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 can source 3 to 12 V with currents up to 500 mA depending only on the transformer....
This circuit was found in an Electronics World of 1968. The transistor can be any general purpose and...
The network formed by resistors and capacitors determines the frequency of this sinusoidal...