INSTALLATION
are inefficient because of the absorption of
8. Unpacking
their radiation by the surrounding growth.
a. Packaging Data. When packed for
The antenna assembly, however, provides
shipment, the components of the antenna
more reliable communications than a
assembly are individually enclosed in
vertical antenna in dense growth areas.
polyethylene envelopes and packed in Bag
b. Locate the antenna in a clearing and
BG-175. Bag BG-175 is enclosed in a
assemble the antenna with the antenna wire
moistureproof barrier and sealed in a cor-
broadside to the direction of the desired
rugated fiberboard carton. Packed for
station. When communication is desired
shipment, the carton weighs 13 pounds and
with two or more stations, orient the an-
is 10 inches high, 9 inches deep, and 10
tenna assembly so that the antenna wire is
inches wide; its volume is 0.5 cubic feet.
broadside to the weakest station.
A typical shipping carton and its contents
are shown in figure 3.
11. Installation
b. Removing contents. To unpack the
a. Determining Length of Antenna Wire.
equipment, proceed as follows:
(1) In the installation procedure in b
(1) Open the carton. Do not cut open
below, use the tape measure to de-
the carton, because the equipment
termine the proper length of an-
may become damaged.
tenna wire for the desired fre-
(2) Open the moistureproof barrier
quency of operation. Unroll the tape
and remove Bag BG-175.
measure to the desired frequency
(3) Open Bag BG-175 and remove its
marking and unroll an equal amount
contents.
of antenna wire from each reel as-
(4) Remove the components from the
sembly (fig. 4). The length indi-
polyethylene evelopes.
cated on the tape measure opposite
the desired frequency marking is
half of the required total antenna
length at that frequency.
a. Inspect the equipment for damage in-
(2) The following chart lists the length
curred during shipment. If the equipment
of each antenna wire (including the
has been damaged, refer to paragraph 2.
reel assembly frame) required for
b. See that the equipment is complete as
frequencies between 1.5 and 20 mc.
listed on the packing slip. If a packing slip
When the tape measure is not avail-
is not available, check the equipment
able, use the chart to determine
against the table of components (para 5) or
each antenna wire length. Pace off
basic issue items list (appx II).
(one stride is approximately 3feet)
the indicated antenna length; make
10. Siting
final adjustment by lengthening or
shortening the antenna assembly
a. In areas, such as jungles, where
for the best transmitter loading.
vegetation is very dense, vertical antennas
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