This circuit was obtained from the April 1978 Radio Electronics magazine. The other circuit is a PLL of the time. The power supply must be 15 V symmetrical.
Obtained from a 1967 documentation, this circuit uses transistors from the time. The galvanometer can be a...
Motors up to 2 A can be controlled by this circuit, which requires a symmetrical source. Although...
This sensitive MW receiver was found in a publication of year 1958., The circuit uses germanium...