TM 11-5985-391-12
TECHNICAL MANUAL
OPERATOR’S AND UNIT MAINTENANCE MANUAL
EQUIPMENT
DATA
SETUP
PMCS
-
STORAGE AND
SHIPMENT
MAC
SETUP REFERENCE CARDS
PAGE
1-6
PAGE
2-3
PAGE
4-13
PAGE
4-43
APP
B
APP
F
SPECIAL OPERATIONS RADIO ANTENNA KIT (SORAK)
ANTENNA GROUP OE-452/PRC
(NSN 5985-01-279-7942)
Distribution authorized to the Department of Defense and DOD contractors only for official use or for administrative or operational purposes. This determination was made on 15 April 1990. Other requests for
this document will be referred to Commander, US Army Communications-Electronics Command and Fort
Monmouth, ATTN: AMSEL-LC-LM-LT, Fort Monmouth, NJ 07703-5000.
DESTRUCTION NOTICE - Destroy by any method that will prevent disclosure of contents or reconstruction
of the document.
HEADQUARTERS, DEPARTMENT OF THE ARMY
JANUARY 1991
1
TM 11-5985-391-12
GUIDELINES FOR SORAK OPERATIONS
Never erect the antenna directly under power lines.
If you must erect an antenna below a power line, power line pole, tower, or building with
overhead power line connections, never put the antenna closer than two times the antenna height from the base of the power line, pole, tower, or building.
Ž Before erecting any SORAK antenna, inspect all the parts making up the antenna
kit. Do not deploy antenna if components are missing or damaged.
Ž When erecting the antenna, allow only team personnel in the erection area.
Ž Make sure the areas for antenna anchor and guy rope stakes are firm. If the
ground is marshy or sandy, use rocks, trees, or bushes to help secure the antenna.
Ž When selecting locations for antenna anchor and guy rope stakes, avoid traveled
areas and roads. If you cannot avoid these areas, clearly mark guy ropes and antenna
wires with the warning flags or signs supplied by your unit. In an emergency, use strips of
white cloth as warning streamers.
Ž If you suspect that power lines nave made accidental contact with your antenna,
stop operating, rope off the antenna area, and notify your superiors.
Ž Keep a sharp eye on your mast guy ropes and stakes, and antenna anchor stakes.
Check them daily and immediately before and after bad weather.
DO NOT ERECT ANY ANTENNA DURING AN ELECTRICAL STORM.
B
TM 11-5985-391-12
SAFETY STEPS TO FOLLOW IF SOMEONE IS
THE VICTIM OF ELECTRICAL SHOCK
DO NOT TRY TO PULL OR GRAB THE INDIVIDUAL
IF POSSIBLE, TURN OFF THE ELECTRICAL
POWER
IF YOU CANNOT TURN OFF THE ELECTRICAL
POWER, PULL, PUSH, OR LIFT THE PERSON TO
SAFETY USING A DRY WOODEN POLE OR A DRY
ROPE OR SOME OTHER INSULATING MATERIAL
SEND FOR HELP AS SOON AS POSSIBLE
AFTER THE INJURED PERSON IS FREE OF
CONTACT WITH THE SOURCE OF ELECTRICAL
SHOCK, MOVE THE PERSON A SHORT DISTANCE AWAY AND IMMEDIATELY START
ARTIFICIAL RESUSCITATION
C/(D blank)
TM 11-5985-391-12
Technical Manual
DEPARTMENT OF THE ARMY
No. 11–5985-391-12
Operator’s and Unit Maintenance Manual
Special Operations Radio Antenna Kit (SORAK)
Antenna Group OE-452/PRC
(NSN 5985-01-279-7942)
REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS
You can help improve this manual. If you find any mistakes, or if you know of a
way to improve the procedures, please let us know. Mail your letter, DA Form
2028 (Recommended Changes to Publications and Blank Forms), or DA Form
2028-2 located in the back of this manual direct to: Commander, US Army
Communications-Electronics Command and Fort Monmouth, ATTN:
AMSEL-LC-LM-LT, Fort Monmouth, New Jersey 07703-5000.
HOW TO USE THIS MANUAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHAPTER 1
Section I
Section II
Section III
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment Description . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Principles of Operation . . . . . . . . . . . . . . . . . .
Washington, DC, 1 January 1991
HEADQUARTERS
Page
ii
1-1
1-1
1-5
1-7
CHAPTER 2
Section I
Section II
Section III
Section IV
Section V
CHAPTER 3
CHAPTER 4
Section I
Section II
Section III
Section IV
Section V
Section VI
OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . . . .
Description and Use of Operator’s Controls. . . . . . . . .
and Indicators
Preventive Maintenance Checks. . . . . . . . . . . . . . . . . . . .
and Services (PMCS)
Operation Under Usual Conditions
Operation Under Unusual Conditions. . . . . . . . . . . . . .
Equipment Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OPERATOR MAINTENANCE INSTRUCTIONS. .
ORGANIZATIONAL MAINTENANCE . . . . . . . . .
Repair Parts, Special Tools, TMDE, . . . . . . . . . . . . . . . .
and Support Equipment
Service Upon Receipt . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preventive Maintenance Checks.
and Services (PMCS)
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance Procedures
Preparation for Storage or Shipment
. . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . .
2-1
2-1
2-1
2-3
2-33
2-37
3-1
4-1
4-1
4-3
4-13
4-19
4-25
4-43
i
TM 11-5985-391-12
APPENDIX A
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page
A-1
APPENDIX B
APPENDIX C
APPENDIX D
APPENDIX E
APPENDIX F
GLOSSARY
INDEX
This manual tells you how to set up and use the Antenna Group OE-452/PRC Special
Operations Radio Antenna Kit (SORAK). It also includes organizational level maintenance instructions and data.
Maintenance Allocation Chart.
Components of End Item . . . . . . . . . . . . . . . . . . . . . . .
and Basic Issue Items Lists
Additional Authorization List . . . . . . . . . . . . . . . . . . .
Expendable and Durable Items List . . . . . . . . . . . . . .
Antenna Deployment Reference Cards
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HOW TO USE THIS MANUAL
. . . . . . . . . . . . . . . . . .
. . . . . . . . . . .
B-1
C-1
D-1
E-1
F-1
Glossary -1
Index -1
The front cover index gives you a quick reference to important information that you will
use most often.
Warning pages are at the beginning of this manual. Study the warnings and always follow
safety procedures when installing, using, or maintaining the equipment.
Units of measurement used in this manual are U.S. standard with metrics units in parentheses.
Read all information found at the start of each procedure. It includes important statements about the equipment and your safety.
Paragraphs in this manual are numbered by chapter and order of appearance within a
chapter. Indexes at the start of each chapter will help you find information quickly.
ii
CHAPTER 1
INTRODUCTION
TM 11-5985-391-12
Subject
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I
Equipment Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II
Technical Principles of Operation . . . . . . . . . . . . . . . . . . . . . . .
Section I. GENERAL INFORMATION
Subject
Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance Forms, Records, and Reports . . . . . . . . . . . . . .
Destruction of Army Materiel to Prevent . . . . . . . . . . . . . . . .
Enemy Use
Preparation for Storage or Shipment . . . . . . . . . . . . . . . . . . . .
Reporting Equipment Improvement . . . . . . . . . . . . . . . . . . . .
Recommendations (EIR)
Nomenclature Cross Reference List.. . . . . . . . . . . . . . . . . . . .
1-1. SCOPE.
TYPE OF MANUAL
Section
III
Para. Page
1-1
1-2
1-3
1-4
1-5
1-6
Page
1-1
1-5
1-7
1-1
1-3
1-3
1-3
1-3
1-4
This manual covers operator setup, operation, and organizational maintenance of the
OE-452/PRC Special Operations Radio Antenna Kit (SORAK).
PURPOSE OF ANTENNA KIT
The SORAK includes all of the components needed to erect a high frequency (HF) or
very high frequency (VHF) antenna for use with low power manpack radios at U.S. Army
Special Operations Forces (SOF) out stations.
tenna can be used to send and receive signals over distances of up to 2500 miles (4000
kilometers). Test equipment is included for checking the antenna’s voltage standing wave
ratio (VSWR) prior to attempting communications.
Five different configurations of the an-
1-1
TM 11-5985-391-12
1-1. SCOPE (CONT).
1-2
1. Transmission Line
(Coaxial Cable)
2. 22 Foot Telescoping
Mast (22 Foot Mast)
3. Balun Transformer
(Balun)
4. Antenna Wire
5. 6 Foot Telescoping
Mast (6 Foot Mast)
6. Wire Reel
7. Termination Assembly
(Termination)
TM 11-5985-391-12
1-2. MAINTENANCE FORMS, RECORDS, AND REPORTS.
REPORTS OF MAINTENANCE AND UNSATISFACTORY EQUIPMENT
Department of the Army forms and procedures used for equipment maintenance will be those prescribed by DA Pam 738–750, as contained in Maintenance Management Update.
REPORTING OF ITEM AND PACKAGING DISCREPANCIES
Fill out and forward SF364 (Report of Discrepancy (ROD)) as prescribed in AR 735-11-2/DLAR
4140.55/SECNAVINST 4355.18/AFR 400-54/MCO 4430.3J.
TRANSPORTATION DISCREPANCY REPORT (TDR) (SF 361)
Fill out and forward Transportation Discrepancy Report (TDR) (SF 361 ) as prescribed in AR
55-38/NAVSUPINST 4610.33C/AFR 75-18/MCO P4610.19D/DLAR 4500.15.
CONSOLIDATED INDEX OF ARMY PUBLICATIONS AND BLANK FORMS
Refer to the latest issue of DA Pam 25-30 to determine whether there are new editions,
changes, or additional publications pertaining to the equipment.
1-3. DESTRUCTION OF ARMY MATERIEL TO PREVENT ENEMY USE.
Destruction of Army electronics materiel to prevent enemy use shall be in accordance
with TM 750-244-2.
1-4. PREPARATION FOR STORAGE OR SHIPMENT.
For information needed to prepare SORAK for storage or shipment, refer to Chapter 4,
Section VI. The information provided covers special preservation, packaging, packing,
and marking requirements.
1-5. REPORTING EQUIPMENT IMPROVEMENT RECOMMENDATIONS (EIR).
If your equipment needs improvement, let us know. Send us an EIR. You, the user, are the only
one who can tell us what you don’t like about your equipment. Let us know why you don’t like
the design or performance. Put it on an SF 368 (Product Quality Deficiency Report). Mail it to:
Commander, US Army Communications-Electronics Command and Fort Monmouth, ATTN:
AMSEL-ED-PH, Fort Monmouth, New Jersey 07703–5000. We ’ll send you a reply.
