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 found in documentation from the 1980s. The circuit can be implemented with other...
This circuit was found in an Electronic Design from 1964. The components are from that time and...
Taking Raytheon's 3900 integrated circuits as an example, uncommon today, this circuit can be used...