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 switched, switched or PWM amplifier was obtained in the 1972 RCA linear integrated circuit...
This excellent preamp for use with guitars was found in a 1986 documentation. The key on the TR2...
This circuit was found in a 2001 documentation. It is a test of zener diodes that uses a voltmeter or...