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 is based entirely on SCRs. The circuit is from an American 80's documentation; and the PUTs...
The integrated circuits used in this 1989 project are uncommon today, including the IF coil that...
September 2016 - Mouser Electronics already has the new TPS54335-2A from Texas Instruments...