This circuit was obtained from HAM Radio magazine in an 80's issue. The FETs are types of the time and the frequency is determined by the crystal. The circuit operates at voltages from 3 to 9 V.
This circuit decodes signals received in SSB (Single Side Band) obtaining an audio signal for...
With a 120 ohms resistor this circuit can also be used as a shield for 3.3 V output voltages. The...
This circuit is from a 1966 American documentation. The circuit uses a photo-FET, an unusual...