4096-226
REVISION M
June 1, 2016
Assembly Manual
3.4M & 3.7M
Polar Truss Mount
General Dynamics SATCOM Technologies
1700 Cable Drive NE
Conover NC 28613 USA
Phone 770-689-2040
www.gdsatcom.com
3.4M & 3.7M
Polar Truss Mount
M
Add Conover Address
6/1/16
RAH
L
Revise Name
4/15/09
RAH
K
Revise Hardware Part numbers Pg 16,17
11/12/03
RAH
J
Revised Address
1/10/02
RAH
-
ORIGINAL RELEASE
11/03/93
R FRYE
DATE
APPROVED
REV.
DESCRIPTION
4096-226
3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
ASSEMBLY MANUAL
Table Of Contents
Section
Title
1.0
1.1
1.2
1.3
1.4
General Information
Unpacking & Inspection
Mechanical Installation Tools
Site Selection
Foundation Requirements
2.0
2.1
2.2
2.3
2.4
2.5
Reflector and Support Structure Assembly
Reflector and Support Structure Part List
Reflector Pre- Assembly
Reflector Assembly
Brace Mount Brackets
Support Structure Assembly
3.0
3.1
3.2
3.3
3.4
3.5
Polar Mount Assembly and Reflector Installation
Canister and Polar Axis Part List
Canister / Polar Axis Assembly
Gimbal and Actuator Arm Part List
Gimbal and Actuator Arm Installation
Reflector Positioning / Mount
4.0
4.1
4.2
4.3
4.4
4.5
Feed Installation
Feed Horn Assembly
Feed System Part List
Feed Support Assembly
Feed Installation
Feed Cover Installation
5.0
5.1
5.2
5.3
5.4
Antenna Alignment and Tuning
Declination and Elevation Adjustment
Azimuth Adjustment
Fine Tuning
Reflector Fine Adjustment
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
SECTION 1
1.1
GENERAL INFORMATION
UNPACKING AND INSPECTION
1.
UNPACKING & INSPECTION - The antenna containers should be
unpacked and inspected at the earliest date to ensure that all material has
been received and is in good condition. A complete packing list for each
major component is supplied.
2.
FREIGHT DAMAGE - Any damage to materials while in transit should be
immediately directed to the freight carrier. He will instruct you on the
matters regarding any freight damage claims.
3.
MATERIAL - MISSING OR DAMAGED - Any questions regarding missing
or damaged materials that is not due to freight carrier should be directed
to General Dynamics's Customer Service Department at:
General Dynamics SATCOM Technologies
1700 Cable Drive NE
Conover NC 28613 USA
Phone 770-689-2040
www.gdsatcom.com
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General Dynamics SATCOM Technologies
1.2
MECHANICAL INSTALLATION TOOLS
HARDWARE SIZE
SAE WRENCH
SIZE
METRIC WRENCH
SIZE
MAXIMUM REC.
TORQUE
# 6 SCREW
5/16”
8 mm
8 in-lbs
1 / 4”
7 / 16”
11 mm
49 in-lbs
3 / 8”
9 / 16”
14 mm
15 ft-lbs
1 / 2”
3 / 4”
20 mm
35 ft-lbs
5 / 8”
15 / 16”
24 mm
70 ft-lbs
1”
1- 1 /2”
38 mm
220 ft-lbs
Also recommended for installation:
Adjustable Wrench 10”
Ratchet ( 3 / 8” & 1 / 2 “ drive)
Inclinometer
Compass
8’ ft Ladder
Gloves
1.3
SITE SELECTION
In order to achieve maximum performance of your antenna system, it is important
to select the correct location for the antenna. The following guidelines should be
observed when selecting a site for the installation.
1.
2.
3.
4.
The line of site to the satellite should be clear of any obstructions, such as
trees or buildings.
The site should be relatively flat and level for ease of installation and
access to the antenna.
The site should be checked for underground obstruction, such as buried
cables or pipes.
All local building codes should be adhered to (i.e. grounding, foundation
requirements, zoning rules, setbacks, etc.).
