Chameleon Antenna CHA TD User manual

Tactical Dipole (CHA TD)
Operator’s Manual
California - USA
WWW.CHAMELEONANTENNA.COM
VERSATILE –DEPENDABLE –STEALTH –BUILT TO LAST

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Table of Contents
Introduction ..............................................................................................................................................3
HF Propagation ......................................................................................................................................... 3
Parts of the Antenna.................................................................................................................................4
Antenna Configurations............................................................................................................................8
Sloping “V” ............................................................................................................................................ 9
Horizontal Dipole ................................................................................................................................11
Sloping Wire........................................................................................................................................12
Inverted “L”.........................................................................................................................................14
Horizontal NVIS ...................................................................................................................................15
Half Rhombic.......................................................................................................................................16
Recovery Procedure................................................................................................................................18
Packing Procedure ..................................................................................................................................18
Troubleshooting......................................................................................................................................18
Specifications ..........................................................................................................................................19
Accessories..............................................................................................................................................22
Chameleon AntennaTM Products............................................................................................................22
References ..............................................................................................................................................24
Be aware of overhead power lines when you are deploying the CHA TD. You could be electrocuted if the
antenna gets near or contacts overhead power lines.
All information on this product and the product itself is the property of and is proprietary to
Chameleon AntennaTM . Specifications are subject to change without prior notice.

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Introduction
Thank you for purchasing and using the Chameleon AntennaTM Tactical Dipole (CHA TD) antenna. The CHA TD is a
broadband High Frequency (HF) antenna specially designed for short to long range portable and man-pack HF
communication. The CHA TD is ideal for military, government agencies, non-governmental organizations (NGOs),
Military Affiliate Radio System (MARS), Civil Air Patrol (CAP), Amateur Radio Emergency Service (ARES) / Radio
Amateur Civil Emergency Service (RACES), Salvation Army Team Emergency Radio Network (SATERN), and amateur
radio operators (hams) involved in field communication and disaster preparedness. The CHA TD is configurable to
facilitate Near-Vertical Incident Sky wave (NVIS) communication and its broadband design supports Automatic Link
Establishment (ALE), frequency-hopping, and spread-spectrum modes without a tuner or coupler. The CHA TD can
be deployed by the operator in the field in less than 15 minutes, using almost any available support, with no masts
or guying required. Antennas built by Chameleon AntennaTM are versatile, dependable, stealthy, and built to last.
Please read this operator’s manual so that you may maximize the utility you obtain from your CHA TD.
HF Propagation
HF radio provides relatively inexpensive and reliable local, regional, national, and international voice and data
communication capability. It is especially suitable for undeveloped areas where normal telecommunications are
not available, too costly or scarce, or where the commercial telecommunications infrastructure has been damaged
by a natural disaster or military conflict.
Although HF radio is a reasonably reliable method of communication, HF radio waves propagate through a
complex and constantly changing environment and are affected by weather, terrain, latitude, time of day, season,
and the 11-year solar cycle. A detailed explanation of the theory of HF radio wave propagation is beyond the
scope of this operator’s manual, but an understanding of the basic principles will help the operator decide what
frequency and which of the CHA TD’s configurations will support their communication requirements.
HF radio waves propagate from the transmitting antenna to the receiving antenna using two methods: ground
waves and sky waves.
Ground waves are composed of direct waves and
surface waves. Direct waves travel directly from the
transmitting antenna to the receiving antenna when
they are within the radio line-of-sight. Typically, this
distance is 8 to 14 miles for field stations. Surface
waves follow the curvature of the Earth beyond the
radio horizon. They are usable, during the day and
under optimal conditions, up to around 90 miles, see
table (1). Low power, horizontal antenna
polarization, rugged or urban terrain, dense foliage,
or dry soil conditions can reduce the range very
significantly. The U.S. Army found that in the dense
jungles of Vietnam, the range for ground waves was
sometimes less than one mile.
Frequency
Distance
Frequency
Distance
2 MHz
88 miles
14 MHz
33 miles
4 MHz
62 miles
18MHz
29 miles
7 MHz
47 miles
24 MHz
25 miles
10 MHz
39 miles
30 MHz
23 miles
Table 1. Maximum Surface Wave Range by Frequency.
Sky waves are the primary method of HF radio wave propagation. HF radio waves on a frequency below the critical
frequency (found by an ionosonde) are reflected off one of the layers of the ionosphere and back to Earth between
300 and 2,500 miles, depending upon the frequency and ionospheric conditions. HF radio waves can then be
reflected from the Earth to the ionosphere again during multihop propagation for longer range communication.
The most important thing for the operator to understand about HF radio wave propagation is the concept of
Maximum Usable Frequency (MUF), Lowest Usable Frequency (LUF), and Optimal Working Frequency (OWF). The
MUF is the frequency for which successful communications between two points is predicted on 50% of the days of

