I kinda imagined you must have been an amateur enthusiast back in the 60s-70s (it just fits you totally
as so many electronics lovers were at those days.
I would think with the Web of today that would be a "redundant hobby" ,but looks like it is still alive and kicking.
Never heard of trombone capacitors tuning till now,
the closest I new about was cavity tuning
(for much higher frequencies than 14Mhz).
In the old days they were called antenna-tuners,
some were fully hand cranked others were automatic-motor driven.
Are you into Morse as well?
What kind of Transmitter are you using,
I guess it is an "all Analog" old one...
I received my Novice Amateur Radio License (KN8UTJ) while serving in the Air Force from 1963 to 1967. IIRC the "ticket" was issued in the summer of 1966 and expired in the summer of 1967, soon after my enlistment was finished. I should have traveled to Columbus OH and taken the tests for either Technician (5 wpm code test) or General class (13 wpm code test) licenses, but didn't. Back in those days it was upgrade or out. The Novice "ticket" was not renewable.
During that year "on the air" I became a passable Morse code operator, eventually sending and receiving about 20 wpm. I only "worked" one band: the lower end of 80m with three (maybe four) crystals to set my home-brew CW transmitter frequency. Back then Novices could not use a VFO (Variable Frequency Oscillator), so we were all "rock bound" as far as transmitter frequency. My receiver was a Heathkit SB-301, assembled from a kit while awaiting the arrival of my Novice license, or "ticket" as the amateur radio license is called. My antenna was an 80m dipole assembled on the roof of my barracks, supported on EMT about ten feet above the tar-and-gravel flat roof. Unfortunately it was oriented east-west so it transmitted and received signals mainly from the north and south, and I was in the upper peninsula of Michigan near the Canadian border. Still, I made a goodly number of contacts and became proficient enough on the straight key to purchase an inexpensive Vibroplex clone from Lafayette Radio Electronics
. I never much cared for mechanical dot generation, so I soon returned to the straight key, which I still have today. My transmitter was based on the venerable RCA 6146 beam power pentode and had an input power of about 70 watts. It has long since disappeared, but I still have the Heathkit receiver.
Flash forward to 2013. I returned to amateur radio and obtained an Amateur Extra License (AC8NS) on April 1, 2013. To celebrate, I purchased an Elecraft KX3 rig that is extensively digital (but NOT an SDR
) with 10 W output power. Lots of control knobs, which IS very old-school. Later I added the Elecraft 100 W KXPA-100 with built-in antenna tuner.
I still aspire to resuming CW (as Morse code transmissions are called) on 80m, hence the construction of an 80m magnetic loop antenna requiring a tuning capacitor as an integral part of the loop. Normally, hams use a Russian military-surplus vacuum variable capacitor for this, but I decided to construct two coaxial capacitors, connected in series, with common tubes moving in and out of two outer tubes... hence the name trombone capacitor. Later, I plan to unsolder the trombone capacitor and fit a vacuum variable in its place. But until that antenna is finished, I have only made a few SSB contacts to nearby states on 40m using an ad-hoc end-fed inverted "L" antenna. I am re-learning Morse code using a Koch trainer app installed on my Android Galaxy 4 cell phone, so hopefully I won't embarrass myself the next time I call CQ using Morse code and failing to recognize the response. Yikes! There are Morse decoders available (one is built into the KX3) but where's the fun in that?
Amateur radio is alive and growing. Since the code requirement was eliminated from the license exam a lot of older hams have gotten back into the game, and younger folks are being recruited in increasing numbers every year. CW ops is great for DX: the narrow bandwidth really punches through the noise. Low power (QRP) operation has become very popular, especially with SOTA activations (Summit On The Air) in places world wide. A popular portable antenna is the Buddipole and the Alexloop, but the KX3 works fine with just two hanks of wire about fifty feet long, one tossed up into a tree, the other laid out on the ground as a counterpoise. It's a fun hobby at any wavelength, almost from DC to Light™. And if you really want a challenge, "moon bounce" or EME (Earth-Moon-Earth) is available, as are amateur orbiting satellites and a whole bunch of digital modulation modes. Twenty-first century technology has really opened up a lot of possible communication paradigms. Or you can just use the Internet, your cell phone, or any of several services such as Skype for world-wide conversations. I don't find that to be as much fun as contacting total strangers having a common interest.