Broadband Amplifier (CB21859E)

This circuit has a voltage gain of 30 times and passband of 14 MHz. The circuit is from the 1974 Ferranti transistor manual.

Wien Bridge Oscillator (CB8089E)
This circuit generates sinusoidal signals between 300 and 3000 Hz. We find a 303 Circuits from the 90's....
Line Amplifier (CB19052E)
This amplifier for audio transmission lines was found in a 1961 American publication. The critical...
Intercom with telephone (CB7829E)
Old phones with dials can be used in a simple home intercom system, as this circuit from Popular...