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in a month. The LUF is the frequency below which successful communications are lost due to ionospheric loses.
The OWF, which is somewhere between the LUF and around 80% of the MUF, is the range of frequencies which
can be used for reliable communication. If the LUF is above the MUF, HF sky wave propagation is unlikely to occur.
The HF part of the Radio Frequency (RF) spectrum is usually filled with communications activity and an
experienced operator can often determine where the MUF is, and with less certainty, the LUF by listening to where
activity ends. The operator can then pick a frequency in the OWF and attempt to establish contact. Another
method is using HF propagation prediction software, such as the Voice of America Coverage Analysis Program
(VOACAP), which is available at no cost to download or use online at www.voacap.com.The operator enters the
location of the two stations and the program show a wheel with the predicted percentage of success based on
frequency and time. ALE, which is the standard for interoperable HF communications, is an automated method of
finding a frequency in the OWF and establishing and maintaining a communications link.
Even under optimal conditions, there is a gap between where ground waves end (around 40 to 90 miles) and the
sky wave returns to Earth on the first hop (around 300 miles). NVIS propagation can be used to fill this gap. The
frequency selected must be below the critical frequency, so NVIS is can normally only be used on frequencies from
around 2 to 10 MHz. Frequencies of 2 –4 MHz are typical at night and 4 –8 MHz during the day.
Parts of the Antenna
The CHA TD is comprised of the following components:
a. Matching Transformer, EMCOMM II
The EMCOMM II Matching Transformer, see plate (1), provides impedance matching for the CHA TD.
b. Antenna Wire
The Antenna Wires, see plate (2), are two 60 foot lengths of black insulated wire, wrapped around Line
Winders (f).
c. Counterpoise Wire
The Counterpoise Wires, see plate (3), are two 25 foot lengths of black insulated wire, wrapped around Line
Winders (f).
d. Isolation loop
Two Isolation loops, one at each end, are permanently attached to the Antenna Wires (b) and Counterpoise
Wires (c), see plates (2) and (3).
e. Carabiner
The Carabiners, see plates (2) and (3) are removable pear-shaped stainless steel hooks with a spring-loaded
gate.

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Plate 1. Matching Transformer, Side View (top), Bottom View (left) and Top View (right).
f. Line Winder
The Line Winders are used to store the Antenna Wires (b), Counterpoise Wires (c), and Paracord (h), see plates
(2) and (3). They enable rapid deployment and recovery of the CHA TD.
Plate 2. Antenna Wire.
g. Termination Resistor, CHA R-300
The Termination Resistors, see plate (4), are non-inductive 300 Ohm resistors. They enable the CHA TD to be
broad-banded without use of a tuner or coupler.

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Plate 3. Counterpoise Wire.
h. Paracord,550
Paracord (not pictured) is used to suspend components of the CHA at the proper height or anchor them to the
ground, depending upon the antenna configuration.
Additional 50 foot lengths of Paracord on a Line Winder are available for purchase from Chameleon
AntennaTM. At least one additional assembly is highly recommended for deployment of some antenna
configurations.
i. Stakes
The four stainless steel stakes (not pictured) are used to anchor various ends of the CHA TD to the ground,
depending upon the antenna configuration.
j. Coaxial Cable
The Coaxial Cable assembly, see plate (5), is a 50 foot length of RG-58 coaxial cable with built-in RF current
isolation, terminated at each end with a UHF Plug, PL-259 (o).
The cable length may be extended using a Double UHF Socket (SO-239 Barrel), and another Coaxial Cable
assembly, which is available for purchase from Chameleon AntennaTM.
k. UHF Socket
The UHF Socket, SO-239, is located on the bottom of the Matching Transformer (a), see plate (1).
l. Top Transformer Connection
The Top Transformer Connection is located on the top of the Matching Transformer (a), see plate (1).

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Plate 4. Termination Resistor.
m. Bottom Transformer Connection
The Bottom Transformer Connection is located on the bottom of the Matching Transformer (a), see plate (1).
n. Transformer Eyebolt
The Transformer Eyebolt is located on the top of the Matching Transformer (a), see plate (1).
Plate 5. Coaxial Cable.

