This SCR circuit can operate on frequencies from 1 to 20 kHz. We found it in an American documentation from the 60's. The SCR must be according to the load. No information is given about the transformer.
This mechanical reverberator circuit for guitar was found in the February 1970 issue of Radio...
Found in an old English publication this circuit uses a dual gate MOSFET. Coils not specified....
This is the receiver for the previous circuit transmitter. Similarly, no information about the...