Null Indicator (CB21930E)

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

Timer 4001 2 (CB16316E)
An interesting timer is shown in the figure, using one of the 4 NAND gates of the integrated 4001....
High impedance window comparator (CB6091E)
General Electric suggests this circuit in a 1980s documentation. The operational of the time is...
0 to 9 V x 200 mA power supply (CB18936E)
This simple adjustable source uses a PNP transistor that can be the BD136 for even slightly higher...