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1.4
FOUNDATION REQUIREMENTS
General Dynamics's recommended foundation for the antenna system is shown
in figure 1. however, each installation must be tailored to the specific
requirements of the site. It may be necessary to contact a local engineer or
building department for foundation design or approval at any particular site.
6 “ SCH 80 PIPE
6.625” OD
A
B
2-5
TYP 2
SECTION A-A
C
3.4M
3.7M
A
24.0
24.0
B
54.0
60.0
C
66.0
72.0
A
A
2 x 2 x 1 / 4 HRS ANGLE
12 INCHES LONG
TYP 2 PL
FIGURE 1.
NOTES:
1.
2.
3.
4.
5.
6.
7.
2 x 2 x 1/4 HRS Angle and schedule 40 pipe should conform with ASTM A36 and ASTM A53 Type E and
S Grade B.
All concrete should conform to building code standards and have a
minimum compressive strength of 3000 PSI at 28 days. (Per ACI-318-77)
Soil bearing capacity should be no less than 2000 PSF.
Concrete should be poured against undisturbed soil.
Allow concrete 24 hours set time before installation of antenna.
The antenna should be properly grounded to meet applicable local codes.
Minimum depth as shown or extend to local frost line.
GENERAL DYNAMICS DOES NOT REPRESENT OR WARRANT THAT ANY PARTICULAR DESIGN
OR SIZE OF FOUNDATION IS APPROPRIATE FOR ANY LOCALITY OR EARTH STATION INSTALLATION
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General Dynamics SATCOM Technologies
SECTION 2
REFLECTOR AND SUPPORT STRUCTURE ASSEMBLY
REFLECTOR AND SUPPORT STRUCTURE PARTS LIST TABLE 2.1
ITEM
PART NO.
1
0179-142
0179-261
REFLECTOR PETAL - W / HOLE
REFLECTOR PETAL - W / HOLE
4
0179-141
0179-260
REFLECTOR PETAL - W/O HOLE
REFLECTOR PETAL - W/O HOLE
4
0217-072
0217-073
FEED SUPPORT CLEVIS
FEED SUPPORT CLEVIS
4
4
0490-297
CENTER HUB
1
1
5
0156-808
CENTER PLATE
1
1
6
0211-404
0211-481
REFLECTOR SUPPORT BRKT.
REFLECTOR SUPPORT BRKT.
8
7
0225-405
SUPPORT BRACE - LONG
8
8
8
0225-406
SUPPORT BRACE - SHORT
8
8
9
8104-007
1 / 2” HEX NUT
8
8
10
8201-043
1 / 2” FLATWASHER
8
8
2
3
DESCRIPTION
7
QTY
3.4M
QTY
3.7M
4
4
4
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
PARTS LIST - CONTINUED
ITEM
PART NO.
11
8202-043
12
QTY
3.4M
QTY
3.7M
1 / 2” LOCKWASHER
4
4
8030-010
1 / 4” - 20 x 1.25 BOLT
6
6
13
8201-040
1 / 4” FLATWASHER
6
6
14
8202-040
1 / 4” LOCKWASHER
6
6
15
8202-010
3 /8” -16 x 1.25 BOLT
72
96
16
8201-042
3 / 8” FLATWASHER
144
192
17
8202-042
3 / 8” LOCKWASHER
72
96
8102-007
3 / 8” HEX NUT
72
96
18
DESCRIPTION
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General Dynamics SATCOM Technologies
NOTE: Assembly of the reflector should be on as level a surface as possible
to prevent warping or misalignment of the reflectors parabolic shape during
assembly. Any loss of contour may affect the antennas signal quality. If a
level surface is not available, refer to section 5.4 for tips on how to check the
reflector shape and correct it if necessary.
2.2
REFLECTOR PRE-ASSEMBLY
The reflector consists of eight interchangeable petals of compression molded
glass-fiber reinforced material. This material is very strong, yet lightweight and
easy to handle. The reflector will possess a very accurate parabolic shape when
properly assembled and will retain its shape for years under harsh environmental
conditions. The microwave reflective surface is provided by a fine mesh screen
that lies just beneath the molded surface of the petals.
[ 10,11,9 ]
[ 9,10 ]
A) Identify the reflector petals and parts of
the reflector support structure according
to the parts list. We recommend that you
hi-lite the column for your specific antenna.
