This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit equivalents although the indicated types can still be found with some ease.
This circuit can be used as a lockable shield. A pulse activates the relay that remains on even...
Found in a 90s documentation, this circuit makes use of D1, a switching diode that is uncommon today....
June 2017 - New Honeywell MT MICROSWITCH Series can be ordered from Mouser Electronics for...