Cable Locator (CB21303E)

This audio detector circuit can be used for cable identification. We found it in a Popular Electronics from the 90s.

Mechanical Reverberator (CB23995E)
This mechanical reverberator circuit for guitar was found in the February 1970 issue of Radio...
11 to 32 MHz amplifier (CB22024E)
Found in an old English publication this circuit uses a dual gate MOSFET. Coils not specified....
Power Grid Data Receiver (CB4810E)
This is the receiver for the previous circuit transmitter. Similarly, no information about the...