[TowerTalk] positive pull down for Tri-ex towers
bmaser at tampabay.rr.com
Thu Jul 10 14:33:19 EDT 2008
When I started reading your response I thought I was going to learn
something then I realized that you could have done the same thing by just
grabbing the bundle of coax lines and pulling down on them as you started
lowering the cable. Your method requires that you continue to take up the
slack in your "manual" cable otherwise it will get tangled with the sections
coming down. You could have attached this "manual" cable to your garden
tractor, aim it away from the tower, put it in gear, rev it up and let it
provide the positive pull action as you cranked the tower down. Now that
would be fun to watch. Of course, the smart thing would be to not crank the
tower all the way up to begin with.
----- Original Message -----
From: "Craig Clark" <jcclark at wildblue.net>
To: "Bob Maser" <bmaser at tampabay.rr.com>
Cc: <towertalk at contesting.com>
Sent: Thursday, July 10, 2008 5:13 PM
Subject: Re: [TowerTalk] positive pull down for Tri-ex towers
> At 16:54 7/10/2008, you wrote:
>>Most towers that were designed not to have positive pull down cannot be
>>EASILY modified to have the pull down feature. It all comes down to the
>>fact that the pull up cable has to wind in at the same rate that the pull
>>down cable is letting out and vica-versa.
> Not completely true. The "however" is you have a manual positive pull down
> I agree that you cannot retrofit the same system as on the larger towers
> that are designed with a positive system.
> Here's what I did. I attached an 7x32 aircraft cable to the bottom of the
> top section. I chained a pulley to the bottom of the tower and ran the
> cable thru the pulley. I used a cable compression clamp to grab the
> aircraft cable and attached that to a come-a-long. Normally I'd use my
> tractor as an anchor point but I also used my truck.
> I'd first tension the top section with the come-a-long. I would then lower
> and tension, lower and tension. I watched to see if the top tower wire
> would go slack and if it did, I'd raise the tower, re-tension and then
> lower again. Normally, after lowering the tower 1-2' gravity would take
> over and there was no more need to use the "positive" system.
> The reality is that my W-67 would not come down without the system I
> designed. I had a friend at the local fire dept come over and I did all
> this work while hooked in to a fire ladder. I would never climb a crank-up
> even if it was blocked with 4x4's. Not never ever.
> 73, Craig Clark, K1QX
> RADIOWARE AND RADIO BOOKSTORE
> PO BOX 209
> RINDGE NH 03461
> 603 899 6957
More information about the TowerTalk