This circuit was found in Motorola documentation from 1968, using high power transistors and operated at 580 Hz. The circuit employs a special transformer.
This simple circuit can work with either 4.5 V or 6 or 9 V if a 1k resistor is added in series with...
We found this receiver for the 144 MHz band in a European publication from the 1970s. The circuit...
This different circuit uses a relay as an oscillator, whose frequency is determined by C1, and to...