With this circuit it is possible to modulate pulses from a pulsating input signal. The PNP transistor can be the BC558 and the power must be supplied with 5 V.
This tone generator for CW was found in a publication by Gernsback from 1960. The circuit makes use...
This circuit was obtained in an old US 1974 documentation when Nixie tube displays were common. The...
This circuit was found in an 80s National Semiconductor documentation. The configuration holds...