4-1Installation Data ..................................................11
LIST OF TABLES
TablePage
1-1Reference Data ....................................................4
1-2Equipment and Documents Supplied ...................................5
4-1Cable and Connector Group Suggestions ..............................10
ii
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VTM-98006F
SECTION 1
GENERAL INFORMATION AND SAFETY PRECAUTIONS
1-1 GENERAL SAFETY PRECAUTIONS. The following general safety precautions are not
related to any specific procedures and therefore do not appear elsewhere in this publication.
These are recommended precautions that personnel must understand and apply during many
phases of operation and maintenance.
WARNING
Keep away from live circuits. Operating personnel must at all times observe all safety
regulations, to prevent serious injury or death due to electrical shock.
Do not service or adjust alone. Under no circumstances should any person service or adjust
the equipment except in the presence of someone who is capable of rendering aid.
Personnel working with or near high voltages should be familiar with modern methods of
resuscitation.
1.2SPECIFIC WARNINGS. The following specific precautions are related to inspecting and
removing the antenna.
Ensure that the transmitting equipment is de-energized prior to inspection of the antenna.
Make sure the test equipment is properly grounded, to prevent electric shock.
Make sure the antenna is properly supported before removing its mounting hardware.
Do not coat the insulator with any substance; do not paint with lead base paints.
WARNING
CAUTION
CAUTION
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VTM-98006F
1-3INTRODUCTION. This manual provides general information, operating and functional
description, and installation data for Valcom's VBBA 2-30 broadband antenna.
1-4EQUIPMENT DESCRIPTION. The VBBA 2-30 Broadband Antenna (see figure 1-1) is a
whip antenna for general use with HF communications equipment. The antenna provides
vertically polarized, omnidirectional azimuth radiation from 2 to 30 MHz when the antenna
is operated with a HF transceiver. It is designed for use under the severe environmental
conditions encountered aboard Naval vessels. It is used for either receiving or transmitting
high frequency signals. The antenna is a two section antenna and is base mounted. The
mounting flange and insulator is a single integral part made from fibreglass.
1-5RELATIONSHIP TO OTHER EQUIPMENT. The VBBA 2-30 Antenna interfaces with the
HF receiving and transmitting equipment.
1-6REFERENCE DATA. Table 1-1 lists the reference data for the antenna.
1-7EQUIPMENT ACCESSORIES, AND DOCUMENTS SUPPLIED. Table 1-2 lists the
equipment and documents supplied.
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VTM-98006F
Figure 1-1 Antenna VBBA 2-30
3
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Table 1-1 Reference Data
PARAMETERSPECIFICATION
Nomenclature Antenna, VBBA 2-30
Manufacturer 35736
Frequency Range 2-30 MHz
VSWR 2.0:1 Maximum
Polarization Vertical
Power Rating 3 kW
Azimuth Coverage Omnidirectional
Input Connection 7/8 EIA Flange (see Note 1)
Temperature -50ºC to 65ºC (-60ºF to 150ºF)
VTM-98006F
Wind Velocity 140 mph (224 kph)
Humidity 0 - 100 %
Shock MIL-S-901C Grade A
Vibration MIL-STD-167-1 Type 1
NOTES:1. For 1 kW operation, an 7/8 EIA to N adapter can be supplied (optional)
Table 1-2 Equipment, Accessories and Documents Supplied
4
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QTY
VTM-98006F
NOMENCLATUREOVERALL DIMENSIONS (INCHES)WEIGHT
(POUNDS)
CRATEDUNCRATED
UNCRATED
HEIGHTDIAHEIGHT DIA
1ANTENNA
VBBA 2-30
P/N VD-97-00061-1
1TECHNICAL
MANUAL FOR
VBBA 2-30 ANTENNA
VTM-98006
1DC-4 ELECTRICAL
INSULATING
COMPOUND
9MS24693-C140
3/8-16 X .75 L
FLAT HD SCREW
1MIL-T-22361
ANTI-SEIZE
COMPOUND
1GROUND STRAP
P/N VC-97-00069-1
--- --- 421 13.0
Base
260
17/8 EIA to N Type
ADAPTER (ANDREW
PN: 2260B )
(NOTE: Optionally
supplied for 1 kW or less
operation)
11/2" HELIAX CABLE
(LDF4-50A)
CONNECTOR
ANDREW P/N: L44R
(NOTE: Optionally
supplied for 1kW or
more operation)
SECTION 2
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VTM-98006F
OPERATION
2-1INTRODUCTION. This chapter provides operating instructions for the antenna.
2-2CONTROLS AND INDICATORS. The antenna contains no controls or indicators.
2-3OPERATING PROCEDURES.
2-3.1Operator Turn-On. No operator turn-on procedures apply since no power is required to
operate the antenna. However, the antenna is coupled to RF equipment
(transmitter/receiver) and to associated systems which may require energizing. For
operating instructions, consult the appropriate technical manuals.
2-3.2Modes of Operation. The antenna operates automatically, and no operator intervention is
required other than interconnecting the associated transmitter or receiver with the
antenna.
2-3.3Operation Under Interfering Conditions. No additional or alternate instructions are
necessary to operate the antenna under interfering conditions.
2-3.4Operator Turn-off. Since no power is required to operate the antenna, no operator turn-
off is required. However, the specific equipment connected to the antenna may require
operator turn-off. Consult the associated technical manuals for turn-off procedures.
2-3.5Emergency Operation. No additional or alternate steps are necessary to operate the
antenna under emergency conditions.
2-3.6Emergency Turn-off. The antenna requires no emergency turn-off. For emergency turn-
off of specific equipment connected to the antenna, consult the associated technical
manuals.
