[Amps] Roller inductor & wiper "grease""

[W5CPT]

When I was in the military, we worked on LTV receivers that used what we called "Blue Grease". It was, obviously, blue and conductive. I even laid a short line of it on a glass plate and measured the resistance, which was remarkably low. That  being said, when applying it to the inductor, the very tiniest amount was needed. Certainly not the amount in the photo. And it was only applied to the contact points of the inductor and to the hinge pin of the wiper. (the inductors were flat and wound like a Nautilus shell).  My concern would be if the grease was in fact conductive and if so I would remove most of it. If it is not conductive I would remove all of it and find some that is.  

Clint - W5CPT

  ----- Original Message ----- 
  From: Gary Smith 
  To: amps at contesting.com 
  Sent: Sunday, November 25, 2007 4:11 PM
  Subject: [Amps] Roller inductor & wiper "grease""


  I just bought a transmatch and the capacitor was extremely loose but 
  I figured I could repair it, it was loose enough that the weight of 
  the rotor would cause gravity to spin it downward. 

  I opened up the tuner and found what looked like black grease on all 
  the friction points of the rotor. I disassembled it, found the 
  friction clutch to govern the tension on the rotor and made all free 
  of grease and now the capacitor works perfectly with good friction.

  I saw a similar grease on the inductor at the same contact points. 
  The seller said he hadn't worked on it and the capacitor seemed to 
  hold for him and I took him at his word and I left the stuff not 
  wanting to backward engineer the design of the thing.

  Now I'm finding when tuning on 10 meters that with the tuner active, 
  higher power causes the reflected power to jump all over the place 
  but when running straight through & bypassing the transmatch there's 
  no jumping of SWR at all.

  I was thinking when I first saw the "grease" that it was there from 
  the beginning but now I'm thinking it was added but a previous owner 
  to make the mechanics works more smoothly without regard to RF issues 
  that would bring.

  Below is a photo of the inductor & wiper asembly. You can't miss the 
  grease or whatever it is on the components. 

  http://doctorgary.net/nye_inductor.jpg

  I am thinking I wasn't told the whole story when I bought the 
  transmatch. So here's some questions for the group;

  Is the black grease you see here something that comes on some edge 
  wound inductors?

  If as I suspect it is something applied by someone before me, what 
  would be an effective way to remove this grease? I hate to have to 
  disassemble the whole thing but will if that's the only way.

  I was thinking about putting rags in the bottom to keep it clean 
  after spraying the greased parts with starting fluid which would 
  surely degrease.

  Not sure what if anything should be applied to the contact surfaces 
  after all the grease is removed. Or does this greasy stuff actually 
  belong there?

  Thanks,

  Gary
  ka1j
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