[Milsurplus] 500 Kc XMTR

[howard holden]

Hue, you might be thinking of the RMCA ET-3650, a so-called "emergency" 
transmitter that ran 4 210s in parallel, in a Colpitts configuration, 
tunable 600 to 800 meters. I have a book titled "Practical Radio 
Communications" by Nilson and Hornung, 1935. It's in there, and it is 
powered by a 12V battery and a small motor-generator set, AC-CW at 700 
cycles.

Looking at the main transmitters, the self-excited oscillator/amp 
circuits were common in the maritime service. A common configuration for 
non-emergency use would be a 203 (or 2 of them) as the oscillator, 
driving several more as amps in parallel, both MF and HF.

Interesting stuff, would love to get my hands one one, either HF or MF, 
just say I had it and used it.....

73, Howie WB2AWQ


On 9/16/2017 1:29 PM, Hubert Miller wrote:
> Remember that (probably) RMCA secondary 500 kHz transmitter that used something like 4 triodes in parallel
> in self excited oscillator? This was also in one Fair catalog one year. I sure wondered where on earth they had
> found some of those. I had two close brushes with acquiring one of those things. Once when I was rooting through
> a shed attic in Seattle, which attice was piled about the knee high in every kind of stuff, some very good stuff,
> but all interesting, up to your knees. I put off dragging out that transmitter, and then with health problems of the
> host owner, the invitations kind of faded away. Then there was one on Ebay and I communicated with the owner,
> but didn't move on it. I do have the matching receiver, it's something like AR-8501, which was also described in
> an AWA OTB article, so I probably should have acquired this transmitter. I never imagined that the LF band
> would be opened. The world moves on, and I'm continually surprised.
> -Hue
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