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VTM-98006F
SECTION 3
FUNCTIONAL DESCRIPTION
3-1FUNCTIONAL DESCRIPTION. The VBBA 2-30 Broadband Antenna is a base
mounted, high-power antenna which provides omnidirectional coverage for general
purpose communications use from 2 to 30 MHz. The antenna consists of a radiating
element, and a fibreglass base insulator/mounting flange. The radiating element tapers
from approximately 8.25 inches in diameter at the insulator to 2.17 inches at the top. The
antenna base insulator electrically isolates the radiating section of the antenna from the
ground and physically supports it. The insulator/mounting base is constructed of highstrength, laminated epoxy fibreglass material. When assembled, the overall length of the
antenna is approximately 35 feet. The antenna disassembles into 2 sections. The
broadband feature of the antenna means no antenna coupler is required. The transmitter
or receiver only is required to be connected to the antenna.
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VTM-98006F
SECTION 4
INSTALLATION
4-1SITE INFORMATION. Valcom's VBBA 2-30 HF Antenna is designed primarily for
shipboard installation. The antenna can also be used at shore installations. The antenna
should be installed in a non-obstructed environment, clear from any contiguous
structures, such as masts, bulkheads, or other metal objects.
4-2TOOLS AND MATERIALS REQUIRED. No special tools and materials are required for
installation.
4-3UNPACKING AND REPACKING. Table 1-2 gives data on the overall dimensions,
volume, and weight of the uncrated antenna. To unpack, carefully pry off the cover, and
remove the antenna from the container. Save the container to pack the antenna for
reshipment. No special handling procedures are required; observed normal precautions
when handling the antenna.
4-4FOUNDATION. The antenna should be installed vertically on a mounting plate that has
bolt holes matching those in the antenna base (see figure 4-1).
4-5INPUT REQUIREMENTS. The antenna has an rf power handling capability of 3 kW in
the 2 to 30 MHz frequency range.
4-6INSTALLATION PROCEDURES. After unpacking the antenna, proceed with its
installation as follows:
a. Examine the exterior of the antenna for damage; make sure that the top of the lower
section and the bottom of the upper section has not been damaged, misaligned, or
fractured.
b. Before assembling the two sections together, the sleeve at top of the bottom section
must be coated with an electrically conducting compatible zinc base anti-seize compound
MIL-T-22361 (supplied).
c. Place the bottom section of the antenna on two saw horses. After applying the antiseize compound to the mating sleeve, carefully slide the antenna top section over the
sleeve making sure the arrows on each section are aligned.
d. Ensure the eight holes are in line between the two sections. Install the eight
countersink flat head screws to the two sections. After installation, seal the screw heads
and the antenna joint using the insulating compound.
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VTM-98006F
e. Carefully lift the antenna to its mounting platform. Align the mounting holes of the
base flange with the mounting holes in the platform.
f. Secure the antenna to its mounting plate with using eight 5/8-11 hex head cap screws,
flatwashers (two per bolt required), split lockwashers and nuts. Bolt length will be
determined by the installing activity.
g. Make sure the ground strap supplied with the antenna is connected to one of the
mounting bolts directly below the input connector on the antenna as shown in Figure 4-1.
h. The VBBA 2-30 antenna input is an 7/8 EIA Flange and is found on the base insulator
below the drip shields. Prior to connecting the system feedline, ensure the equipment has
been de-energized and proper lock out procedures followed. Once the lockout
procedures have been performed, connect the system feedline to the antenna. For 1 kW
operation with the antenna, an 7/8 EIA to N Adapter can be supplied for connecting to an
N type feedline cable connector. For more than 1 kW operation, a 7/8 EIA Flange can be
supplied for the feedline used. Ensure the ground wire supplied has a secure connection
at the input connector on one end and the other end to the antenna mounting bolt. Seal
the ground connection at both ends using the insulation compound provided.
4-7CABLES AND CONNECTORS. Other types of cables and connectors can be used to
connect the antenna’s input connector to the radio equipment. Some suggestions can be
found in table 4-1.
Table 4-1 Cable and Connector Group Suggestions
Group 1
(Heliax Cable)
Cable:LDF4-50A (Andrew)
(½" Dia., 50 S, 3 kW @ 30 MHz)
Connector:7/8 EIA Flange L44R (Andrew)
Group 2
(Heliax Cable)
Cable:LDF5-50T (Andrew)
(7/8" dia., 50 S, 14 kW @ 30 MHz)
Connector:7/8 EIA Flange L45R (Andrew)
Group 3
(1kW)
Cable:RG-214/U
Connector: N-type UG-21E/U
4-8INSTALLATION CHECKOUT. Checkout of the antenna after installation can only be
accomplished by operating the receiving and transmitting equipment that is used with the
antenna.
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VTM-98006F
Figure 4-1 Installation Data
10
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5.1Scheduled Maintenance
The antenna is virtually maintenance free. The external finish is a silicone alkyd paint.
The minimum finish life before showing signs of deterioration should be at least six years
under normal climate conditions.
When used in salt-water environments, it is recommended to wash the antenna base with
fresh water to remove any build-up of dried salt residue. This should be performed on a
monthly basis or after prolonged exposure to sea-spray.
Use a small wire brush to clear any debris from the drain groove found in the bottom of
the antenna base.
5.2Corrective Maintenance
Generally, no corrective maintenance is possible or required. If one section is severely
damaged, it must be replaced by a new section. Workshops having experience in
handling epoxy fibreglass composite structures and/or aluminum construction may
attempt the repair of minor surface damage if practicable.
VTM-98006F
5.0 MAINTENANCE
NOTE
DO NOT USE LEAD BASE PAINT TO TOUCH-UP OR
REPAINT THE ANTENNA. USE ONLY EPOXY BASE PAINT.
11
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