Wattmeter (T1351E)

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

Code Practice Oscillator CK722 (CB23662E)
This simple oscillator with just one transistor has a frequency determined by the characteristics of the...
Zero Crossing Detector (CB14048E)
This Zero Crossing Detector was found in a 1972 RCA manual, but it can be made using any modern...
2-Transistor MW Portable Radio (CB18846E)
The circuit shown was found in a Japanese publication from the 1960s. Transistors can be...