Modulator Amplifier (V1574E)

This circuit is from a 1938 tube manual. Transformers are the critical components. Component values are given.

Power supply for amplifier (CB23879E)
This is the power supply circuit for the amplifier in the previous circuit. The source is...
Sensitive light relay 2 (CB22104E)
This version operates in the opposite way to the previous one, triggering when light falls on the...
Temperature indicator (CB9308E)
The sensors in this circuit are NTCs and PTCs that work in a differential way by directly...