This circuit filters low frequency noise from the turntable motor. We found it in a 1989 documentation. The font doesn't have to be symmetrical, but it should have excellent filtering.
The frequency of this circuit, which uses one of the LM139 comparators, depends on C1. The circuit...
Using this circuit the lamps glow in sequence in a speed given by the capacitors. The SCRs present a...
This circuit was found in the June 1980 issue of Radio Electronics magazine. The circuit uses an...