Signal Tracer (T1340E)

This two-tube signal tracer was found in Radio Electronics February 1949. The circuit has good gain with speaker output. Power is with batteries.

1V Voltage Reference LT6654BX (CB4740E)
This circuit was found in an Analog Devices manual and can supply a 3 mA current or drain a 10 mA...
Optical control notch filter (CB6717E)
This 1967 Raytheon circuit uses an optical coupler of the era and has a range of 800 to 200 Hz....
Speed Control LM13080 (CB4859E)
The integrated circuit used in this project is not common today. It was found in a 2000...