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Philco 90: expecting too much?
#10

Ron Ramirez Wrote:Yes - 1000 ohms/volt was the standard for many years. 20K ohms/volt is much better, and the modern DMMs are in the 1 meg/volt or better range.

Just to clarify Very old volt ohm meters were 1K per volt. I would suspect these where used for testing B batteries. The meter would load the battery and give better more accurate reading under a load and 1000 ohms would do it. Most radio circuits you don't want to load. It will give you an inaccurate reading. Later I'm guessing late 1920's better vom's 10k and 20k per volt. Vtvm ( vacuum tube voltmeter) and Dmm (digital multi meter) all are 1meg per volt or better (higher). Personal preference is use dmm for resistor. Very accurate. Use vtvm for voltage. Two reasons: 1 Problaby what was use when set was made to measure the voltages that are on the documentation. 2 Dmm's sometimes can give an incorrect reading. They are sensitive to any sort of signal that maybe be mixed in with the voltage you are measuring. This happens a lot with measuring voltages on TV's and things like ham transmitters. This can be very frustrating!!!
I'm jumping off my soap box.
Terry

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got it!

Terry


Messages In This Thread
Philco 90: expecting too much? - by Guest - 02-05-2010, 01:28 AM
Re: Philco 90: expecting too much? - by Guest - 02-05-2010, 08:41 PM
Re: Philco 90: expecting too much? - by Guest - 02-06-2010, 11:34 PM
Re: Philco 90: expecting too much? - by exray - 02-07-2010, 09:48 AM
Re: Philco 90: expecting too much? - by 7estatdef - 02-07-2010, 04:01 PM
Re: Philco 90: expecting too much? - by 7estatdef - 02-07-2010, 04:19 PM
Re: Philco 90: expecting too much? - by 7estatdef - 02-07-2010, 05:07 PM
Re: Philco 90: expecting too much? - by codefox1 - 02-07-2010, 05:45 PM
Re: Philco 90: expecting too much? - by Guest - 02-08-2010, 12:27 AM
Re: Philco 90: expecting too much? - by 7estatdef - 02-08-2010, 08:59 AM
Re: Philco 90: expecting too much? - by codefox1 - 02-09-2010, 06:31 PM



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