Three-phase converter (CB21931E)

This circuit was found in the RCA Power Transistor manual from the 70's. The circuit uses power transistors of the time.

Digitally Controlled Filter (CB14368E)
We found this circuit in the Linear Applications Handbook by National Semiconductor. The circuit is...
Radiation monitor (CB5923E)
This wide-range radiation monitor was found in a 1980s documentation. The circuit uses a diode as a...
Guitar Preamplifier (CB24305E)
This circuit is from an article that appeared in the June 1974 issue of Radio Electronics...