio has always been a place for discovery, innovation, creating and building the better mousetrap, so to speak. It has also been a place that has been open for a broad range of different interests and applications.
I would like to think that is still the case because, as I see it, there is still a lot of “Undiscovered Country” to be traveled and a lot of innovation to be embraced. That is why I find the ruckus that RM-11831 has created disturbing and potentially existential.
I’ve written about RM-11831 previously. It is a rulemaking proposal now before the FCC that could snuff out the exploration of digital communications in the Amateur Radio Service. The petition that led to RM-11831 has sharply divided the Amateur Radio community. On one side of the argument are operators who seem to think Ham Radio should be relegated to dits, dahs, analog voice (maybe) and the continuation of the old “party line”. Anything more than that violates their “safe space”.
On the other side of the argument are operators who see Ham Radio as a place to experiment, to innovate and, in the process, to increase the pragmatic value of Amateur Radio with new applications. They are willing to embrace change in a world that is constantly changing.
At a time when commercial communications interests are beating the FCC’s doors down for more spectrum, Amateur Radio cannot afford to stand still. The old saying of “use it or lose it” has never been more applicable to Amateur Radio than now. I can only hope the FCC will quash RM-11831 and allow Amateur Radio to move forward to explore more of the Undiscovered Country.
Speaking of challenges, an update on a couple of other items of interest. A proposal in Europe to re-assign the 144 MHz-146 MHz Amateur Radio spectrum worldwide to Aviation has been sidelined. So for now, the Two Meter band will remain available for all Hams to use.
And there is a new challenge on the table to a chunk of spectrum that is currently assigned, at least in the USA, to Amateur Radio. Authorities in Hong Kong have published a proposal to auction off 3300 MHz – 3400 MHz to commercial interests for mobile data usage. This is prime RF real estate for the development of an Amateur Radio broadband network. If WE don’t do something with this spectrum (3.3-3.5 GHz), you can bet there are commercial interests here that will be more than happy to move in on it.
-September 20, 2019
The 2017 Hurricane Season officially begins this week. Unofficially, it got underway several weeks ago with a bona fide Tropical Storm that spun for several days in the Central Atlantic. And if the forecasters at the National Hurricane Center are to be believed, we may be in for an above average season, possibly the most active since 2005.
A few weeks ago, I was re-discovering a portable radio I purchased about ten years ago. When I acquired my Kenwood TH-F6A, my motivation was to have a Ham Radio transceiver that could transmit and receive on 2 meters (VHF), the 222 MHz band and 70 cm (UHF). At the time, I knew a couple other Hams who had purchased the radio and were happy with how it operated. So, I took the plunge.
While re-discovering the radio and what it could do, I was pleasantly reminded the F6A had a really cool feature that every Ham operator needs to have at their fingertips, particularly during large-scale emergencies. That feature is the ability to receive Broadcast AM and Broadcast FM stations. The F6A also tunes the three domestic Broadcast Television bands, too, although the migration of TV stations to digital now makes this capability a moot point.
Why is the ability to receive AM and FM broadcast stations so important? In a large-scale emergency, broadcast stations, particularly those who are the designated EAS LP1 and LP2 stations, are an authoritative resource for information vital to the community. These broadcasters have direct links to local and State Emergency Managers and other authorities whose job it is to mitigate the disaster, whatever it is. This includes information on road closures, power outages, emergency ice and water resources and much more, including the weather forecast. These broadcast stations can operate for as long as necessary on generator-based backup power.
After the Hurricane Charley disaster thirteen years ago, I spent a day serving as a liaison between Charlotte Co. Emergency Management and the local AM-FM broadcast station in Charlotte County. My task was to convey information transmitted to me via Ham Radio to the radio station so they could then relay it to the general public and those most severely impacted by the storm. It didn’t hurt that I am an ex-broadcast journalist and could take raw information and turn it into an easy to read script.
