"John Gilmer" wrote in
net:




Besides, it may be that it just isn't worth it to fix it. Radio Shack
(Micronta) multimeters are mediocre quality at best. Better to get a
*real* meter, like an old Simpson, Triplett, etc.

The old Simpson meters (c. 1960) weren't particulaly accurate. Their
accuracy was expressed as "Percent of full scale."

Thus, if you measured a nominal 10 volts on the 100 volt scale, your
reading could be up to 1 volt in error with a 1% full scale accuracy
meter. Use a 2% meter (Most Simpsons were 2%), and you can be off by
20% on a 10 volt measurement on the wrong scale.

I didn't take that seriously until I had to make a LOT of measurements
on microwave diodes and found that my "simpson" meter readings were so
inaccurate as to make my data worthless.

You can pick up a digital meter from Harbor Freight for less than $5
that's more accurate than any "analog" meter.

You might want to keep the old meter around as a curiosity (or in case
you fear that WWIII will fry everything electronics) but except for
"fun" purposes, they aren't worth fixing.




the DMMs from Harbor Freight are only 1 megohm input Z.
any good DMM is at least 10 MegR.
And the first one I had measured a 1.5V alkaline cell at 1.8 volts.
I would NOT rely on them for accuracy.

--
Jim Yanik
jyanik
at
kua.net