On 2/12/2014 3:12 PM, Dan Cisson wrote:
I had a TH-5 2' above the top of a 100' 45G, a 7L C3i 50M7 6-meter yagi,
30 ft boom 15' above the top, and a 14' cross boom 30 ft up with 2 12L
C3i 2 meter yagis and a pair of 11L 440 C3is inboard of those for about
7 years. Mast was 2" 1/4" wall, structural steel tube, with a short
1.5" stub that held the cross boom.
The 7L 50M7 at 15' was fine, but on those high wind days, the cross boom
would whip around like a Bluegill fly rod that had just tied into a
record Bass. It also withstood two major ice storms. The only real
problem was it beat the snot out of a TB-3 and TB-4 while they were up.
The races wore so badly that the top sat right down on the base. The
edges of the races were like razors.
I knew it was well beyond the ratings, but I just had to try it. <:-))
73
Roger (K8RI)
Matt....an opinion only... You are really not accomplishing much if
anything...You say you are guying the mast 12 inches out the top of
the tower ?? All you are doing at this point is asking a storm to bend
the mast above the guy ring...Long masts are asking for trouble, there
is a heck of a lot of leverage on the top of a long mast in high
winds...You could possibly be OK with a 6 meter beam atop the mast, or
a 2 meter beam, its a gamble !!. But if you put up an antenna that is
much bigger than a 10 meter yagi,, you are asking for PROBLEMS !!I
have took down too many of them in my days of tower work. Other
alternatives are another tower(probally not an option for most hams)..
or fixed antennas down the tower...It is expensive, but you can rotate
the complete tower!! I would check with antenna manufactures and see
how close you can stack their antenna to other antennas on the same mast.
It will be interesting to see what other opinions you get here on TT..
Good Luck, and be CAREFUL !! ,,Dan N4GNR
----- Original Message ----- From: "Matt" <bluewaterpro@yahoo.com>
To: <towertalk@contesting.com>
Sent: Wednesday, February 12, 2014 2:45 PM
Subject: [TowerTalk] Guying mast above rotor
I know the subject line sounds dumb,, but I have 15' of mast above my
tower and live in South Florida. Read on...
Im thinking of putting a guy ring at about 12' above the top of the
tower, and, only in event of a severe storm, attach 3 guy wires,
which would be anchored in concrete, the cables sitting on the
ground, affixing them to the collar in event of storm.
I've also thought of having short guy wires permanently mounted on
the guy ring collar, with the short guy cables running down the mast
to the top of the tower. Then i could climb up and attach the guy
wires, if needed. No need for a bucket truck.
I think this would provide additional survivability to the mast in
heavy wind
Any thoughts on this? Good idea, bad?
Thanks/73
Matt w1mbb
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