I'm not sure of the construction on the xm240 but the 40-2cd had a common
problem that sounds like that. They used a sheet metal screw to hold the
wire from the loading coil to the element and then put that shrink tubing
over it... unfortunately it didn't seal very well and eventually the screw
corrodes causing an intermittent. The fix is to remove the end of the
shrink wrap, drill through the element and use a ss machine screw to secure
the end of the coil then seal with a better heat shrink that has the melting
goop in it.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://www.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
> -----Original Message-----
> From: towertalk-bounces@contesting.com [mailto:towertalk-
> bounces@contesting.com] On Behalf Of Hector Garcia XE2K
> Sent: Monday, January 02, 2006 22:58
> To: Kelly Jones; towertalk@contesting.com
> Subject: Re: [TowerTalk] Cleaning inside tubing
>
> Kelly:
>
> Kelly maybe you must doble check the Coils in the
> elements,
> how much is the swr increase ?? a few or just to the
> infinity ?
>
> i read several time the problem in the tribanders and
> some monoband antennas from cushcraft
>
> good luck and Happy New Year
>
>
>
> --- Kelly Jones <kelly@dxcentral.com> wrote:
>
> > Hi TTers,
> >
> > I have a Cushcraft XM240 that I think has developed
> > an intermittent loose
> > connection. I bought this antenna used and put it
> > up this past fall. What
> > I noticed is that the person that owned it before me
> > must have used some
> > type of "goop" inside the element tubings. The only
> > thing I can assume is
> > that it was some type of stuff to keep the tubing
> > joints in good contact
> > with each other. On the joints I took apart, I
> > completely cleaned the
> > outside of each smaller tube as it slid into the
> > other. However, I had a
> > difficult time cleaning the inside of the larger
> > tube that the smaller slid
> > into. This was some really nasty stuff and took a
> > boat load of elbow
> > grease and sandpaper (yes, sandpaper) to get the
> > elements cleaned up. This
> > stuff was really sticky and had all kinds of crud
> > that have accumulated
> > over time. The stickiness is what caused me the
> > most problem with getting
> > inside the tubes. Steel wool, fine grit sandpaper,
> > etc. all would just go
> > in and stick, probably causing more bad than good.
> >
> > Well, needless to say I think some of that junk is
> > now causing me
> > problems. I seem to have an intermittent where my
> > SWR will go high, then
> > back to normal, then high, etc. I'm suspecting that
> > there is an element
> > that has a piece of tubing that's not making good
> > contact at one of the
> > joints. So my question is, does anybody have a way
> > to clean out the
> > insides of the tubing sections. I'm obviously going
> > to have to take the
> > antenna down to fix it (in the middle of the
> > Colorado winter!) and I want
> > to be sure I don't have to do this again.
> >
> > Also, I seem to recall some talk flying around with
> > regards grounding the
> > reflector to the boom with a strap. Can somebody
> > point out the reason for
> > this? And finally, what's the consensus of using an
> > MFJ86 (or whatever the
> > number is) balun versus a coax wound balun? I have
> > an older W2AU (I think)
> > balun that I'm toying with replacing the MFJ with,
> > but am now thinking
> > about just making a coax one. Thoughts on this?
> >
> >
> > 73
> > Kelly - N0VD
> >
> >
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> >
> http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
>
> Hector Garcia XE2K / XF1K
> Mexicali B.C DM22
> _______________________________________________
>
>
>
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