[3]
B) Note that four of the petals (item 1) have
a 1 / 2” hole thru the center. These holes
are for the feed clevises. Pre assemble
these four petals as follows.
1.5
[1]
3.4M
[ 9,10 ]
[ 10,11,9 ]
C) Run the 1 / 2” nut (item 9) up the threads
of the clevis (item 3), and place a 1 / 2”
flatwasher (item 10) against the nut. Adjust
the nut until the distance from the far side
of the washer and the center of the clevis
hole is 2” for the 3.7M and 1.5” for the 3.4M
[3]
D) From the face of the petal, insert the clevis
assembly thru the hole in the center of the
petal. Secure with 1 / 2” hardware.
Tighten these nuts hand tight at this time.
2.0
[1]
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
2.3
REFLECTOR ASSEMBLY
3.7M
STEP 1:
[1]
When assembling the reflector petals
(items 1,2), note the orientation of
the petals. Every other petal contains
a feed clevis.
[2]
STEP 2:
[1]
Place two petals rim down on a level
surface with their flanges next to each
other. A wooden support (23.25” long
for the 3.4M and 24” for the 3.7M), such
as a 4x4, will help support the narrow
ends of the petals.
[2]
Wood
Support
STEP 3:
H
G
F
E
D
C
B
A
A) Begin the assembly at the flange
with 3 / 8” hardware (items 15,
16, 17, 18), in holes A, B, C, etc.
Note that this illustration shows
a 3.7M petal which has eight
holes. The 3.4M petal only has
five holes.
B) Do not fully tighten bolts until
instructed. You may notice that
the hardware fits snugly in the
holes. This is to assure the
accurate alignment of the petals.
If necessary, gently tap or thread
the bolts into the holes.
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
STEP 4
[ 16, 17, 18 ]
Alignment tabs
( 3.4M only)
[ 16 ]
[ 15 ]
See Detail
A) Continue assembling additional petals
as above. The wooden support should
be moved as necessary to support the
weight of the petals being assembled.
Before installing the last petal, place
the center plate (item 5) on top of the
wooden support - underneath the
center of the reflector - and attach the
center hub (item 4) on top with 1 / 4”
hardware (items 12, 13, 14). Leave
hardware loose enough to rotate hub.
B) Place the last petal in position, insuring
that the lip on its inner edge is located
between the center hub and plate.
Attach this petal to the adjacent petal
at holes A and B. At this time, the
reflector is strong enough to sustain
the weight of the installer to place the
bolts in holes C, D, E etc. Be sure to
step only on the ribs, not on the surface
in between.
[4]
[12, 13, 14]
C) Now tighten all reflector bolts. Before
tightening, check to be sure that all the
petals are aligned properly. It may be
necessary to adjust one petal in or out
(radially) until the rim is flush. Also
check up and down alignment. It is
possible to lift the reflector slightly to
feel the front surface, making sure that
it is flush. Tighten all A bolts first. Next
tighten all B bolts, then C, then D etc.
Note: Before tightening the last set of
reflector bolts, the ones closest to the
hub, check to make sure that the lip on
the inner edges of all petals are located
between the center plate and the
center hub plate.
Petal
[5]
Wood Support
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
2.4
BRACE MOUNT BRACKETS FOR 3.4M, AND 3.7M
3.7M
[6]
Existing 3 / 8”
Hardware
C
D
12
Attach the reflector support brackets
(item 6) to the reflector at locations C
and D at the left side of all eight petal
seams. Be sure that the shorter, more
pointed leg of each bracket is toward
the reflector center. Use the existing
3 / 8” hardware. Do not tighten this
hardware until instructed.
4096-226
3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
3.4M
Attach the reflector support brackets
(item 6) to the reflector at locations B
and C at the left side of all eight petal
seams. Be sure that the shorter, more
pointed leg of each bracket is toward
the reflector center. Use the existing
3 / 8” hardware. Do not tighten this
hardware until instructed.
[6]
Existing 3 / 8”
Hardware
2.5
C
B
SUPPORT STRUCTURE ASSEMBLY
STEP 1:
Rotate the Center Hub until the
elevation tab is centered over a
petal without a feed clevis.
