Technique that I have used for years for tramming yagis to various heights on my
two 100 ft. towers:
1. Use 1/4 inch guy wire and secure at a point 3 to 5 ft above the point you
want the antenna to be placed and secure at the ground level, some distance away
from the tower so as to clear other guy wires, antennas, etc. I have a 200 ft.
length of 1/4 inch guy wire that typically puts me at a ground point about 100
ft. or more from the tower base. Use deadends or cable clamps to secure to the
end points.
2. Use an old pulley from a come-along that fits nicely over the 1/4 inch guy
wire with a non-moveable hook (spring loaded closure) that rides up the tram
cable (1/4 inch guy). After the pulley is on the guy wire, I would tension the
cable with a come-along to ensure a comfortable ride.
3. A short rope is used to secure the boom to the hook and is positioned such
that when the antenna arrives at the tower (mounting location) it is in the
correction position - boom to mast plate on the correct side, antenna level. It
takes a little effort to position the antenna so it is balanced at that point
and with the short ropes tied such that the antenna does not rotate while it is
being pulled up the cable. This short rope is tied either side of the
boom-to-mast plate (two points on the boom to minimize rotation of the antenna
at the balance point).
4. The elements of the beam point at the tower and are parallel to the tram
cable.
5. Use my heavy pull rope to pull the antenna along the tram cable, with the
pulley located 1 foot below the point on the tower where the tram is secured.
The antenna end of the rope is tied to the hook on the pulley that travels up
the cable. It is better to have the pulling forces at this point (close to the
tram pulley) so the pulley on the guy wire does not bind or cause a jerky
action.
6. If the antenna is destined for a mast mount spot, I pull the antenna up to a
point below the final location, secure the antenna (tied off at the ground or on
the tower) then drop the tram cable and pulley (pass the tram cable over the
boom and below the antenna so it can continue to go higher on the tower) then
pull the antenna up to the mounting point. This is usually the only physically
challenging part - lifting the full weight of the antenna. It helps to have
some short ropes on your climbing belt to serve as a "third" hand that have
hooks on each end for rapid tower attachment.
Typically it takes more time to set up the tram system and pull rope/pulley than
it does to put the antenna up.
As an example, recently put up a 3 element Force 12 40 M yagi at 55 ft.
(actually only part of the the 6 element 20/3 element 40 duo-bander on a 44 ft.
boom) using this technique - by myself! Did have to use some tag lines on a
couple of elements (Director and Reflector) to keep the element tips from
dragging (and bending) until it was off the ground. The antenna was balanced
and slid up the tram cable effortlessly. After rigging the tram system, total
time to put up the antenna was 35 minutes.
Of course none of this practical when the area surrounding your tower is filled
with trees, this is the first QTH where I have been able to take advantage of
this technique!
Regards,
Mark, K1RX
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