3-tube receiver (T1602E)

Found in a 1949 Radio Electronics, this circuit employs vacuum tubes of the time. Power supply not provided.

Timer with Relay 14538B (CB18466E)
This timer, like the previous circuits, uses a currently uncommon integrated circuit. The time is...
Polarity Indicator (CB17589E)
This circuit indicates the polarity of a voltage applied to the input. The circuit can make use of...
Magnetic Transducer Amplifier LM139 (CB14230E)
The circuit shown below was found in the National Semiconductor Linear Applications Handbook...