1-3
TM 11-5985-391-12
1-6. NOMENCLATURE CROSS REFERENCE LIST.
Common Name
Anchor/Ground Rod
Anchor Stake
Grounding Rod
Antenna Kit,
SORAK, or
Special Operations
Radio Antenna Kit,
Group OE-452/PRC
Balun,
Balun Transformer
Coaxial Cable,
Coax
Return Loss Bridge
or RLB
RLB Battery
Termination,
Termination Assembly
Official Nomenclature
Anchor/Ground Rod Assembly
Antenna Group, OE-452/PRC
Coupler, Transmission Line
Line, Transmission or
Cable Assembly, Coax
Antenna System
Test Set (TS-4351/PRC)
Battery, Nonrechargeable
Absorber, RF Radiation
Wattmeter
Wire Reel
6 Foot Mast,
6 Ft. Mast
Telescoping Mast
22 Foot Mast,
22 Ft. Mast,
Telescoping Mast
1-4
Ratio Frequency Power
Test Set (TS-4350/PRC)
Cable Hand Reeling Machine
Telescoping Mast Assembly, 6 Foot
Telescoping Mast Assembly, 22 Foot
TM 11-5985-391-12
Section Il. EQUIPMENT DESCRIPTION
Subject
Location and Description of Major Components. . . . . .
Equipment Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety, Care, and Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-7. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS.
The major components of the SORAK include 22 foot mast/guy assembly (1), two 6 foot
mast/guy assemblies (2), antenna assembly (3), and test sets (4). Refer to Section III for
a functional description of the major assemblies and their components.
Para.
1-7
1-8
1-9
Page
1-5
1-6
1-6
1-5
TM 11-5985-391-12
1-8. EQUIPMENT DATA.
Applicable equipment data for the SORAK are as follows:
WEIGHTS AND DIMENSIONS
Deployment Bag and Equipment:
Weight
Width
Height
Length
Mast Bag and Equipment:
Weight
Width
Height
Length
ENVIRONMENTAL CONDITIONS
16 lbs (7.3 kg)
9 in. (22.9 cm)
7 in. (17.8 cm)
18 in. (45.7 cm)
8 lbs (3.6 kg)
7 in. (17.8 cm)
4.5 in. (11.4 cm)
28 in. (71.0 cm)
Ambient Operating Temperatures
Storage/Transport Temperatures
OPERATING RANGE
Antenna Length/Configuration:
117 ft. (36 m)
Sloping Dipole
117 ft. (36 m) Sloping Vee
234 ft. (71 m) Sloping Vee
468 ft. (143 m) Bent Longwire
175 ft. (53 m) Bent Longwire
1-9. SAFETY, CARE, AND HANDLING.
Warnings, safety precautions, and safety procedures are provided at the front of this
manual. Operators should become thoroughly familiar with all warnings, safety precautions, and safety procedures before handling or operating the equipment.
-51 to + 122°F (-46 to + 50°C)
-51 to + 160°F (-46 to + 71°C)
Range, Communication (comm.)
Mode, and Frequency
0 to 250 mi. (0 to 400 km),
HF comm. over 2 to 12 MHz
250 to 650 mi. (400 to 1000 km),
HF comm. over 4 to 14 MHz
650 to 1500 mi. (1000 to 2500 km),
HF comm. over 4 to 32 MHz
1500 to 2500 mi. (2500 to 4000 km),
HF comm. over 6 to 32 MHz
0 to 20 mi. (0 to 30 km), VHF
comm. over 30 to 88 MHz
1-6
TM 11-5985-391-12
Section Ill. TECHNICAL PRINCIPLES OF OPERATION
Subject
SORAK Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SORAK Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-10. SORAK COMPONENTS.
22 FOOT MAST/GUY ASSEMBLY
The antenna wires can be elevated by a 22 foot mast to maximize antenna performance.
The assembly includes a telescoping mast supported by four 21 foot guy ropes, two 32
foot guy ropes, and four guy stakes. The mast is intended for use when existing structures
(poles, buildings, trees, etc.) are not available. A spare 21 foot guy rope, 32 foot guy rope,
and guy stake are included in the kit.
Para.
1-10
1-11
Page
1-7
1-10
1-7
TM 11-5985-391-12
1-10. SORAK COMPONENTS (CONT).
6 FOOT MAST/GUY ASSEMBLIES
Two 6 foot mast/guy assemblies are provided to maintain a minimum wire height of 6 feet
(1.8 meters) above ground to improve antenna efficiency. Each assembly includes a telescoping mast and three adjustable guy ropes with metal guy stakes.
ANTENNA ASSEMBLY
The antenna assembly includes two wire reels. Each wire reel is equipped with a 250 foot
(76 meter) antenna wire.
tenna wires.
1-8
The wire reels allow you to quickly deploy and rewind the an-
TM 11-5985-391-12
1-10. SORAK COMPONENTS (CONT).
The 40 foot halyard is used to raise the antenna wire on the 22 foot mast. In some configurations, a shorting stud on the halyard is used to short two antenna wires together.
The field radio transmits or receives signals through a coaxial cable connected to the
SORAK balun transformer. The balun converts the unbalanced 50 ohm transmission
line (coax) to a balanced 450 ohms for hookup with the antenna wires.
The termination assembly absorbs nonradiated transmission power to reduce standing
waves on the antenna wire. This gives the antenna a broadband response, eliminating the
need to adjust the antenna wire length to the operating frequency.
1-9
TM 11-5985-391-12
1-10. SORAK COMPONENTS (CONT).
TEST SETS
A radio frequency power test set (TS4350/PRC) is provided, This test set, or
wattmeter, allows the user to check the
antenna’s VSWR or the radio’s output
power prior to communication.
An antenna system test set (TS4351/PRC) is also provided. This test set,
or return loss bridge, allows the user to
check antenna VSWR with the
the receive mode.
radio in
1-11. SORAK OPERATION.
The SORAK is designed for use by U.S. Army Special Operations Forces (SOF). The
SOF missions may be conducted in various climates and terrains, using a variety of HF
and VHF low-power manpack radios to communicate over a wide range of distances.
The SORAK can be set up in one of four HF antenna configurations or one VHF antenna configuration. These configurations allow you to establish communications between VHF radios within the line of sight or at distances up to 2500 miles (4000
kilometers) using HF radios.
ponents. The components are easily connected to one another, allowing you to quickly
assemble and disassemble the antenna.
Typical field radios used with the SORAK are HF or VHF low-power manpack types.
These include the following radios currently in use:
Radio:
Ž AN/PRC-70
Ž AN/PRC-74,-74A
Ž AN/PRC-74B,-74C
Ž AN/PRC-77
Ž
AN/PRC-104A,-104B(V)1,-104B(V)4
Ž AN/PRC-l19
Ž AN/PRC-l32
The SORAK is composed of strong, lightweight com-
Frequency Range (MHz):
2 to 76 (HF/VHF)
2 to 12 (HF)
2 to 18 (HF)
30 to 76 (VHF)
2 to 30 (HF)
30 to 88 (VHF)
2 to 30 (HF)
1-10
CHAPTER 2
OPERATING INSTRUCTIONS
TM 11-5985-391-12
Subject
Description and Use of Operator’s Controls
and Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preventive Maintenance Checks
and Services (PMCS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II
Operation Under Usual Conditions . . . . . . . . . . . . . . . . . . . . .
Operation Under Unusual Conditions . . . . . . . . . . . . . . . . . . . IV
Equipment Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V
Sect. Page
I
III
2-1
2-1
2-3
2-33
2-37
Section I. DESCRIPTION AND USE OF OPERATOR’S
CONTROLS AND INDICATORS
The SORAK has no operator controls or indicators.
Section Il. PREVENTIVE MAINTENANCE CHECKS
AND SERVICES (PMCS)
All PMCS for the SORAK are done by organizational level personnel. There is no
operator PMCS for the SORAK.
2-1/(2-2 blank)
TM 11-5985-391-12
Section Ill. OPERATION UNDER USUAL CONDITIONS
Subject
Packing . . . . . . . . . . . . . . . .
Site Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Antenna Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Antenna Deployment General Instructions . . . . . . . . . . . . . . . 2-4
Erecting 22 Foot Mast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
175 Ft. Bent Longwire Antenna. . . . . . . . . . . . . . . . . . . . . . . .
117 Ft. Sloping Dipole
and l17/234 Ft. Sloping Vee Antennas . . . . . . . . . . . . . . . .
468 Ft. Bent Longwire Antenna . . . . . . . . . . . . . . . . . . . . . . . .
Observe all safety precautions at the front of this manual. Failure
to follow safety precautions may result in serious injury or death.
2-1. PACKING.
The SORAK is packed in two carrying bags for transport, or storage at the containment
center. When staging for deployment in the field, pack the SORAK as follows:
1. Pack the two 6 foot mast/guy assemblies into the two smaller sleeves of the
mast bag.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Para.
2-1
2-5
2-6
2-7
2-8
Page
2-3
2-5
2-6
2-8
2-8
2-15
2-18
2-26
2. Pack the 22 foot mast into the large sleeve.
3. Pack the remaining SORAK components in deployment bag as shown. Pockets are also marked for components. Secure pocket flaps.
2-3
TM 11-5985-391-12
2-1. PACKING (CONT).
2-4
2-1. PACKING (CONT).
4.
TM 11-5985-391-12
2-2. SITE SELECTION.
PRECAUTIONS
Observe the following precautions when selecting a site for setting up the SORAK:
Never set up an antenna directly under power lines.
Avoid setting up antenna near power lines, if possible. If antenna must be
near power lines, maintain at least 50 feet between antenna and power line.
Avoid using guy stakes in sandy or marshy areas. If firm support is not available, reinforce with stakes, rocks, or use longer stakes, etc.
Avoid stringing antenna wires or guy ropes near or across footpaths or roadways.
GROUND COVER
The preferred installation site is a level clearing with only a few small trees or bushes.
High trees and heavy growth make setup difficult and can reduce antenna performance.
However, trees and other vegetation can provide cover for covert operations. Use or
avoid ground cover based on the needs and priorities of your mission.
2-5
TM 11-5985-391-12
2-2. SITE SELECTION (CONT).
CLEARANCES
Overhead clearance is needed for setting up the 6 foot and 22 foot masts.
Antenna wires should not touch tree branches, grasses, shrubs, or any structure. Contact
may affect antenna performance.
2-3. ANTENNA SELECTION.
