This transmitter for the 3.5 and 7 MHz ham radio was found in a 1950s Japan publication. No information was given on the coils and the power supply.
This two-transistor amplifier can be used as power stage for intercom, experimental receivers,...
This sensitive circuit was found in old English documentation. Transistors may be modern...
This configuration, already presented in other points of this section and website, is of a...