[Antennas] Inductor cleaning

[Chris BONDE]

I am trying to help an older ham.  He is older than I, and I am retired.  So I need 
help as well.

We are try to make a Butternut vertical work.  I think that the roller inductor on his 
match box is dirty as when he adjust it , the readouts on my MFJ antenna analyser 
jumps around.  How do we clean the roller and contact?

Also, are the readout good seeing that it is on a vertical which can indicate a low 
SWR but no transmit.  What should we be looking for.

TANX   Chris  opr VE7HCB