KD9ZDY Gets a New Antenna

Since earning my technician's license this past fall, I've basically just been listening in to various HAM frequencies, scanning for signals and learning about my equipment. In spite of passing my exam, there was still a lot I felt I needed to know before really getting started. Beginner's anxiety generally kept me away from transmitting with my call sign, and even when I did try, I found that my limited antennas (handheld "rubber duckies") were not really well-tuned enough to generate an audible signal that would travel more than a few miles. Even if there were some other HAM operators in my listening range, it wasn't likely they'd be able to hear me unless they were tuned-in right at the same time I was transmitting, and also within a short distance from my location. I could listen in on signals as far as 100 miles out, but I could not transmit that far. I needed a bigger antenna, something to really put my 50 watt ICOM IC-2730a transceiver to work. 

So, I began my latest HAM project: installing the telltale antenna -the ones that easily identify the radio enthusiasts in your neighborhood, and sometimes run afoul of the maligned home owners' association. I ended up buying a 2-meter and 70-centimeter band antenna from HYS. This fiberglass antenna had good reviews, and is basically a slightly less-expensive copy of the similarly tuned name-brand Comet antenna, which has a good reputation in the radio industry. The HYS is white and flexible, so it blends in nicely with the front of my house, and it should hold up to heavy Midwest winds. Outside of the good reviews, and attractive price point, I chose this model because it's tuned for the 2-meter and 70-centimeter bands which are the most common frequency ranges for local FM HAM communications. The length in meters and centimeters, is roughly equal to one wavelength between 144-148 MHz "2m" band and 420-450 "70cm" band. The 5-foot, 7-inch pole with three steel radials at the base is perfectly tuned to transmit at the 2m and 70cm frequency ranges. The HYS also boasted a 1.5 standing wave ratio (SWR), meaning it was well-suited to provide the most gain (signal strength) for the 50 watt power output that my transceiver was capable of providing. An SWR that is too high can cause damage, as too much of the power pushed into an antenna will feed back into the radio. An SWR of 1.5 or less means that the antenna is sufficiently resonant to safely transmit. But, I'd still need to install and test the antenna to make sure it works as advertised. 

Before the tough business of mounting the antenna and wiring the it to the base station, I first connected my a hand-held Baofeng UV-5R transceiver to the antenna to make sure it wasn't blatantly faulty. I dialed up the input frequency for my local repeater, and listed for its response "beep" on the output frequency. Sure enough, I heard the beep. So, at the very least, the HYS antenna would be as good as what I was already using. 

Set-up was actually quite straight-forward. I only needed a mount, a lightning arrestor, grounding rod, and about 30 feet of all weather HF coaxial cable, plus some siding hooks and wire clips to run the the wire neatly around the back of the house and in through the basement window where my radio is. I chose this location and set-up as a compromise between getting the antenna as high as possible without drilling into my home's plastic siding, and being able to install the antenna, and potentially remove it safely, without having to climb onto the roof. You can see from the photo above that a person can easily access the antenna from the front porch without a ladder. The other main safety precaution was adding a lightning arrestor and ground rod near the point where the cable enters the back of the house. The 4-foot copper rod is buried straight down 2-feet from the base of the house with three, 4-foot copper radial wires extending away from the home to disperse any charge from a lightning strike. 

Now it was time to test station KD9ZDY's new antenna with the real transceiver from the comfort of my basement HAM "studio." First, I wanted to make sure the antenna has a safe SWR of 2 or less as advertised, before transmitting. For this, I used my handy NanoVNA network analyzer. Success! The analyzer, calibrated to measure SWR between 100 and 500 MHz, shows two deep troughs at the 144 and 420 MHz ranges where the ratio dips below 1.5. So, the antenna came as advertised and is safe for my transceiver to transmit on the 2m and 70cm bands.

The final step was to get on the air and announce myself with a radio check to see if anyone or anything could hear me. Success again! While I didn't immediately hear from any other HAM operators, I could hear the beacon, or courtesy "tone", from repeater antennas I'd never been able to contact before. Repeaters, automated transceivers, which listen for your transmission and repeat it over a much longer range often send a beacon, tone or squelch tail (the static fuzz that denotes an end of transmission), if it successfully receives a transmission. In the video above, you can hear the repeater's beacon when when I made contact with it. Not long after confirming my station's new capabilities, I was getting responses from other HAMs across the region, confirming that they got my signal loud and clear.

