[TowerTalk] Cleaning inside tubing

[Kelly Jones]

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