SORAK provides you with five antenna configurations. The preferred antenna configuration depends on the radio and the distance between out station and base station.
Refer to Table 2-1 when selecting an antenna configuration. Table 2-1 gives approximate
communication ranges for each antenna configuration. Refer to Table 2-2 for each antenna configuration radiation pattern.
Table 2-1. Antenna Selection Data.
Compatible
Field Radios
AN/PRC-70, -77,
-119
AN/PRC-70, -74,
-74A, -74B, -74C,
-104A, -104B(V)1,
-104B(V)4, -132
AN/PRC-70, -74,
-74A, -74B, -74C
-104A, -104B(V)1,
-104B(V)4, -132
AN/PRC-70, -74,
-74A, -74B, -74C,
-104A, -104B(V)1,
-104B(V)4, -132
AN/PRC-70, -74,
-74A, -74B, -74C
-104A, -104B(V)1
-104B(V)4, -132
Comm. Range,
Miles (km)
0 to 20
(0 to 30)
0 to 250
(0 to 400)
250 to 650
(400 to 1000)
650 to 1500
(1000 to 2500)
1500 to 2500
(2500 to 4000)
Recommended SORAK
Configuration
175 Foot Bent Longwire
117 Foot Sloping Dipole
117 Foot Sloping Vee
234 Foot Sloping Vee
468 Foot Bent Longwire
2-6
2-3. ANTENNA SELECTION (CONT).
Table 2-2. Typical Antenna Radiation Patterns
TM 11-5985-391-12
2-7
TM 11-5985-391-12
2-4. ANTENNA DEPLOYMENT GENERAL INSTRUCTIONS.
Deploy antennas according to the following paragraphs. Each deployment starts with
erecting the 22 foot mast, paragraph 2-5. After erecting the mast, set up the antenna con-
figuration best suited to your mission.
2-5. ERECTING 22 FOOT MAST.
1. Extend only bottom two sections of mast and lock in place per illustrated procedure.
Extend and hold upper section up-
A.
ward.
B.
Full down and twist lower section
counterclockwise until it stops.
Push upper section down to lock.
Reverse twist to check locking ac-
C.
tion.
2-8
2. Use compass
(Appendix D) to find
direction of transmission. Lay mast down
with guy ring aimed
in transmit direction.
2-5. ERECTING 22 FOOT MAST (CONT).
NOTE
21 foot guy rope spools have one button on edge of spool handle.
3. Drive four guy stakes
at points shown. At
each stake,
loose end of 21 foot
guy rope. Take guy
rope spool back to
mast and hook to guy
ring.
hook
TM 11-5985-391-12
2-9
TM 11-5985-391-12
2-5. ERECTING 22 FOOT MAST (CONT).
NOTE
When tightening guy ropes, allow enough slack to facilitate raising guy ring
tube section.
4. Raise mast upright and pull each spool outward to tighten guy ropes.
2-10
NOTE
32 foot guy rope spools have two buttons on edge of spool handle.
5. Hook loose ends of 32 foot guy ropes to top of mast. Take guy rope spools
and hook to guy stakes per the diagram for your configuration. Leave 32 foot
guy ropes loose.
NOTE
Halyard spool has no buttons on spool handle.
2-5. ERECTING 22 FOOT MAST (CONT).
TM 11-5985-391-12
2-11
TM 11-5985-391-12
2-5. ERECTING 22 FOOT MAST (CONT).
6. Feed loose end of halyard or antenna wire through mast eyelet and connect
per illustration that applies to your configuration. Lay halyard spool or reel
on ground.
2-12
2-5. ERECTING 22 FOOT MAST (CONT).
TM 11-5985-391-12
Extend sections of mast, one at a time
7.
as shown, starting with the innermost
section. To avoid tangling wires, turn
only lower mast sections. Extend guy
ring section last.
Extend and hold upper section up-
A
ward.
B.
Pull down and twist lower section
counterclockwise until it stops.
Push upper section down to lock.
Reverse twist to check locking ac-
C.
tion.
8. Apply tension to 32 foot guy ropes. Set guy rope tension as follows:
Ž If deploying 175 foot bent long-wire, mast should be vertical.
2-13
TM 11-5985-391-12
2-5. ERECTING 22 FOOT MAST (CONT).
Ž If deploying 117 foot slop-
ing dipole or 468 foot bent
longwire, mast should be
bent slightly beyond vertical and opposite to pull of
first antenna wire
deployed.
Ž If deploying a sloping vee,
preload top of mast for an
offset of 1 to 1.5 feet (0.3
to 0.5 meters) from verti-
cal. A weighted halyard
line can be used to
measure the offset of the
mast top from the mast
base.
2-14
Refer to the illustrated procedures that follow for the balance of the deploy-
9.
ment procedures. Refer only to the following pages for the procedures that
apply to your antenna configuration:
175 foot bent longwire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2-15
117 foot sloping dipole and 117/234 foot sloping vee . . . . . . . . . . . . . page 2-18
468 foot bent longwire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 2-26
2-6. 175 FOOT BENT LONGWIRE ANTENNA.
Set up 175 foot bent Iongwire antenna as follows:
1. Deploy one antenna wire per the following illustrated procedures.
TM 11-5985-391-12
Pick up deployment bag. Unhook
A.
antenna wire and walk off 85 feet
(28 paces) opposite transmit direction per diagram.
Line up wire with mast along line
B.
of transmission.
C. Drive anchor/ground rod and hook
antenna wire snaphook to anchor
rope snaphook. Return to mast.
D. Pick up wire reel and deploy an-
tenna wire to 175 foot marker (2
beads on wire).
E. Lock reel with locking loop.
2-15
TM 11-5985-391-12
2-6. 175 FOOT BENT LONGWIRE ANTENNA (CONT).
Do not overtighten antenna
wire. Excess tension may
cause mast to buckle.
F. Line up wire with opposite half of
antenna. Pull wire to remove most
of the slack. Drive anchor/ground
rod.
G. Hook anchor rope to reel and wind
in excess slack.
2. Terminate the deployed antenna wire per the following illustrated procedures.
Do not allow ground wire to
short against antenna wire or
wire reel. Shorting will reduce
antenna performance.
Loosen wing nut (1), raise retain-
A.
ing sleeve (2), and place antenna
wire (3) in groove of retaining nut
(4) as shown. Tighten wing nut (1)
to clamp wire.
B.
Connect ground wire to opposite
end of termination.
Return to mast and snug up guys.
C.
2-16
2-6. 175 FOOT BENT LONGWIRE ANTENNA (CONT).
Shorting across balun terminals will prevent communication and may severely
damage radio during transmit.
D. Hook up balun, ground wire, and
coax at opposite end to complete
antenna setup.
3. Connect radio and check antenna performance per instructions in Section V,
paragraphs 2-13 and 2-14.
TM 11-5985-391-12
Dismantle the 175 foot bent longwire antenna as follows:
1. Disconnect radio.
2. Disconnect coax, ground wire, and balun. Unhook antenna wire from anchor
rope and pull out anchor/ground rod. Pack components in deployment bag.
After collapsing guy ring section, make sure lower guy ropes are
tight enough to keep mast upright while lowering upper sections.
3. With deployment bag, return to mast. Collapse mast by starting with guy ring
(third) tube section. Pull sections apart to unlock and twist lower section
clockwise. When completely collapsed, make sure inner tube sections lock in
base.
2-17
TM 11-5985-391-12
2-6. 175 FOOT BENT LONGWIRE ANTENNA (CONT).
4. Move to reel end of antenna. Disconnect termination and ground wire. Pull
out anchor/ground rod.
NOTE
Keep tension on antenna wire during reeling process to avoid
snarls.
5. With termination and anchor/ground rod, return to mast reeling in antenna
wire as you go.
6. Unhook guy ropes from mast and guy stakes; pull out stakes.
7. Pack mast in mast bag and all other components in deployment bag.
2-7. 117 FOOT SLOPING DIPOLE AND 117/234 FOOT SLOPING VEE
ANTENNAS. Set up antenna as follows:
1. Rig antenna assembly at 22 foot mast per the following procedures.
Snap halyard to balun as shown.
Connect antenna wire snaphooks,
terminal leads, and loose end of
coax to balun.
Place wire reels between guy ropes
with reel cranks facing up. Wire
reels should be about 6 feet (2
meters) apart.
2-18
TM 11-5985-391-12
2-7. 117 FOOT SLOPING DIPOLE AND 117/234 FOOT SLOPING VEE
ANTENNAS (CONT).
2. Use compass to find antenna wire deployment heading per applicable
diagram. Sight a landmark, if possible.
The first antenna wire deployed on the 117 foot sloping dipole antenna must
pull against the 32 foot guy ropes that anchor the top of the mast. Failure to
have upper mast support when pulling the first antenna wire may cause
damage to the mast.
3. Turn reel tension knob for a slight drag on the antenna wire. Pick up mast
bag, deployment bag, and one wire reel. Make sure that the pull of the antenna on the upper mast is opposite to and balanced by the pull of the 32 foot
guy ropes.
2-20
TM 11-5985-391-12
2-7. 117 FOOT SLOPING DIPOLE AND 117/234 FOOT SLOPING VEE
ANTENNAS (CONT).
4. Deploy antenna wire along proper heading.
along deployed wire. At proper distance, lock reel with rope loop.
Watch for distance marker heads
Ž If deploying 117 foot sloping dipole or sloping vee, unreel wire to first
single-bead marker.
Ž If deploying 234 foot sloping vee, unreel wire to second single-bead
marker.
Do not overtighten antenna wire. Excess tension may cause mast to buckle.
5. To determine antenna anchor point, pull antenna until full length of wire is
just off ground. Drive anchor/ground rod. Hook anchor rope to wire reel.
2-21
TM 11-5985-391-12
2-7. 117 FOOT SLOPING DIPOLE AND 117/234 FOOT SLOPING VEE
ANTENNAS (CONT).
6. Erect 6 foot mast per the following procedures.
A. Extend 6 foot mast and place on ground, Line up one of three notches
in top of mast with antenna wire. Make sure the guy rope in the notch
aligned with antenna wire is down or away from wire.
should not rest on guy rope when mast is raised.
Antenna wire
2-22
B. Separate guy ropes from rope
retainer.
TM 11-5985-391-12
2-7. 117 FOOT SLOPING DIPOLE AND 117/234 FOOT SLOPING VEE
ANTENNAS (CONT).
C. Lay out guy ropes to avoid tangling. Make sure that no guy rope crosses
over antenna wire. Drive the two guy stakes nearest to the wire reel.
D. Raise mast to vertical position.
Center the mast beneath antenna
wire placing wire in notch.