As our society has become more cellular and wireless data-centric, we need to be reminded these resources will be the first one to go down in a large scale disaster. That’s why having a battery-powered radio capable of receiving local AM and FM broadcast stations is vitally important. Much to my delight, that capability is part of my multi-band Ham Radio transceiver that is always close by.
Should a tropical weather system threaten West Central Florida, the NI4CE Repeater System also stands ready as a communications and information resource you can count on.
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Even though Ham Radio is all about “wireless communications”, getting the RF signal from the radio to the antenna efficiently and effectively requires using the right cable. That sounds easy and it is. But it requires a bit of education and some calculation to come up with the numbers and the right cable selection.
First, let’s shine a little light on your cable options. There are many different kinds of coaxial cable on the market. Two-way radio for Ham and commercial use is designed to use fifty-ohm cable. That will provide your radio with the best impedance match, lowest power loss, and lowest reflected power.
There are lots of different fifty-ohm cables to choose from. Let’s focus on some of the more popular cables. They include RG-58U, RG-8X, RG8U, RG-213, LMR-400, Belden 9913 and LMR-600.
Most mobile installations require a cable that is relatively thin, flexibility and something that will not break easily. RG-58U and RG-8X are most often used because they use a stranded center conducted. These two cable types work because the length of cable required is usually short, less than twenty feet. Even at that length, the loss you can expect from RG-58 is typically 2 dB. Using RG-8X nets a loss of 1.6 dB. If you are using a quarter wave antenna with a gain of 3 dBbi or 0 dBd, you will experience a NET LOSS.
RG-58 and RG-8X are not the most efficient cables to use for a Base Station application. Here, you want something beefier. A fifty foot run of RG-8 will net you a loss of 1.2 db at 146 MHz, 2.2 db at 446 MHz. RG-213 has similar loss numbers. Time Mirror LMR-400 lowers the loss at 146 MHz to 0.8 db, at 446 MHz to 1.3 db. Belden 9913’s numbers are similar. If you are looking for even lower loss, LMR-600 reduces the loss at 146 MH to 0.6 db and at 446 MHz to 0.9 db.
What makes one cable type better than another? The most dramatic feature is the gauge of the center conductor. RG-58 is a stranded, 20 AWG (0.033”) wire. By comparison, LMR-400 and Belden 9913 uses a solid core center conductor that is 0.108” in diameter, 10 AWG or what is used for most 20A electrical circuits in your home.
Times Mirror has an easy to use Cable Performance Calculator on their website that makes it easy to determine which cable type is best for your application. Go to: http://www.timesmicrowave.com/calculator/?productId=121&frequency=445&runLength=100&mode=calculate
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When I was first licensed over twenty years ago, I was faced with the same daunting challenge that every new Amateur Radio operator faces: “What should new FIRST Amateur Radio purchase be?” Should my first radio be a Portable I can take everywhere? Should it be a Mobile radio that I can use as a Base Station (with a power supply) or in the car? Decisions, decisions, decisions. Well, here is what I decided.
My first radio was (wait for it) a MOBILE radio. A curious choice you are thinking. But in retrospect, if I had to do it again, I would make the same choice. Here’s why.
Portable radios, no matter the brand or model, are limited in their power output. Now, if the repeater you are trying to talk through has an output of fifty watts and the portable radio you have chosen transmits at five watts, you will be operating at a distinct disadvantage. That difference in power output is 10 dB. That may not sound like a big difference. But believe me, it is. Now, let’s compare Antenna Gain. The repeater is probably using a high gain antenna to boost the Effective Radiated Power by 6 dBd to 10 dBd, maybe even more. But comparison, most portable radios are outfitted with antennas that have a negative gain maybe as much as -4.0 dBd. Now, add up the differential and, as you can see, that portable radio you are trying to use has a -20 dBd or more disadvantage. And just got good measure, let’s say you are trying to use your portable radio inside a vehicle or a well built structure. You can tack on -15 dBd to the RF hole you are in.
