Suitable for clandestine listening and in SMD assembly, this circuit was found in the Radio Eletronics magazine of August 1988. The listening is in headphones and the amplifier is electret.
This circuit can be powered by 2 or 3 small batteries. The resistor can have values between 220...
This circuit shows how to use a fixed 5 V regulator on a variable 1 A source. The integrated...
This circuit generates an FM signal of 4.7 or 10.7 MHz for audio signals on analog TV or FM, with...