This circuit is from NASA documentation from the 1980s. The circuit shows how to obtain a stable optical coupler system. The circuit can be used as a shield.
This transmitter for the 40 meter or 7 MHz band was found in a magazine 73 for radio amateurs of...
This shortwave preselector was found in the July 1994 issue of Radio Electronics magazine. The...
This circuit was found in a 1967 RCA documentation. The components are of the time. The circuit...