Transistorized Voltmeter (CB21916E)

We found this circuit in a Raytheon manual from 1956. The transistors are germanium of the time, and the accuracy depends on the resistors.

Ultra High Gain FET Stage (CB14146E)
The circuit shown has a voltage gain of 500 times and can use equivalent FETs like the BF245. The...
Light comparator (CB7368E)
Found in a 1968 Novel Electronics Circuit, this circuit compares two light intensities using...
Proximity Relay (CB12835E)
We found this circuit in an old publication from Argentina. The relay must be of the sensitive type,...