Foundations of Amateur Radio

One of the things I love most about this hobby is the ability to randomly dart off into any related direction and learn new stuff. For example, the names Nikola, Guglielmo, Heinrich and Edwin emblazoned on a t-shirt sent to me by a very appreciative listener Jack KI4KEP, started an exploration into the deeds and misdeeds of the people behind those names.

The first three might be somewhat familiar, Nikola Tesla whom we have to thank for inventions like Alternating Current, the Tesla coil, wireless power, radio remote control and many others. The Tesla company is named as a tribute to him. The magnetic flux density uses the letter T as its symbol and its called the Tesla.

As a side note, if you've ever struggled to decide if a symbol needs to be a capital letter or not, like say the V for volt, the A for ampere, the O for ohm, the m for meter, the s in second or the K in kelvin, you just need to remember that if the unit is named after a person, the symbol needs to be a capital letter. That does assume that you know that the unit is named after an actual person, like say the Earl of Sandwich.

Name two in our list, Guglielmo Marconi is the person whom we can thank for the practical development of radio communication, using improved spark-gap transmitters, the development and commercialisation of long-distance radio transmissions and his association with many other services such as a transatlantic radio-telegraph service, providing communications to shipping such as Jack Phillips and Harold Bride who were employed by the Marconi International Marine Communication Company to act as radio operators on the RMS Titanic on its fateful voyage.

Our third name, Heinrich comes into sharp focus when I add his surname, Hertz. His name continues on in our day-to-day language and Heinrich Hertz is responsible for validating many of the underlying principles of our hobby. Using a spark-gap transmitter he was the first to conclusively prove the existence of electromagnetic waves which were predicted by James Clerk Maxwell. He also came up with the parabolic antenna, the dipole antenna, measurement of electric field intensity, electromagnetic waves and many other experiments. If you've ever seen a bullet hole in glass, you've seen a Hertzian cone.

The last name had me stumped. It took a question to learn that Edwin shares a name with a famous cyclist and a famous astronaut, namely Armstrong. Edwin Howard Armstrong has been called "the most prolific and influential inventor in radio history".

If you're like me you may not have heard of Edwin Armstrong. You might be surprised to learn that he's responsible for the regenerative circuit, the super-heterodyne circuit and while he was working on defending his invention against a claim made by a patent attorney he stumbled on the super-regeneration circuit. If you're a radio amateur, you'll likely have heard those terms, if not, they're electronic circuits that make radio receivers more sensitive which forms the basis of many radios in use today. My Yaesu FT-857d is a super-heterodyne radio for example.

It doesn't stop there. The biggest claim to fame that Edwin Armstrong brings to the table is the invention of FM radio. It took many years and a protracted lawsuit that lasted until almost a year after he died to finally have Armstrong formally established as the inventor of FM.

Not for a minute will I suggest that my exploration was comprehensive or in-depth, but it made my day when I put on a t-shirt with the names of those inventors who made it possible for me to be here and share this with you today.

On the shoulders of giants wearing a t-shirt with their names I stand.

I'm Onno VK6FLAB