[ARC5] Sort of OT - Fuzzy VCs

[J Mcvey]

Maybe moving a long stiff bristled brush between the plates , then blow it out?I've resorted to such methods on a few "tough cases" and it seemed to work.Yours sounds rather extreme, though.
It only takes one errant whisker to cause a problem. Air alone does not always have enough force 
to dislodge the tentacles from their moorings. Good ol' friction can have more of a scraping effect.
We used to see whiskers growing on some transistor leads on older equipment. scraping the leads off 
seemed to fix the problem for quite a long time.


 

    On Saturday, December 2, 2017 8:43 PM, Peter Gottlieb <kb2vtl at gmail.com> wrote:
 

 I was thinking whiskers when I started reading your post.  Can you identify 
where they are coming from?  Some metal surface is growing whiskers; is it the 
cap plates themselves?  My initial thought is no, that they are aluminum 
(presumably, correct me if I'm wrong), and, rather, it is some other item in the 
radio such as the chassis.  I know zinc grows whiskers like mad, is the chassis 
galvanized?  Other metals do, too, like tin.

If it's the cap I'm not sure what to do except that if others aren't reporting 
the same problem then maybe a replacement would help.  If it's something like a 
chassis then you have to find, clean then encapsulate in paint of some kind.  
You will then have to blow the entire thing out very carefully outside (wear a 
mask, do you want to breathe metal whiskers?) especially the cap.

Peter
kb2vtl


On 12/2/2017 8:30 PM, Jim Falls wrote:
> I have a Swan 350, and I have had fits with arcing on the tank VC from Day 1. It’s a 350pF Hammarlund-style straight line C unit and spacing is a tad wider than a BCB VC.
>
> The consensus on the Swan list was dust. It’d blow it out several times a week, filter the air going thru the Final cage, all to no avail.  Zapped and hissed like a feral cat after a day or two. Got disgusted. Put it away in the garage last year.
>
> Pulled it out yesterday. Under bright light, it appears to have metallic whiskers all over the place, especially on the stator plates. That thing was clean as a whistle when I put it away. Now it looks like I cleaned it with fine steel wool.
>
> I recall someone here or on the milsurp list posting a photo like that, but I don’t recall any cure.
>
> Is this “fixable”, or am I SOL?
>
> Jim K6FWT
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