We found this circuit in American documentation from the 1980s. Transistors can be of general use. The frequency range of the generated signals ranges from 500 kHz to 10 MHz.
This circuit has a 200 kHz bandwidth and a low input current. The circuit is from the 80's, but...
For analog lines, this circuit was found in the August 1994 issue of Electronics Now magazine. The...
This proximity relay circuit was found in the July 1990 Radio Electronics magazine. The supply...