Null Indicator (CB21930E)

This bridge was found in a Raytheon transistor manual from the 1960s. The transistors are germanium from the time.

SCR Passage Alarm (CB13378E)
We found this circuit in an old documentation from the 70s. The sensor is an LDR that must be...
2 meters preamplifier (CB20274E)
This circuit with junction field effect transistors was found in documentation from the 1980s. The...
1.2 to 1.4 V Power-Supply (NI025E)
Common general purpose silicon diodes when direct biased provide a voltage fall of about 0.6 to...