E. Drive third guy stake and tighten
all guy ropes with tensioning
blocks.
F. Reel in excess antenna wire slack.
Tighten anchor rope.
2-23
TM 11-5985-391-12
2-7. 117 FOOT SLOPING DIPOLE AND 117/234 FOOT SLOPING VEE
ANTENNAS (CONT).
7. Terminate ends of deployed antenna wire per the following procedures.
Do not allow ground wire to
short against antenna wire or
wire reel. Shorting will reduce
antenna performance.
Loosen termination wing nut (1),
A.
raise retaining sleeve (2), and place
antenna wire (3) in groove of
retaining nut (4) as shown.
Tighten wing nut (1) to clamp antenna wire.
B.
Connect ground wire to opposite
end of termination.
Return to 22 foot mast and repeat steps 2 through 7 of paragraph 2-7 to
8.
deploy other leg of the antenna.
9.
Return to 22 foot mast and connect field radio. Check antenna performance
per instructions in Section V, paragraphs 2-13 and 2-14.
If longer coax is needed from balun to radio, use coax adapter from
installation kit and connect together two coax cables.
Dismantle the 117 foot sloping dipole and 117/234 foot sloping vee antennas as follows:
1. Disconnect radio.
2. Untie halyard rope and lower balun and antenna wires. Disconnect coax and
antenna wires, and unhook halyard from balun.
2-24
TM 11-5985-391-12
2-7. 117 FOOT SLOPING DIPOLE AND 117/234 FOOT SLOPING VEE
ANTENNAS (CONT).
After collapsing guy ring section,
enough to keep mast upright while lowering upper sections.
Collapse mast by starting with guy ring (third) tube section. Pull sections
3.
apart to unlock and twist lower section clockwise. When completely collapsed,
remove halyard. Unhook guy ropes from 22 foot mast and guy stakes; pull out
stakes. Make sure mast inner tube sections lock in base. Pack mast in mast
bag and all other components in deployment bag.
4.
With deployment bag, move to the termination end of one of the antenna
legs. Collapse the 6 foot mast and pull out guy stakes. Place guy ropes in rope
retainer. Wrap guy ropes around ends of mast and secure with utility tape as
shown. Pack mast in mast bag.
Disconnect termination and ground wire. Unhook anchor rope from reel and
5.
pull out anchor/ground rod. Pack termination and anchor/ground rod in
deployment bag.
make sure lower guy ropes are tight
NOTE
Keep tension on antenna wire during reeling process to avoid snarls.
With deployment bag, return to 22 foot mast, reeling in antenna wire as you
6.
go.
Repeat steps 4 through 6 for remaining antenna leg.
7.
Pack 6 foot mast in mast bag and wire reel in deployment bag.
8.
2-25
TM 11-5985-391-12
2-8. 468 FOOT BENT LONGWIRE ANTENNA. Setup antenna as follows:
1. Rig antenna assembly at 22 foot mast per
the following illustrated procedures.
Connect antenna wire snaphooks
and antenna terminal leads to
shorting stud as shown.
Place wire reels between guy ropes
with reel cranks facing up. Wire
reels should be about 6 feet (2
meters) apart.
2-26
Pull halyard rope to hoist antenna.
C.
Tie off halyard at mast guy ring.
D.
Visually check that halyard rope
and antenna wires are not twisted
at top of mast.
both antenna wires will be above
21 foot guy ropes when deployed.
Also check that
2-8. 468 FOOT BENT LONGWIRE ANTENNA (CONT).
2. Use compass to find antenna wire deployment heading per transmit direction
diagram. Sight a landmark, if possible.
TM 11-5985-391-12
The first antenna wire deployed must pull against the 32 foot guy ropes that
anchor the top of the mast. Failure to have upper mast support when deploying antenna wires may cause damage to the mast.
3. Turn reel tension knob for a slight drag on the antenna wire. Pick up mast
bag, deployment bag, and one wire reel. Make sure that the pull on the upper
mast is balanced by the pull of the 32 foot guy ropes.
4. Deploy antenna wire along proper heading. Watch for the second single-bead
marker. At the proper distance, lock reel with locking loop.
2-27
TM 11-5985-391-12
2-8. 468 FOOT BENT LONGWIRE ANTENNA (CONT).
Do not overtighten antenna wire. Excess tension may cause mast to buckle.
5. To determine antenna anchor point,
pull antenna until full
length of wire is just
off ground.
anchor/ground rod.
Hook anchor rope to
wire reel.
Drive
6. Erect 6 foot mast per the following illustrated procedures.
A.
Extend 6 foot mast
and place on
ground.
one
notches in top of
mast with antenna
wire. Make sure the
guy rope in notch
aligned with an-
tenna wire is down
or away from wire.
Line up
of three
2-28
2-8. 468 FOOT BENT LONGWIRE ANTENNA (CONT).
TM 11-5985-391-12
Lay out guy ropes to avoid tangling. Make sure that no guy rope
crosses over antenna wire.
the two guy stakes nearest to the
wire reel.
Raise mast to vertical position.
Center the mast beneath antenna
wire placing wire in notch.
Drive third guy stake and tighten
all guy ropes with tensioning
blocks.
Reel in excess antenna wire slack.
Tighten anchor rope.
Drive
2-29
TM 11-5985-391-12
2-8. 468 FOOT BENT LONGWIRE ANTENNA (CONT).
7. Terminate end of deployed antenna wire per the following procedures.
Do not allow ground wire to
short against antenna wire or
wire reel. Shorting will reduce
antenna performance.
A. Loosen termination wing nut (l),
raise retaining sleeve (2), and place
antenna wire (3) in groove of
retaining nut (4) as shown.
Tighten wing nut (1) to clamp an-
tenna wire.
B. Connect ground wire to opposite
end of termination.
2-30
8. Return to 22 foot mast and repeat steps 2 through 7 to deploy the other leg
of the antenna.
9. Terminate end of second antenna wire per the following procedures.
Do not allow ground wire to
short against antenna wire.
Shorting across balun terminals will prevent com-
munication and may severely
damage radio during transmit.
A. Attach one balun terminal to an-
tenna wire as shown.
B. Connect end of ground wire to op-
posite balun terminal.
C. Hook up coax to balun. Connect field radio. Check antenna perfor-
mance per instructions in Section V, paragraphs 2-13 and 2-14.
2-8. 468 FOOT BENT LONGWIRE ANTENNA (CONT).
Dismantle the 468 foot bent longwire as follows:
1.
Disconnect radio.
2.
Collapse the 6 foot mast and pull out guy stakes. Place guy ropes in rope
retainer. Wrap guy ropes around ends of mast and secure with utility tape as
shown. Pack mast in mast bag.
3.
Disconnect coax, ground wire, and balun. Unhook antenna wire from anchor
rope and pull out anchor/ground rod. Pack components in deployment bag.
NOTE
TM 11-5985-391-12
Keep tension on antenna wire during reeling process to avoid
snarls.
4.
With mast and deployment bag, return to 22 foot mast, reeling in antenna
wire as you go. Place reel on ground at mast.
5.
Untie halyard rope and lower antenna wires. Disconnect antenna wires from
halyard shorting stud. Reel in remaining antenna wire on reel at mast.
After collapsing guy ring section, make sure lower guy ropes are
tight enough to keep mast upright while lowering upper sections.
6.
Collapse 22 foot mast by starting with guy ring (third) tube section. Pull sections apart to unlock and twist lower section clockwise. When completely collapsed, remove halyard. Unhook guy ropes from 22 foot mast and guy stakes;
pull out stakes. Make sure mast inner tube sections lock in base. Pack mast in
mast bag and all other components in deployment bag.
2-31
TM 11-5985-391-12
2-8. 468 FOOT BENT LONGWIRE ANTENNA (CONT).
7.
With deployment bag, move to the termination end of the remaining antenna
leg. Collapse the 6 foot mast and pull out guy stakes. Place guy ropes in rope
retainer. Wrap guy ropes around ends of mast and secure with utility tape.
Pack mast in mast bag.
Disconnect termination and ground wire. Unhook anchor rope from reel and
8.
pull out anchor/ground rod. Pack termination and anchor/ground rod in
deployment bag.
9.
With mast and deployment bags, return to 22 foot mast reeling in antenna
wire as you go.
10.
Pack 6 foot mast in mast bag and wire reel in deployment bag.
2-32
TM 11-5985-391-12
Section IV. OPERATION UNDER UNUSUAL CONDITIONS
Subject
Alternate Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operation in Severe Weather . . . . . . . . . . . . . . . . . . . . . . . . . .
Swimming or Fording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setup in Deep Sand or Snow... . . . . . . . . . . . . . . . . . . . . . . . .
2-9. ALTERNATE COMPONENTS.
ANTENNA SUPPORTS
Shock hazard. Never use utility poles or other power line structures to support the antenna. Use of power line supports can lead
to serious injury or death.
When using a tree to support the antenna, use a spring or strip of
rubber at one end of the antenna wire. If a flexible tie is not available, leave plenty of slack in the wire.
Para.
2-9
2-10
2-11
2-12
Page
2-33
2-35
2-35
2-35
You can use poles, trees, or buildings to support antenna wires. However, reduced antenna performance may result. Avoid using metallic supports, if possible.
To deploy antenna using alternate supports such as a tree or building, attach one or both
weights to loose end of halyard and toss over tree branch or building. Hoist antenna in
normal fashion.
If longer coax is needed from balun to radio, use coax adapter from installation kit and
connect together two coax cables.
2-33
TM 11-5985-391-12
2-9. ALTERNATE COMPONENTS (CONT).
ANTENNA WIRES
Any metal wire can be used as an antenna. Examples include power cords, barbed wire,
other fence wire, or metal-core clothesline.
A bent longwire antenna can be set up with only one wire reel.
GROUNDING RODS
Explosion hazard. Piping or underground tanks may contain flammable materials. Failure to check contents of piping or underground tanks before use may result in serious injury or death.
Any metal can be used as a grounding rod. Water pipes, reinforcing rods, or metal posts
often provide good earth grounds.
Always check for flammable materials in piping or tanks. If in doubt about contents,
don’t use the container for a ground.
Remove paint from all ground rod surfaces to be in direct contact with termination
ground wire.
When attaching ground wire to pipe or similar
object, use one full turn around pipe as shown to
ensure ground connection.
Also follow this procedure if ground screw is missing from anchor/ground rod.
.
2-34
TM 11-5985-391-12
.
2-10. OPERATION IN SEVERE WEATHER.
Observe the following warnings before attempting to set up or operate the SORAK in
severe weather conditions.
