Lie Detector (T1534E)

This circuit was found in a Popular Electronics from December 1956. Power is provided by batteries.

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...