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o. UHF Plug
UHF Plugs, PL-259, are attached to both ends of
the Coaxial Cable (j) assembly.
p. Resistor Connection
The Resistor Connection, see plate (4), are
located at both ends of the Termination Resistor
(g).
q. Resistor Eyebolt
The Resistor Eyebolts, see plate (4), are located
at both ends of the Termination Resistor (g).
r. Wire Connector
The Wire Connectors are located at both ends of
the Antenna Wires (b) and one end of the
Counterpoise Wires (c).
s. Backpack
The Backpack, see plate (6), stores and
organizes the components of the CHA TD,
enabling rapid deployment and recovery, and
making the antenna portable and man-packable.
Plate 6. Backpack.
Antenna Configurations
Using the supplied components, the CHA TD can be deployed into a number of configurations. Six configurations
are described in this manual, each with unique performance characteristics. Table (2) shows the antenna
configurations described in this manual. The table can assist the operator to quickly select the most appropriate
antenna configuration to meet their operational requirements.
Configuration
Ground
Short
Medium
Long
Directionality
Deployment
Sloping “V”
↕
↑
Unidirectional
Deliberate
Horizontal Dipole
↓
↕
↑
Bidirectional
Deliberate
Sloping Wire
↓
↕
Omnidirectional
Hasty
Inverted “L”
↓
↕
Unidirectional
Deliberate
Horizontal NVIS
↓
↑
Omnidirectional
Hasty
Half Rhombic
*
↕
Unidirectional
Hasty
Table 2. Antenna Configuration Selection.
To use the table, decide which distance column (Ground = 0 to 90 miles, Short = 0 - 300 miles, Medium = 300 –
1500 miles, Long > 1500 miles) best matches the distance to the station with whom you need to communicate.
Then, determine if the OWF is in the lower (↓ = 1.8 – 10 MHz) or upper (↑ = 10 – 30 MHz) frequency range.
Finally, select the CHA TD configuration with the corresponding symbol in the appropriate distance column. All

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CHA TD configurations provide some capability in each distance category, so depending upon the complexity of
your communications network, you may need to select the best overall configuration. The directionality column
indicates the directionality characteristic of the antenna configuration. When using NVIS, all the configurations are
omnidirectional. “Hasty” and “Deliberate” in the deployment column indicate the relative complexity of site
selection and setup for each antenna configuration. (Note: * see configuration for coverage)
Sloping “V”
The CHA TD Sloping “V” configuration, see figure (1), is a broadband medium to long range HF antenna. This
configuration exhibits directionality towards the opening of the “V” at medium to higher frequencies, while on
lower frequencies it is bidirectional to the sides of the “V”. It requires only a single support and can be mounted at
heights from 3 to 40 feet, with around 25 feet providing good overall results. An opening angle of 90° will provide
good overall performance, but angles from 180° to 60° can be used to fit the antenna to the site or to improve
performance. Larger opening angles increase performance on lower frequencies and smaller angles on higher
frequencies. At 180°, the antenna becomes an Inverted “V” antenna. The antenna may also be mounted
horizontally using three 10 foot tall supports.
Figure 1. Sloping V Antenna Configuration.
Site Selection and Preparation.
1. Select a site to deploy the CHA TD Sloping V
configuration, see figure (1). The best site
should have a tree or other support that would
enable the Matching Transformer to be at a
height of around 25 to 40 feet. If a tall support
is unavailable, any convenient object, such as a
fence post or the top of a vehicle, may be used
as a field expedient support with reduced
performance.
2. Remove the Matching Transformer (a), Paracord
(h), Antenna Wires (b), Coaxial Cable (j), and two
Stakes (i) from the Backpack (s).
3. If not already attached, connect a Carabiner to
each end of both Antenna Wires.
Connect the Matching Transformer. Refer to figure
(2) for steps (4) –(9).
4. Connect a Carabiner (e) from one Antenna Wire
(b) to the Transformer Eyebolt (n).

