If you have no tall trees or other object to hang your dipole on, the
telescoping mast sounds like a good plan. This configuration should work
reasonably well on 40m and it will probably work OK on 15m also. I would
not use Phillystran or turnbuckles on the ends of the dipole. You don't
need much pressure to support the antenna wires and a little sag will not
hurt the antenna's performance If you tie the balan to the mast, it really
doesn't matter how much it weighs or how much the coax weighs as it will not
put any downward force on your antenna wire.
John KK9A
To: towertalk@contesting.com
Subject: [TowerTalk] How To Avoid Telescoping Mast Colapse
From: Wayne Willenberg <wewill747@gmail.com>
Date: Wed, 16 Nov 2011 12:04:04 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
<snip>
The ends of the dipole opposite the antenna wire from each feedpoint will
be connected to H1200 Phillystran. The Phillystran will go through a small
marine-grade stainless steel pulley at the top of the mast and then
continue to the bottom of the mast. The center of the dipole is heavy
because of the DXEngineering balun (rated at 2,000 W) and the RG213
connected to the balun. My reason for using Phillystran for the dipole
halyards is the strength vs weight ratio. I know I can't make the dipole
horizontal to the ground, but I hope to avoid an acute angle on each side
of the feedpoint by exerting significant horizontal force on the halyards.
Thanks for your help.
Wayne KK6BT
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