This circuit was obtained from a 1947 amplifier manual. The circuit makes use of a transformer source, but it can also be battery powered.
Suggested by the General Electric Hobby Manual of 1965 this circuit measures voltages from 0 to...
) The circuit in the figure uses an old OC71 germanium transistor. Performance depends on...
We find this circuit in an American documentation from the 80's. The circuit has the coil given by the...