Severe shock hazard.
electrical storms. Handling equipment during electrical storms may
lead to serious injury or death by electrocution.
To avoid frostbite, use arctic gloves when setting up or adjusting
SORAK in cold weather conditions.
Due to slower body motion and the use of arctic gloves, SORAK installation in cold
weather may take much longer than usual.
2-11. SWIMMING OR FORDING.
Electrical shock hazard. Do not use return loss bridge if recently
submerged or exposed to large amounts of water.
The deployment bag is designed to be water-repellent during heavy rain or short submersion. If recently submerged or exposed to a large amount of water, unscrew battery compartment cover of return loss bridge and drain water.
Do not set up or adjust antenna during
2-12. SETUP IN DEEP SAND OR SNOW.
To improve holding strength of guy stakes and anchor/ground rods in deep sand or snow,
use one or more of the following suggestions:
Ž Tie off or pin down guy ropes and/or anchor/ground rod with heavy objects
(rocks, logs, etc.), if available.
Ž Dig down to find firm ground for anchoring.
2-35
TM 11-5985-391-12
2-12. SETUP IN DEEP SAND OR SNOW (CONT).
Ž Dig down two or three feet at each anchor point. Tie off guy rope at middle
of guy stake as shown. Bury the guy stake. When burying guy stake, wet
down sand or snow to aid packing and anchor strength.
Ž If buried guy stake doesn’t hold, tie off guy rope to a stick, item of clothing,
or other bulky item and bury it.
To improve grounding of antenna in deep sand, use one of the following methods:
Ž Use additional wire as a counterpoise.
Ž Dig down until firmer ground is found.
Ž Wet down area around anchor/ground rod just prior to transmit.
To improve grounding of antenna in deep snow and frozen ground, use one of the follow-
ing methods:
Ž Use additional wire as a counterpoise.
Ž Dig down until thawed ground is found.
Ž Wet down area around anchor/ground rod just prior to transmit.
2-36
Section V. EQUIPMENT CHECKS
TM 11-5985-391-12
Subject
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking Voltage Standing Wave Ratio (VSWR) . . . . . . . . .
2-13. GENERAL.
Failure to check SORAK performance before attempting communication can result in damage to equipment.
When possible, test SORAK antenna performance before use. Either the wattmeter or
the return loss bridge (RLB) can be used to determine the voltage standing wave ratio
(VSWR). In hostile areas, use the return loss bridge to avoid unnecessary signal transmission.
NOTE
The maximum acceptable VSWR is different for different radios.
Refer to the radio’s technical manual for the maximum acceptable
VSWR value.
Normally, a low VSWR indicates high antenna performance:
Para. Page
2-13
2-14
2-37
2-38
Ž A VSWR between 1.0:1 and 2.0:1 is desirable.
Ž A VSWR between 2.1:1 and 3.5:1 is generally acceptable.
Ž If the VSWR is above 3.5:1, antenna performance may be poor.
2-37
TM 11-5985-391-12
2-14. CHECKING VOLTAGE STANDING WAVE RATIO (VSWR).
The following procedures allow you to
check the VSWR with either the watt-
meter or return loss bridge. Both are
included in the SORAK.
WITH WATTMETER
1. Connect antenna coax to
wattmeter ANT port.
2. Connect 6 foot coax be-
tween wattmeter XMTR
port and radio.
2-38
TM 11-5985-391-12
2-14. CHECKING VOLTAGE STANDING WAVE RATlO (VSWR) (CONT).
It is necessary to disconnect the antenna when operating wattmeter
internal load. However, reconnect antenna or stop keying transmitter before releasing load button. Releasing load button while
transmitter is keyed without antenna connected may damage equipment.
Wattmeter in LOAD position places all radiated power on
wattmeter’s internal load. Apply load for one minute, maximum.
After LOAD check, allow 10 minutes before further use of internal
load. Failure to follow this caution may cause severe damage to
your wattmeter.
Turn radio on, adjust to operating frequency, and tune radio if necessary.
3.
Key transmitter (not to exceed 50 watts) and record forward (FWD) power
reading on wattmeter.
4.
Key transmitter (not to exceed 50 watts). Press and hold FWD/REF button
down and record reflected (REF) power reading on wattmeter.
Select VSWR table that matches rated wattage output of your radio. Inter-
5.
sect Reflected Power and Forward Power values. Extend a line from origin
(0,0) through intersect, to right-hand border of table. Read approximate
VSWR from right hand column.
EXAMPLE: (See dotted lines in VSWR table for 2, 5, and 15 watt radios.)
With a forward power reading of 14 watts and a reflected power reading of
2.4 watts, the line from the origin, through the intersect, to the right column
indicates a VSWR of just under 2.5:1.
2-39
TM 11-5985-391-12
2-14. CHECKING VOLTAGE STANDING WAVE RATIO (VSWR) (CONT).
2-40
TM 11-5985-391-12
2-14. CHECKING VOLTAGE STANDING WAVE RATIO (VSWR) (CONT).
WITH RETURN LOSS BRIDGE (RLB)
1. Connect antenna cable
return loss bridge ANT port.
2. Connect 6 foot coax
tween return loss bridge
RCVR port and radio.
to
be-
2-41
TM 11-5985-391-12
2-14. CHECKING VOLTAGE STANDING WAVE RATIO (VSWR) (CONT).
Do not transmit into RLB. Transmitting signal to RLB will cause
severe damage to the unit.
3. Turn RLB VOL knob clockwise until only internal radio noise is audible
through headset. Then, turn VOL knob counterclockwise until steady tone
becomes audible.
4. Press and release internal reference button several times and listen for a
change in tone volume.
Ž If tone volume decreases with internal reference button pressed, antenna
performance is good.
Ž If tone is same or slightly louder with button pressed, antenna performance
is acceptable.
Ž If tone gets louder, antenna performance is poor.
2-42
TM 11-5985-391-12
CHAPTER 3
OPERATOR MAINTENANCE INSTRUCTIONS
3-1. OPERATOR MAINTENANCE.
All maintenance work for SORAK is done by organizational level personnel. There is no
operator maintenance for the SORAK.
3-1/(3-2 blank)
TM 11-5985-391-12
CHAPTER 4
ORGANIZATIONAL MAINTENANCE
Subject
Repair Parts, Special Tools, TMDE, and . . . . . . . . . . . . . . . . . . . . I
Support Equipment
Service Upon Receipt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II
Preventive Maintenance Checks and Services . . . . . . . . . . . . . . . . III
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV
Maintenance Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V
Preparation for Storage or Shipment . . . . . . . . . . . . . . . . . . . . . . . VI
Section
Page 4-1
4-3
4-13
4-19
4-25
4-43
Section I. REPAIR PARTS, SPECIAL TOOLS, TMDE,
AND SUPPORT EQUIPMENT
Subject
Common Tools and Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Special Tools, TMDE, and Support Equipment . . . . . . . . . . . . . . 4-2
Repair Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
4-1. COMMON TOOLS AND EQUIPMENT.
Refer to your unit’s Modified Table of Organization and Equipment (MTOE) for
authorized common tools and equipment.
Para. Page
4-1
4-1
4-1
4-2. SPECIAL TOOLS, TMDE, AND SUPPORT EQUIPMENT.
All tools and support equipment required are in the SORAK kit.
4-3. REPAIR PARTS.
Repair parts are listed and illustrated in TM 11-5985–391–20P.
4-1/(4-2blank)
TM 11-5985-391-12
Section Il. SERVICE UPON RECEIPT
Subject
Unpacking SORAK Components . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Checking SORAK Components . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Preliminary Servicing and Adjustment of . . . . . . . . . . . . . . . . . . . 4-6
Equipment
4-4. UNPACKING SORAK COMPONENTS.
On initial receipt or return of SORAK from field, refer to illustrations in paragraph 4-21
and unpack all items from mast bag and/or deployment bag. Check unpacked components against Components of End Item and Basic Issue Items lists in Appendix C to
verify that all components of the SORAK are on hand.
SORAK are missing, replace them at this time.
4-5. CHECKING SORAK COMPONENTS.
Inspect general condition and, if necessary, clean or replace SORAK components in ac-
cordance with the Preventive Maintenance Checks and Services (PMCS) in Section III.
Record the results of the PMCS on DA Form 2404, Equipment Inspection and Main-
tenance Worksheet.
4-6. PRELIMINARY SERVICING AND ADJUSTMENT OF EQUIPMENT.
Perform the following preliminary tests to qualify electrical components of the SORAK
for further inspection and/or return to service.
Para.
If any components of the
Page
4-3
4-3
4-3
The general test procedures below are used to check the performance of the electrical
components of the SORAK, including the wattmeter and return loss bridge. The procedures are designed to help you isolate a faulty SORAK component through a process of
elimination. The test will also help you detect a faulty field radio, a required part of the
test setup.
No adjustments of the SORAK components are required and no special tools are required.
The following tests should be performed only after the radio has been proven operational
by test. Refer to your radio’s technical manual for test procedures.
Coax cables used in transmit-mode tests must be proven serviceable
by test. Use of faulty coax cables in transmit-mode tests may cause
serious damage to the transmitter.
4-3
TM 11-5985-391-12
4-6. PRELIMINARY SERVICING AND ADJUSTMENT OF EQUIPMENT (CONT).
PRELIMINARY COAX TEST
1.
Turn radio off. Connect 6 foot SORAK coax (coax “A”) from ANT input of
manpack radio to RCVR input of return loss bridge (RLB).
2. Connect 6 foot SORAK coax (coax “B”) from ANT output of return loss
bridge to XMTR input of wattmeter.
4-4
TM 11-5985-391-12
4-6. PRELIMINARY SERVICING AND ADJUSTMENT OF EQUIPMENT (CONT).
Do not transmit into the return loss bridge (RLB). Transmitting
into the return loss bridge will cause permanent damage to the unit.
Turn squelch off at radio. Put the radio in the receive mode. Hookup head-
3.
set to radio.
Turn RLB volume (VOL) knob clockwise to ON position and listen for a
4.
steady tone from the headset.
Ž If steady tone is heard, proceed to step 5.
Ž If no tone is heard, turn RLB off, replace coax “A”, and recheck for tone.
Ž If no tone is heard with replacement coax, RLB may have low battery, be
defective, or second coax may be faulty. Replace battery or substitute RLB
or coax as needed to achieve steady test tone.
Push wattmeter internal load button. Steady tone should disappear.
5.
Ž If the tone disappears when the internal load button is pushed, the coax
cables in the test setup should be rated in good working order.
