This amplifier for electrometer can work with currents of 0.1 pA in a band of 1 Hz. The circuit is from NASA in a publication of the 60s. Transistors are general purpose types.
The purpose of this circuit is to increase the sensitivity of a common multimeter in its voltage...
This is the modern version of the Galena radio in which the detector is a germanium diode (which can...
This circuit allows the measurement of very weak currents indicated on an analog instrument or...