>From K3MM: Didnt they have a problem with using some thinner wall tubing for
the caps at one point?
Response:
I suspect Tyler's talking about the problem with the cap tubes some years
ago while it was still KLM. I seem to recall that problem was with the outer
tubes rather than the innner 3/8 ones.
In my case, a couple of the 3/8 inch tubes were replaced with the M2 34XA to
36XA kit. As I did the rebuild I noticed that the plastic caps slid over the
3/8 inch tubing much more easily than they did with the new XA I assembled
back in the mid 80s and the ones I rebuilt in 91. Things looked great when I
got it up, but after the first rain the VSWR once again became a problem on
all bands. I pulled it down and it was very evident from discoloring
patterns that water was getting into a couple of the fifteen meter tubes.
Discoloration on the 3/8 inch tubes at the point that the plastic insulator
caps surround them told me where the water was getting in. I tried sealing
them with silicone, but that didn't help for very long. I ended up
unplugging the drain holes on the tubes that were resused from the 34 and
bored holes in the ones from the 36 kit. SWR still rises when there's heavy
rain, but they drain fairly quickly.
To help with Al Crespo's questions, for all the experience I've had with
problems related to various things such as resistance at the old shorting
straps, to water in the tubes, to icing, when I have problems it affects all
bands including 20.
I know with icing the resonant frequency drops on all bands. I think I
remember the same with water in the tubes. What has happened to resonance on
15 and 10?
73 de Lar K7SV
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