Center Hub
Elevation Tab
Edge Flanges
[1]
Center Flange
[2]
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
[ 15, 16 ]
STEP 2:
Attach the chamfered end of the
long support brace (item 7) to the
underside of the upper ring with
3 / 8” hardware (items 15, 16, 17, 18).
Do not tighten.
Upper Ring
Center Hub
[7]
STEP 3:
[ 16, 17, 18 ]
[7]
A) Position the remaining end of the long
support brace (item 7) to the right of
the support bracket .
[ 15, 16 ]
B) Attach brace with 3 / 8” hardware
(items 15, 16, 17, 18). Do not tighten
until instructed.
Support
Brackets
C) Attach the remaining long support braces
from each of the support brackets to the
center hub in the same manner.
[ 16, 17, 18 ]
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General Dynamics SATCOM Technologies
Center Hub
STEP 4:
[ 15 ]
Attach one end of the short support brace
(item 8) to the lower ring on the center
hub with 3 / 8” hardware (items 15, 16, 17,
18). Do not tighten until instructed.
[ 16 ]
[8]
[ 16,17,18 ]
Lower Ring
STEP 5:
A) Attach the other end of the short support
brace (item 8) to the left side of the long brace
(item 7) with 3 / 8” hardware (items 15, 16,17,
18). When all braces are attached, begin
tightening as follows:
[7]
[ 15, 16 ]
[8]
[ 16, 17, 18 ]
B) Be sure the reflector is laying flat, as after
tightening the reflector structure, its shape will
be fixed.
C) Center in the center hub by tightening the
1 / 4” bolts to the center plate. Next, tighten
all the hardware that attaches the support
brackets to the reflector. Tighten the
outermost bolts securing the long braces to
the support brackets all around. Now tighten
the bolts connecting the long braces to the
center hub all the way around. Next tighten
the hardware connecting the short brace to
the long brace all around. Finally tighten the
hardware securing the short braces to the
center hub. The assembly of the reflector
and the support structure is now complete.
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
SECTION 3
REFLECTOR INSTALLATION
REFLECTOR MOUNT PARTS LIST TABLE 3.1
ITEM
PART NO.
DESCRIPTION
1
0490-151
CANISTER
1
2
0181-236
POLAR AXIS ASSEMBLY
1
3
0490-157
ELEVATION ADJUSTMENT ROD
1
4
0490-158
DECLINATION ADJUSTMENT ROD
1
5
0168-095
ADJUSTMENT BLOCK
2
6
8317-106
5/8-11 x 1.50 SQ. HD BOLT
6
7
8036-048
1-8 x 6.00 BOLT
8
0220-039
1-8 x 7.50 STUD
1
1
9
8201-046
1” FLATWASHER (NG)
8
10
8202-046
1” LOCKWASHER
16
QTY
2
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
PARTS LIST - CONTINUED
ITEM
PART NO.
DESCRIPTION
11
8107-003
1-8 HEX NUT
7
12
8051-008
5/8-11 x 1.00 BOLT
4
13
8034-016
5/8 –11 x 2.00 BOLT
2
14
8202-044
5/8 LOCKWASHER
6
15
8105-007
5/8 - 11 HEX NUT
2
17
QTY
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
NOTE: At least three persons are required for the installation of the antenna on the
mast. After the reflector is positioned on the canister, two can steady the reflector while
the other secures it to the canister.
3.2
CANISTER & ELEVATION ASSEMBLY
STEP 1:
Canister
Insert 5/8” square head bolt assembly
(item 6) into the canister, only
a few turns, so that the bolts do not
extend into the canister. Position the
canister on the mast and insure that it
is seated all the way down on the mast
pipe and that it can rotate freely.
[6]
6 PL
Mast
STEP 2:
Canister
Lift the Polar Axis assembly (item 2)
into place between the ears of the
canister and secure with 1” hardware
(items 8, 9, 10, 11) .
[2]
[8]
[ 9, 10, 11 ]
[ 9, 10, 11 ]
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General Dynamics SATCOM Technologies
STEP 3:
For both the elevation rod (item 3) and
the declination rod (item 4), Thread a
1” hex nut (item 11) well up onto the
rod followed by a flatwasher (item 9),
elevation block (item 5), another flatwasher and nut.
