Found in a 90s English documentation, this circuit consists of an RF detector for testing in RF stages. The diode can any germanium type.
We found this circuit on Radio Electronics from July 1990. It triggers a relay with a touch of the...
These three circuits have different treble responses. We found them in the February 1970 issue of...
This photoelectric cell light relay was found in Radio Electronics magazine from April 1958. The...