By comparison, most VHF mobile radios transmit at up to 50 watts. UHF radios can transmit at up to 45 watts maximum output. Most mobile antennas will offer a gain factor that will offset any losses introduced by the coax cable needed to connect the antenna to the radio. And because your mobile antenna is located on the exterior of your vehicle and the radio is powered by the vehicle’s alternator, you will not be added to the losses described above with a portable radio. Base Station antennas may actually offer you enough gain to increase your Effective Radio Power (ERP) by a factor of two or more. And a Base Station antenna will likely be mounted at some elevation that will allow you to eliminate losses from trees, buildings and other vertical obstructions.
Why is all this important for a new Ham? You have heard the saying “Success begets success!” A successful first radio experience will encourage and motivate a new Ham (and, for that matter, any Ham) to want to do more. Ham Radio is not a spectator hobby. You learn by doing. And the more you do, the better you will be.
More on your First Radio in my next post.
In my first post on this subject, I discussed my rationale for selecting a MOBILE radio as my first Ham Radio. When I added up the numbers including Transmit Power Output and Antennas Gain and factored in other losses I could expect using a Portable radio, it just made more sense to make that first radio a MOBILE radio.
But there were other important criteria I took into consideration for that first purchase. Many new Hams will purchase a VHF, single band radio. It is less expensive than many VHF+UHF dual band models. And, in many parts of the country, there is more activity on the VHF (Two Meter) band or so many people believe. But even though a dual band, VHF-UHF radio was going to cost more, I thought going that direction was worth the every investment. And that decision turned out to be a good one.
Another factor was audio quality. Once again, the MOBILE radios I had been exposed to before making that first purchase just sounded cleaner and more full bodied than their Portable Radio counterparts. That still holds true today for most ANALOG radios. Digital Mobiles and Portables (e.g. NXDN, DMR, P25, Fusion, etc.) tend to have virtually identical audio quality. There are other factors, including the Speaker/Mic you may be using and the digital format itself, that make once format better than another. More on this topic in another post.
Perhaps the most important item I factored into my first radio purchase was how I wanted to use the radio. Did I want to talk with other Hams going to and from work? YES! Did I want to participate in Nets? YES! Did I want to get involved with emergency/public service activities, like SKYWARN and ARES? YES! How about Club activities? YES! With those criteria in mind, a MOBILE radio made the most sense.
Now, in all fairness and in full disclosure, it became pretty clear within three months that a VHF-UHF dual band Portable radio was going to be in my immediate future. Ultimately, an active, energized, engaged Ham is going to have at least one MOBILE and one PORTABLE radio.
More on DIGITAL Ham Radio in my next post.
A new Ham in the 1990s had some important choices to make when selecting his/her first radio. Was it going to be an ICOM, Kenwood, Yaseu, Alinco or one from a handful of lesser known brands, like Standard or Azden. Or maybe, you knew someone who could convert an old Motorola or GE mobile or portable that had been used by a commercial user.
Twenty years later, the choices are a lot more numerous. Yes, the Big Four in Ham Radio are still around and still innovating with radios that include color LCD screens, PL+CTCSS+DTCS tone control, voice compression and more. Many of the lesser known brands have been replaced by radios from Chinese manufacturers who have flooded the market with low cost (and, in some cases, dubious quality product).
While most ANALOG Amateur Radio repeaters still operate Wide Band FM, that is with a 25 KHz channel bandwidth, the Narrowband Mandate (12.5 KHz bandwidth) imposed on commercial and government users in 2013 has dried up the availability of commercial radios capable of 25 KHz operation. We are also seeing older WBFM repeaters now being replaced by new models that must operate at 12.5 KHz NBFM.
The FCC mandate for commercial radio has also brought with it new DIGITAL operating modes that some Hams are experimenting with. P25, NXDN, DMR, Fusion, TERTA and D-Star are just some of the DIGITAL modes out there. All but D-Star and Fusion (which are Ham Radio only) are gaining prominence in commercial and government use. All of these DIGITAL modes are feature rich. Some allow multiple VHF and UHF repeaters to be connected via IP. Interoperability, one mode to another and one manufacturer to another, is still a problem (just as computer networking was twenty years ago). And each mode has its strengths and weaknesses. No two modes are created equally.
