This game was found in Radio Electronics from the 90s. The components used are common except some that are from that time and that can no longer be found easily.
This modulator circuit is nothing more than an audio amplifier that serves to modulate amplitude...
This circuit is from 1995 documentation. When the phone is lifted, the relay closes its contacts by...
The basic idea of this circuit found in a 1988 documentation is to transmit a signal modulated using...