6AC7 Amplifier (T450E)

Obtained in MIT documentation, this 4-stage circuit has high gain for small signals. The power supply sources 150 V.

Simple function generator (CB20950E)
Found in Popular Electronics from the 1980s, this circuit uses two operational amplifiers from...
JFET Current Drain (CB13422E)
This circuit was obtained in a 1974 documentation. It shows how to use a JFET as a low intensity...
Double Manipulator Luminous Experimental Telegraph (CB17967E)
The telegraph communication system has been out of use for a long time, so the montage presented has...