It actually consists of a tunable field strength meter. The circuit is of an old documentation and the circuit must be tuned to the frequency to be monitored. The circuit offers the option to use a headset.
This circuit was obtained from a 1977 magazine, but can still be mounted using BC548 for TR1 and...
CHANDLER, Ariz., LABEGE, France - Oct. 26, 2016 – Microchip Technology Inc. (NASDAQ: MCHP), a...
This zero crossing detector is of the 1993 Motorola Linear Interface ICs. The source is...