This circuit was found in the April 1971 Radio Electronics magazine. It uses common transistors and can be adapted to use an LED or audible indicator instead of a light bulb.
This circuit is basically the same configuration as the previous one with a power stage with...
Found in a 1969 documentation, this circuit for the 20 MHz band does not use a transformer. The circuit is...
This circuit can provide a voltage of up to 900 V depending on the input voltage. The diodes must...