This 1967 Raytheon circuit uses a Raystor, an optical coupler with a lamp and an LDR. The circuit can be adapted to use another type of coupler.
This crystal fundamental frequency oscillator can operate at frequencies up to a few tens of...
This circuit produces signals in the range of 200 Hz to 2 kHz. We found it in the magazine...
This circuit is from a 1964 Electronic Design, appearing in this section and website with...