This circuit is from old documentation, but it can be implemented with modern transistors such as 2N2222 for bipolar and BF124 for FET. The crystal determines the operating frequency.
This coupler allows the triggering of a TTL port or flip-flop from an SCR. The resistor R must be...
This amplifier with very high input impedance was suggested by Texas Instruments in a manual of...
This circuit was found in a 1980s documentation for amateur radio. The circuit makes use of...