I personally like NXDN, created by ICOM and Kenwood jointly in 2005. Each manufacturer’s radios are interoperable. The repeaters can be networked easily. And equipment is readily available from dealers and on the Internet. I also happen to like the range and clarity of NXDN radios, which rivals WBFM despite the fact they use one quarter the bandwidth of WBFM.
DMR offers two talk paths per RF carrier, a feature some Hams find desirable and fascinating, although you can only talk on one at a time. DMR repeaters tend not to cover the same amount of real estate as NXDN repeater do. And there have been some interoperability issues between Type 2 and Type 3 formats. Yet, DMR is popular in many areas, in part because of the availability of product.
P25 has two versions, the older Phase 1 mode and the newer Phase 2 mode. Both are designed for the Public Safety market and, as a result, P25 radios are a lot more expensive than most other Digital radios.
More on the Ham Radio only DIGITAL modes in my next post…..
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In my last post, we started talking about DIGITAL two-way radio, why it exists and why you should seriously consider a DIGITAL radio. Let’s expand on that with a look at the several DIGITAL radio protocols and radios that are available.
First, no two digital modes are created alike. Each of the several CAI (Common Air Interface) has their strengths and weaknesses. NXDN is the only mode that meets all of the FCC’s 2004 engineering mandates for Ultra Narrow Band Digital. In a Report and Order issued in December, 2004, the FCC told the radio manufacturers they wanted to see radios that used 6.25 KHz bandwidth, FDMA modulation and a data rate of 4800 baud. That is what NXDN, jointly created by ICOM and Kenwood, is.
In that same R&O, however, the FCC gave manufacturers like Motorola some wiggle room allowing their two channel TDMA mode to operate. DMR radios, the generic term for TDMA, uses 12.5 KHz bandwidth with two simultaneous voice paths. Some early DMR offerings are not compatible with the newer Type 3 radios that include products from Hytera, Tait and others.
P25, the modes (there are two) adopted by APCO for Public Safety are also 12.5 KHz. P25 Phase 1 uses a FDMA modulation schema while the new P25 Phase 2 mode is a two voice path TDMA offering that uses one modulation type for the uplink (radio to the repeater) and a different modulation schema for the downlink (repeater to radio).
Radios using all these operating modes have been created primarily for commercial and government use. But they are also is use on Amateur Radio bands. Why? What are the benefits of DIGITAL?
ANALOG transmissions are subject to all kinds of noise and disruption. Weak signal analog voice transmissions are often difficult to copy because of the inherent noise that is part of the signal. Then, add to that “snap, crackle pop” from atmospherics in the area, disruptions caused by multipath, trees and other vertical obstacles. In short, analog transmissions have drawbacks that can make communications difficult.
DIGITAL transmissions are usually much cleaner, clearer and easier to comprehend. That’s because the transmitting radio turns your voice into a stream of “zeroes and ones”, sends them over the air to the receiving radio that decodes the stream and re-creates the voice communications. With some exceptions, digital voice is far more stable than analog voice. Digital voice transmissions are generally usable at RF signal strengths up to 20 dBm weaker than analog signals. Most digital radios also feature ambient noise reduction to eliminate or substantially reduce road noise.
One drawback with most of the commercially available digital radios: they are single band only.
More on DIGITAL radio in our next post….
Some of you have heard me state that “Amateur Radio was the FIRST Social Media”. That is a rather bold statement given all the other Social Media offerings that now grace the digital landscape. The fact that Ham Radio, in Analog or Digital mode, is still a relevant Social Media, is pretty remarkable.
Let’s close the loop on DIGITAL radio before we get too far off topic. Here are some thoughts on the several DIGITAL modes available to all Hams.
