This powerful transmitter for the 27 MHz band was found in a Japanese publication from 1961. The circuit is powered by battery and has the details of the coils given next to the diagram.
This code switch was found in a 1990 Electronics Handbook. It can be mounted with BC558...
In this application we use an additional input circuit to enable the logic command with keys,...
This circuit was suggested by Signetics in 1980s documentation. The circuit makes use of the...