This is a field strength meter found in an 80's Hands On. The circuit operates at frequencies up to 500 MHz and has a buzzer as its indicator. Can be used as a detector for spy transmitters.
This circuit drives two-color LEDs at a speed that is set in the 100k pot. The circuit can be...
The circuit shown was found in a 1967 RCA manual. Modern equivalent components can be used. The...
Indicated for automotive applications, this circuit was found in the November 1980 issue of Radio...