Null Indicator (CB21930E)

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

Gain 40 000 Amplifier (CB20672E)
Suggested by Philips documentation from 1968, this circuit uses components from the era that can...
SCR Alarm (CB19223E)
This circuit uses NO sensors and was found in an American publication in the 90s. The supply must...
Tunable UHF Oscillator (CB21144E)
Found in American documentation from the 1990s, this circuit generates signals in the 350 to 500...