Two-input amplifier (CB21661E)

The critical component of this 1967 amplifier is the driver transformer. The circuit has both high and low impedance input.

Battery Low Indicator (CB4796E)
This circuit triggers the LED when the monitored battery voltage drops below 9 V for 12 V...
Capacitive relay (CB23765E)
We found this circuit in a Radio Electronics from January 1967. The SCR is already the C106, which...
Old power supply (CB23622E)
This power source with silicon diodes at a time when valves were still used was found in Radio...