Hy-Gain DIR-73, Instruction Manual

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CHAPTER 4
INSTALLATION
Installation
Make sure all element compression clamps
and anchor screws are securely tightened.
Also, make sure all beta match hardware is
tightened securely and free of corrosion.
IMPORTANT: The Discoverer 7-3 is a very
large and heavy antenna and requires
consideration as to how you are going to get it
to the top of the tower. Thoroughly read this
section before beginning to install your
antenna.
Installation on a Crank-Up Tower
Crank the tower down completely or as low
as it will go, and block all sections from
moving by using a 2" x 4" piece of wood or a
solid iron bar for heavier towers. The block
should be inserted through the lattice structure
before the tower is completely down, then the
tower can be cranked down until the block
takes the weight off of the winch.
Use a ladder to reach the top of the tower.
NEVER CLIMB THE LATTICE STRUC-
TURE OF ANY CRANK-UP TOWER!
Attach the mast to the tower and rotator. (The
cast aluminum boom-to-mast brackets (Item
No. 1) should be installed on the mast as
shown in Figure 15.) Attach a gin pole to the
tower to assist in lifting the Discoverer 7-3.
This antenna weighs approximately 96
pounds, therefore, make sure that your rope is
strong enough and that you have enough help
on the ground to lift.
held by the ground crew, so that the guide
rope can be retrieved.
Attaching the Antenna to the Mast
When the antenna reaches the mast bracket,
the four (4) 5" bolts should be inserted
through the holes in the mast bracket and
secured using 5/16"-181ockwashers and nuts
(Item Nos. 23, 27, & 26). Tighten all bolts
securely. You may wish to use a deep-well
socket set to tighten these bolts. You may
notice a considerable amount of sag in the
boom. This is normal.
The mast clamps may now be untaped from
the boom and attached to the mast, as shown
in Figure 14, Detail C. Loosen the turnbuckles
and slide the entire assembly up the mast until
the boom support wires are straight. Tighten
the 3/8"-16 bolts securely. Take up any slack
in each wire with the turnbuckles, until the
boom is level. When taut, tie off the
turnbuckles. See Figure 14, Detail B. Tape the
transmission line to the boom and mast for
strain relief.
Attach the lifting rope to the balance point of
the antenna. The lifting rope should be fed
through the gin pole or other pulley
arrangement attached to the tower. The other
end should be at ground level, available to the
ground crew for lifting. Guide ropes may be
loosely looped over the boom ends and used
by the ground crew to guide the antenna away
from the tower and ladder. The guide rope's
two loose ends should be