[TowerTalk] T500 bearing and rotor placement

[Gene Smar]

Rusty:

     Welcome to the group.  You'll find this one of the most educational and
h elpful reflectors in Ham radio.

     I have a T-500-64 at my QTH.  Installing the rotator at the bottom of
the top section is OK.  The gives you about 8 feet between the rotator and
the top bearing.  I haven't done the math for this, but but Trylon's info
(printed and on the web) list no precaution against installing the rotator
just as you're considering.

     I have my Skyhawk HF Yagi one foot above the top of the tower.  Three
feet for yours will be ok, but the Trylon series of towers is rated with the
antenna load's sail area within two feet of the top.  That is, you'd have to
derate the capacity of your Trylon if you start installing antennas more
than two feet above the top.

     I used Trylon's calculator
http://www.trylon.com/lightdutytowers/towercalc.asp to determine what I
considered an allowable load for my T-500-64.  On the tower I now have the
Skyhawk at 65 feet, a CC D-40 rotatable dipole at 78 feet and a Comet GP-15
at 80 feet on a 2 inch diameter mast.  According to my (and Trylon's) calcs,
this should survive with a comfortable margin (for me) winds in excess of 70
mph here in the DC area.

     Remember:  The Titan series of towers is a LIGHT-DUTY design.  Trylons
says so themselves.  So don't try to put a stack of KT-34-XA's on a long
mast.  Likewise, I'd give more thought to your plans for installing an (HF?)
LPDA above the SteppIR.  If the LPDA is only for V/UHF ( you weren't clear
what bands the antenna is on) it might be acceptable, but you'll have to
check with Trylon, etc.

GL es 73 de
Gene Smar  AD3F

----- Original Message ----- 
From: "Rusty Richards" <rwb9fiu at earthlink.net>
To: "towertalk" <towertalk at contesting.com>
Sent: Wednesday, May 26, 2004 11:34 AM
Subject: [TowerTalk] T500 bearing and rotor placement


> Hi
> I'm new to the group and look forward to hearing other opinions on tower
topics.
> I have a Trylon T500 up. It came with angle brackets in the top section
for placing plates under a thrust bearing and rotor in the top and middle of
the top section.
> Would it be better to lower the rotor down into the next section below,or
is it ok in that top section?
> I would also like an opinion on the antenna height above the thrust
bearing. Will raising it  to 3 ft or more above the bearing have any effect
on how low i should nest the rotor? The antenna is going to be a 4 element
SteppIR,about 10 sq ft. Would like to have a log peridioc for the higher
bands above the SteppIR,but am not committed to that.
> Any ideas would be most appreciated.
> Thanks
> Rusty
> rwb9fiu at earthlink.net
> _______________________________________________
>
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