In message
on Sat, 19 Mar 2011 07:08:00 -0700 (PDT)
Tabby wrote:

On Mar 18, 4:59Â*pm, Terry Casey wrote:
In message
on Fri, 18 Mar 2011 08:52:07 -0700 (PDT)
Â*Tabby wrote:

Â*... or if that cant be done fitting a fixed R to the wiper and ground or
one of the other terminals.

That will modify the 'law' of the pot and change the wiper position for most
settings. If the track is worn in the area that is most usually used (not
surprising!) moving the operating point to a relatively unused section can
work.

Fine as a diy work around but not worthwhile if a replacement is to hand as
that will give a better guarantee of a long term solution.


I wasnt quite clear was I. Sometimes the pot is wired such that if the
wiper goes oc, the output, which connects to the wiper, is o/c. Adding
a fixed R across the pot's output prevents this, ie from wiper to
ground end. It can be high enough value to have only a trivial effect
on the 'law' of the pot, which is a fairly trivial matter anyhow.


You are implying that you have understood my reference to changing the law of
the pot to be derogatory. This is not so - if you read it carefully, you will
see that I was simply pointing out that changing the law of the pot (within
reasonable limits, of course!) is the reason that your idea can successfully
move the normal operating point away from the worn area of the track.

However, if the wiper goes o/c *after* you've made your modification - and that
is the way I interpret your post - then the pot is useless: the only solution
is replacement.

--

Terry