[volt-nuts] Newbie here...

[Bob Albert]

I am the owner of a few fairly accurate and/or precise voltmeters and would like some information if it's available.


First, my Electro Instruments model 3000 5-digit antique with Nixie tube readout, and the accessory AC converter.  It hasn't been calibrated in decades but seems pretty close.  I have no manual.


Second is the recently acquired, not working HP 3456A.  Struggling with that repair.

Third is the Valhalla 4440.  I have most of a manual but it differs somewhat from mine.  Mine has an issue on one range of volts.

Fourth is the Racal-Dana 4200.  This works fine but after it warms up for a half hour starts to get erratic.

Fifth is a Calibration Standards model DC-110A.  No manual.  It has some trouble on range overlap.

Can anyone help me with any of these units?  Documentation, reputation, etc.  Photographs supplied if needed.

Bob