I personally like NXDN, created by ICOM and Kenwood jointly in 2005. The radios from both manufacturers are interoperable. The repeaters can be networked over IP easily. And equipment is readily available from commercial dealers and on the Internet. I also happen to like the range and clarity of NXDN radios, which rivals WBFM despite the fact they use one-quarter the bandwidth of WBFM. NXDN radios also support Text Messaging and GPS.
DMR offers two talk paths per RF carrier, a feature some Hams find desirable and fascinating, although you can only talk on one at a time. DMR repeaters tend to come up short on coverage compared to NXDN and P25 Phase 1, a product of their modulation schema. And there have been some interoperability issues between Type 2 and Type 3 formats. Yet, DMR is popular in many areas, in part because of product availability and local dealer support. There is also the Motorola name recognition that has helped popularize DMR.
P25 has two versions, the older Phase 1 mode and the newer Phase 2 mode. Both are designed for the Public Safety market and, as a result, P25 radios are a lot more expensive than most other Digital radios.
There are two digital products that are “Ham Only”: ICOM’s D-Star and Yaesu’s Fusion. D-Star remains ICOM’s prominent Ham Radio offering, even though its GMSK modulation schema is hardly state of the art. The end user D-Star radios will do both analog and digital modes. D-Star repeaters are digital only. D-Star has become less of a “proprietary” mode thanks to the proliferation of D-Star dongles that turn your computer into a virtual radio. Still, if you want to operate wirelessly, ICOM is your radio source.
Fusion, from Yaesu, is a ‘proprietary’ created only for Ham Radio product. Its C4FM modulation schema has some P25 Phase 1 characteristics. Fusion radios support both analog and digital mode operations. And Fusion repeaters can be programmed to automatically convert analog to digital and vice versa. Fusion has gained a foothold with some Ham Radio Clubs, in part, because of an early marketing campaign that made Fusion repeaters available at Fire Sale prices. Yaesu’s success with Fusion may also be based on a belief that the majority of Hams will only buy Ham-class radios.
The West Central Florida Group, Inc. currently has two NXDN repeaters in operation at our Riverview and Verna repeater sites. Like our analog repeaters, the NXDN repeaters are linked full time to create a large coverage footprint along Florida’s West Coast.
If you have forty dollars or so invested in a radio, you probably consider it a “disposable appliance”. In the accounting world, it would be considered an “expense item” rather than a more expensive “capital investment”. Nevertheless, you are going to want to continue reading because what I am about to share with you is important. Now, if you have made a more substantial investment into your radio, you want to do everything you can to protect and optimize your investment. So, you will want to continue reading.
PM is short for Preventive Maintenance. It is a process and series of procedures that many radio owners, commercial and Amateur Radio, undertake on an annual basis. PM looks at key metrics of a radio that determine just how well the radio performs, no matter what bands it operates on. PM can also provide valuable clues about key components in your radio and whether your radio is working well or may be getting ready to fail.
Most radio Preventive Maintenance procedures examine several key metrics. For example, how far off the center frequency is your radio operating. Very few devices will ever be exactly “on frequency”. The question is just how far off the center frequency has your radio deviated. If your center frequency is plus or minus fifty Hertz, your radio is considered to have an acceptable error. If your radio is a couple hundred Hertz high or low from the assigned center frequency, the radio needs some tweaking or adjustment. And if your radio is, let’s say, a kilohertz off frequency, your audio is probably sounding a bit fuzzy and your radio has likely lost some of its sensitivity or so it seems. Your radio’s best friend is a qualified radio technician equipped with a frequency counter or more appropriately a Service Monitor.
Once you have your radio back on frequency, it will likely perform a lot better and sound a lot better on the air, too. But a Frequency Check is only the first metric to test. Another key metric is the TX Power Output of your radio. With age, the components in your radio change value. This can cause your radio’s power output to degrade. A portable radio rated at five watts may now only be putting out four watts. Optimizing the transmit power output of your radio is your best chance for getting the most out of your radio and cleanly getting into your favorite repeater. While your radio is on the bench, make sure any “fixed” power settings are also optimized. I recently discovered a Medium fixed power setting on one of my radios was only registering a nineteen-watt output. This setting is rated at a twenty-five-watt output.
