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Phil G4SPZ · 12th Jul 2018, 11:32 pm

Jerry, I've replied to your PM and it seems that I have said much the same as David. I'll add here for the benefit of others that the EA113 has an input impedance on all AC ranges of 1 Megohm shunted by ~25pF, according to the instruction manual. Hence if you can find a sensitive valve voltmeter or high impedance AC millivoltmeter (even a DVM) you may be able to shunt it to simulate an EA113.

I haven't got a VCM163 myself, but I reckon you have done pretty well using your own calibration method. Perhaps testing a couple of valves with known characteristics would give you more confidence.

Phil

12th Jul 2018, 11:32 pm	#6
Phil G4SPZ Dekatron Join Date: Apr 2005 Location: Bewdley, Worcestershire, UK. Posts: 4,748	Re: VCM163 Calibration Question Jerry, I've replied to your PM and it seems that I have said much the same as David. I'll add here for the benefit of others that the EA113 has an input impedance on all AC ranges of 1 Megohm shunted by ~25pF, according to the instruction manual. Hence if you can find a sensitive valve voltmeter or high impedance AC millivoltmeter (even a DVM) you may be able to shunt it to simulate an EA113. I haven't got a VCM163 myself, but I reckon you have done pretty well using your own calibration method. Perhaps testing a couple of valves with known characteristics would give you more confidence. Phil __________________ Phil Optimist [n]: One who is not in possession of the full facts Last edited by Phil G4SPZ; 12th Jul 2018 at 11:33 pm. Reason: Spelling