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5. Connect the Wire Connector (r) from the same
Antenna Wire to the Bottom Transformer
Connection (m). Tighten the wing nut finger
tight.
Figure 2. Matching Transformer Electrical and
Mechanical Connections.
6. Connect the Carabiner from the end of the
other Antenna Wire to the Carabiner from step
(5).
7. Connect the Wire Connector from the Antenna
Wire to the Top Transformer Connection (l).
Tighten the wing nut finger tight.
8. Using a Bowline or similar knot, tie one end of
Paracord to the Carabiner from step (5).
9. Connect the UHF Plug (o) from the Coaxial Cable
to the UHF Socket (k) on the Matching
Transformer.
Raise the antenna.
10. Using a throw weight or some other method,
loop the Paracord over the support.
11. Raise the antenna to the desired height and
secure the free end of the Paracord to the
support with a Round Turn and two Half Hitches
or similar knot.
Extend the Antenna Wires into a “V”.
12. Using a Bowline of similar knot, tie a short
length of Paracord (around 4 feet) to the
Carabiners at the unconnected end of both
Antenna Wires.
13. Extend one Antenna Wire to its full length.
14. Drive a Stake in the ground around two feet
beyond the end of the Antenna Wire.
15. Using two Half Hitches or similar knot, tie the
short length of Paracord from the Antenna Wire
to the Stake, such that the Antenna Wire is not
quite taut.
16. Extend the other Antenna Wire to its full length
along the approximate opening angle chosen to
form the antenna into a “V” (60 feet between
the ends of the “V” for 90°).
17. Drive a Stake into the ground around two feet
beyond the end of the Antenna Wire.
18. Using two Half Hitches, tie the short length of
Paracord from the Antenna Wire to the Stake,
such that the Antenna Wire is not quite taut.
19. Remove the Counterpoise Wires (c), and
Termination Resistors (g) from the Backpack.
Attach the Termination Resistors. Refer to figure (3)
for steps (20) –(25).
Figure 3. Termination Resistor Electrical and Mechanical
Connections.
20. Connect the Carabiners at the ends of both
Antenna Wires to the Resistor Eyebolts (q) of
both Termination Resistors.
21. Connect the Wire Connectors from both
Antenna Wires to the Resistor Connection (p).
Tighten the wing nuts finger tight.
Attach the Counterpoise Wires.

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22. If not already attached, connect a Carabiner to
the Wire Connector end of both the
Counterpoise Wires.
23. Connect the Carabiners to the unconnected
Resistor Eyebolts of the Termination Resistors.
24. Connect the Wire Connectors to the Resistor
Connections of the Termination Resistors.
Tighten the wing nuts finger tight.
25. Extend both Counterpoise Wires along the
ground to their full lengths. The counterpoise
works best if extended in a straight line along
the path of the Antenna Wires, but they can be
bent or ran in different directions, if needed.
26. Perform operational test.
Horizontal Dipole
The CHA TD Horizontal Dipole configuration, see figure (4), is a broadband short to long range HF antenna. The
Horizontal Dipole is the standard for wire HF antennas and will provide good sky wave (including NVIS)
propagation. It requires at least two supports (one at each end). A center support is also recommended. The CHA
TD Horizontal Dipole should be mounted at a height of around 25 feet for good overall results. When mounted at
this height, the antenna is mostly omnidirectional at lower frequencies. At higher frequencies the pattern is
predominately bidirectional broadside to the antenna. If the center of the antenna is supported and the ends are
sloped down to the ground, the antenna becomes an Inverted “V” (see Sloping “V” configuration). If the
Termination Resistors are not installed, the antenna becomes an Un-terminated Broadband Horizontal Dipole. If
the Termination Resistors are not installed and a Counterpoise Wire is substituted for one of the Antenna Wires,
the antenna becomes a Multiband Off-Center-Fed (OCF) Dipole for 60 meters and above.
Figure 4. Horizontal Dipole Configuration.
Site Selection and Preparation.
1. Select a site to deploy the CHA TD Horizontal
Dipole configuration, see figure (4). A good site
should have two trees or other supports that
are 120 feet apart and are tall enough that the
Termination Resistors at each end of the
Horizontal Dipole will be at a height of around
25 feet. The best site will have an additional
tree or other support for the center of the
antenna. If tall supports the right distance apart
are unavailable, any convenient objects, such as
fence posts or the tops of vehicles, may be used
as a field expedient supports with reduced
performance.
2. Remove the Matching Transformer (a), Paracord
(h), Antenna Wires (b), and Coaxial Cable (j)
from the Backpack (s).
3. If not already attached, connect a Carabiner to
each end of both Antenna Wires.
Connect the Matching Transformer. Refer to figure
(2) for steps (4) –(9).

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4. Connect the Carabiner from one end of the
Antenna Wire to the Transformer Eyebolt (n).
5. Connect the Wire Connector (r) from the
Antenna Wire to the Bottom Transformer
6. Connection (m). Tighten the wing nut finger
tight.
7. Connect the Carabiner from the other end of
the other Antenna Wire to the Carabiner from
step (4).
8. Connect the Wire Connector of the Antenna
Wire to the Top Transformer Connection (l).
Tighten the wing nut finger tight.
9. Connect the UHF Plug (o) from the Coaxial Cable
to the UHF Socket (k) on the Matching
Transformer.
Extend the Antenna Wires.
10. Fully extend both Antenna Wires in a straight
line in opposite directions along the ground.
11. Using a throw weight or some other method,
loop the Paracord over the end supports.
12. Using a Bowline or similar knot, tie Paracord to
the Carabiners at the ends of the Antenna
Wires.
13. If a center support is available, use a Bowline or
similar knot, tie one end of the Paracord to the
Carabiner from step (4).
Attach the Termination Resistors. Refer to figure (3)
for steps (14) –(19).
14. Remove the Counterpoise Wires (c), and
Termination Resistors (g) from the Backpack.
15. Connect the Carabiners at the ends of both
Antenna Wires to the Resistor Eyebolts (q) of
both Termination Resistors.
16. Connect the Wire Connectors from both
Antenna Wires to the Resistor Connection (p).
Tighten the wing nuts finger tight.
Attach the Counterpoise Wires.
17. If not already attached, connect a Carabiner to
the Wire Connector end of both the
Counterpoise Wires.
18. Connect the Carabiners to the Resistor Eyebolts
of the Termination Resistors.
19. Connect the Wire Connectors to the Resistor
Connections of the Termination Resistors.
Tighten the wing nuts finger tight.
Raise the antenna.
20. Raise the antenna to the desired height and
secure the free ends of the Paracord to the
supports with a Round Turn and two Half
Hitches or similar knot.
21. Perform operational test.
Sloping Wire
The CHA TD Sloping Wire configuration, see figure (5), is a broadband medium range HF antenna. It should provide
acceptable ground wave and sky wave propagation. This configuration is predominately omnidirectional, slightly
favoring the direction of the low end of the antenna on lower frequencies, broadside around 10 MHz, and the high
end of the antenna on higher frequencies. The Sloping Wire requires one support, is a good general-purpose
antenna, and is excellent for hasty deployment. It should be mounted at a height of 25 to 40 feet for best
performance.
Site Selection and Preparation.
1. Select a site to deploy the CHA TD Sloping Wire
configuration, see figure (5). The best site
should have a tree or other support that would
enable the Termination Resistor to be at a
height of around 25 to 40 feet. If a tall support
is unavailable, any convenient object, such as a
fence post or the top of a vehicle, may be used
as a field expedient support with reduced
performance.
2. Remove the Matching Transformer (a), Paracord
(h), one Antenna Wire (b), Coaxial Cable (j), two
Stakes (i), both Counterpoise Wires (c), and one
Termination Resistor (g) from the Backpack (s).
3. If not already attached, connect a Carabiner to
each end of the Antenna Wire.
4. If not already attached, connect a Carabiner to
the Wire Connector end of both the
Counterpoise Wires.

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Figure 5. Sloping Wire Configuration.
Connect the Matching Transformer. Refer to figure
(2) for steps (5) –(10).
5. Connect the Carabiner from the Counterpoise
Wire to the Transformer Eyebolt (n).
6. Connect the Wire Connector (r) from the
Counterpoise Wire to the Bottom Transformer
Connection (m). Tighten the wing nut finger
tight.
7. Connect the Carabiner from one end of the
Antenna Wire to the Carabiner from step (5).
8. Connect the Wire Connector from the Antenna
Wire to the Top Transformer Connection (l).
Tighten the wing nut finger tight.
9. Using a Bowline of similar knot, tie one end of
short length (around four feet) of Paracord to
the Carabiner connected in step (5).
10. Connect the UHF Plug (o) from one end of the
Coaxial Cable to the UHF Socket (k) on the
Matching Transformer.
Connect the Terminating Resistor. Refer to figure (3)
for steps (11) –(14).
11. Connect the Carabiner from the unconnected
end of the Antenna Wire to the Resistor Eyebolt
(q) of the Termination Resistor (g).
12. Connect the Wire Connector from the Antenna
Wire to the Resistor Connection (p) of the
Termination Resistor. Tighten the wing nut
finger tight.
13. Connect the Carabiner from the Counterpoise
Wire to the other end of the Termination
Resistor.
14. Connect the Wire Connector from the
Counterpoise Wire to the Resistor Connection of
the Termination Resistor. Tighten the wing nut
finger tight.
15. Using a Bowline or similar knot, tie one end of
the Paracord to the Carabiner from step (11).
Raise the Antenna.
16. Using a throw weight or some other method
loop the Paracord over the support.
17. Raise the end of Sloping Wire antenna to the
desired height and secure the Paracord to the
support using a Round Turn and two Half
Hitches or similar knot.
Extend the Antenna Wire and Counterpoise Wire.
18. Fully extend the Antenna Wire.
19. Drive a Stake around two feet beyond the end
of the Antenna Wire.
20. Using two Half Hitches, tie the short length of
Paracord from the Matching Transformer to the
Stake, such that the Antenna Wire is not quite
taut.
21. Extend the Counterpoise Wire that is attached
to the Matching Transformer along the ground
in any convenient direction.
22. Perform operational test.

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Inverted “L”
The CHA TD Inverted “L” configuration, see figure (6), is a broadband medium range HF antenna. This
configuration is somewhat unidirectional, favoring the Terminating Resistor end of the antenna as the frequency
increases. It is also provides effective ground waves communication during the day time on frequencies between
1.8 –4.0 MHz without using sky wave propagation. The Inverted “L” requires two supports and should be
mounted at a height of 25 feet for best performance, but will provide good performance at a height of 10 to 20
feet and is usable when mounted as low as 3 feet.
Figure 6. Inverted L Configuration.
Site Selection and Preparation.
1. Select a site to deploy the CHA TD Inverted “L”
Wire configuration, see figure (6). The site
should have two trees or other support that
would enable the Termination Resistor and the
corner of the “L” in the Antenna Wire to be at a
height of around 25 feet. If a tall supports are
unavailable, any convenient object, such as a
fence post or the top of a vehicle, may be used
as a field expedient support with reduced
performance.
2. Remove the Matching Transformer (a), Paracord
(h), one Antenna Wire (b), Coaxial Cable (j), two
Stakes (i), both Counterpoise Wires (c), and one
Termination Resistor (g) from the Backpack (s).
3. If not already attached, connect a Carabiner to
each end of the Antenna Wire and to the Wire
Connector end of both Counterpoise Wires.
Connect the Matching Transformer. Refer to figure
(2) for steps (4) –(9).
4. Connect the Carabiner from the Counterpoise
Wire to the Transformer Eyebolt (n).
5. Connect the Wire Connector (r) from the
Counterpoise Wire to the Bottom Transformer
Connection (m). Tighten the wing nut finger
tight.
6. Connect the Carabiner from one end of the
Antenna Wire to the Carabiner from step (4).
7. Connect the Wire Connector from the Antenna
Wire to the Top Transformer Connection (l).
Tighten the wing nut finger tight.
8. Connect the UHF Plug (o) from one end of the
Coaxial Cable to the UHF Socket (k) on the
Matching Transformer.
9. Using a Bowline of similar knot, tie one end of
short length (around four feet) of Paracord to
the Carabiner connected in step (4).
10. Drive a Stake in the ground near the support
closest to the location of the radio set.

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11. Using two Half Hitches, tie the short length of
Paracord from the Matching Transformer to the
Stake.
Connect the Terminating Resistor. Refer to figure (3)
for steps (12) –(15).
12. Connect the Carabiner from the end of the
Antenna Wire to the Resistor Eyebolt (q) of the
Termination Resistor.
13. Connect the Wire Connector from the Antenna
Wire to the Resistor Connection (p) of the
Termination Resistor. Tighten the wing nut
finger tight.
14. Connect the Carabiner from the Counterpoise
Wire to the Resistor Eyebolt at the other end of
the Termination Resistor.
15. Connect the Wire Connector from the
Counterpoise Wire to the Resistor Connection of
the Termination Resistor. Tighten the wing nut
finger tight.
Raise the Antenna.
16. Using a Bowline or similar knot, tie the end of
the Paracord to the Carabiner from step (12).
17. Using a throw weight or other method, loop the
Paracord over the support that is closest to
where the radio set will be located.
18. Pull the Counterpoise Wire, Termination
Resistor, and Antenna Wire over the support.
19. Using a throw weight or some other method,
loop the Paracord over the other support.
20. Raise the Inverted “L” antenna so that the
vertical and horizontal sections are not quite
taut.
21. Secure the Paracord to the support using a
Round Turn and two Half Hitches or similar knot.
Extend the Counterpoise.
22. Extend the Counterpoise Wire, attached to the
Matching Transformer, along the ground under
the horizontal section of the antenna.
23. Perform operational test.
Horizontal NVIS
The CHA TD Horizontal NVIS configuration, see figure (7), is a special configuration designed to provide good NVIS
propagation on lower frequencies. It is predominately omnidirectional and also provides medium range sky wave
propagation on frequencies above 10 MHz. It is suitable for hasty deployment and requires two supports that will
enable the antenna to be raised to a height of 10 –12 feet. This configuration will require an antenna tuner or
coupler.
Site Selection and Preparation.
1. Select a site to deploy the CHA TD Horizontal
NVIS configuration, see figure (7). The site must
have two trees or other supports that will
position the Matching Transformer and the end
of the Antenna Wire to be at a height of
between 10 and 12 feet and 60 feet apart.
Higher or lower heights may be used, but may
reduce NVIS performance.
2. Remove the Matching Transformer (a),
Paracord, Antenna Wires (b), and Coaxial Cable
(j) from the Backpack (s).
3. If not already attached, connect a Carabiner (e)
to each end of the Antenna Wires.
Connect the Matching Transformer. Refer to figure
(2) for steps (4) –(8).
4. Connect the Carabiner from one the Antenna
Wires to the Transformer Eyebolt (n).
5. Connect the Wire Connector (r) from the
Antenna Wire to the Bottom Transformer
Connection (m). Tighten the wing nut finger
tight.
6. Connect the Carabiner from the other Antenna
Wire to the Transformer Eyebolt.
7. Connect the Wire Connector from the Antenna
Wire to the Top Transformer Connection (l).
Tighten the wing nut finger tight.
8. Connect the UHF Plug (o) from one end of the
Coaxial Cable to the UHF Socket (k) on the
Matching Transformer.
Raise the Antenna.
9. Using a Bowline or similar knot, tie the end of
the Paracord to the Carabiner from step (6).

