In a message dated 12/19/03 9:11:29 AM Pacific Standard Time,
k4oj@tampabay.rr.com writes:
> When suspending an antenna from a tram line usually the biggest hassle
> for me has been that when you get to the top the antenna is "trapped"
> under the tram line which often is NOT on the mast above the target area.
>
> To overcome this you have to be able to undo the tram line before that
> final lift vertically of the antenna.
True enough. This is one of the 'learning curve' items. There are two
options.
1) Mount the tramline higher up on the mast. WARNING: mounting it too high
has its own risks if the mast isn't suitably strong enough; i.e. water pipe or
aluminum. If in doubt, use a backguy. As you increase the tension on the
tramline, check the mast from the side to see how much deflection you've got.
If
everything is rigged correctly, the antenna will hit the mast so that it can be
bolted in easily. Sadly, this doesn't happen very often.
2) Install the antenna in 2 steps. The first step is to get the antenna to
meet the tower or mast somewhere - it's not important where. Secure the antenna
to a convenient spot using slings and carabiners. Slacken and then disconnect
the tramline. Once it's out of the way, you can use a comealong or move your
haul line as high on the mast as you'd like and then the ground crew can pull
it up into place. Since it's going to be a dead vertical lift and not sideways
like the tramline, any mast should be able to handle it.
Method #2 is more time consuming but works everytime.
>
> By using a gin pole as the pulley at the top of the line that pulls the
> antenna up the tram you can also use it to act as the booster to get the
> antenna to its destination.
I'm not a big fan of using a ginpole for this operation. First, a ginpole
meant for dead vertical lifts so any sideways force is discouraged. And also
it's another bunch of hardware at the top of the tower that'll probably just
get in the way. You can always use the mast since it's basically a fixed
ginpole anyway.
>
> The critical thing to watch for though is NOT to have the gin pole
> extended much above the clamp as you are putting horizontal pull on the
> gin pole... this is not what it is designed for... so... if the top of
> the gin pole is low it is not much help as far as the final boost.
It's redundant since the mast is already there. This is assuming, of
course, that the mast is long enough to be of any use. Always make your mast a
couple of feet longer than you'll need and it'll be useful for any tower
hauling
type situation.
>
> I use a clevis at the top of the tram line where it attaches to the
> tower or mast - the end of my tram line has a permanent eye on it and
> once it is slack, it is easy to undo by removing the pin of the clevis.
Clevises, or shackles, take 2 hands to use and have 2 parts that take
5-10 seconds to install or remove. A carabiner is one-piece and can be put on
instantly with one hand - both major advantages over clevises. If you're still
using clevises, you're working too hard!
Cheers,
Steve K7LXC
TOWER TECH -
Professional tower services for commercial and amateur
888-833-3104
Cell: 206-890-4188
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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