This circuit converts signals from the shortwave band to the 118 to 130 MHz VHF band used in aviation. The circuit uses a 55 MHz crystal. We found it in documentation from the 90s.
This circuit warns when the headlight bulb is on. We found it in a Popular Electronics from the...
The oscillator shown in the figure keeps its frequency constant in an active cycle adjustment...
This circuit was found in an Argentine publication from the 1970s. The circuit can be assembled with...