RTL-SDR: Home-made Air Traffic Control

If you've read my previous article, "Flight Tracking: I Guess I'm a Plane Guy Now...", you're well aware of my interest in air traffic control (ATC) and flight tracking. If you look to the right of the Cubicalruins homepage, you'll even see my embedded flight tracking window from FlightRadar24.com, my favorite flight tracking website. But, radio -and specifically SDR- allow me to take my hobby a step further. Rather than depending on web-based flight tracking websites, I'm now able to run my own air traffic control system from home. 

A screenshot of RTL1090 and Virtual Radar Server on my PC

Anyone involved in aviation or flight-tracking will already know this, but air traffic controllers and airport towers used to use radar to identify incoming and outgoing planes. But now they primarily use unique transponder (radio) signals from each individual aircraft to identify and track all flights. The most commonly used transponder system is the Automatic Dependent Surveillance Broadcast (ADS-B) system which broadcasts on 1090 MHz, and some smaller aircraft use a Universal Access Transceiver (UAT) system, which broadcasts on 978 MHz. While radar is still used as a secondary tracking system by both military and civilian air controllers, the ADS-B and UAT systems now allow a hobbyist like myself to pull actual, real-time flight data from the planes, helicopters, blimps and sometimes weather balloons directly to our PCs. Using SDR, we can see everything the FAA air traffic controller sees.       

In my previous article I discussed setting up and testing my RTL-SDR dongle and antenna to pull AM and FM voice radio into my PC. This was a pretty simple initial test. But, getting ATC signals into the PC, decoding them, and plotting the data onto a viewable air-traffic map was considerably more difficult. In the end I was able to run the RTL-SDR with two different ATC/plane-tracking applications, PlanePlotter and Virtual Radar Server. Both provided challenges, but after multiple troubleshooting attempts I got both systems up and running. 

Using Carl Laufer's "The Hobbyists Guide to the RTL-SDR," I started my my home-made air-traffic control project. Page 67 provides a brief intro to plane tracking on the RTL-SDR; page 69 describes how to download and install Dump1090, a primary decoder of ADS-B data from 1090 MHz; page 72 provides instructions on installing RTL1090, another decoder; and page 75 describes how to install and use PlanePlotter, an application for viewing the planes on a map. While the instructions were very useful, I did run into a few hitches along the way, and I'm not sure if these were due to my Windows 11 operating system, outdated versions of the software, or my own lack of knowledge on PC's -normally I use a MAC. However, I'll try to provide some helpful step-by-step guidance at the end of this article for SDR enthusiasts hoping to run Planeplotter or Virtual Radar server.

The F-14 "Tomcat" on display at the MAPS Air Museum in North Canton, Ohio

My first hitch was that the suggested decoding software, Dump1090, simply did not work on my PC. My command console just did not recognize the command "--net-ro-port 30002 --net-beast" when added to the dump1090.bat file necessary to run the decoder. I'm still unsure why. Thankfully, Laufer's book had an alternate suggestion for a decoder, RTL1090, which I downloaded from Jetvision at https://rtl1090.com/. The funny thing is RTL1090 didn't work either until certain dll files such as rtlstr.dll were also installed; and guess which zip file had exactly the dll files I needed? The dump1090 zip! So, regardless of which decoder you use, I'd recommend downloading both RTL1090 and Dump1090, the IMU version and source code, and extract them into the same folder. That way you'll know you have all the dll files needed to run each application. Ultimately, I was able to successfully install and run RTL1090. 

My next challenge was installing a program to visualize the data from RTL1090. I downloaded Planeplotter at https://www.coaa.co.uk/planeplotter.htm as well as Virtual Radar Server at https://www.virtualradarserver.co.uk/. Both were easy to download and install. But, I should mention, PlanePlotter requires a one-time 25 Euro (roughly $30 USD) license fee and software registration if you plan to use it beyond the two-week free trial period. The next step is to set up your new visualization apps to accept the ADS-B data from your antenna and decoder. You must set up your decoder (RTL1090 or Dump1090) as a TCP/IP client in the options menus, using port 30002 for Dump1090, or 31001 for RTL1090. Once the correct port is saved in the options, and you begin running the application, you should see planes flying in your app! 

