Found in a 73 magazine from the 1980s, this circuit generates signals from 3.2 to 22 MHz. FETs can be general-0purpose current types. No information about the coils is given.
This is an old test circuit for integrated TTL counters, feeding a Nixie tube, common at the time....
I found this circuit in an Electronics Handbook from 1989. The circuit can be assembled with a...
This circuit makes use of a 2N301 germanium power transistor. We found it in a documentation from...