Hi Glenn, wow that's a great model you built up to test your setup. I think
that's really cool. I was going to cut the corners of my top plate off to
eliminate any sharp corners etc but seeing what you did here I may just attach
a larger plate on top of the existing plate to give the turns of coax something
to sit on and to hold it up. Mt top plate is only about 6"-7" on each side
(Universal Aluminum tower). That's a really neat idea, I was trying to make one
large drooping loop work but your idea uses several tight turns. I may even
have enough length in the coax I currently have cut. All I would have to do is
wind them up around the mast much tighter. Could you send me directly a close
up of the actual installation? The URL allowed me to zoom once but there was
not enough magnification and resolution to clearly see how it finally turned
out. Thanks for sharing this.
Gedas, W8BYA
----- Original Message -----
From: "KD0Q" <kd0q@traer.net>
To: "Gedas" <w8bya@mchsi.com>, towertalk@contesting.com
Sent: Tuesday, November 15, 2016 9:40:51 PM
Subject: Re: [TowerTalk] Rotor Loop Question
Hi Gedas,
What I did was coil the bundle around the mast 3 times so the bundle winds
and unwinds, less lateral flex that way. A 45 deg PVC elbow protects the
bundle from the top plate.
Here's a pic of the mock-up I did -
http://s171.photobucket.com/user/gathorne/media/Rotor%20Loop/DSCF0528.jpg.html
Here's the actual tower install -
http://s171.photobucket.com/user/gathorne/media/Tower/DSCF0536.jpg.html.
Zoom in and you can see the white 45 deg elbow.
73, Glenn - KD0Q
On Tue, Nov 15, 2016 at 7:25 PM, Wayne Kline <w3ea@hotmail.com> wrote:
> Hi Gedas
>
>
> I have in the past with multi antennas on one mast, I grouped the
> coaxes together ( the most I had was three coaxes
>
> RG 213 ) I taped them in a loop and inserted the coax in a 1" id HD
> tubing/hose . This prevented the edges from chaffing the coax
>
> in the rotation .
>
> As for hardline to coax I run them just below the rotor shelf
> and then group the coax up one leg into the hose cover .
>
>
> Wayne W3EA
>
>
> ________________________________
> From: TowerTalk <towertalk-bounces@contesting.com> on behalf of Gedas <
> w8bya@mchsi.com>
> Sent: Tuesday, November 15, 2016 6:58 PM
> To: towertalk@contesting.com
> Subject: [TowerTalk] Rotor Loop Question
>
> I am hoping to get a better idea on how to implement my rotor loop for one
> of my towers. The tower is a 70' aluminum universal that I use for my VHF &
> UHF antenna in addition to a short rotateable dipole for 40m. The stack
> consists of: a 17B2 at ~85', a 23 elem 70 cm yagi at ~81', a 5 elem 6m yagi
> at ~76', and the 40m dipole at ~71'. I am using new Davis BuryFlex (a low
> loss RG-8 type coax) for all my loops. I have 3 runs of 7/8" heliax going
> up the tower for 6m, 2m, and 70 cm, and use the BuryFlex for the 40m
> dipole. All 3 heliax ends currently stop about 1' below the very top of the
> tower plate. That top plate BTW is a square aluminum plate with sharp
> edges. I plan to use a sawzall to cut the corners off and file them smooth
> to help lessen the chances of damage to the coax loops if they touch that
> plate while rotating the mast.
>
> Today I made my initial connections of the BuryFlex cables to the antennas
> and roughly taped all of them in place along the booms and down the mast. I
> have all 4 rotor loops tightly bundled together and held in place with
> electrical tape every foot or so. I formed the rotor loop with a length of
> about 5' and have it secured to the mast several inches below the 40m
> dipole then to the top of the tower about 6" down off the top.
>
> Here is the issue.....that bundle of 4 coaxial cables seems to be so stiff
> & easy to get twisted up into a mess it just does not seem like it will
> work well when I raise the tower back up. The tower is currently tilted
> over via a home-brew mechanism I designed & built and can work on the loop
> in comfort so I can try different ideas. I am wondering:
>
> 1. What is the best length for the loop(s) to be? And what shape should
> the loop be? I define the loop to be the lowest place on the mast where the
> cables are taped to the first place the bundle is taped to the tower top.
>
> 2. Should I separate the bundle of cables so it is not a single stiff
> "clump" of cables ? I.e., maybe just let all the coax loops droop freely
> and not be bound to each other?
>
> 3. I am able to change where the ends of the heliax ends up near the tower
> top....how far off the top should the heliax end to make the best rotor
> loops?
>
> Appreciate any thoughts and ideas you may have.
>
> Gedas, W8BYA
>
>
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