07-11-2024, 12:34 PM
I found an old transistor regen FM radio yesterday that I made out of scrap maybe in 1990. It was tuned by a straw in the coil that had a cut off piece of brass screw at one end and a piece of ferrite at the other end to give super wide band. The BBC stations marked on straw. Used 1x AAA cell and 32 Ohm headphones. More audio stages than usual so as to use very low current on all but o/p, which reduces gain. For example 2 x 100uA = 200 uA might be 1/2 gain of one stage at 1 or 2 mA. I forget the details. Probably the parts came from a pocket MW only radio. The RFC in the super-regen RF transistor's emitter looks like the "cup" type ferrite taken from a Japan/Chinese 455 kHz IFT. That point feeds the audio amp. Made on stripboard. I had maybe only an Antex soldering iron and a cheap meter then. Was job hunting and it passed the time. It wasn't built from a design.
