My 1975 copy of The Radio Amateur’s Handbook is dog-eared and marked up from studying for my first US amateur (“ham”) license back in high school. I pulled this classic off my bookshelf the other day to check a topic and noticed that in it, there are a lot of parallels between Wi-Fi and amateur radio. Then, I was cleaning up some old ham radio antennas over the holidays (we all have an antenna pile somewhere around our homes…) and I was thinking of how much the amateur radio hobby lends itself to Wi-Fi antenna technology. As I cleaned up a used HyGain Explorer 14 antennas, I began to ponder the study topics in ham radio that are similar in the study of Wi-Fi. Maybe getting involved in ham radio can help you out as an engineer as you pursue your WLAN career. Take a look at the following topics in ham radio and how they can help as you study for your next Wi-Fi certification:
- Antennas, RF, Transmission Lines, Oh My! All of these concepts and study topics are covered in depth in amateur radio. Yagi and dipole antennas, impedance and SWR, polar charts and beamwidth, attenuation and polarization are all required subjects on the amateur radio exams. One of the first antennas built by most amateur radio operators is the classic dipole antenna. Measuring the antenna via the wavelength formula, tuning to lower the SWR and knowing how the signal is strong off the broadside of an dipole are all the concepts that we cover in ham radio. Seeing how these technologies are explained in another field of study can help boost your knowledge of RF in Wi-Fi.
- Hams use digital radios too! Phase-shift keying (PSK), BPSK, QPSK and even 64-QAM are all digital radio transmission technologies used by ham radio operators. radio packets, PSK31, RTTY, PACTOR, APRS and Olivia are all digital modes ham operators use for communication. Check out these ham digital operating modes and see what parallels there are to Wi-Fi–and even take a listen to what these digital transmissions sound like!
- The FCC regulates both Wi-Fi and amateur radio. In the US regulatory domain, the Federal Communications Commission monitors both Wi-Fi and ham radio transmissions. You might want to take a look at Chapter 97 which is the FCC regulations that monitor amateur radio in the US. This regulatory body specifies frequencies, power levels, types of transmissions, etc in a similar fashion that the FCC does for Wi-Fi communications.
- It’s not a jammer–it’s a ham on 2.4 GHz! Ham radio operators can use the unlicensed frequency band of 2.4 GHz, also known as the 13 centimeter bands. Hams use this band for repeater links, digital voice, digital TV, and amateur satellite communications. Check out these transmission opportunities that must share in the 2.4 GHz band.
- Microwave in Wi-Fi = microwave in ham radio. Most RF and microwave concepts in amateur radio microwave design apply to Wi-Fi as well. One of the questions from the amateur extra exam questions pool is “Why is it important to keep lead lengths short for components used in circuits for VHF and above?” and the correct answer is “To avoid unwanted inductive reactions”. Microwave transmissions can be affected by long lead lengths and nearby metal objects, which is one reason why it is best practice to keep mounted APs at least a meter away from metal. The next question in the pool asks “What is a microstrip?”, which is “a precision printed circuit conductor above a ground plane that provides constant impedance interconnects at microwave frequency”. Take a look at the US amateur extra test question pool and see if there are no questions on microwaves that can help clarify and reinforce your knowledge of Wi-Fi.
- Amateur radio is a great hobby! No, this isn’t a study topic, but ham radio is rewarding and a lot of fun. Most WLAN engineers I know do a lot of study and work in the evenings and really need to take a break. But our technological minds usually don’t stop, so why not keep up with technology by engaging with ham radio? Maybe you can build a Raspberry-PI SDN radio, build your own loop antenna, or even talk to the International Space Station! The sky’s not the limit when it comes to ham radio–why not try EME communications (earth-moon-earth or “moonbounce”)? Who knows—maybe one day, you’ll even talk directly to the South Pole!1
If you are interested in ham radio, check out the American Radio Relay League (ARRL) website. Here you’ll find info to help you get started in ham radio. In the US, you can start out with the Technician class licensethen move on to the general class and finally, scale up and achieve the highest level in US amateur radio, the Extra class license. Get the latest copy of The Amateur’s Radio Handbook or The ARRL Antenna book. (if these are too pricey, find an older used copy on Ebay–much of the material is the same). Both are great resources and you will learn a ton that has parallels with Wi-Fi and have fun at the same time. You might even know an “Elmer” in your area (a ham operator who mentors others) who can give you some beginning tips or might have used a “rig” (radio) that will get you started.
The only problem with ham radio is when you get bitten by the “ham radio bug”! That’s right — you can and will get infected by ham radio and won’t want to put it down–whether it is learning Morse Code or working DX, you will always find something interesting, new and exciting in amateur radio. And look around– a lot of ham operators are WLAN engineers as well. However, don’t worry about getting bitten by the bug, because ham radio is a healthy addiction! 🙂
So, check out amateur radio–you will find it helps you in your Wi-Fi study and provides a great and rewarding hobby that lets you expand your technology. Ham radio is a lot of fun!
Hope to hear you on the water!
73 ES BEST DX DE KA9FNL K2
1My South Pole QSO story: I worked second shift at a tire factory in Indiana during my college days and of course I had my ham radio installed in my car. “Skip” conditions (bounce your HF signal off the ionosphere for long distances) had really been good that week and driving home on a country road lined with corn fields, I tuned around the 20 meter band and heard “QRZ, QRZ, this is KC4AAA”. Wow—I knew by the special call sign that this station was located at the Amundsen-Scott Base, precisely on the South Pole. I sent my call sign on SSB voice, having no hope of getting back to this station, but the control operator answered me and gave me a signal report (that’s about all a specialty DX station gives–so many stations try to call at the same time that should just call it a “pile up”). I had just talked to the South Pole-–from my car—on a midnight July evening in Indiana! The tires of my Chevy did not touch the ground until I got home! (“Q” signals are used a lot by ham radio operators.)
2To translate some CW (continuous wave or Morse code) lingo, here we go:
- 73 means “Best regards”
- ES means “and” (This is easy to send in Morse code!)
- BEST DX means “I hope you have good ‘DX’ or international contacts”
- DE means “from” or “this is” (taken from French)
- KA9FNL – that’s my US amateur call sign!
- K means “Invitation to transmit”
- But whatever you do, please do not call me a LID!