Bob,
It is easier than you think if it is the modern pop off the front square
plastic cover on the meter.
The things that make them sluggish are either dirt in between the rotating
armature coil and the magnet, or heaven forbid a spec of iron. However, you
can sweep out debris using the edge of a sheet of bond paper, if you can see
the place that has something in the gap. Use a strong (halogen) light, a
steady hand, and a good 3X or more magnifier, like a desk model.
If, nothing is seen, use a rubber bulb like is used to clean camera lens,
and "puff" some air into the gaps. Maybe that will dislodge the debris,
especially if it is somehow in the pivot bearings. Do not blow on the
movement with your own breath.
If neither of these fix the problem, and actually, to determine if you have
a problem, test the meter without the cover, using a test circuit, limiting
resistance and voltage source, to limit current to no more than full scale
value, (often printed in tiny type at edge of scale, below the regular
scales off to one side).
If the meter is OK with cover off, the problem you have may be static
electricity buildup on the inside of the plexiglas cover. To fix this, wash
the cover in dishwashing liquid detergent and water, and drain off excess
and let the plastic dry. Then, if there is no cloudy film, you can
reassemble the meter cover to the face. If there was a cloudy film formed
by the detergent treatment, you need to clean that off and start your
washing with a more dilute solution. Done correctly, there will be no
visible detergent film once the cover dries, and static will dissipate,and
not build up on the inside of the plastic thus opposing the field of the
meter movement.
Finally, if you are still doubtful of your ability to do this, take these
instructions and the meter movement to a clock and watch repairman who works
on mechanical movements. (Not just the mall guys who change out batteries).
The watchmaker will have the tools to work on hairsprings, bearings and
other more exotic problems that rarely do crop up in good quality meters.
GL and 73,
Stuart K5KVH
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