I had an A3W up which went south on me in terms of SWR. Tested
everything to no avail. The problem occurred after a significant period
of wind and rain. Finally got the antenna down and every one of the
traps, drain holes facing down, was jammed with wasp carcasses, larvae,
etc. Apparently this had been going on for a long time but the unusual
storm somehow allowed water to get in the traps where it was "trapped"
by all the stuff in there. When dry, I imagine the debris didn't affect
the performance but once it got wet, that was it. I imagine if I had
waited a little longer, it all would have dried out and things would
have gotten back to normal. It is hard to describe how much insect
matter was in those traps.
Steve, N4JQQ
PS, I have a Force 12 now. :)))))))
On 4/9/2013 4:55 AM, Brian Alsop wrote:
I lost one trap due to exactly this. Wood wasp got into the trap and
built his mud and saliva nest.
I've taken a bit different route. I use fine mesh plastic window
screen. The reasoning of course is that it's designed to keep out
insects. I simply place a strip of it over the holes. Several strips
of Scotch 33 tape is used (wrapped around the circumference of the
trap) to secure it. Of course one doesn't tape up the holes!
A balun I recently purchased recommended drilling 1/16" weep holes
where the water would accumulate with the balun in place. Apparently
this diameter is small enough to keep out the bigger insects which
cause trouble. Supposedly it it large enough to still allow water to
escape.
73 de Brian/K3KO
On 4/9/2013 03:17, Dan Hearn wrote:
The ideal antenna drain hole would have a reasonably large diameter but
would not allow insects to enter and build nests. I believe there is
a way
to accomplish this.
There is a material used in sanding pads which is springy and
would allow
water to pass but not insects or debris. It is somewhat similar to steel
wool physically but is not electrically conductive as far as I can
tell. I
have been using strips of it to wrap around wires into and out of metal
cabinets at the base of my towers to discourage Wasps from entering.
It is
quite springy and I have noticed no deterioration over 5 or more
years here
due to sun and weather conditions .
If you have a coil in a PVC cover I would drill a hole possibly
1/2 inch
or so in diameter , cement a short piece of PVC tubing into it at the
bottom maybe an inch or so long and insert some of the springy
sanding pad
material into it.
None of my antennas have traps so I have not tried this. I plan to
get
some of the stuff and check if it affects the inductance of a coil
out of
curiosity
There are probably readers out there who know more about this
material
than I do and I invite comments on this idea..
Dan, N5AR
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2012.0.2240 / Virus Database: 2641/5733 - Release Date: 04/08/13
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|