My home ATC set-up with RTL-SDR dongle and antenna

After all this, the results were well worth the effort. I've always been fascinated by air travel, and the complexities of keeping all those thousands of aircraft above our head safely moving. The ADS-B signals on 1090 MHz is a big reason why this is possible. Plus, I live very close to the Kent State University Airport home to the FedEx Aeronautics and Academic Center; there are always maybe 1 to 6 little KSU aircraft buzzing over our heads at any given moment pinging their data to 1090Mhz. So, there is always something to watch. Additionally, not only am I using a web-based app to see aircraft, but now I'm an actual contributor to these sites, providing my own flight data to help others see planes over my reception area.      

I've done my best to provide quick step-by-step tutorials on each set-up below. 

RTL1090

1.) Go to RTL1090.com and download the IMU version of the software.

2.) Go to https://github.com/MalcolmRobb/dump1090 and download the zip file for the application. Extract all files into the same single folder as the RTL1090 IMU. 

3.) Install and run RTL1090. If any dll files, such as rtlsdr.dll, are missing, search the directory at the url in the previous step for those files and add to your single extracted file for dump and rtl1090. 

4.) Once installed, open RTL1090 and click "start," if your RTL-SDR is plugged in and connected to an antenna you should see numbers scrolling in the List tab. This is the raw ADS-B data coming from 1090Mhz. You're all set!  

5.) [Optional] Download and extract all files for the RTL1090 "Scope" version from RTL1090.com, and run this version if you'd like to see the Scope and Plug-in tabs in the newest "beta" version of the application. 

NOTE: I was unable to connect RTL1090's IMU or standard versions with Planeplotter. For some reason, the RTL1090 "Scope" version worked. Plus the Scope version has it's own small visual aid with planes and headings as well.

RTL1090 + Virtual Radar Server 

1.) Follow steps one through five above. 

2.) Download Virtual Radar Server at https://www.virtualradarserver.co.uk/Download.aspx. 

3.) Open Virtual Radar Server, then go to Tools > Options. Click Receivers, and click the plus (+) icon to add a receiver. Name the new receiver RTL-SDR (or whatever you choose). 

4.) Make the data source "AVR or Beast Raw Feed."

5.) Keep the IP address 127.0.0.1. Make the Port: 31001 for RTL-SDR. (It should be 31001 even if your RTL1090 window says 31011.)

6.) Click start on RTL1090 and have it running in a different window. Then click the http://127.0.0.1:8081/VirtualRadar link in the middle of the Virtual Radar Server window. In the browser, you should see planes within receiving range of your antenna. You're all set!

7.) [OPTIONAL] In Tools > Options you can click on Receiver Location and enter your coordinates to save your current location. The next time you open your browser map, it will automatically center on your location. 

RTL1090 + Planeplotter

1.) Follow steps one through five under the RTL1090 instructions above. 

2.) Download and install Planeplotter at https://www.coaa.co.uk/planeplotter.htm, and open the application. 

3.) [OPTIONAL] When prompted, you can register your download and pay for a lifetime license through PlanePlotter's payment service. Once the payment is made, you'll get an email at the registered email address with the registration confirmation code which is good forever. Otherwise, skip this step and simply use the free trail. 

4.) [OPTIONAL] When prompted, enter your current coordinates to set your location on the map.

5.)  In PlanePlotter, go to Options > Mode-S Receiver > AVR Receiver > TCP/IP Client. Make the address and port 127:0.0.1:31001. (Again, even if your RTL1090 window shows the port as 31011). 

6.) Go to Options > I/O Settings and check MODE-S/ADS-B. Then, click AVR Receiver TCP and OK. This will set your RTL-SDR up as a TCP/IP client. 

7.) In the main window, click the green circle and make sure RTL1090 is running in another window. You should see planes on your map. You're all set! 

8.) [OPTIONAL] Obtain a MapQuest API key at https://developer.mapquest.com/documentation/ by clicking "Grab the key." You may need to create an account with developer.mapquest, but the API key is free. 

