This circuit, obtained from old documentation, doubles the frequency of the pulses applied to the input. The circuit must be powered by a voltage of 5 V.
This tone generator for CW was found in a publication by Gernsback from 1960. The circuit makes use...
This monotone alarm oscillator circuit was found in July 1975 Radio Electronics magazine. Power is...
This circuit automatically activates the relay when the phone is answered, closing the record...