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.
Found in Popular Electronics this circuit will trigger a buzzer if the ignition key is removed...
Found in Popular Electronics, this sophisticated short-wave receiver requires a lot of skill from...
This circuit is from an old American documentation using LEDs in the rectification. The circuit...