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 control panel allows the use of NO and NC sensors, turning the alarm on after 30 seconds...
This circuit, found in a 1989 publication, only works with incandescent lamps. The maximum power...
We found this circuit in a 1968 Electronics World. The potentiometer should be set to trigger the SCR...