|Jack Ganssle's Blog
This is Jack's outlet for thoughts about designing and programming embedded systems. It's a complement to my bi-weekly newsletter The Embedded Muse. Contact me at firstname.lastname@example.org. I'm an old-timer engineer who still finds the field endlessly fascinating (bio).
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50 Years of Ham Radio
January 9, 2019
It dawned on me that 2019 marks 50 years since I got a ham radio license.
Legally known as Amateur Radio, ham has a rich history that goes back to the very earliest days of radio. Probably the most important aspect of this is that it is indeed for amateurs; commercial activity is not permitted. You can't conduct any sort of business with a ham license. So ham hobbyists are generally those who are smitten with the electronics, talking to distant operators, or both.
When I got my first license in 1969 there were many classes of ham operators. My "Novice" ticket, which was the bottom of the pack, was the easiest to get with the fewest operating privileges. There was a written test administered only at FCC offices. My dad drove me to one in DC.
I vividly remember the Morse Code test given in the same session. Holy crap, was I nervous! Novices only needed to copy and transmit at 5 words per minute (WPM), a deadly slow pace that took me forever to master. "Words" were nominally five characters, so 5 WPM was about two seconds per character.
Years later I upgraded to a General license which had a 13 WPM test. That was my limit; I could just barely copy code at that speed and never mastered even a single WPM faster. The top license, Amateur Extra, beckoned but was out of reach due to its 20 WPM requirement. A friend could copy at over 40 WPM, and he often never wrote anything down; he'd sit back and listen to a conversation in Morse and break out laughing when sent something funny.
Morse Code was considered important for a variety of reasons. It's an extremely low-bandwidth way to transmit information. Novices were considered so lacking in radio skills that they were only allowed to use Morse, except for a little bit of voice on line-of-sight 2 meters. How much interference could one cause with a range of maybe 40 miles? Many hams built their own radios, especially transmitters, in those days, and voice transmission can be overmodulated, creating all sorts of havoc.
The FCC abandoned the Morse requirement long ago for all ham licenses. Today each level has a multiple-choice test. Some time ago I upgraded to Extra. The 50-question test was absurdly easy for a techie, though one does have to memorize a bit of law. However, the FCC publishes the 400 or so questions that the test draws from. Anyone can pass the test.
Some old-timers grouse about the Morseless requirements. "Real hams know the Code!" I disagree. Perhaps this culling was needed in the days of home-made gear, where low barriers to entry might means hams building poorly-designed transmitters that could interfere with other services. Today most of us buy our radios. On the HF bands (under 30 MHz where signals propagate world-wide) single-sideband (SSB) is the usual modulation, and an SSB radio is a challenging thing to build.
Morse came in handy in other ways. It used to be that many lighthouses also transmitted a Morse three-character identification code on low-frequency (hundreds of KHz) radios. Mariners had radio direction finders; you'd tune to the right frequency (given on the charts) and identify the lighthouse by the Code, then triangulate on a couple of these signals to estimate your position. Those transmissions are long gone, done away with by ubiquitous GPS. An old sailor theme is "never trust a single aid to navigation," as these can be wrong, so I rail against our utter reliance on GPS. I still use a sextant as a backup and have found GPS to be seriously wrong on more than one occasion.
Some embedded developers transmit Morse, via a speaker or LED, to extract limited debugging info from their devices. It's a clever way to get data from a small system.
Here are some links to code that will generate Morse code.
My interest in ham radio was always much more in the electronics than in talking to people. So as a teenager I was always building transmitters and associated devices. (Most of my receivers were WWII-surplus units, as the war had ended just a couple of decades earlier. I got RBC and RBB radios for next to nothing from a US government surplus center; they were marvelous receivers).
One of those transmitters, the poorly-designed sort the FCC feared, used about four vacuum tubes. My best contact ever as a Novice: the FCC picked me up on my second harmonic (totally illegal) all the way across the country in Spokane, Washington.
I proudly hung the angry notice they sent on the wall!
Today we have an HF transceiver on our sailboat. The only time I'm on the radio anymore is when we're at sea. But amateur radio was a good thing for me. I learned a lot about electronics through it, especially radio-frequency electronics, which is rather outside of the embedded systems domain.
And it is cool to make one of those long-distance contacts. Yeah, we can pick up the cell and call our buddy in Australia for little to no money today. But think of that 20 meter signal bouncing off the ionosphere and the Earth multiple times as it wings its way around the globe!
73, everyone, from N3ALO
Feel free to email me with comments.
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