This interesting 1924 triode tube receiver was found in a documentation by Gernsback. Observe supply voltages. Coils are for tuned wavebands.
This circuit was found in the February 1983 issue of Radio Electronics magazine. It is a 4-digit...
The circuit shown consists of a single switched power supply. We found it in English...
This logic level indicator was found in a 1988 documentation. The circuit can be used with both...