It looks very similar to the Sencore FET Voltmeter of the 70's. Regards, Jim > -------- Original Message -------- > Subject: [EE] Recalibration + good analog multimeter? > From: veegee > Date: Tue, July 09, 2013 1:01 pm > To: PICLIST >=20 >=20 > Hi all, >=20 > I have a 1960s/1970s(?) Meratronik Meratester analog multimeter (made in > Poland). >=20 > http://www.radiomuseum.org/r/meratronik_meratester_v4028.html >=20 > This unit might be known by some other names. Someone was throwing it > out only because they lost the battery cartridge for it. Silly goose, > the typewritten manual says any 12-18V source will do. >=20 > It's a *very* high precision and accuracy analog multimeter with high > impedance FET inputs. Came with schematics and user manuals. It easily > outdoes all of my cheap digital multimeters in every way. These guys > thought of everything. Even applies "motor brakes" (whatever the actual > term is for magnetic braking) on the needle so it doesn't get damaged > during transportation. Also fully specified, with schematics and part > numbers. That's something I really appreciate. >=20 > 1. The multimeter has a zero knob on it and manual says to zero the > device by selecting the 1.5mV range and adjusting to zero with the leads > shorted before using. However, after doing so, the other voltage ranges > are not zeroed, as the manual implies. They're each offset up to +/- 2 > ticks on the dial. And zeroing in another range of course leads to > different offsets in the rest of the ranges. Essentially means that one > must zero every time after selecting a new voltage measurement range. > However, when zeroed, the actual accuracy of the multimeter is > incredible. Testing 1.25V and 5V 0.05% shows that the needle deflects to > exactly where it should be. And I mean *exactly*. >=20 > Q1: The manual implies that the whole device should be zeroed after > zeroing the 1.5mV range. But this is definitely not the case. Is this > normal behaviour? Or are all voltage ranges expected to be zeroed after > the 1.5mV (smallest) range is zeroed? Is there a need to open it up and > somehow try to adjust (recalibrate(?)) it? >=20 > 2. I really like this thing and I would like to buy another one or > something similar. It's sad that such multimeters are so hard to find > these days. The only analog multimeters I can find now are cheap ones > without high impedance inputs. I'm guessing the needle is deflected with > energy taken from the circuit being measured. Not acceptable. >=20 > Q2: Can anyone suggest some good analog multimeters and where they can > be bought? They don't have to be antique. > --=20 > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .