Wattmeter (T1351E)

This circuit is from a February 1949 Radio Electronics magazine. The circuit uses 3 tubes and includes the power supply.

Mini Organ or Music Box (CB13836E)
This circuit was obtained in a Radio Shack documentation from 1977. The circuit generates a...
Headset Amplifier H530 (CB18399E)
This commercial circuit of 3 transistors was found in Japanese documentation from the 1960s. The...
Electronic Lock (CB16566E)
This electronic car lock was found in a 1988 magazine. It uses a code key that must be activated to...