If you enter the Mapquest API key in Options > Charts under the Mapquest option, and save, you can download a more detailed map to view beneath your planes by holding the right Shift key and clicking the globe or "MAP" buttons in the toolbar of the main PlanePlotter window. The stock map is very, very, basic. 

NOTE: For some reason, I could only get the Mapquest chart to work by holding the Shift key and then clicking the MAP button. 

"The Hobbyist's Guide to the RTL-SDR: Really Cheap Software Defined Radio." Fourth Edition. (2024), Carl Laufer.

RTL-SDR: Decoding Radio Signals on your PC

"They have the radio on computers now?" That was my first thought when I learned about Software Defined Radio (SDR) after I started studying for my HAM radio license exam. It was one of the more interesting tidbits I passed over while hitting the main question pool info such as antenna set-up, band plans, basic circuitry etc. But, it intrigued me. It was one area where HAM radio has taken a leap forward, providing inexpensive access to digital signal decoding to learners and hobbyists.

My PC showing SDR# software

Home SDR for hobbyists got a big boost in 2012 when Realtek launched the RTL-SDR dongle; it's a USB plug-in about as big as a "fun"-sized Halloween candy. One end plugs into your PC's USB port, and the other side has a coaxial connection that can be fixed to an antenna, or antenna system. Once the RTL-SDR is installed with all the drivers, and attached to an antenna, it will immediately begin feeding radio signals from the air to your PC. 

The big difference between SDR and most PC radio applications is that sound is not simply being streamed through your internet service provider, it's actually being picked up from the airwaves flying around you every second of everyday. You can un-plug your Wifi or data connection, and the RTL-SDR will still pick up those radio frequencies. It can even listen for, and decode, signals no normal PC or radio would ever get such as the amateur radio bands, nautical communications between boats and ships, and ADS-B and UAT transponder data from all aircraft both large and small. None of these signals are encrypted, and it's perfectly legal for hobbyists to listen in, provided they do not transmit on these frequencies in a way that could disrupt normal communications. 

The RTL-SDR dongle & antenna 

When I first unpacked my RTL-SDR and antenna set, which I ordered at RTL-SDR.com for roughly $60 USD including all components and shipping, I didn't quite know where to start. So, I also ordered The Hobbyist's Guide to The RTL-SDR by Carl Laufer as my starter guide. The book is a well-indexed set of step-by-step tutorials and trouble shooting techniques combined with general information about SDR and the various signals hobbyists can decode. Page nine discusses the initial installation of the RTL-SDR dongle, its drivers, plug-ins, and port numbers; page 13 provides a step-by-step tutorial on SDR# (or SDR sharp), a basic application for decoding, viewing and listening to signals received by the dongle. 

After a few read-through's, I was ready to test my new set-up. For my first test, I decided to get the daily weather. I tuned my SDR# app to 162.400 MHz, the frequency for NOAA Weather Radio for Akron and inland northeast Ohio, and it worked! I used my RTL-SDR to get weather (in possibly the most complex way possible). 

But, the test was a success. I could not only hear the weather report clearly, I could see all of the RF and modulation info-graphics necessary to locate and tune lots of different voice broadcasts and data transmissions. In the video above you can see the graph peaking at exactly 162.400 MHz, the NOAA station for Akron. The smaller peak just to the right is 162.550 MHz, the weather station for Cleveland and the Lake Erie shore. Both are in listening rage of my little antenna, but the higher peak is the closer signal. The digitally decoded graphics, and filtering options offered by RTL-SDR and SDR# are the perfect addition to any HAM radio base station. 

"The Hobbyist's Guide to the RTL-SDR: Really Cheap Software Defined Radio." Fourth Edition. (2024), Carl Laufer.

Advice from the HAM Radio Community

If anyone says the HAM radio community is a bunch of old guys playing around with out-dated toys, stop them right there! 

There's nothing "OLD" about HAM technology; and, there were a few young women at the HAM fest put on by the Massillon (OH) Amateur Radio Club as well.

In fact, an enterprising fellow named Daniel Estévez just recently landed the first amateur radio on the Moon, with the help of The Japan Aerospace Exploration Agency (JAXA). You can check out his blog, here.

Unfortunately, I was not able to connect to his signal, even after running out of my Mother's house with my big antenna. The broadcast lasted only for a few days on 437.41 MHz, and I missed it. But, I think Daniel and JAXA, paved the way for more space exploration, specific to the radio field. 

