Scale Expander for 12V Meter (CB21330E)

This circuit was found in a QST from the 1990s. The circuit expands the scale of a 10V instrument to measure 20V.

Balance Control (CB6310E)
This balance control for the channels of a stereo system was found in a 1969 Mullard...
Electronic Bongos (CB23959E)
The article that teaches the assembly is from a Radio Electronics issue from July 1969. The...
Undervoltage alarm (CB22186E)
Found in old English documentation, this circuit is still current. The circuit trips with a sound...