This Linear Technology circuit can measure currents from 100 pA to 100 uA. The circuit is from the 80's, using a component of the era. Transistors are general purpose types.
The presented circuit can be implemented with a BC548 and for larger currents a BD135 can be used....
This circuit for decoding QUAM AM stereo signals, a system that was little developed, was found in the...
This medium- or short-wave receiver circuit was found in documentation from the 1980s. The circuit...