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 in an English publication of 1975. It is a circuit that stabilizes an...
This timer for long time intervals is from the 1990 Motorola Linear Databook. The setting applies...
We found this circuit in a 90s Popular Electronics. It increases the duration of a pulse in a...