At the Joplin, Missouri hamfest a number of years ago I passed a table that had a beautiful GE Sweep generator on display with a $15 price tag. No one was behind the table. I always carry a few of my QSL cards when attending swap meets. I borrowed a magic marker from another table and wrote sold on a QSL and attached it to the generator. It worked. Later the owner returned to his table and put the generator on the floor under his table.
The GE unit was unbelievable. I salvaged parts to complete 95% of a nice regen from it. The stability of the set is amazing—.46 kHz drift in one hour—from a COLD start.
* EHA Receiver named after Edwin Howard Armstrong, inventor of the regenerative detector.