This is the circuit for the HM-10ª, an instrument sold by Heathkit. The circuit is from a Radio Electronics from May 1963. The indication is by an analog instrument.
This circuit was found in an English publication from 1991. As in that country the power grid is...
Obtained in a 1968 Electronics World, this circuit uses transistors from the time and the sensor...
This circuit, of a Popular Electronics of 1969 is destined to firing a gas LASER of the time. The...