Keithley 642 Restoration Part 1

In this video on ‪@RetroAmpere‬ we restore a very rare and collectible electrometer—the Keithley 642. While it already employs a low-leakage MOSFET at the input, it retains features of older technology, including a highly complex low-leakage input relay and sapphire insulators. It lacks active input guarding, so it relies fully on the low-leakage input-stage design #testequipment #vintageelectronics #testequipmentrestoration #keithley #K642 #electrometry #restoration #electronics