This sensitive circuit was found in the June 1995 Electronics Now magazine. R1 can be from 10k to 1M depending on the desired sensitivity. Power is supplied by the relay.
This 80's circuitry decodes stereo signals used in analog TV at the time. The circuit can be used...
This preamplifier for magnetic cartridges was found in the February 1990 issue of Radio...
Suggested by a 90s Radio Elecrtronics, this circuit is intended to supply mobile equipment of the time....