PTT or Push to Talk is the control that switches the speak-hear function on a transceiver. This circuit was found in the magazine of radio amateurs 73, in an edition of the 90s.
The CK722 transistor used in this circuit is one of the first commercial types in the world. The...
This automatic dimmer for incandescent lamps was found in a European publication from the 1980s. The...
This traditional doubler configuration with the 555 can be found in other articles on the author’s site....