Found in American documentation from the 1990s, this circuit uses coils with multiple outlets to get the best reception, the diode is a general-purpose crystal diode.
We found this multiple thermostat circuit in July 1980 Radio Electronics magazine. It uses...
This circuit is from a 1986 Revista Española de Electrónica. It consists of an amplifier with...
Suggested by a 1968 Philips documentation this Eccles Jordan rocker as it was called can operate...