Volume expander amplifier (T364E)

This circuit was found in the 1961 RCA tube manual. The circuit includes a power supply stage.

50kHz Optical FM Transmitter Receiver (CB4949E)
This circuit allows reception and decoding of 50 kHz FM modulated optical signals. The circuit can...
Direct shield for triac (CB5185E)
This shield circuit was found in an American publication from the 80's. The triac is of low...
Piezoelectric Alarm (CB4879E)
When the base of the general purpose transistor is grounded the circuit produces a signal that is given...