[TowerTalk] Inverted V on a retractable tower

[SPWoo]

Hi Larry,

Thanks for the reply.  I get a lot of wind here and I'm afraid that the counterweight would swing in the wind and cause stress on the rope/wire.  I wonder if there's a device that would retract the wire on a reel.  Since I retract my tower after I'm done with each operating session I need an automatic device where I don't have to make a trip to the outside.  I do have one of those coax arm supports already on the mast.

My tower is also loaded to the max. so a rotatable dipole is out of the question.  My other options are to mount the apex at the top of the bottom tower section, or to shunt feed the tower for 80m.

 
Best Regards,
Jonathan Woo
(970) 646-1711


________________________________
 From: Larry Loen <lwloen at gmail.com>
To: SPWoo <jj_2_woo at yahoo.com> 
Cc: "towertalk at contesting.com" <towertalk at contesting.com> 
Sent: Saturday, October 6, 2012 1:58 PM
Subject: Re: [TowerTalk] Inverted V on a retractable tower
 

I have seen this very thing done.

Basically, you need some sort of extender (if you're talking about US Tower, they sell such a device) so that the summit of the inverted V clears the tower sections.

Then, you just need to have some sort of system at the ends of the antenna that amount to some fairly simple pulley system with weights to allow the wires to fall down when the tower is cranked over for service. 

On a tower at W0IBM, I saw something like a commercial product that did this.  It was tubes of maybe 2 inches in diameter attached to courtyard walls (the tower was in a courtyard).  When the tower came down, the weight-and-rope at the end of the wire antenna retracted into the tubes well enough.  We could detach or keep the thing intact from the top of the "V" when we tilted it over.  I believe we typically detached it for service; the system was designed such that 
the wire was simply "where it needed to be" when the tower was retracted (but not cranked over) so we could reattach it 
after we cranked the tower back from horizontal to vertical.

At my forever under development new shack, I plan to do something similar with my US Tower retractable.  I have an old trick of putting conduit over rebar as a distant antenna support for simple wire antennas.  I'll probably resort to the same weight-and-pulley trick -- I may even settle for a simple "eye hook" instead of bothering with a pulley.

The nice thing about the rebar-covered-by-conduit is that while it is plenty stable, it is easy enough to simply lift the conduit off of the end of the rebar (the fit is tight, but not overly so). So, everything is serviceable.  With my simpler scheme, the wire may end up on the ground, but most of it would be away from the tower and, I presume, easy to manage without kinking and coiling.

If I discover I can manage 20 feet of conduit with my scheme, then it is more like the W0IBM installation, because it would be at about the same height as the retracted tower.


Larry Wo0Z


On Sat, Oct 6, 2012 at 11:29 AM, SPWoo <jj_2_woo at yahoo.com> wrote:

Hi All,
>
>Does anyone know how to install an inverted V antenna for 80m on a retractable tower?  Is there anything that could be done to prevent the wires from laying on the ground when the tower is retracted?  Thank you and 73.
> 
>Best Regards,
>Jonathan Woo
>(970) 646-1711
>_______________________________________________
>
>
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk at contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>