This circuit was found in the February 1983 issue of Radio Electronics magazine. It is a 4-digit circuit with dedicated integrated circuits, with no power supply indicated.
With the change of the coil, the circuit can operate at frequencies between 30 MHz and 150 MHz....
The frequency of this Pierce oscillator, found in 1969 documentation, depends on the crystal. The...
This simple circuit can be used to power a simple communication system using ordinary telephones....