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Re: [TowerTalk] More possible RCS8V problems

Subject: Re: [TowerTalk] More possible RCS8V problems
From: "Kelly Johnson" <>
Date: Tue, 5 Dec 2006 10:37:25 -0800
List-post: <>
I must have a loose connection somewhere.  I'm not sure if it is in
the switch or not.  I've had no problem for a couple of days now.  I'm
beginning to distrust the RCS8-V though.  Maybe I should consider an

On 12/5/06, Joe Giacobello <> wrote:
> Frankly, I don't know what would make them self cleaning either, but
> what you describe makes sense.  I haven't burnished my contacts for
> several years now and they keep working OK even in a windy environment
> where there's bound to be a lot of vibration.
> 73, Joe
> Jim Lux wrote:
> > At 08:33 AM 12/5/2006, Joe Giacobello wrote:
> >> Some time ago, another correspondent on this or a similar list said that
> >> the relays in the RCS8 were self-cleaning.  Up until that time I had
> >> been doing an annual PM by using a burnishing tool on the contacts.  Are
> >> you guys saying that they are not self-cleaning and do require periodic
> >> cleaning?
> >
> > I don't know if the RCS-8V relays are self cleaning; since they're a
> > MFJ custom part, there's no data sheet to go look at, although an
> > inquiry to Tom, W8JI, might be productive on this point, since he's
> > probably seen more of these relays than I've had hot dinners.
> >
> > There are other relays that have been mentioned on this list which ARE
> > standard parts, and for which the datasheet says what the behavior is.
> >
> > To be honest, I'm not sure precisely what makes a contact self
> > cleaning, at least by looking at it.  There needs to be some lateral
> > wiping action, but I suspect it doesn't take much. The overall
> > mechanical slop in the mechanism, in combination with the contact
> > surface being slightly convex, might be all you need.  In a high
> > current contactor (a starting relay for an airplane), the cleaning was
> > accomplished by setting the contacts at a slight angle, so every time
> > it closed, the copper ring that served as the contacts for the
> > armature rotated a few degrees. A very clever scheme.
> >
> > The contact material also has something to do with it.
> >
> > Jim, W6RMK
> >
> >
> >
> >
> >

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