On the F-12 issue, I would like to add some data, as well as ask for
some creative input.
Over the past three years, I have been putting together a remote contesting
station in NNJ. When the project started, I was stationed in HZ land, so a
lot of my activities were restricted to email related activities, as that
was the only activity available there. I have been a TT lurker for about
2-3 years now, and at about the time that Jim KH7D was putting up his C-4, I
had one of my friends order up a C-3 for use as our multiplier station
antenna in the then upcoming season.
We put it up in Oct., by it's lonesome on 80 feet of R-25, and it
performed as well as a 2 element beam could be expected. We used it in both
weekends of that years CQ WW. By January, it had blown itself into little
pieces. It vibrated terribly. At first element ends came off. Finally the
longest element sheared as well. And it was turned into a pile of aluminum
bits. Since I was in HZ by then, I did not witness the demise, and have
asked the person who did to summarize his observations in detail. If he
does, I will post it here. For the record, the site is on a mountaintop, and
the wind can indeed get severe at times, and the antenna is above the
treetops.
Knowing the general attitude of the majority of this reflectors
subscribers with regards to the F-12 product, I didn't mention anything. We
just wrote it off as a bad experience with F-12. I waited for the
appropriate time to mention it, and this appears to be it. My buddy now
feels that they are junk, but I have reserved judgement since it is clear
that there are plenty of F-12 installations that work just fine.
Other antennas at the site include 105BA, 155CA, 20M5, 40-2CD, A4, A3 204BA
and none of these has failed in any way (even the 40-2CD tips are intact).
Anyway to make a long story short, when I saw Steve K2WE (also a TT member)
selling his F-12 magnum 340/520Z antenna, I decided to give F-12 another
shot. I intend to mount this antenna at about 120 feet, and that will put
it up higher than any other antenna at the site. I see that another user
has reported failures with a 340 model.
Any suggestions on fixes/mods I can perform to ensure that this beast
doesn't blow apart once in place would be greatly appreciated. I will go the
rope route for sure, and will also beef up the rivets with sheet metal
screws. Any others ??
With regard to the F-12 statement about using rope in the elements will
void your warranty, I really can't see why this decision was taken. Can
anyone shed some light on that issue ? Seems like adding the rope could only
help, and couldn't hurt.
73's Dave K2XR
|