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 trips when the input voltage exceeds 30 V. Its base is a DIAC and it can be used to...
This is an improved circuit from the earlier version also found in the April 1972 Radio...
This filter, with a cut-off frequency of approximately 1 kHz, has a high Q and employs two...