[Top] [All Lists]

Antenna Erection

To: <>
Subject: Antenna Erection
From: (
Date: Wed, 19 Jun 1996 18:32:49 -0400
In a message dated 96-06-19 16:21:40 EDT, you write:
>  Sounds like
>  just what I need to put up a 4 EL DX Eng. 20M monobander (40' boom).  I
>  had planned to use a tram type line attached to the mast about 5 feet
>  above where the beam will be bolted to the mast.  This should compensate
>  for the distance between the tram line and the boom (lifting sling and
>  pulley distance).  The mast is only 2" x .250 wall so I had also planned
>  to back guy the mast at the same point that the tram line is attached
>  thus preventing bending the mast from the weight of the antenna.  What
>  material do you use for the tram line?  I was thinking of 3/16" guy line,
>  but would you trust 1/8"?

Hi, Gary --

    Be sure to backguy that thing!  Actually I would be hesitant about going
that high up the mast  in the first place.  My suggestion is to tram this big
antenna up right at the top of the tower; hang it by the bridle to the tower
or lower mast; remove the tram apparatus; NOW re-rig the haul pulley and haul
line up the mast (3 or 4 wraps of a nylon sling choker does a great job); now
pull it up into place.  The second lift is dead vertical and puts no sidepull
on the mast.  It only takes a  little bit longer than just tramming it but
it's a lot safer for your mast.  

    As far as the size of the tramline wire, I suggest using 1/8 inch
galvanized wire rope or aircraft stainless steel.  Anything smaller is hard
to get cable clamps for and the safe working load of it (200 pounds for
galvanized) makes it reasonable for ham antenna tram loads.  It's also very
easy to work with unlike stiff EHS.

73 and good luck,  Steve   K7LXC

    TOWER TECH -- professional tower supplies and services for amateurs

<Prev in Thread] Current Thread [Next in Thread>