When I first got interested in ham radio, 1957, you could still get WW2 mil surplus electronic gear. My first tast of ham radio was an ARC-5 modified for 40 meters.
Yeh I've had some ARC-5 stuff mostly "already butchered" LOL
One interesting project of note was some magazine, 73? Had a high level balanced modulator to produce DSB, not SSB. You took an ARC-5 transmitter, and fed push pull high level audio to the screens. I don't remember what you did to the grid drive, I think it was also push pull. Anyhow, I used a juke box transformer "backwards" for a modulation transformer, drive by a juke box 6L6 push pull audio amp. I got a signal out of it all right, but it was almost impossible to zero beat, as the poor receiver was completely overloaded---nothing shielded LOL
Another "weirdo" was a modified command receiver that was bandspread for 80M. It was jacked up as a converter, using the IF output. But we had a local station on 1400, and it caused problems, so the previous owner had jacked around the IF and I don't recall offhand what that was. (Just looked it up---the 3-5Mhz command rx had a 1410 IF, I think the converter had been jacked up to 1500khz or so.)
So a friend gave me a "bucket" of (really nice) hermetically sealed 24VDC relays. The converter had a B+ on/off switch, so I wired the 24V relay coil in series with the B+ so that when you energized the converter, the relay performed antenna switching for the receiver/ converter.
At the time the receiver was a Heath AR-3
Not long after that, because of the retired Colonel in the club, I bought a used RME-4350A from WRL for 50-75 bucks. As with all those RME's the dial drive was worn out. They were a poor design. He had already bought one for the club, and installed two of the little Jackson ball reducer drives in it, and I did the same with mine
They were a "hot" receiver, and fairly unique as they used "doubled up" IF cans, loosely coupled, to increase selectivity. These were not a "xtal converter" type receiver like Collins, Drake, etc. They still used the old scheme of individual coils for each band, therefore the bandspread was crunched in the upper end, somewhat. There was a later, more expensive receiver that "I think" was designed to imitate the 75A-4, but it, the RME 6900, was not xtal mixing either, as I recall
Also they had RCA jacks on the rear, all set up for the factory "SSB adapter" AKA product detector. I built my own, which did not work that bad. I still have mine, which came from WRL with an extra hole butchered in the front panel, as well as another one I bought a few years ago. "Maybe" one of these days I'll get one of them "rebooted"
I had a 6900 for a short time, in the 80's but somebody wanted it "bad" so I sold it