Null Indicator (CB21930E)

This bridge was found in a Raytheon transistor manual from the 1960s. The transistors are germanium from the time.

DC voltmeter with FET (CB7349E)
This circuit was obtained in a Motorola documentation from 1966. The circuit can use a common FET...
Flyback converter (CB9674E)
Found in documentation from the 1980s, this circuit uses a SG1524. It is an uncommon integrated circuit...
Automatic Noise Canceller (CB24304E)
What this circuit does is act as an automatic gain control for an automotive stereo. It increases the...