Capacitive Relay (T1527E)

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

80m Transceiver (CB17092E)
This transceiver circuit was found in a 1997 documentation. The circuit operates in the 80 meters...
CMOS Output Zero Crossing Detector (CB14158E)
We found this circuit in the Linear Applications Handbook published by National Semiconductor in...
Wien Bridge Oscillator (CB14117E)
The configuration presented below was obtained in the Linear Application Handbook of the National...