Ž If the steady tone is still heard when the internal load button is pushed,
coax “B’ may be faulty. Replace coax “B” and repeat step 5.
Ž If replacing coax “B’ does not change test result, then replacement coax or
wattmeter internal load may be faulty. Replace coax “B” or wattmeter as
needed to achieve proper test result.
TRANSMIT TEST SETUP
Coax cables used in transmit-mode tests must be proven serviceable
by test. Use of faulty coax cables in transmit-mode tests may cause
serious damage to the transmitter.
1.
Connect 6 foot SORAK coax (coax “A”) from ANT input of manpack radio
to XMTR input of wattmeter.
2.
Connect 6 foot SORAK coax (coax “B”) from ANT output of wattmeter to
coax connector of balun.
4-5
TM 11-5985-391-12
4-6. PRELIMINARY SERVICING AND ADJUSTMENT OF EQUIPMENT (CONT).
Do not allow wires to short circuit the balun terminals. Do not allow balun terminals, wires, or termination ends to contact a metal
surface.
3. Use two 4 to 6 inch lengths of antenna wire to connect the termination across
the balun terminals.
4.
Connect a manual Morse key or handset to the radio.
4-6
TM 11-5985-391-12
4-6. PRELIMINARY SERVICING AND ADJUSTMENT OF EQUIPMENT (CONT).
TRANSMITTER/WATTMETER TEST PROCEDURE
Burn Hazard. Keying transmitter heats up the wattmeter internal
load resistor when the internal load button is pressed. Avoid
keying transmitter for more than 30 seconds. Failure to follow this
warning may result in a burn on contact with the wattmeter or
damage to the equipment.
1.
Adjust HF radios to 10 MHz or VHF radios to 30 MHz. Tune radio, if
necessary.
Key transmitter only when load button is depressed. Be sure to
release transmitter key before releasing load button. Keying transmitter with load button released can cause damage to the radio.
2.
Disconnect coax “B’ from ANT output of wattmeter. Put radio in transmit
mode.
Press and hold wattmeter internal LOAD button. Key the transmitter
3.
momentarily and read the wattmeter.
(FWD/INT) power.
4.
Press and hold both the FWD/REF and LOAD buttons. Key the transmitter
momentarily and read the wattmeter.
(REF/INT) power.
5.
Isolate equipment faults or continue testing per the instructions that apply to
your radio.
For radios with rated output power exceeding 10 watts:
Record the reading as forward
Record the reading as reflected
Ž If forward (FWD/INT) power exceeds 80% of the radio’s rated output and
the reflected (REF/INT) power is less than 20% of the forward power, the
radio and wattmeter can be rated operational; proceed to antenna components test procedure.
4-7
TM 11-5985-391-12
4-6. PRELIMINARY SERVICING AND ADJUSTMENT OF EQUIPMENT (CONT).
Ž If forward (FWD/INT) power is less than 80% of the radio’s rated output,
retune the radio and repeat steps 1 and 2. If the same result occurs, replace
coax “A” and repeat steps 1 and 2 again. If the result is again the same, the
wattmeter and/or radio maybe faulty.
Ž If the reflected (REF/INT) power exceeds 20% of the forward power, the
wattmeter internal load circuit may be faulty; replace wattmeter and repeat
test.
For radios with rated output power less than 10 watts:
Ž If forward (FWD/INT) power exceeds 60% of the radio’s rated output and
the reflected (REF/INT) power is less than 20% of the forward power, the
radio and wattmeter can be rated operational; proceed to antenna components test procedure.
Ž If forward (FWD/INT) power is less than 60% of the radio’s rated output,
retune the radio and repeat steps 1 and 2. If the same result occurs, replace
coax “A” and repeat steps 1 and 2 again. If the result is again the same, the
wattmeter and/or radio may be faulty.
Ž If the reflected (REF/INT) power exceeds 20% of the forward power, the
wattmeter internal load circuit may be faulty; replace wattmeter and repeat
test.
Reconnect coax “B” to ANT output of wattmeter.
6.
ANTENNA COMPONENTS TEST PROCEDURE
Burn Hazard. Keying transmitter heats up the termination. Avoid
direct contact with termination during or after keying transmitter.
Failure to follow this warning may result in minor burn on contact.
4-8
TM 11-5985-391-12
4-6. PRELIMINARY SERVICING AND ADJUSTMENT OF EQUIPMENT (CONT).
Coax cables used in transmit-mode tests must be proven serviceable
by test. Use of faulty coax cables in transmit-mode tests may cause
serious damage to the transmitter.
NOTE
The transmitter and wattmeter should be rated operational by test
before you start the following test procedure.
1.
Tune the radio and apply power by keying the transmitter momentarily.
With the transmitter keyed, read the wattmeter. Record the reading as for-
2.
ward (FWD) power.
High reflected power can damage the radio. Failure to halt keying
transmitter when a high reflected power is indicated may result in
serious damage to the radio.
Press and hold the wattmeter FWD/REF button. Key the transmitter
3.
momentarily and read the wattmeter. Record the reading as reflected (REF)
power.
Isolate equipment faults or continue testing per instructions as follows:
4.
Ž If reflected power does not exceed 20% of forward power, the components
of the test setup can be rated operational; discontinue testing.
4-9
TM 11-5985-391-12
4-6. PRELIMINARY SERVICING AND ADJUSTMENT OF EQUIPMENT (CONT).
Ž Replace coax “B” and repeat steps 1 through 3. If fault condition is cor-
rected, original coax should be rated faulty. If fault condition persists, continue.
Ž Replace termination in test setup with 2nd SORAK termination and repeat
steps 1 through 3. If fault condition is corrected, 1st termination should be
rated faulty. If fault condition persists, continue.
Ž Replace balun if an alternate is available. If fault condition is corrected,
original balun should be rated faulty. If fault condition persists, both terminations should be considered faulty; replace terminations.
RETURN LOSS BRIDGE TEST PROCEDURE
NOTE
The following test will only be valid if all components in previous
test setup are proven good.
1. Disconnect the wattmeter from the previous test setup. Connect coax “A”
from ANT input of manpack radio to RCVR input of RLB.
Do not transmit into the RLB. Transmitting into the RLB will
cause permanent damage to the unit.
2. Hook up headset to radio. Turn squelch off. Put the radio in the receive
mode.
3. Turn RLB volume (VOL) knob fully clockwise to minimum volume level.
4. Put headset on and adjust radio volume until internal background noise can
be heard.
4-10
TM 11-5985-391-12
4-6. PRELIMINARY SERVICING AND ADJUSTMENT OF EQUIPMENT (CONT).
Slowly turn RLB volume knob counterclockwise until a steady tone becomes
5.
clearly audible. The internal receiver noise should still be audible in the background.
Press and hold the internal reference button for one second; then release it
6.
for one second. Listen for a change in tone when the button is pressed and
released.
4-11
TM 11-5985-391-12
4-6. PRELIMINARY SERVICING AND ADJUSTMENT OF EQUIPMENT (CONT).
7.
Repeat pressing and releasing button as needed to identify the tone change.
Assess operating condition of RLB as follows:
Ž If the tone volume increases when the internal reference button is pressed,
the RLB should be rated in good working order.
Ž If no change in tone volume is noticeable when the internal reference but-
ton is pressed, the RLB should be rated unfit for service.
Ž If the tone volume is low or zero when the internal reference button is
pressed, replace the 9 volt battery and repeat test. If a new battery has no
effect, try tuning the radio to a different frequency. If retuning has no effect,
the RLB unit should be considered unfit for service.
4-12
TM 11-5985-391-12
Section Ill. PREVENTIVE MAINTENANCE CHECKS
AND SERVICES (PMCS)
Subject
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Explanation of Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
4-7. INTRODUCTION.
The PMCS table lists the checks and services to be performed at organizational level.
PMCS items are listed in the order they should be performed, regardless of the interval.
Refer to Table 4-1 for maintenance checks and services to be performed at the organizational level.
4-8. EXPLANATION OF COLUMNS.
a.
Item No. Column. An item number is assigned to each procedure. This
column shall be used as a source of item numbers for the TM Number Column on DA
Form 2404, Equipment Inspection and Maintenance Worksheet, when recording results
of PMCS.
b.
Interval Column. Entries in this column indicate how often the PMCS
item should be performed. A listing above the table gives you the meaning of each entry
used in the interval column.
Para. Page
4-13
4-13
c.
Item to be Inspected/Procedure Column. This column lists the as-
semblies and components to be checked and/or serviced. Components that are part of a
major assembly are grouped together. Accessory items are listed separately. The common
name of the assembly or component is used so you can identify the item easier.
This column also describes the check and/or service procedures to be performed. When
part replacement or repair is required, the maintenance procedure required is given by
reference.
4-13
TM 11-5985-391-12
Table 4-1. Preventive Maintenance Checks and Services
B - Before mission D - During mission A - After mission
ITEM
NO.
1
[NTERVAL
—
D
—
—
A
—
X
—
B
—
ITEM TO BE INSPECTED
PROCEDURE
Inspect housing and connectors for obvious signs of
damage or corrosion.
damaged.
Return Loss Bridge (RLB).
Replace wattmeter if visibly
2
4-14
X
Inspect housing coax connectors and battery connections
for obvious signs of damage or corrosion. Replace RLB
unit if housing is damaged.
TM 11-5985-391-12
Table 4-1. Preventive Maintenance Checks and Services (CONT)
B - Before mission D - During mission A - After mission
ITEM
NO.
3
4
INTERVAL
—
—
B
D
—
—
X
ITEM TO BE INSPECTED
—
PROCEDURE
A
—
Guy Rope Assemblies.
Check rope (1) for cuts or fraying. To repair, cut out
damaged rope and tie loose ends in square knot.
X
Inspect for cuts, abrasions, or knots in rope (l). Check for
cracked or broken rope spool (2) and snaphooks (3). Replace damaged parts.
Transmission Lines (Coax).
X
5
X
Check for loose, dirty, corroded, or
otherwise damaged coax connectors
(l). Replace coax if damaged.
4-15
TM 11-5985-391-12
Table 4-1. Preventive Maintenance Checks and Services (CONT)
B - Before mission D - During mission A - After mission
ITEM
NO.
6
INTERVAL
—
—
B
D
—
—
X
—
A
—
ITEM TO BE INSPECTED
PROCEDURE
Antenna Wire/Reel Assemblies.
Inspect full length of antenna wires (1) for breaks, fraying,
or cuts. To repair, cut out any defective wire and tie loose
ends with a square knot.