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Figure 7. Horizontal NVIS Configuration.
10. Using a throw weight or other method, loop the
Paracord over the support that is closest to
where the radio set will be located.
11. Raise the Matching Transformer end of the
antenna to a height of 10 to 12 feet and secure
it to the support using a Round Turn and two
Half Hitches or similar knot.
12. Using a Bowline or similar knot, tie another
length of Paracord to the Carabiner at the end
of the Antenna Wire.
13. Using a throw weight or some other method,
loop the Paracord over the other support.
14. Raise the end of the Antenna Wire to a height of
10 to 12 feet, such that the Antenna Wire is not
quite taut, and secure it to the support using a
Round Turn and two Half Hitches or similar knot.
Extend the Counterpoise.
15. Position the dangling Antenna Wire so that it
drops vertically from the Matching Transformer
and then horizontally under (parallel) to the
raised Antenna Wire. This is the counterpoise
for this antenna configuration.
16. Perform operational test.
Half Rhombic
The CHA TD Vertical Half Rhombic configuration, see figure (8), is a low noise broadband medium range HF and
line-of-sight VHF Low Band (30.0 - 54.0 MHz) antenna. This configuration is unidirectional in the direction of the
Matching Transformer below 12 MHz and the Termination Resistor above 25 MHz. This configuration will produce
line-of-sight and sky wave propagation, with best performance above 25 MHz. It requires one support at least 18
feet high and is a good choice when hasty deployment, directionality, and coverage of typical tactical frequencies
are required.
Site Selection and Preparation.
1. Select a site to deploy the CHA TD Half Rhombic
configuration, see figure (8). A good site should
have a support that is tall enough to suspend
the apex, at the center of the antenna, to a
height of around 18 feet.
2. Remove the Matching Transformer (a), Paracord
(h), Antenna Wires (b), one Termination Resistor
(g), two Stakes (i), and Coaxial Cable (j) from the
Backpack (s).
3. If not already attached, connect a Carabiner to
each end of both Antenna Wires.
Connect the Matching Transformer. Refer to figure
(2) for steps (4) –(9).
4. Connect the Carabiner from one end of the
Antenna Wire to the Matching Transformer
Eyebolt (n).
5. Connect the Wire Connector to the Bottom
Transformer Connection (m). Tighten the wing
nut finger tight.

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Figure 8. Half Rhombic Configuration.
6. Connect the Carabiner from the other end of
the other Antenna Wire to the Carabiner from
step (4).
7. Connect the Wire Connector to the Top
Transformer Connection (l). Tighten the wing
nut finger tight.
8. Attach a short length (4 feet) of Paracord to the
Carabiner from step (4).
9. Connect the UHF Plug (o) from the Coaxial Cable
to the UHF Socket (k) on the Matching
Transformer.
Extend the Antenna Wires.
10. Extend both Antenna Wires on the ground to
their full lengths alongside each other with the
center of the Antenna Wires close to the
support.
Attach the Termination Resistor. Refer to figure (3)
for steps (11) - (13).
11. Connect the Carabiners at the end of both
Antenna Wires to the Resistor Eyebolts (q) of
the Termination Resistor.
12. Connect the Wire Connectors to the Resistor
Connections (p). Tighten the wing nuts finger
tight.
13. Attach a short length (4 feet) of Paracord to the
Carabiner from step (11).
Raise the Antenna.
14. Using a throw weight or some other method,
loop the Paracord over the support.
15. Using a Fisherman’s or similar knot, tie the
Paracord to the center of one of the Antenna
Wires.
16. Raise the apex at the center of the Antenna
Wire to a height of 18 feet and secure the
Paracord to the support using a Round Turn and
two Half Hitches or similar knot.
17. Drive a Stake around two feet beyond the
Termination Resistor.
18. Secure the Paracord from the Termination
Resistor to the Stake using two Half Hitches or
similar knot.
19. Drive a Stake around two feet beyond the
Matching Transformer.
20. Pull the Paracord attached to the Matching
Transformer so that the elevated Antenna Wire
is not quite taut and secure the Paracord to the
Stake using two Half Hitches or similar knot.
21. Position the other Antenna Wire so that it is on
the ground mostly under the elevated Antenna
Wire. This Antenna Wire is the counterpoise for
this configuration.
22. Perform operational test.

