This two-microphone amplifier was found in a April 1961 Radio Electronics Magazine. The circuit is powered by battery and has a 600-ohm line output.
This is a very simple atomic radiation detector circuit using a Geiger-Muller tube. The circuit was...
This power source, obtained in a 1973 publication, suggests the use of partially burned germanium...
Using a V/F converter this circuit was found in the June 1991 issue of Radio Electronics magazine. The...