Modulator Amplifier (V1574E)

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

International oscillator (CB9646E)
This OF-1 LO oscillator was found in a 1980s American documentation. The transistor can be any...
Video amplifier CA3100 (CB9177E)
Found in a Popular Electronics from the 90s, this amplifier uses an operational amplifier of the time....
Low active cycle pulse oscillator (CB8920E)
Short pulses can be found in this 90's EDN circuit. The load is 50 ohms and the transistors are from that...