Another thing I wanted to message was just how helpful the HAM community can be. 

A new set-up with the appropriate SWR meter

I needed an SWR meter for my new rig, I got an extremely in-expensive Astatic PDC1. I won't get into more details, but for those of you who don't know, SWR stands for Standing Wave Ratio. HAM operators need to know they have a low SWR ratio to make sure the output of their radio does not cause damage to their radios. 

Well, this inexperienced blogger used the Astatic PDC1. And, I did not know at-the-time that my particular model was designed ONLY for CB Radio, also known as Citizens Band Radio... And, my new SWR meter started to SMOKE. This is not to suggest that the Astatic is a bad product. It was just the wrong one for my set-up. 

Where did I go for better advice? Reddit of all places. (I know, the home of neck-bearded dorks who live in their moms' basements). However, it turns out this community is not-all bad. They were the ones who suggested the appropriate model for my set-up! 

What I ended up going with was the MFJ-862 UHF/VHF meter, which was a little more expensive and did not burn out. So, in the end, I got good advice from a Reddit user whose username was very NSFW ;)

Rig Step-up & Basic Electronics

This past January, I upgraded to a more advanced VHF/UHF transceiver for HAM radio communication, the ICOM IC-2730. Previously, I'd only been using a handheld Baofeng UV-5R. Though the IC-2730 is built to be a mobile transceiver mounted in a vehicle for talking and receiving on-the-road, it makes a good stationary base station at a much more affordable price than dedicated stationary transceivers such as the IC-7300.

The advantage of the new ICOM is a 50 watt output allowing for greater signal range, a dual-band input allowing the listener to tune in to two different frequencies at the same time, a big bright user-friendly display, a microphone with channel and volume controls as well as adjustable squelch knob to block out weak frequencies while scanning for audible chatter. In short, the IC-2730 is a nice stepping-stone between the economical handheld and the powerful, but expensive, base station. For an experienced HAM, it's the perfect mobile counter-part to a dedicated base transceiver. 

However, when I opened the box and examined my new IC-2730 my inexperience was on full display. When I attempted to fire it up I found only bare high-gauge wires -nothing to go into my wall socket. How the heck was I supposed to plug this thing in? I thought maybe the box was missing the "plug." But, after reading the manual it was clear everything that was supposed to be delivered was in the package. I guess that's why there's a whole section on basic electronics in the HAM radio technician license exam; I was going to need to do some basic wiring.

Because my IC-2370 is a mobile unit, it was made to run off a stand-alone power supply such as a car battery. So, the input and ground wires are lengthy and come with naked leads that can be cut to any length and attached to any type of power source by solder or a connector. (A lot of people have these installed in their cars by a professional, rather than mess with all that themselves.) Additionally, my radio needs a fairly high amount of power to reach the output signal it advertises, and it uses direct current (DC). Home power sockets use alternating current (AC). 

So, in addition to my radio, I'd need a power supply that can be plugged into the wall, accept AC current, convert the AC current to DC and amass a specified amount of voltage (13.8 V), then force a high enough current (30 Amps) to the radio to achieve it's maximum signal range. My solution was the BTech RPS-30PRO bench power supply. This adjustable power box is what gets electricity from the wall socket, converts it to DC and stores the 13.8 (or more) volts needed to power most HAM radios. 

Now I needed to figure out how to connect my radio's bare wires to the BTech power supply box. With some basic research, I found out this could be done with some very basic insulated fork connectors and a crimping tool. Connectors in all shapes and sizes are exceedingly cheap and typically available in the wiring and electronics section of any hardware store. A crimping tool usually runs from about $10-25 dollars (USD). Once I had the right hardware, I crimped the bare wires to two fork-shaped connectors and screwed them into the output leads of my power supply. On the first try, I was ready to go!

While the extra wiring and installation steps seemed at first like a drag, it turned out to be nice learning experience for this not-so-handy blogger. If fact, like many HAMs and DIYers, I took the opportunity to build a small wiring kit for my workshop that includes a set of connectors, wires, a crimping tool as well as an all-in-one wire cutter/stripper. I'm now ready to take on the installation and set up requirements for any new HAM radio or component for either a mobile station or base station. Plus, the screw-knob design of the power box leads allows multiple transceivers or HAM components to be attached at once. So, hopefully, it's the last bench power supply I'll ever need to buy. 