7
4-16
X
Inspect full length of antenna wires (1) for breaks, fraying,
cuts, or knots. Check for broken or missing snaphooks (2)
and/or antenna terminal leads (3). Check operation of wire
reel cranks (4) and tension (drag), adjust knob (5). Check
that locking loop (6) is intact. Replace missing or damaged
parts.
TM 11-5985-391-12
Table 4-1. Preventive Maintenance Checks and Services (CONT)
B - Before mission D - During mission A - After mission
INTERVAL
—
ITEM
NO.
8
.
9
—
—
D
B
—
X
ITEM TO BE INSPECTED
PROCEDURE
A
Balun.
X
Check for corrosion or damaged balun. Replace balun if
damaged.
Halyard.
Check rope (1) for cuts or fraying.
damaged rope and tying loose
ends with square knot.
Repair by cutting out
10
X
Inspect for cuts, abrasions, or
knots in rope (l). Check for
smooth operation of wing nut on
shorting stud (2). Check for
cracked, broken, or missing
snaphooks (3). Replace halyard if
components are missing or
damaged.
4-17
TM 11-5985-391-12
Table 4-1. Preventive Maintenance Checks and Services (CONT)
B - Before mission D - During mission A - After mission
ITEM
NO.
11
INTERVAL
—
B
—
—
ITEM TO BE INSPECTED
PROCEDURE
Anchor/Ground Rod Assemblies.
Inspect anchor/ground rod (l),
screw (2), flat washer (3), and
ground wire (4) for corrosion
and/or damage. Check that each
anchor rope assembly (5) is
equipped with serviceable tensioning block (6) and snaphook
(7). Replace damaged or missing
items.
4-18
Section IV. TROUBLESHOOTING
TM 11-5985-391-12
Subject
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Introduction to Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
4-9. GENERAL.
NOTE
In many cases, the only symptoms of a deployed antenna system
malfunction are high VSWR readings and/or prolonged failure to
communicate. Communication failures also can result from radio
failures, improper frequency selection, improper antenna configura-
tion, or improper antenna positioning. Natural phenomena such as
solar flares and geomagnetic storms also may degrade communica-
tions at high frequency. The troubleshooting section in this manual
addresses only high VSWR readings and indications of faulty
VSWR measuring devices.
Look through the symptom index for symptoms found during operation or maintenance
of the SORAK. The index refers you to the associated malfunctions listed in Table 4-2,
Troubleshooting. Refer to paragraph 4-10 for use of the troubleshooting table.
SYMPTOM INDEX
Para. Page
4-19
4-19
Troubleshooting
Procedure
VSWR CHECK INDICATION
Low forward power reading (wattmeter) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High reflected power reading (wattmeter) . . . . . . . . . . . . . . . . . . . . . . . . . . .
High VSWR (return loss bridge) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
No audibe tone from RLB . . . . . . . . . . . . . . . . . . . . . . .
Weak tone from RLB . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-10. INTRODUCTION TO TROUBLESHOOTING.
The troubleshooting table lists the common malfunctions that you may find during the
operation or maintenance of the SORAK or its components. You should perform the
tests/inspections and corrective actions in the order listed.
This manual cannot list all malfunctions that may occur, nor all tests or inspections and
corrective actions. If a malfunction is not listed or is not corrected by listed corrective actions, notify your supervisor.
. . . . . . . . . . . . . . .
. . . . . . . . . . . . . . .
(Item No.)
1
2
3
4
5
4-19
TM 11-5985-391-12
Table 4-2. Troubleshooting
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. LOW FORWARD POWER READING ON WATTMETER
Step 1. Make sure that radio batteries are fully charged and that radio func-
tions properly.
Step 2. Retune radio (if applicable) and recheck forward power reading.
Step 3. Check field radio for proper transmit power setting (low/high).
Adjust transmit power setting and recheck forward power read-
ing.
Step 4. Check coax cable between radio and wattmeter for loose, dirty,
damaged, or corroded connectors. Also check cable for damage.
Clean surface dirt and/or corrosion from cable and connectors. If
damaged or if corrosion is not removable, replace coax per
paragraph 4-16.
Step 5. Check for dirty or corroded coax connectors on radio.
Clean radio connectors if dirty or corroded.
Step 6. Check for faulty wattmeter operation per instructions in paragraph
4-6.
Replace faulty wattmeter per paragraph 4-12.
2. HIGH REFLECTED POWER READING ON WATTMETER
Step 1. Check coax cable between wattmeter and balun for loose, dirty,
damaged, or corroded connectors. Also check cable for damage.
Clean surface dirt and/or corrosion from cable and connectors. If
damaged or if corrosion is not removable, replace coax per
paragraph 4-16.
4-20
TM 11-5985-391-12
Table 4-2. Troubleshooting (CONT)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
2. HIGH REFLECTED POWER READING ON WATTMETER (CONT)
Step 2. Check for corroded or loose connections between balun and antenna
wires or ground rod wire. Also check for corroded contact surfaces
on balun terminals.
Tighten loose connections to antenna wires and remove corrosion
to expose clean, bare metal. Reconnect balun and recheck
VSWR.
Step 3. Check for broken antenna wire.
Tie broken wire together with square knot.
Step 4. Check for loose connections at termination assembly and
anchor/ground rod. Unhook ground wire at grounding rod and termination assembly and check all components for dirty or corroded
contact surfaces.
Remove all dirt or corrosion to expose clean, bare metal. Reconnect ground wire and recheck VSWR.
Step 5. Check grounding rod area for poor grounding conditions (dry earth,
ground rod not driven deep enough, etc.).
Moisten earth around anchor/ground rod and/or drive rod deeper
to improve grounding. Recheck VSWR.
Step 6. If possible, check for faulty termination or balun transformer per in-
structions in paragraph 4-6.
Replace faulty termination or balun per paragraph 4-16.
3. HIGH VSWR INDICATION WITH RETURN LOSS BRIDGE
Step 1. Listen with headset for interference on communication frequency.
Change frequency by about 10 kHz. Continue changing frequency until interference-free channel is found. Recheck VSWR.
4-21
TM 11-5985-391-12
Table 4-2. Troubleshooting (CONT)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
3. HIGH VSWR INDICATION WITH RETURN LOSS BRIDGE (CONT)
Step 2. Check coax cable between return loss bridge and balun for loose,
dirty, damaged, or corroded connectors. Also check coax cable for
damage.
Clean surface dirt and/or corrosion from cable and connectors. If
damaged or if corrosion is not removable, replace coax per
paragraph 4-16.
Step 3. Check for corroded or loose connections between balun and antenna
wires or anchor/ground rod wire.
on balun terminals.
Tighten connections and remove corrosion to bare metal. Reconnect and recheck VSWR.
Also check for corroded surfaces
Step 4. Check for broken antenna wire.
Tie broken wire together with square knot.
Step 5. Check for loose connections at termination assembly and
anchor/ground rod. Unhook ground wire at grounding rod and termination assembly and check all components for dirty or corroded
contact surfaces.
Remove all dirt or corrosion to expose clean, bare metal. Recon-
nect ground wire and recheck VSWR.
Step 6. Check anchor/ground rod area for poor grounding (dry earth,
grounding rod not driven deep enough, etc.).
Moisten earth around anchor/ground rod and/or drive rod deeper
to improve grounding. Recheck VSWR.
Step 7. If possible, check for faulty termination or balun transformer per in-
structions in paragraph 4-6.
Replace faulty termination or balun per paragraph 4-16.
4-22
Table 4-2. Troubleshooting (CONT)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
4. NO AUDIBLE TONE FROM RETURN LOSS BRIDGE
Step 1. Check RLB gain (VOL) adjust knob.
Turn VOL knob on and listen for audible tone.
Step 2. Check for proper test setup.
Make sure radio is connected to RCVR input on RLB. Also
check that radio is in receive mode.
Step 3. Check coax cable between radio and RLB for loose, dirty, damaged,
or corroded connectors. Also check coax cable for damage.
Clean surface dirt and/or corrosion from cable and connectors. If
damaged or if corrosion is not removable, replace coax per
paragraph 4-16.
TM 11-5985-391-12
Step 4. Replace 9 volt battery if replacement is available. Then repeat checks
in steps 1 through 3.
Replace faulty RLB with working unit.
5. WEAK TONE FROM RETURN LOSS BRIDGE
Step 1. Check RLB gain (VOL) adjust knob.
Turn VOL knob on and listen for audible tone.
Step 2. Check coax cable between radio and RLB for loose, dirty, damaged,
or corroded connectors. Also check coax cable for damage.
Clean surface dirt and/or corrosion from cable and connectors. If
damaged or if corrosion is not removable, replace coax per
paragraph 4-16.
Step 3. Replace 9 volt battery if replacement battery is available. Then
repeat checks in steps 1 and 2.
Replace faulty RLB with working unit.
4-23/(4-24 blank)
TM 11-5985-391-12
Section V. MAINTENANCE PROCEDURES
Subject
Introduction . . . .
Antenna Group OE-452/PRC (SORAK) . . . . . . . . . . . . . . . . . . . 4-12
Antenna System Test Set (Return Loss Bridge) . . . . . . . . . . . . . . 4-13
22 Foot Mast/Guy Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
22 Foot Mast Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Antenna Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
6 Foot Mast/Guy System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
6 Foot Mast Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Installation Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
4-11. INTRODUCTION.
The following maintenance procedures are authorized at the organizational level in ac-
cordance with the Maintenance Allocation Chart in Appendix B of this manual.
4-12. ANTENNA GROUP OE-452/PRC (SORAK).
INSPECT
1.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspect deployment bag, mast bag, and wattmeter to make sure they are fit
for service.
Para. Page
4-11
4-25
4-25
4-26
4-27
4-29
4-33
4-37
4-37
4-41
2.
Inspect, test, and, if necessary, repair all other antenna group components in
accordance with instructions in paragraphs 4-13 through 4-19.
TEST
Test antenna transmission components and VSWR check devices according to the procedures in paragraph 4-6.
4-25
TM 11-5985-391-12
4-12. ANTENNA GROUP OE-452/PRC (SORAK) (CONT).
REPAIR
1.
If visual inspection of deployment bag, wattmeter, or mast bag indicates that
an item is not fit for service, replace it.
2.
If wattmeter or antenna transmission components fail tests in paragraph 4-16,
replace it.
4-13. ANTENNA SYSTEM TEST SET (RETURN LOSS BRIDGE).
INSPECT
Inspect return loss bridge (1) for breakage, dents, corroded connectors, or
1.
other defects that could prevent its use.
2.
Check that all four screws (2) are placed in battery compartment cover (3).
Open battery compartment and check for 9 volt battery (4). Check battery
3.
for corrosion and leakage.