Digital radios have another metric that must be measured, Modulation Fidelity. This metric is an indicator of how accurately the Zeroes and Ones are being transmitted. A Mod Fidelity error of three percent or less will result in a low Bit Error Rate and optimal reception of the stream of Zeroes and Ones you are sending.
One other very important metric to maintain clear, concise voice communications is your audio output. In Wide Band FM mode (WBFM), your radio should be transmitting a 3 KHz deviation. Anything less and your modulation is not optimal. If your deviation is 5 KHz (or more), you are over-modulating and likely have a hard time holding a repeater.
An annual PM will help you operate by the numbers. And that’s a good thing because the quality of your on-the-air signal is your radio personality.
Amateur Radio was the great proving ground for many of the communications devices that ultimately ended up in the hands of the masses. In fact, the whole concept of portable, go anywhere two-way radios was a staple in Amateur Radio long before the cell phone came along.
But in the mid-1980s, cellular communications devices and infrastructure made their way to the marketplace. Early cell devices were big, bulky and heavy. Let’s not forget about heavy. My first cell phone was a three watt “bag phone”. I recall dragging that thing over my shoulder on business through airports, hotel elevators and the like. I also remember having to drag it into Disneyland with me on vacation (I was supporting a very high profile computer imaging product at the time).
Cell phones in late 2017 are a lot less like portable telephones and more like a portable, hand-held computer that is a one size fits all. Sure, you can still make a phone call. But you can also send text messages, read email, navigate using the internal GPS receiver and any number of apps. In fact, the term “smartphone” really is an inaccurate descriptor for the personal communications devices used by most people.
Now, by comparison, two-way radio and Amateur Radio devices could be compared to the forgotten “red headed” stepchild that nobody wants to talk about. Land Mobile Radio and Amateur Radio, in many ways, are tied at the hip. While many of the radios have gotten physically smaller, their functionality remains limited, in fact, almost primitive, when compared to personal cellular devices. Most LMR and Amateur portable radios do one thing, one to many voice communications, something cellular has tried several times to do unsuccessfully. Digital LMR and Amateur Radio devices are now capable of Talkgroup and Individual calling. Some recent product releases now have a built-in GPS receiver (not necessarily for navigating) and Bluetooth support for wireless headsets. But LMR and Amateur Radio devices in 2017 are still much like their predecessors from the 1970s and 1980s. Any color displays are too small to support a touch screen keypad. There are virtually no apps available. What apps that do exist require a separate computer or tablet in tow. And only really high end Public Safety class radios are equipped with some form of WiFi. It’s hard to attract new people into the Amateur Radio realm when the technology seems like something from Jurassic Park!
I would love to have an Amateur Radio transceiver that could support operations on VHF, UHF, WiFi (both bands), a touch screen interactive color display, USB connectivity, built-in GPS and apps to support navigation as well as APRS, and apps for text messaging, NTS messaging, even email. Yes, I might have to sacrifice some range (i.e. antenna size and lower power output, maybe 2 watts instead of four or five watts). Battery technology has gotten so much better that such a device should be able to be made without weighing twenty pounds. No, such a device is going to cost more than your typical Bao-feng. But if Apple and Samsung can build their latest smartphones for around a grand, LMR and Amateur Radio manufacturers should be able to do so, too.
When the first NI4CE repeater went on the air in 2001, it was a Wide Band FM Analog repeater. Fast forward almost eighteen years. The actual repeater is a different make and model. But it still operates in WBFM analog mode as do the other five NI4CE analog repeaters.
But in the eighteen years that NI4CE has been on the air a lot of other things have changed and changed dramatically. For example, cell phones are now digital. The major cellular providers all operate high speed LTE-based wireless data networks that allow you to take a hand held computing device (your cell phone or tablet) to surf the Internet, send and receive email, shop online and much more.