[ 11 ]
[5]
[9]
[ 3 or 4 ]
[ 9, 11 ]
STEP 4:
A) Attach the tabbed end of the elevation
Rod to the tab on the polar axis assembly
With 5/8” hardware (items 13, 14, 15 ).
[ 14, 15 ]
B) Place the adjustment block between the
two tabs on the canister and secure with
two of (items 12, 14). Adjust the elevation
until the polar axis assembly is roughly in
a vertical position.
Tab
[ 12, 14]
[ 13 ]
Elevation Rod
[ 12, 14 ]
Adjustment Block
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
STEP 5:
[ 12, 14 ]
Attach the assembled declination rod
to the polar axis assembly by placing
the adjustment block in between the
tabs on the axis assembly and secure
with 5/8” hardware (items 12, 14).
Adjustment
Block
Declination Rod
Polar Axis Assembly
[ 12, 14 ]
3.3
GIMBAL AND ACTUATOR ARM PART LIST
GIMBAL & ACTUATOR ARM PART LIST TABLE 3.3
ITEM
PART NO.
DESCRIPTION
1
0181-342
GIMBAL ASSEMBLY
1
2
8032-016
3/8 –16 x 2.00 BOLT
2
3
8232-042
3 / 8 LOCKWASHER
2
4
8102-007
3 / 8 –16 HEX NUT
2
5
8033-008
1 / 2 –13 x 1.00 BOLT
4
20
QTY
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
PARTS LIST - CONTINUED
ITEM
PART NO.
DESCRIPTION
QTY
6
8202-043
1 / 2 LOCKWASHER
5
7
8033-021
1 / 2 – 13 x 1.50 BOLT
1
8
8201-043
1 / 2 FLATWASHER
2
9
8104-007
10
0162-183
1
1 / 2- 13 NUT
ACTUATOR SPACER
21
2
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
3.4
GIMBAL AND ACTUATOR ARM INSTALLATION
Gimbal
STEP 1:
Locate the factory pre-assembled
actuator arm (item 1) and loosely install
the 3/8 hardware ( items 2, 3, 4) in the
gimbal sleeve.
[ 3, 4 ]
[2]
Polar Axis
Assembly
B
C
D
A
STEP 2:
Depending on your location, the gimbal arm can be
installed in one of four possible positions on the polar axis
assembly for optimum tracking of the satellite arc.
Position A = Locations east of 88 degrees west longitude.
Position B = Locations between 88 and 104 degrees.
Position C = Locations west of 104 up to 120 degrees.
Position D = Locations west of 120 degrees.
(Note: that for positions A and C, you must rotate the arm)
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General Dynamics SATCOM Technologies
[ 5, 6 ]
STEP 3:
Attach the gimbal arm to the polar
axis assembly in the correct position
with 1/2 hardware (items 5, 6 ).
Tighten securely.
Polar Axis Asm
[ 5, 6 ]
Gimbal Arm
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General Dynamics SATCOM Technologies
3.5
REFLECTOR POSITIONING AND MOUNT
STEP 1:
Bring the completed reflector assembly
to the pedestal and locate it about 1-1/2
to 2 feet away from the mast. Be sure to
orient the reflector so that the actuator
bracket on the center hub is located on the
same side as the gimbal arm on the polar
axis assembly. Use the reflector carton (or
similar object) as a rest for under the edge
of the reflector.
Polar Axis
Center Hub
Mast
Carton
Reflector Assembly
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
[ 9, 10, 11]
STEP 2:
Swing the reflector up until the ears on
the end of the center hub slip around
the polar axis assembly tube. Line up
holes and insert 1” bolt and flatwasher.
Note: For east coast installations (east
of 104 deg. west longitude): insert the
bolt from the right. For west coast
installations ( west of 104 deg.) insert
the bolt from the left. Secure with
flatwasher, lockwasher and nut.
[7]
[9]
Center Hub
STEP 3:
Raise or lower the reflectors edge until
you can place the end of the declination
rod between the mounting tabs on the
center hub. Secure with 5/8 hardware
( items 13, 14, 15).
