Two-tube regenerative receiver (T1595E)

This circuit is from a Radio Electronics from 1949. The circuit is battery powered and has high impedance listening.

Sensitive Light Relay (CB14635E)
This circuit makes use of a sensitive 5 mA reed-relay to be driven directly by a phototransistor. The...
6V battery charger (CB6400E)
This circuit was found in a 1967 RCA manual. The transistors are of the time. The adjustment is made to...
20 W amplifier TDA1520Q (CB16670E)
This powerful amplifier was part of commercial sound circuits from the 90s. The integrated circuit...