> From: "Charles Geilfuss" <charles.geilfuss@xxxxxxxxx>
>
> The one in the Wiki photo is *very* similar to the one in my scope.
These typically have the resistance stamped on the back of the wiper
-- the metal part that rotates and makes contact with the wire.
> I tested mine still wired in place.
You need to remove the bulb. Otherwise, you're measuring the rheostat
in parallel with the bulb and transformer windings, and will most
likely get readings of about half the actual resistance.
Regardless, a two-wire ohmmeter is not good at measuring such
resistance, due to lead and contact resistance. Any reading below a
few ohms is probably inaccurate.
Are you sure the rheostat is irretrievable? These can generally be re-
vitalized by 1) lightly sanding the area where the wiper makes
contact, 2) lightly sanding the contact, 3) removing the shaft and
lightly bending the wiper, to give it more spring. (Sorry if I missed
the part where you already tried these things.)
If you're interested in functionality over restoration, there exists
another path: leave it on its brightest setting and run the whole
thing through a plug-in dimmer that you can find in many hardware
stores.
:::: The tragedy of modern war is not so much that young men die but
that they die fighting each other... instead of their real enemies
back home in the capitals. -- Edward Abbey
:::: Jan Steinman, http://www.Bytesmiths.com/Events
--
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