Land Mobile Radio, the commercial “Big Brother” to Amateur Radio VHF and UHF repeater systems, no longer allows WBFM operations. In 2013, LMR users were forced to migrate to Narrow Band FM Analog or a Digital operating mode.
Broadcast Television went all digital in 2010 and is about to embark on ATSC 3.0, a new digital TV standard with improved screen resolution and throughput.
In case you did not realize it, NI4CE does not just play in the WBFM sandbox. We have been operating parallel NXDN digital repeaters at our Riverview and Verna sites for many years. We also are working cooperatively with Dave-KG4YZY on the operation of an NXDN repeater in Pasco County. These repeaters are IP linked and connect to a master server in Orlando that allows NXDN-equipped Hams to talk with other NXDN Hams in the USA, Canada and a number of other parts of the world including Europe and Australia
So, why did we choose NXDN? There are other digital operating modes including DMR and P25 as well as Amateur Radio only D-Star and Fusion. Simple! NXDN was jointly created in 2005 by ICOM and Kenwood (two familiar names) to meet the FCC’s ultimate Ultra Narrow Band standard, 6.25 KHz bandwidth operation. It uses very efficient FDMA modulation. It natively supports digital voice, digital messaging, GPS Tracking and allows linking multiple repeaters via IP or RF. NXDN radios are readily available. And new portable and mobile NXDN radios are on the way.
Another important attribute of NXDN is repeater coverage. Commercial LMR users discovered a substantial loss of coverage when they made the migration to Narrow Band FM in 2013. But those that went from WBFM to NXDN actually realized about a ten percent increase in coverage in many cases. NXDN provides clear voice and data signaling at lower signal strengths because of its efficient modulation schema.
WBFM repeaters and radio are still pre-dominant in Amateur Radio after all these years. But that will change. If you want to get out ahead of the curve, NXDN Ham Radio is here in West Central Florida NOW! Turn it on, tune it in and discover the power and effective communications possibilities. And if you need help getting started, there are local Hams and local resources readily available like the NI4CE-NXDN-Users group on Google.
When the NI4CE Repeater was first conceived sixteen years ago, it had two primary objectives: Provide a VHF-UHF platform that ALL Hams in West Central Florida could communicate through. This included support for the several Nets the ARRL West Central Florida Section conducts each week. The second objective was to provide a VHF-UHF communications platform to support the National Weather Service’s SKYWARN severe weather spotter program.
Ham Radio has played an integral and vital role since the SKYWARN program first started in the late 1950’s in “Tornado Alley”. Trained Ham operators were the eye and ears of the NWS during severe weather outbreaks in Kansas, Oklahoma and Texas using their radio communications privileges to report severe weather directly to NWS meteorologist. It wasn’t until the 1970s when the program was rolled out nationwide. In the 1990s, when the Weather Service was downsized and re-organized into the 118 offices it now operates from, SKYWARN took on an even more important role.
The technology used by the National Weather Service has changed dramatically since the early days of the SKYWARN program. Forecasters now have geo-synchronous satellites and 3D Doppler radar to help predict severe weather and issue warnings to keep all of us safe. Spotters who were limited to telephone and Ham Radio now have a plethora of social media and email to send in reports, including still images and video.
So, why is Ham Radio still relevant to the SKYWARN program and to the general public? The answer is simple. Ham radio does not require the Internet, a working telephone or any other technology (other than a portable or mobile radio) to get severe weather reports from spotters to the NWS forecasters. Moreover, that same Ham Radio link can also be used by the forecasters to push out severe weather warnings and other guidance to all the SKYWARN Hams as needed in a timely manner.
Let’s turn the question around. Is SKYWARN still relevant to Ham Radio? Absolutely!!! SKYWARN is a year-round opportunity for Ham Radio operators to demonstrate our importance at a time when society is cell phone and Internet centric, so much so that many people think Ham Radio, the original “social media”, is a thing of the past. And SKYWARN participation is a great opportunity to fulfill one of the prime justifications for the Amateur Radio Service’s existence.
