Modulator Amplifier (V1574E)

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

Controlled Oscillator 4093 (CB12025E)
This circuit is from a Popular Electronics of December 1993. In it we have the way to externally connect...
Automotive equipment source (CB9116E)
With this power supply it is possible to use automotive devices with currents up to about 8A on the...
Tone decoder (CB9675E)
This circuit was found in a 80’s American documentation. The adjustment trimpot is from 47k to...