On Wed, 17 Mar 2010 07:13:23 -0700, John Larkin
wrote:

On Wed, 17 Mar 2010 01:11:11 -0700, Archimedes' Lever
wrote:

On Tue, 16 Mar 2010 19:36:55 -0700, John Larkin
wrote:

On Tue, 16 Mar 2010 18:38:48 -0700, Archimedes' Lever
wrote:

On Tue, 16 Mar 2010 17:16:30 -0700, John Larkin
wrote:


You're an expert on this sort of thing, so estimate the resistance
before it was stretched, and how much it changed.

John


I question the efficacy of both sets of measurements.

You, saying that "you measured" something doesn't give one any warm,
fuzzy feelings upon contemplating the declared "observed results".


Why didn't you just say "I don't know how to do that"?

John


No, John, you ****ing idiot. My statement was that YOU do not know
what you are doing.

The prestretch resistivity was very close to the value predicted from
wire tables.

You do not measure a segment at the ends. You measure the central five
or six inches, and never go anywhere near the stressed end points.

It is at that point that you are measuring a stretched conductor.

The variables that even you yourself mentioned alone would mean that the
areas near the clamping points would be out of bounds for any valid test
point selection. All of your tests would have to be on an inboard
segment of your "stretched wire". Inboard meaning NOT anywhere near
where you clamped it at either end.

IF you did that, then I would give your "tests" more credibility,
considering what I am reading below.

The stretch delta was interesting but of course the
stretch force wasn't quantified... I just pulled on the wire until I
felt it yield a little. It looks like the elongation pretty much
accounts for all the delta-R, without work hardening being
significant.

You ain't real bright, John. Copper work hardens. That is what
happened during the stretch operation, whether you want to believe it or
not. ALL the copper in those stretched areas crystallized the moment you
stopped pulling on the lattice.

Stuff like that is always worth knowing.

As long as you have all the particulars down, sure.


Fortunately, I have a home-made precision 1 amp current source and
some oil-filled cal-lab precision resistors, so I can measure
milliohms to PPM stability. I design wideband current shunts now and
then use this stuff for my measurements:

ftp://jjlarkin.lmi.net/Manganin.zip


zip files?


You bluster and to decline to calculate the resistance of a length of
wire.

I never declined a goddamned thing, ****er. You dumb****s need to STOP
accusing me of not taking some goddamned lame **** challenge one of you
dumb ****s present. I barely read your horse****, so I am not going to
run off to another desktop to do calculations for Johnny boy of all
idiots. **** on you, bluster boy.


Wise move on your part, as you would inevitably get it wrong.


There was no IT, you dumb ****tard.