Indicated for adjustment in transmitters for the 11-meter band, this circuit with analog meter was found in the Radio Electronics magazine of January 1978. The circuit does not use a power supply.
This circuit is given in two versions, having been found in a publication from the 90s. The second...
This circuit was found in an ancient American documentation. Used integrated circuits are uncommon...
This Texas Instruments circuit uses a phototransistor to fire a TTL trigger port. Other...