Using the 723 integrated circuit, this power supply has the voltage determined by R2 and R3, which can be changed. The circuit is from a Radio Electronics magazine from July 1971.
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....