Just a word of caution when it comes to drain holes. It would seem
something so simple can sometimes end up being a complex problem, but as has
already been mentioned, the alignment can be critical. In addition, here in
Michigan and I'd suspect most other places you need to be careful not to
make the hole too big.
Here, anything over 1/8" is almost guaranteed to become the home of
Mud-dobbers (wasps) or other unsavory characters that you don't want in
there.
Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com
> FYI -
>
> My TH7 has exhibited high SWR, especially at high power, when it's
> wet. On my antenna, some of the DE trap cover drain holes were either
> misaligned or missing.
>
> The trap end covers on the outboard end of the traps, that is the end
> furthest from the boom, should have drain holes. If not, pull the
> trap cover off or at least away from the body of trap before
> carefully drilling a pilot hole and then enlarge to 1/4 inch. The
> hole should be on the tapered part of the cover where it meets the
> larger circumference that fits onto the trap body. (No drain holes
> are on the covers on the inboard trap ends.)
>
> Even if current production does not have these end cover holes, I
> would add them. This is something to be considered for trap end caps
> on any brand of trapped antenna.
>
> It's also a good idea to make sure that the screws under the trap
> inboard end cover are hand tight.
>
> At final assembly, the trap drain and end cover holes should all be
> in the same plane and aligned directly towards the ground.
>
> YMMV.
>
> 73 - Steve WB6RSE
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