This electronic Morse Key for telegraph message transmission was found in an American 1980s amateur radio documentation. The circuit uses TTL technology and must be powered by a 5V voltage.
The circuit shown in figure 1 serves to control a servo motor with a current of up to 200 mA. The...
The L3 coil is what basically determines the resonant frequency, around 1 MHz, in this oscillator found...
This circuit was found in a 1973 Radio Elettronica magazine. The Italian magazine no longer...