The tools, wires and connectors allow me to use wires specific for radio frequency transmission and cut them to the perfect length for my set up. This reduces signal loss and RF interference, and avoids the tangle and clutter of excess wiring. And, because my licensing exam required me to know basics in electric safety, I was confident in doing the job without damaging my equipment, and most-importantly myself. Safety first!

Now I'm up and running with my new base station, and able to connect with repeaters and HAM groups in both Ohio and Illinois. So, far I've made contacts with The North Shore Amateur Radio Club (ns9rc) using a 147.345 Mhz repeater frequency operating from a tower in Northfield, IL from Chicago as well as a HAM net via a 442.000 Mhz repeater frequency from a tower in Uniontown, OH from Kent, OH. So, I'd say my new ICOM IC-2730 is working well.

Spurious Signals: Technology, Espionage and Football

For anyone who's never paid close attention to a college football sideline, it may look like a troupe of prop comics dancing all at once. The signs, props and posters are all part of a complex coding system intended to relay plays and strategies to the players on the field without tipping off the opponents. But beginning in Autumn of 2024, things will look much different. Prompted by a high-profile scandal involving sign-stealing, the National Collegiate Athletics Association (NCAA) will adopt in-helmet radio communications between coaches and players.

With a presumably private line of communication between player and coach, there will no longer need to be a system of audible and visual queues to coordinate strategies on the field. Or will there? Will radio communication end sign-stealing, and even the playing field? Or, will it complicate things even more? 

A college coach advises a player

In-helmet coach to player radio transmissions are common place in professional football already, and so far the results appear to be good. The National Football League (NFL) allows one player on offense (typically the quarterback) and one player on defense to hear play calls and advice from the sideline via a small radio in their helmet. Now, college football, often bound by history and sense of old-school tradition, has finally followed suit. 

As both an amateur radio operator and avid football fan, I was immediately curious about how these radio communications would be protected. How sophisticated are these radios? Is a sports team or league well-enough prepared to offer fully encrypted end-to-end communication without the possibility of transmissions being intercepted or blocked by bad actors? That may sound paranoid, but when you consider that the NFL is a close-to 20 billion dollar per-year industry, and that collegiate sports generate hundreds of millions for universities, conferences, coaches and now the players themselves, the financial pressure to cheat must be at an all-time high. Additionally, with recent legalization of online sports gambling, third parties now have another way to potentially cash-in on illicit activities involving sports. Could radio waves be a way to hack the system?

I, as an inexperienced amateur radio operator, can surreptitiously listen in on a lot of seemingly private radio conversations. With a scanner, I can pick up police, public works, commercial and aviation communications very easily. The Uniden BC125AT scanner, which retails at about $105 (USD) not only scans through all available radio frequencies stopping on any "hits" or active/open conversations, it also scans for and prioritizes privacy tone, or DCS/CTCCS, protected calls as well as "Close Call" hits that originate within a certain distance. With the Uniden, I can hear air traffic control, police, emergency services, commercial, GMRS, MURS and family walkie-talkie communications within reception distance. This would include business, event and organization, security, parking and other radio-to-radio communications. When programmed correctly, I don't even need to know there's a conversation happening, the scanner simply searches all frequencies and stops when it gets a hit.

If I take my Uniden to the airport, I can hear the gate attendant talk with the baggage crew on the runway, the pilots or airport security -assuming they are using a commercially radio or walkie-talkie. If I go to a NASCAR or Formula 1 car race, I can hear the drivers talk to their mechanics during the race. With a strong enough antenna (but still small enough to fold and carry in a small bag), I can even hear the astronauts on the International Space Station. So, I thought, what type of radio systems are these football teams going to be using to relay schemes and strategies with the potential to win or lose a game? If, I, an inexperienced amateur, can eavesdrop on police transmissions and air traffic, what protections are in place to stop an advanced user with better equipment from accessing a team's private channel? 