2017 has the potential to be a very active Hurricane and Severe Weather year, maybe the most active since the 2004 and 2005 seasons. Now is the time to get ready. Attend an upcoming SKYWARN Training session scheduled for your area or take the online SKYWARN training offered by the National Weather Service. Participate in the SKYWARN Information Net every Tuesday night at 9:00 PM on NI4CE. Be ready to be part of the solution when severe weather threatens your county, your neighborhood. And when you finish reading this article and feel so motivated, find the PayPal “Contribute” buttons on our main NI4CE.org webpage to help keep NI4CE on the air and ready for whatever Mother Nature will throw at us this year.
A correction to my comment about ICOM being the sole source for D-Star radios in my last column. Kenwood’s TH-D74 portable now provides Hams with a second source for operating in D-Star mode wirelessly.
So far, the Spring of 2019 has been relatively quiet when it comes to severe weather here in West Central Florida. The SKYWARN activation on Good Friday was the first major regional event this year. The strong straight-line winds associated with the storm system caused a lot of trees and tree limbs to be blown on top of power lines. This plunged thousands of residents and businesses into the dark. It could have been worse, a lot worse. No lives were lost, no major injuries were reported.
It is hard to know what the rest of the Spring and Summer will bring. Early Hurricane Season forecasts suggest a slightly below normal year. But all it takes is one Andrew, one Katrina, one Maria or one Michael to dramatically change the landscape. The “new normal” will be drastically different than what it is today. And recovery will be measured in years, not months or weeks or days as our neighbors in the Panhandle are discovering.
Maria in Puerto Rico and Michael here in Florida exposed a number of shortcomings in short term storm recovery planning. One of those shortcomings was with civilian communications. To put it mildly, there was none for the first few days. Cell towers were blown down. Telephone and Internet services were unavailable. Getting the word out to friends and loved ones was next to impossible, even when they may have lived the next town or county away. Never mind vital information about the availability of ice, water, food stuffs and medicine even with all our “normal” technology because there is usually nothing “normal” operating when a CAT 5 Hurricane or EF5 Tornado blows through your neighborhood or town.
But here are a couple of thoughts I would like to offer that may be able to make a difference for the next disaster. For all the Ham operators reading this post, take as many of your critical communications tools with you when you evacuate. Not only will you need them in working order when you return, so, too, will your friends and neighbors. They will be relying on you to deliver Health and Welfare messages so their friends and loved ones know they survived.
If you are not familiar with how to take a formal Health and Welfare message, Dave-W4PXE, the Manager of the Eagle-Net, conducted nightly at 8:30 on the NI4CE Repeater System can help. Dave is conducting some “over-the-air” training sessions this week and for the next several weeks that will help you become fluent with message taking and message receiving. Yes, the process may seem antiquated given all the email and SMS texting technology most people now have on their phones. But, remember, when the phones aren’t working, Ham Radio usually does.
If you are not a licensed Ham and would like to become one, contact a local Ham Radio Club or your local Emergency Management officials. A list of local Ham Clubs can be found at www.wcfarrl.org or www.arrl.org. And every Emergency Management agency in our area has a Ham Radio contingent who can be a resource and point you in the right direction.
But maybe the most important thing EVERYONE can do is get to know your neighbors! Know if they plan to evacuate as the storm approaches or if they are going to try to ride it out. Hams can be a real resource getting Health and Welfare Messages out for their neighbors. Many Hams also have generators to power refrigerators, keeping vital medicines cold.
One contingency that has not been adequately addressed is identifying one or more distribution points for outgoing H&W Messages. Specifically, how do we get these messages from the local neighborhoods to one or more HF equipped (and manned) transmission points to send the messages to locations where they can be relayed by phone, email and other available means to the target recipients? I think local broadcasters, particularly local radio stations could play a huge role with this, speaking as a former broadcaster.
I have gone a bit long in the tooth with this article. So I will pick this subject up again, soon, in future posts.
-April 22, 2019