Using a 4046 PLL we found this circuit in the December 1989 issue of Radio Electronics magazine. The circuit operates at 220kHz, but this frequency can be changed by changing C3.
This full wave source uses germanium diodes, and its current is a few milliamps. We found it in an...
This circuit is from a 1968 documentation. It makes use of thermistors (NTC) to indicate...
This small transmitter has an RF amplifier stage with coupling made from the central socket of the...