Found in a 1969 documentation, this circuit for the 20 MHz band does not use a transformer. The circuit is a phase detector that makes use of the transistor of the time.
This shield circuit allows recording of the signal from a serial output on a cassette recorder, with...
The model aircraft spark plug filaments operate with a low voltage of the order of 1.5 V. This...
This circuit, found in US documentation, can measure the power of transmitters up to 10 W, given...