This circuit was found in the April 1978 Radio Electronics magazine. The power supply must be symmetrical, and the maximum operating frequency is around 100MHz.
Connected to the output of a small amplifier or receiver, this circuit triggers a relay in the...
This oscillator version is from an RCA documentation from the 1970s. Transistors support modern...
We found this circuit in an American documentation of the 80's, being indicated for the test of...