Thankfully, if the NCAA adopts the same security protocols as the NFL next season, players and fans can be relatively confident that no such spy-craft will be happening. A 2012 article by Katie Lindendoll on ESPN.com explains it better than I can. According to Lindendoll's article, and Dan Viglione, former employee of the Federal Communications Commission (FCC), the NFL's system is quite sophisticated. It involves encryption (which is illegal for amateur use), and both teams' communications are monitored by the league office. Unlike a standard walkie-walkie or GMRS radio, where transmission occurs directly from one user's radio to others, the NFL helmet radios transmit audibly, only to a central hub somewhere in the stadium and then connect the audio to a press box or the sideline. The transmission is digitally encrypted, so even if a person managed to find which frequencies were carrying the message -which is illegal, if done intentionally- all they would hear is fuzz, if anything at all.

The same happens when a coach in the press box or on the sideline talks back to the player wearing the helmet. During this process, the league monitors for any abnormalities such as jamming or spurious interference, which while possible, would likely block both teams radios, as well as other phones and devices in the area. If such a thing were to happen, officials could stop the game, and locate the culprit. 

Essentially, the helmet communications are a slightly more sophisticated version of your cellular or WiFi network. Your phone calls and texts don't go directly to the recipient, they go to an antenna somewhere nearby, forwarded to the intended recipient, and get decoded on the listener's end. And, it is very illegal to look for or attempt to decipher messages on the cellular bands. In this way, your cell provider acts like a hardwired switching board protecting your call each step of the way. (It's why you can be sure I'm not listening in on your private cellphone calls). Your WiFi network works like a mini cell service in your own home with the router acting as the switchboard. If you have your network set-up properly using WPA-type encryption and a strong password (that you don't give away readily!), the data in your home should be just as safe. 

The key factor here is less about the technology and more about the common-sense physical steps we as people take to protect our privacy. A well-secured network is only as good as the password it uses, and how well we protect that password. If our WiFi access info is written on a Post-it note, and someone else sees it, it's not the technology that failed, but the person who put the code out there for any passersby to see. Can we be sure that the staff members working for both the teams and the league are taking the appropriate steps to secure access to helmet radio communications? Who outside of the teams and officials could have the access info, or simply be present while a coach messages a player?  

From instant replay in football to the shot clock in basketball, just about every sport has adopted some sort of technology on the field of play. Whether it's for officiating or strategizing, teams and officials have slowly but surely adopted technologies invented for commerce, science and governing for the purpose of competition. While sports tend to lag behind broader society in adopting technology, the possibility to gain an unfair or illegal advantage, or to cheat, has always been present. It's no surprise, then, that as technology in sport grows so to do the vectors from which bad actors can game the system, including electronic communications.

College football seems to be the latest battlefield in the fight to keep playing field equal for all teams. A high-profile cheating scandal involving this past year's national champion, and nationally popular football powerhouse, The University of Michigan Wolverines, erupted in the mid-2023 season. A paid member of the Michigan coaching staff was caught at multiple opponents' games filming the teams' sidelines, in an apparent attempt to record and break future opponents' vocal and visual signal codes. After the revelation, many of Michigan's opponents expressed that they had long held suspicions that something was afoot, that somehow Michigan knew what plays their competitors intended to run in advance. If this all sounds a bit too outlandish, like something out of a Cold War spy novel, you clearly have a lot to learn about college football in the United States. It is that crazy. 

The Michigan scandal is still being investigated by both the Big Ten conference and the NCAA, and the result remains to be seen. Furthermore, sign-stealing and code breaking have been common place in both professional and amateur football since the invention of the sport itself. It's actually not against the rules to try and de-code a signal system during the game itself. What Michigan is accused of is traveling to future opponents' facilities and filming games where they are not involved, which is illegal. Still the NCAA regulations themselves allow for a considerable "grey area," where the line between breaking and bending the rules is often thin. 

Will radio communication lead to a more well-defined rule book, and put an end to this sort of rule-bending, or will it further complicate ethics surrounding the sport. Worse, could it lead to methods of cheating so clandestine and advanced that they go unnoticed by both fans and officials? Only time will tell, but until the results are clear, lets hope the only interceptions happening in football are those involving throwing and catching the pigskin. 

Lindendoll, Katie, “Are NFL teams hacking helmet headsets,” ESPN.com, ESPN, 2012.