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 can be used as a low Power audio booster for experimental projects such as radios,...
We found this circuit in a 2005 Linear Technology manual. Observe the component values and...
I found this simple zener diodes voltage divider circuit in an old documentation. The resistor...