Driver for oscillograph (T459E)

This circuit from an old MIT documentation excites an oscillograph element, an old waveform viewer.

Crystal Signal Generator (CB6189E)
This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit...
Opto-isolated AC switch with triac (CB25859E)
This shield was found in the June 1995 Electronics Now magazine. The circuit uses a low-power...
Low input current adder (CB4908E)
This circuit has a 200 kHz bandwidth and a low input current. The circuit is from the 80's, but...