Declination
Rod
[ 14, 15 ]
Mounting Tabs
Center Hub
[ 13 ]
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General Dynamics SATCOM Technologies
STEP 4:
Motor
A) The recommended actuator should
be a 24” stroke ball screw type with
a 2” diameter barrel. Dynamic thrust
1500 lbs. Static load : 3000 lbs.
Actuator
B) Install the actuator by removing the
motor and placing the barrel through
the gimbal swivel collar and attaching
the end to the hubs actuator bracket
with the 1/2” hardware and spacers
from part list table 3.3.
Gimbal Swivel
C) Re-attach the motor securely, rotate
the barrel until the motor is in a vertical
position with the arrow pointing up and
tighten the gimbal collar about the
barrel with the 3/8 “ hardware in the
collar. The reflector installation is now
complete.
1/2” Hardware
Actuator Bracket
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
SECTION 4
4.1
FEED INSTALLATION
FEED HORN ASSEMBLY
Ku-BAND FEED
SINGLE POL - Coat the o-ring (item #2) with the silicone grease from the capsule
provided and place it in the feed horn o-ring groove. Place the square adapter (item #3)
on the feed horn flange and line up the four hole pattern in the adapter with four of the
eight holes in the feed horn flange. (Note that the adapter will only line up one way.)
Place the LNB (customer provided) on the adapter so that the holes in the LNB line up
with the feed/adapter holes and secure with four screws (item #4). See figure 1. Tighten
securely.
Ku-BAND - SINGLE POL - PARTS LIST
ITEM #
PART #
DESCRIPTION
1
0183-277
FEED HORN ASSEMBLY
1
2
0198-120
O-RING
1
3
0202-067
TRANSITION ADAPTER
1
4
8300-017
#6-32 x 7/8" SS STD
6
5
8200-010
#6 LOCKWASHER
6
27
QUANTITY
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
[2]
CUSTOMER PROVIDED LNB
[3]
[1]
[5]
[4]
FIGURE 1.
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3.4M & 3.7M POLAR TRUSS MOUNT
General Dynamics SATCOM Technologies
Ku-BAND FEED
DUAL POL - Coat the o-ring (item #6) with the silicone grease from the capsule
provided and place it in the feed horn o-ring groove. Attach the OMT (item #1) to the
feed horn (item #2) with the #6 hardware (item #'s 3,4,& 5). Attach two LNB's (customer
provided) to the OMT with the o-rings and hardware provided with the LNB's. See figure
2. Tighten securely.
Ku-BAND - DUAL POL - PARTS LIST
ITEM #
PART #
DESCRIPTION
1
0183-272
OMT, Ku-BAND - DUAL - RECEIVE
1
2
0183-276
FEED HORN ASSEMBLY
1
3
8300-012
#6-32 x .75 S.S. STD. SCREW
6
4
8200-010
#6 LOCKWASHER
6
5
8112-001
#6-32 S.S. STD. HEX NUT
6
6
0198-120
O-RING
1
[5]
[3]
[4]
[2]
QUANTITY
[6]
[1]
CUSTOMER PROVIDED LNB
FIGURE 2.
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General Dynamics SATCOM Technologies
C-BAND FEED
Attach the LNB's (customer supplied) to the feed horn flange with the 1/4" hardware and
gaskets (item #'s 2 ,3,4,5,& 6) provided. See figure 3. (SINGLE POL ONLY - Attach the
cover plate (item #7) and gasket (item #2) to the bottom of the feed horn as shown.)
Tighten securely.
BAND - PARTS LIST
ITEM #
PART #
DESCRIPTION
QUANTITY
1
0183-294
FEED HORN ASSEMBLY
1
2
0170-074
GASKET
2
3
8030-010
1/4-20 x 1.25 BOLT
20
4
8201-040
1/4" FLATWASHER
20
5
8202-040
1/4" LOCKWASHER
20
6
8100-007
1/4-20 HEX NUT
20
7
0156-576
COVER PLATE (SINGLE POL ONLY)
1
[3]
[4]
[ 5, 6 ]
[ 4, 5, 6
[2]
[7]
[4]
[1]
[3]
FIGURE 3.
