Found in a 1967 Electronic Design, this circuit changes the phase of a signal in 8 different ways, given by the formulas next to the diagram. Equivalent general-purpose transistors can be used.
This circuit for VCR recording heads was found in the February 1990 issue of Radio Electronics magazine....
This very simple continuity tester uses a small 1.5 V lamp (type used in flashlights). Can be...
This commercial radio with 3 earphone listening transistors was manufactured in Japan in the...