This circuit, found in a 1977 documentation, indicates when the grid voltage goes through zero. Under these conditions, it produces an output pulse whose duration depends on the capacitor.
Shown in Radio Electronics June 1953, this circuit needs a small adjustable source of 0 to 3 V and...
This circuit is suitable for the calibration of old analog oscilloscopes. It was found in...
This circuit was found I a 1965 Radio Schack documentation. The transistors are from that time,...