This circuit is from American documentation from 1970. It can be designed with a BC558 and for the operational, we can use equivalents. The FET can be the BF245.
This circuit was found in the May 1982 issue of Radio Electronics magazine. The circuit inverts the...
This circuit must have its input connected to the collector of the last IF transistor of the FM...
The circuit shown can measure currents less than 1 uA and is powered by two 1.5 V batteries in a...