Super heterodyne reflex (T1215E)

This receiver from a 1948 Radio Craft combines reflex and super heterodyne configuration. The 3-tube circuit with speaker output is mains powered.

Low Noise Infrared Detector (CB6369E)
We found this circuit in a Linear Technology documentation from the 80's. It has a demodulator, being...
75 W Amplifier (CB4419E)
In the 1992 publication, this amplifier is announced as having 400 W pmpo. Power transistors should...
Headphone Amplifier (CB4386E)
Found in a 1964 magazine, this is a small headphone amplifier from 500 ohms to 10 k ohms (magnetic...