This toy transistorized organ was found in the May 1970 issue of Radio Electronics magazine. The trimpots are adjusted to the musical notes according to the key.
This circuit was found in a 1967 Delco Radio documentation. The circuit has an input voltage of 250...
This interesting idea of a radio detector for a medium-wave radio is from a 1966 documentation. The critical...
This circuit is from an English publication from 1978, but it can be assembled with BC548 for TR2...