This is a field strength meter found in an 80's Hands On. The circuit operates at frequencies up to 500 MHz and has a buzzer as its indicator. Can be used as a detector for spy transmitters.
In the figure we have the way to make the connection of voltage regulators in series to obtain a...
This circuit was obtained from HAM Radio magazine in an 80's issue. The FETs are types of the time...
This mixer uses only four passive component and can be used with high impedance sources. The input and...