4.
Check that VOL knob (5) is in place and not broken.
4-26
TM 11-5985-391-12
4-13. ANTENNA SYSTEM TEST SET (RETURN LOSS BRIDGE) (CONT).
REPAIR
If visual inspection of return loss bridge indicates unit is not fit for service,
1.
replace it.
2.
If any screws (2) in battery compartment cover (3) are missing, replace them.
If 9 volt battery (4) is missing or defective, replace it.
3.
4.
If VOL knob (5) is broken or missing, replace it.
4-14. 22 FOOT MAST/GUY ASSEMBLY.
INSPECT
1.
Check that the kit includes a 22 foot telescoping mast, five 21 foot guy rope
assemblies, three 32 foot guy rope assemblies, and five guy stake assemblies.
Check that each guy rope assembly is equipped with serviceable
spool/tensioner (l), and snaphooks (2 and 3). Check each guy rope (4) for
cuts or fraying.
Check general condition of each guy stake assembly to determine if stake (5)
is serviceable. Check each rope loop (6) for cuts or fraying.
Inspect telescoping mast per paragraph 4-15.
4-27
TM 11-5985-391-12
4-14. 22 FOOT MAST/GUY ASSEMBLY (CONT).
REPAIR
1.
If spool/tensioner (1), snaphooks (2 or 3), or guy rope (4) is damaged or
missing, cut end of guy rope, replace damaged component and retie assembly
as shown.
2.
If guy stake (5) is not serviceable, replace guy stake assembly. If rope loop (6)
is damaged or missing, tie new loop of rope through guy stake as shown.
3.
If telescoping mast is damaged, disassemble per procedures in paragraph 4-15
and survey extent of damage. If three or more tube sections are damaged,
replace mast assembly.
4-28
4-15. 22 FOOT MAST ASSEMBLY.
INSPECT
1.
Extend all sections of telescoping mast per instructions shown. Check for
smooth extension of tube sections. Clean all dirt from mast tube surfaces.
TM 11-5985-391-12
A. Extend and hold upper section
upward.
B. Pull down and twist lower section
counterclockwise until stop.
Push upper tube section down to
lock.
C. Reverse twist to check locking ac-
tion.
Verify that each inner tube section (1) operates smoothly and locks into posi-
2.
tion in mating tube section (2).
Check that mast tube sections are not chipped, gouged, broken, or split.
3.
4.
Check that guy ring (3) is secured in place by guy ring retainer (4). Check
that top assembly (5) is in place.
top assembly are intact.
5.
Check that base cover (7) is held in place by four flat head screws (8).
Check that drain hole (9) in base cover (7) is not clogged. Unclog drain hole,
6.
if necessary.
7.
Check that caution label (10) and instruction label (11) are in place and
legible.
Collapse mast assembly and check that assembly locks in place when fully col-
8.
lapsed.
Check snaphook holes (6) in guy ring and
4-29
TM 11-5985-391-12
4-15. 22 FOOT MAST ASSEMBLY (CONT).
4-30
4-15. 22 FOOT MAST ASSEMBLY (CONT).
REPAIR
If three or more mast tube sections are unfit for service, replace mast as-
1.
sembly.
2.
If less than three mast tube sections, top assembly, guy ring, base assembly, or
locking mechanism is defective or missing, replace according to the procedure
shown.
If caution label (12) or instruction label (13) is missing or not readable, re-
3.
place it on a clean portion of outermost tube.
4.
Replace any missing flat head screws (3).
MAST DISASSEMBLY/ASSEMBLY:
TM 11-5985-391-12
A. Unscrew top assembly (1) from
innermost tube section (2).
B. Collapse all sections of telescop-
ing mast.
C. Remove screws (3). Remove
base cover (4) and gasket (5)
from outermost tube section (6).
D. Pull out nested tube sections (7)
from bottom of outermost tube
section (6) until you reach guy
ring tube section (8).
E. While lifting up on guy ring (9),
use screwdriver to push the three
guy ring retainer buttons (10) in,
one at a time. Remove guy ring
retainer (11) and guy ring (9).
4-31
TM 11-5985-391-12
4-15. 22 FOOT MAST ASSEMBLY (CONT).
MAST DISASSEMBLY/ASSEMBLY (CONT)
F.
Replace faulty tube section or attaching part. Refer to 22 foot
mast tube section, Table 4-3, to
identify tube sections.
Insert tube sections in reverse
G.
order of removal.
H.
After inserting guy ring tube section (8), install guy ring (9) and
lock in place with guy ring
retainer (11). Make sure that
retainer buttons (10) seat in locking holes of mast tube section.
Insert remaining sections.
Install gasket (5), base cover (4),
I.
and secure with screws (3).
J.
Screw top assembly (1) into innermost tube section (2) at top of
mast.
4-32
Table 4-3.
22 Foot Mast Tube Sections
TM 11-5985-391-12
Item
No.
1
2
3
4 No. 4 section
5
6
7 No. 7 section
8
9 No. 9 section
10
11
4-16. ANTENNA ASSEMBLY.
Tube Section/
Description
Outermost section 3.83 (9.73) 26.89 (68.30)
No. 2 section
Guy ring section
No. 5 section
No. 6 section
No. 8 section
No. 10 section
Innermost section
Tube Tube
Diameter Length
In. (cm) In. (cm)
3.53 (8.97) 26.95 (68.45)
3.23 (8.20) 27.30 (69.34)
2.92 (7.42) 27.42 (69.65)
2.62 (6.65) 27.42 (69.65)
2.32 (5.89) 27.42 (69.65)
2.02 (5.13) 27.42 (69.65)
1.72 (4.37) 27.42 (69.65)
1.41 (3.58) 25.09 (63.73)
1.11 (2.82) 25.09 (63.73)
0.81 (2.06) 24.46 (62.13)
Replacement
Tube
Part No.
A3158117
A3158118-2
A3158137
A3158118-4
A3158118-5
A3158118-6
A3158118-7
A3158118-8
A3158118-9
A3158118-10
A3158119
INSPECT
1.
Perform maintenance
test procedure in
paragraph 4-6 to
check performance of
coax cables, termina-
tions, and balun.
4-33
TM 11-5985-391-12
4-16. ANTENNA ASSEMBLY (CONT).
2.
Check that 25 and 40 foot coax cables are equipped with a serviceable spool.
Check that coax adapter is on hand and in serviceable condition.
3.
4.
Check that all components of anchor/
ground rod assemblies are on hand
and in serviceable
condition.
Check anchor/ground
5.
rod assemblies for
visible corrosion.
4-34
4-16. ANTENNA ASSEMBLY (CONT).
Inspect full length of
6.
antenna wires for
breaks, fraying, cuts,
or knots.
Reel in wire to check
7.
operation of reels.
Tighten tension adjust knob and check
for drag on antenna
wire. Check that
snaphooks, terminal
leads, and locking
loops are intact.
TM 11-5985-391-12
Check that halyard is
8.
equipped
serviceable spool,
shorting stud, and
snap-hooks. Check
halyard rope for cuts
or fraying.
Check that lead
9.
weights are on hand
and check rope loop
for cuts or fraying.
with a
4-35
TM 11-5985-391-12
4-16. ANTENNA ASSEMBLY (CONT).
REPAIR
1.
If a coax cable or halyard spool is missing or not serviceable, replace it.
2.
If anchor rope, tensioning block, or snaphook is damaged or missing, install
new component(s) and tie rope as shown.
4-36
If halyard rope, shorting stud, or snaphook is damaged or missing, install new
3.
component(s) and tie halyard rope as shown.
4.
If lead weight rope loop is damaged or missing, replace with new rope and tie
loose ends.
If any other component part of the antenna assembly is missing, faulty, or
5.
found not to be in a serviceable condition, replace it.
4-17. 6 FOOT MAST/GUY SYSTEM.
INSPECT
Check 6 foot mast/guy system for
two mast guy assemblies.
REPAIR
If mast/guy assembly is missing or
unfit for service, replace it.
4-18. 6 FOOT MAST ASSEMBLY.
TM 11-5985-391-12
INSPECT
1.
2.
3.
4.
Unwrap guy ropes from
mast/guy assembly.
Visually inspect that each
mast/guy assembly
equipped with three guy
ropes.
Check that each guy rope is
equipped with a serviceable
tensioning block and guy
stake.
Check each guy rope for
cuts or fraying.
4-37
TM 11-5985-391-12
4-18. 6 FOOT MAST ASSEMBLY (CONT).
Extend telescoping mast per instructions shown. Check for smooth extension
5.
of tube sections. Clean all dirt from mast surfaces.
A. Extend and hold top section up-
ward.
B. Pull down and twist lower section
counterclockwise until it stops.
Push upper tube down to lock.
C. Reverse twist to check locking ac-
tion.
6.
Check that top assembly (l), screws
(2), and base cover
(3) are in place and
serviceable.
7.
Verify that each tube
section (4) operates
smoothly and locks
into position with
mating tube section
(5).
8.
Check that mast tube
sections are not
chipped, gouged,
broken, or split.
9.
Check that instruction label (6) is in
place and legible.
4-38
4-18. 6 FOOT MAST ASSEMBLY (CONT).
REPAIR
If a guy rope or its attaching parts are missing or are not in a serviceable con-
1.
dition, replace the guy rope assembly as shown.
TM 11-5985-391-12
Remove damaged guy rope assembly from mast.
Feed loose end of replacement
guy rope through line retainer (if
needed) and through hole in guy
stake.
Feed opposite end of line back
through open hole in tensioning
block, through mast top, and tie
to tensioning block as shown.
Tie knot at guy stake as shown.
4-39
TM 11-5985-391-12
4-18. 6 FOOT MAST ASSEMBLY (CONT).
2. If a mast tube section or an attaching part is damaged or defective, replace
the tube section or attaching part as shown.
MAST DISASSEMBLY/ASSEMBLY:
A.
Unscrew top assembly (1) from
innermost tube section (2).
B.
Collapse all sections of telescoping mast.
Remove four screws (3) from
c.
base cover (4).
cover (4) and gasket (5) from
outermost tube section (6).
D.
Pull out nested tube sections (7)
from bottom of mast assembly
until faulty tube is removed.
Remove base
Replace faulty tube section(s) or
E.
attaching part(s). Refer to 6 foot
mast tube section, Table 4-4, to
identify tube sections.
Insert tube sections in reverse
F.
order of removal.
Install gasket (5), base cover (4),
G.
and secure with screws (3).
H.
Screw top assembly (1) into innermost tube section (2) at top of
mast.
4-40
Loading...