I recently was so lucky to run into a gentleman selling two vintage Fluke differential voltmeters, a Fluke 891 (DC only) and 893 (AC and DC) for 10 Euro each. What could go wrong?
Both instruments were in a fairly questionable state so I took them through a thorough cleaning cycle and re-calibrated them. All knobs were rinsed ultrasonically and one of the meters had to be disassembled and oiled to bring it back to life. I could not find a manual for the 891 but since the 893 is practically the same instrument, all the information is there.
Luckily I had seen W2AEWs excellent Video review, so I knew what to expect.
What a fabulous instrument! How amazing is it to have an instrument which is almost as old as myself that can measure a voltage to the nth decimal digit?
What had to be done was:
- Thorough cleaning
- Fixing the meter on the 891
- Recalibrating both instruments
- Adding a power cord plug to the 893