Signal Tracer and Capacitor Tester (T1241E)

This mains powered two-in-one instrument was found in a Radio Craft from March 1948. The headphone must be high impedance.

RF probe (CB21194E)
Found in a publication for radio amateurs from the 1990s, this circuit makes it possible to...
Sequential 4017 and Neon Lamp (CB10508E)
I found this circuit in a Popular Electronics from November 1999. The magazine is no longer...
3 to 12 MHz Receiver (CB18520E)
This simple transistorized receiver with earphone was found in a Japanese publication from the...