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 from old European documentation. R1 depends on the output voltage of the...
This SCR circuit activates a buzzer when triggered. The circuit is from a Popular Electronics from...
This 130 V drive uses an integrated circuit not very easy to find, which is the LM143. The circuit is...