Phil Nelson wrote:
"Crazy George" wrote in message
...
I suspect someone replaced a failed movement in your original
meter with a standard movement.
Hmm, a light bulb flickers dimly in my brain. That would explain why it
looks stock but works backwards. The case of this meter is split to heck all
around and bound together with friction tape, but I figured that was not
that unusual for such old meters. When I opened the smallest electrolytic
can to restuff it, the danged thing split into about five pieces in my
fingers! But I could believe that somebody pried this case apart with a
screwdriver.
The meter enclosures in some variants of the SX-28 were famous for
cracking. Crap probably got inside the original movement after the case
cracked, and that's why it was replaced.
This problem is common enough that someone is actually producing a kit
to fix it. For more info:
http://bama.sbc.edu/Lloyd%20Godsey's%20Blooming%20Meter%20Fixer.htm
If you can engage a meter repair person, that movement can be made
right resting, and the leads reversed inside, and you will be back to
where you want to be.
Is this something a fumble-fingers like me could attempt? What's involved in
making a movement right resting? I have little to lose at this point . . . .
I'm not sure I would attempt it. I had a friend once that did this on a
replacement movement on a radio he was fixing (an SX-24, IIRC). The fix
involved reversing the little spring on the base of the needle AND
reversing the internal wires. Nerves of steel doesn't even begin to
describe the economy of movement required to do this. This guy was an
orthopedic surgeon, so it was something he did everyday. Mere mortals
such as ourselves shouldn't even try it. I would definitely take it to a
pro, or look for a replacement meter on eBay. They do pop up from time
to time there.
Check carefully and see if the leads to the meter are reversed on the
back. If they are, then
the second step above is not necessary, just return the wires to their
correct locations. But the mechanical internal
adjustment is still required.
Living dangerously, I reversed the leads on the back of the meter. Now it
behaves the same, but instead of zeroing at the middle (OK, the 7 marker)
and deflecting to dead left (the 1 marker), it zeros at dead left and
deflects off the scale farther left. So I assume further surgery is
indicated.
Thx again for any advice.
Regards,
Phil Nelson
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