Capacitive Relay (T1527E)

Found in Popular Electronics from August 1956 this sensitive two-tube relay is powered directly from the mains power supply.

Electronic Banjo (CB9095E)
This circuit produces a signal that has the waveform of the sound produced by or near the banjo....
Voltage reference with REF01 (CB24681E)
This is a circuit with a period component that consisted of a voltage reference. The circuit is...
Rectangular folder (CB9242E)
This circuit doubles the frequency of a rectangular signal applied to its input. The circuit has a...