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General Dynamics SATCOM Technologies
C/Ku-BAND FEED
Attach the four feed mounting brackets to the scaler of the c/ku band feed (customer
supplied) with the hardware provided. (Figure 4). Tighten securely.
C/Ku-BAND FEED PARTS LIST
ITEM #
PART #
DESCRIPTION
QUANTITY
1
0211-405
BRACKET, FEED SUPPORT
4
2
8030-006
1/4-20 x .75 BOLT
4
3
8202-040
1/4" LOCKWASHER
4
4
8100-007
1/4-20 HEX NUT
4
CUSTOMER PROVIDED
C / Ku - BAND
[4]
[1]
[3]
[2]
FIGURE 4.
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General Dynamics SATCOM Technologies
FEED SYSTEM PARTS LIST TABLE 4.2
ITEM NO.
PART NO.
DESCRIPTION
QUANTITY
1
VARIES
FEED HORN ASSEMBLY
1
2
VARIES
FEED SUPPORT ROD
4
3
8031-008
3/8-16 x 1.00 BOLT
8
4
8201-042
3/8" FLATWASHER
16
5
8202-042
3/8" LOCKWASHER
8
6
8102-007
3/8" HEX NUT
8
Ku-BAND SINGLE POL ONLY
4.3
7
0156-819
FEED COVER TAB
4
8
0250-276
FEED COVER
1
9
8320-001
#8 x 1/2" TAPPING SCREW
4
10
4075-003
FEED COVER CAP
1
FEED SUPPORT ASSEMBLY
STEP 1:
Reflector
Attach each of the feed support rods
(item 2) to the feed support clevis with
3/8” hardware (items 3, 4, 5, 6 ).
Note that each rod should be attached
to the same side of the clevis - (inside
or outside).
[3]
[4]
[2]
[4]
Feed Support Clevis
[5]
[6]
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General Dynamics SATCOM Technologies
4.4
FEED INSTALLATION
1.
FOCAL LENGTH - As shown in figures 5 thru 7, attach the feed horn assembly
to the four feed rods with the same 3/8" hardware as above. (For ku-band single
pol only, insert the feed cover tab (item #7) between the feed horn and the 3/8"
nut). Tighten the four bolts securely at this time. Check the focal length by
measuring from the face of the feed horn to the reflector cover plate as shown in
figure 8. If the focal length is incorrect, adjust the feed clevises in or out at the
reflector surface as needed. Be sure that the clevises are adjusted equally. When
the focal length is correct, tighten all feed support and clevis hardware securely.
The focal lengths are: 46-7/8" for the 3.4M and 54" for the 3.7M. The F/D ratios
are: .35 for the 3.4M, and .37 for the 3.7M.
Face of
Feed Horn
[1]
[1]
Face of
Feed Horn
[ 4, 5, 6 ]
[ 4, 5, 6 ]
[7]
[4]
[4]
[3]
[2]
[2]
[3]
FIGURE 6.
FIGURE 5.
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General Dynamics SATCOM Technologies
C / Ku-BAND
Face of
Feed Horn
[1]
[ 4, 5, 6 ]
[4]
[3]
[2]
FIGURE 7.
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General Dynamics SATCOM Technologies
FOCAL
LENGTH
FIGURE 8.
2.
POLARITY ADJUSTMENT - On C-band and Ku-band feed systems, polarity is
adjusted by loosening the feed horn bolts (see figures 9 and 10) and rotating the
OMT or feed horn 90 degrees, then retighten the bolts.
FEED HORN BOLTS
C - BAND
FIGURE 9.
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General Dynamics SATCOM Technologies
Ku-BAND SINGLE POL
A
A
B
FEED HORN BOLTS
VIEW “A” - “A”
Ku-BAND DUAL POL
B
FEED HORN BOLTS
VIEW “B” - “B”
FIGURE 10.
4.5
FEED COVER INSTALLATION
1.
FOR SINGLE POL Ku-BAND FEED ONLY - After completion of the feed
installation, connection of the cable and polarity adjustment, bend the feed cover
tabs (item #7) in and then slide the feed cover (item #8) over the tabs. Attach the
cover to the tabs with the tapping screws (item # 9) and slide the cap (item #10)
over the cover as shown in figure 11.
