This FM receiver tuning step circuit was found in a 1960 documentation. No information about the coils is given, but the FI used at the time was 10.8 MHz.
This circuit is from the 80's documentation. The integrated circuit is from the time but can be...
This circuit was found in old publication from 1958. The circuit uses germanium transistor, common in...
This version is from an old 80's documentation. The SCR can be the TIC106 and the unijunction...