This primitive solar radio was found in a Gernsback publication from 1960. The transistor is made of germanium of the time and the earphone is magnetic with high impedance.
This circuit was presented in a January 1990 Radio Electronics magazine article as part of a home...
The circuit shown is for testing both signal diodes (low current) and rectifiers (high current). The...
Found in 90s American documentation, this circuit generates an alternating voltage of 120 V x 150...