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General Dynamics SATCOM Technologies
[ 10 ]
[7]
[8]
[9]
SINGLE POL Ku-BAND FEED
FIGURE 11
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General Dynamics SATCOM Technologies
SECTION 5
ANTENNA ALIGNMENT AND TUNING
5.1
ELEVATION ADJUSTMENT
1.
Set the polar axis angle to zero (due south) by sliding the actuator in the clamp.
Place an inclinometer on the hub as shown in figure 12, then on the polar axis as
shown. The difference between these two readings should be 90 degrees plus
the declination angle. Table 5.1-1 gives the recommended declination angles as
a function of site latitude. Adjust the declination rod until the correct setting is
achieved, then tighten all declination hardware.
2.
Set the elevation (latitude) angle by placing the inclinometer on the polar axis
assembly as shown. Adjust the elevation rod until the correct elevation angle is
read., as shown in figure 13. Snug the elevation axis bolt and adjustment
hardware.
5.2
AZIMUTH ADJUSTMENT
1.
Loosen the actuator clamp and slide the actuator into the clamp as far as
possible (rotating the antenna about the polar axis). Rotate the barrel until motor
is in a vertical position WITH THE ARROW POINTED UP. Tighten the actuator
clamp about the barrel with the 3/8" hardware in the collar.
2.
Operate the actuator until the antenna is in the correct elevation angle for a
selected satellite (measured off the hub as in figure 13). Sweep the antenna in
azimuth until a signal is found. Rotate the antenna in azimuth until loss of signal
is observed. Rotate the antenna in the opposite direction until the signal
strengthens, then weakens again. Set the azimuth midway between these two
points and snug canister bolts.
5.3
FINE TUNING
1.
After setting the azimuth, operate the actuator until another satellite is found. It is
best to use two satellites at opposite ends of the arc for these adjustments.
Return to the elevation adjustment and fine tune in the same way, splitting the
difference between the two points where loss of signal is first observed. Operate
the actuator to check reception of all satellites in the arc. It is best to adjust
elevation when high in the arc (antenna east to west). Continue fine tuning
elevation and azimuth until the entire arc can be tracked.
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General Dynamics SATCOM Technologies
5.4
REFLECTOR FINE ADJUSTMENT
1.
As discussed in section 2, a level surface is necessary for assembly of the reflector. If a level surface is not available, the reflector may be checked for accuracy
by use of strings across the aperture.
2.
Use thin cord across the reflector diameter from rim to rim, at four places. One
end of each string should be taped to the rim just to one side of the seam
between two petals. The other end should be fastened 180 degrees opposite. All
four strings should lightly touch where they cross at the center. The distance from
center of the reflector (hub to plate) to the strings should be 23.22" for the 3.4M
and 24" for the 3.7M.
3.
If the reflector does not check out as described above within approximately a
1/4", reflector adjustment may be done. Identify the point on the rim that is either
high or low. Loosen the four bolts on the long and short angle brace behind the
radial line of the reflector. Gently push or pull on the reflector rim until it is
brought into position. While one installer holds the rim, the other should tighten
all the brace bolts fully. Repeat this process as required, loosening and tightening
only one set of braces at a time.
DECLINATION ANGLE TABLE 5.1-1
SITE LATITUDE
DECLINATION O
SITE LATITUDE
DECLINATION O
0
0.0
47.5
6.4
10
1.5
50
6.6
20
3.0
52.5
6.9
22.5
3.3
55
7.1
25
3.7
57.5
7.3
27.5
4.0
60
7.5
30
4.4
62.5
7.6
32.5
4.7
65
7.8
35
5.0
67.5
8.0
37.5
5.3
70
8.1
40
5.6
80
8.4
42.5
5.9
90
8.6
45
6.1
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General Dynamics SATCOM Technologies
DECLINATION ADJUSTMENT
INCLINOMETER
90 + DECLINATION
FIGURE 12
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General Dynamics SATCOM Technologies
ELEVATION
INCLINOMETER
HORIZONTAL
LATITUDE
ELEVATION
ADJUSTMENT
FIGURE 13
41
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