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Recovery Procedure
To recover the CHA TD, perform the following steps:
1. Disconnect the Coaxial Cable (j) from the radio set.
2. Lower the antenna to the ground.
3. Disconnect the Coaxial Cable from the Matching Transformer (a).
4. Carefully roll (do not twist) the Coaxial Cable.
5. Untie the Paracord (h) from the Antenna Wire (b).
6. Disconnect the Antenna Wires from the Matching Transformer (a).
7. Disconnect the Antenna Wires from the Termination Resistors (g) or Matching Transformer, depending upon
the configuration.
8. Wind the Antenna Wires onto their Line Winders (f) and secure with attached shock cord.
9. Pull the Stakes (i) from the ground.
10. Disconnect the Counterpoise Wires (c) from the Terminating Resistors or Matching Transformer, depending
upon the antenna configuration.
11. Wind the Counterpoise Wires onto their Line Winders and secure with attached shock cord.
12. Remove dirt from antenna components and inspect them for signs of wear.
Packing Procedure
Note: If you have just received your CHA TD, you may want to go through this procedure to pack your new antenna
in its backpack.
Note: This suggested packing procedure will make deployment easier and help to ensure you don’t lose any CHA TD
components during recovery.
To pack the CHA TD in the Backpack (s), perform the following steps:
1. Place the Matching Transformer (a) into the lower front pouch.
2. Place the Paracord (h) into the lower front pouch and zip up the pouch.
3. If not already connected, attach a Carabiner (e) to the Isolation Loops (d) at each end of both Antenna Wires
(b), see plate (2).
4. Place both Antenna Wire assemblies into the middle pouch.
5. Place Coaxial Cable (j) assembly into the middle pouch.
6. Place the Stakes (i) into the middle pouch and zip up the pouch.
7. If not already connected, attach a Carabiner to the Isolation Loop at the Wire Connector end of the
Counterpoise Wires (c), see plate (3).
8. Place the Counterpoise Wire assemblies into the rear pouch.
9. Place the Termination Resistors (g) into the rear pouch and zip up the pouch.
10. The front top pouch can be used to store small items or tools.
11. Store the Operator’s Manual in the rear pouch.
Troubleshooting
1. Ensure Wire Connectors (r) are securely connected.
2. Inspect Antenna Wires (b) and Counterpoise Wires (c) for breakage or signs of strain.
3. Ensure UHF Plugs (o) are securely tightened.
4. Inspect Coaxial Cable (j) assembly for cuts in insulation or exposed shielding.

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5. If still not operational, replace Coaxial Cable assembly. Most problems with antenna systems are caused by
the coaxial cables and connectors.
6. If still not operational, connect a Standing Wave Ratio (SWR) Power Meter and check SWR.
7. If SWR is greater than 3:1, connect a Multi-Meter to Termination Resistors (g). Termination Resistor should
measure 300 Ohms. Replace if they measures less than 285 Ohms or greater than 315 Ohms.
8. If still not operational, connect a Multi-Meter to the Antenna Wires to check continuity. Replace assemblies
that do not pass a continuity check.
9. If still not operational, replace Matching Transformer (a).
Specifications
Frequency: 1.8 MHz through 30.0 MHz continuous (including all Amateur Radio Service bands 160m to
10m), 30 .0 MHz through 54.0 MHz continuous (including the 6m Amateur Radio Service band) also
available when the CHA TD is installed in the Half Rhombic configuration
Power: 100 W continuous duty cycle (CW, AM, FM, RTTY), 300 W intermittent duty cycle (SSB and SSB-
based digital modes)
RF Connection: UHF Plug (PL-259)
SWR: Subject to frequency and configuration, but typically less than 2.5:1 (2.75:1 below 2 MHz)
Length: 120 ft (maximum), 112 ft (typical), 35 ft (minimum)
Footprint: 1,800 sq ft (maximum)
Weight: Less than 10 lbs
Personnel Requirements and Setup Time: one trained operator, less than 15 minutes
Far Field plots for the various CHA TD are shown in figures (9) through (13)
Figure 9. Sloping “V” Far Field Plot, 7 MHz (left), 14 MJHz (right).

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Figure 10. Horizontal Dipole Far Field Plot, 3.7 MHz (left), 14 MHz (right).
Figure 11. Sloping Wire Far Field Plot, 7 MHz (left), 14 MHz (right).