On Wed, 22 Oct 2003 12:43:20 GMT, "Ronald Walters"
wrote:

I have been using a MFJ-989C tuner for about (5) years without any problems.
Just recently I have noticed that on the higher band, 24 MHz that the SWR
occasionally would jump from an adjusted 1:1 SWR to infinity.

According to the downloadable manual, page 3, the roller inductor has
a self-resonance killer that is switched in and out of the circuit
automatically, and you may feel a slight bump when it happens. That
may be causing your swr jump. The manual says not to be alarmed.

My roller inductor has some black, moist stuff on it. I just assumed
it was lubricant and haven't tried to remove it.

My tuner, about 10 years old, seems to tune my dipole just fine on
multiple bands.

Bob
k5qwg

A slight
adjustment of the roller inductance appeared to solve the problem although I
haven't ruled out a balum or antenna problem. I plan on investigating that
this weekend, however, before I open the cabinet and look for problems I
would ask the group for recommendations on cleaning the roller assembly and
inductor to ensure good conductivity after I am done.

I still have some old cleaning solutions from the old TV tuner days, some
electrical cleaner (Appears heavy duty stuff) but maybe there is some other
solutions someone might recommend.

Your thoughts and recommendations are appreciated

Ron - W4LDE