It would tell a lot to do a ohmeter check of some of the black goo on a glass
plate. Its interesting that Clint found some some conductive grease that does
not rely on granular particles as a slurry in the grease. I haven't seen
conductive grease that did not rely on the slurry of particles.
The black goo you have on the inductor, may be something like Noalox, or
Oxguard that is a slurry of metal particles in an iinsulating grease carrier,
and make contact when a THIN layer is clamped or pressed between metal
surfaces.
I see your Dr prefix, it would be interesting to smear a slide with the goo.
You might be able to see the metal particles, with
a microscope. In any event removal of about 90 percent of what is there would
not hurt.
All the Best, 73,
Pat Barthelow aa6eg@hotmail.com
http://www.jamesburgdish.org
Subscribe: http://bambi.net/jamesburg.html
Jamesburg Earth Station Moon Bounce Team
> From: w5cpt@bellsouth.net
> To: Gary@doctorgary.net; amps@contesting.com
> Date: Sun, 25 Nov 2007 16:31:28 -0600
> Subject: Re: [Amps] Roller inductor & wiper "grease""
>
> 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@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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