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 low noise audio amplifier step uses only one transistor and is high enough to operate with low...
August 2016 –It can be purchased from Mouser Electronics the new converters BD7F100 and BD7F200...
This circuit can be used as a shield for microcontrollers. The circuit is from American...