[Amps] Lube for roller inductor

Stan Gammons s_gammons at charter.net
Wed Aug 1 19:38:27 EDT 2018

Hi Carl,

I had taken the roller inductor out of the MFJ tuner to clean the roller 
since a couple of spots made a noticeable amount of static in the 
received signal when I tuned across those spots on the inductor. Perhaps 
too much power dumped in it from my L-4B :)   When I took it out I 
noticed the rear Delrin plate had came back apart.  It was broken when I 
got the tuner and I tried to repair it when regular epoxy.  It held for 
a good while.  This time I used some Loctite plastic bonder which will 
bond to Delrin if you rough the surface up with some 220 grit sand 
paper.  After gluing the Delrin part and letting it cure for 24 hours, I 
reassembled the roller inductor. It feels different now and is easier to 
turn. If my Sencore LC75 is correct, the roller doesn't contact the coil 
in various places. So, I guess it's time get another roller inductor.  
Or use the Murch tuner I have. It has a beefy roller inductor in it. 
Looks like #8 aluminum.  I don't think it will match as well as the T 
network used in the older MFJ-989C tuner though. The Murch tuner only 
has an 18 uh roller inductor too. The one in the MFJ is 30 uh.

I'm not sure when OEP quit making roller inductors. Seems like the email 
I got from Steven Elliot said around 20 years ago. I had sent an email 
and picture asking about the Delrin part because MFJ seem to think OEP 
made it, but Steven said that wasn't a part for the inductor they made.  
OEP still makes air variable caps.

Thanks for telling me about Cardwell Condenser.  I didn't know anyone 
still made any of the E.F. Johnson stuff.  May need some of that when I 
ever get around to building that GI-7B amp.  Too many projects and too 
little time...



On 08/01/2018 05:01 PM, Carl wrote:
> Stan, I wasnt aware that OEP quit production, I used to buy many some 
> years ago.
> Another place to check is Cardwell Condenser who is now part of Viking 
> and they still make the old Johnson 229 series..
> Carl
> ----- Or
> iginal Message ----- From: Stan Gammons
> To: Carl ; amps at contesting.com
> Sent: Wednesday, August 01, 2018 3:38 PM
> Subject: Re: [Amps] Lube for roller inductor
> Hi Carl,
> MFJ said they use SAF-T-EZE anti-seize.
> Oren Elliot no longer makes roller inductors. They said they stopped 
> selling them to MFJ around 20 years ago and MFJ makes their own roller 
> inductors now.
> 73
> Stan
> On August 1, 2018 10:32:17 AM CDT, Carl <km1h at jeremy.qozzy.com> wrote:
> Why not contact MFJ who builds theirs as well as Oren Elliot Products 
> plus Multi Tech Industries who builds "big" ones.Carl----- Original 
> Message -----  From: "Stan Gammons" <s_gammons at charter.net>To: 
> <amps at contesting.com>Sent: Sunday, July 29, 2018 11:29 PMSubject: Re: 
> [Amps] Lube for roller inductor On 07/07/2018 01:05 PM, Bert wrote: I 
> don't think Penetrox is a good idea for a roller inductor. As far as 
> I  know, Penetrox is only conductive if put under pressure. I would 
> suggest one of the CAIG DeOxit products, e.g. DeOxit 5. Bert VE3NR 
> Kind of reviving this thread since I have a roller inductor that was 
> acting a bit flaky, so I took it out and gave it a good cleaning in 
> my  ultrasonic cleaner. No lubes left on it now and it's very clean. 
> So, what  is general consensus, DeOxit D5 is Ok to use to use on the 
> roller? Unsure  how much of a lubricant it is, but I know it's a great 
> contact cleaner. 73 Stan KM4HQE Amps mailing list Amps at contesting.com 
> http://lists.contesting.com/mailman/listinfo/amps ---This email has 
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