This variable frequency oscillator for radio transmission covers the range from 1.6 MHz to 20 MHz, depending only on the coil used. The circuit is very stable and can be used in amateur equipment.
This circuit has very high input impedance and a differential input. The gain is 1,000 and the...
This circuit is more elaborate than the previous one. It was obtained from an 80s circuit manual. The...
This simple circuit for an audio link uses a lamp, which has a very poor frequency response, but...