Logic level indicator 7400 (CB22407E)

In the figure we have a simple logic level indicator for TTL circuits or powered by 5 V.

Bipolar Transistor Colpitts Oscillator (CB13083E)
The oscillator shown in the figure can generate signals between approximately 3 and 15 MHz,...
General purpose amplifier (CB8950E)
This circuit was obtained in a QST magazine from the 90s. The circuit makes use of components that are...
Driver for Nixie Tube (CB6612E)
Suggested by General Electric in 1966 documentation, this circuit uses unusual components today....