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.

Inverter (CB15728E)
This circuit synthesizes a sinusoidal signal from logic pulses that can be obtained from an...
4 MHz TTL Oscillator (CB17391E)
This oscillator can be found in other articles on the site. This is from a 4 MHz documentation, remembering...
Touch operated lamp (CB20491E)
This circuit has its battery charged by a solar system. The circuit uses components that admit...