CHAMELEON ANTENNA EMCOMM III Portable Antenna Instruction manual

EMCOMM III Portable Antenna
Operator’s Manual
Nevada - USA
WWW.CHAMELEONANTENNA.COM
VERSATILE – DEPENDABLE – STEALTH – BUILT TO LAST
Updated: January 2020
Table of Contents
Introduction............................................................................................................................................... 3
HF Propagation .......................................................................................................................................... 3
Parts of the Antenna ................................................................................................................................. 4
Initial Assembly ......................................................................................................................................... 6
Antenna Configurations............................................................................................................................. 7
Inverted “L” / Sloping Wire Configurations ........................................................................................... 8
End-Fed Inverted “V”............................................................................................................................. 9
Horizontal End-Fed (NVIS) ................................................................................................................... 10
Recovery Procedure ................................................................................................................................ 12
Troubleshooting ...................................................................................................................................... 12
Accessories .............................................................................................................................................. 12
Specifications ........................................................................................................................................... 12
Chameleon AntennaTM Products ............................................................................................................ 15
References ............................................................................................................................................... 16
!
WARNING! Never mount this, or any other antenna near power lines or utility wires! Any materials:
ladders, ropes, or feedlines that contact power lines can conduct voltages that kill. Never trust insulation to protect
you. Stay away from all power lines.
!
WARNING! Never operate this antenna where people could be subjected to high levels of RF exposure,
especially above 10 watts or above 14 MHz. Never use this antenna near RF sensitive medical devices, such as
pacemakers.
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.
EMCOMM III Portable
Page 2
Introduction
Thank you for purchasing and using the Chameleon Antenna TM EMCOMM III Portable antenna. The EMCOMM III
Portable antenna, see plate (1), is a portable High Frequency (HF) antenna specially designed for short to long range
portable and man-pack HF communications. The EMCOMM III Portable antenna is ideal for hiking, backpacking, and
both tent and Recreational Vehicle (RV) camping. It is also highly suitable for military, government agencies, nongovernmental 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 EMCOMM III Portable antenna is configurable to
facilitate Near-Vertical Incident Sky wave (NVIS)
communication and will support most Automatic Link
Establishment (ALE), frequency-hopping, and spreadspectrum modes and operations. An antenna tuner
or coupler may be required for in some instances. The
EMCOMM III Portable antenna 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.
maximize the utility you obtain from your EMCOMM
III Portable antenna.
The EMCOMM III Portable antenna is comprised of a
matching transformer, a 73-foot antenna wire on a
line winder, and a 25-foot counterpoise - making a
highly portable and effective HF antenna system.
Antennas built by Chameleon AntennaTM are
versatile, dependable, stealthy, and built to last.
Please read this operator’s manual so that you may
Plate (1). EMCOMM III Portable Antenna.
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 EMCOMM III Portable’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
EMCOMM III Portable
Page 3
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.
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.
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.
HF radio waves can then be reflected from the Earth to the ionosphere again during multi-hop 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 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 EMCOMM III Portable antenna is comprised of the following components, refer to plate (2):
EMCOMM III Portable
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a.
Matching Transformer
The Matching Transformer provides impedance matching for the EMCOMM III Portable antenna. It is
permanently affixed to the Line Winder (b).
EMCOMM III Portable
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b.
Line Winder
The Line Winder is used to store the Antenna and Counterpoise Wires and enables rapid deployment and
recovery of the EMCOMM III Portable antenna. The Matching Transformer (a) is permanently affixed to the
Line Winder. The Line Winder is also used as the end support for the erected antenna.
c.
Antenna Connection
The Antenna Connection is the wing nut on the left side of the Matching Transformer (a) marked “A”. It is
used to connect the Antenna Wire (g) to the Matching Transformer.
Plate 2. EMCOMM III Key Components.
d.
Counterpoise Connection
The Counterpoise Connection is the other wing nut on the right side of the Matching Transformer. It is used to
connect the Counterpoise Wire (m) to the Matching Transformer.
e.
UHF Socket
The UHF Socket, SO-239, is located on the bottom of the Matching Transformer.
f.
Suspension Attachment Point
The Suspension Attachment Point is a hole in the top of the Center Line Winder (b) used to allow attachment
of Paracord (k) for suspension of the erected antenna.
g.
Antenna Wire
The Antenna Wire consist of a 73-foot length of black insulated wire, wrapped around the Line Winder (b).
EMCOMM III Portable
Page 6
h.
Isolation Ring
An Isolation Loop is permanently attached to end of the Antenna and Counterpoise Wires. There is also a
floating Isolation Loop along the Antenna Wire. They are used to attach Paracord (k) for suspension of the
erected antenna.
i.
Wire Connectors
The Wire Connectors are wing nuts used to connect the Antenna and Counterpoise Wires to the Antenna and
Counterpoise Connections on the Matching Transformer.
j.
Carabiner
The Carabiner is used to attach the Antenna Wire and Counterpoise Wires to the Strain Relief Holes (n) in the
Line Winder.
k.
Paracord, 550
Paracord (not pictured, not supplied) is used to suspend components of the EMCOMM III Portable antenna at
the proper height or anchor it to the ground, depending upon the antenna configuration.
l.
Coaxial Cable Assembly
The Coaxial Cable Assembly (not pictured, not supplied) connects to the UHF Socket (e) at one end and the Radio
Set at the other. The use of an RF choke at the feed point of the antenna will improve the performance of the
antenna. A 50-foot coaxial cable assembly, with an integrated RF choke, is available purchase from Chameleon
AntennaTM.
m. Counterpoise Wire
The Counterpoise Wire (not pictured) is a 25-foot length of black insulated wire used in most configurations of
the EMCOMM III Portable antenna. An optional Counterpoise Kit, which contains four 25-foot wire radials
secured around Line Winders and four steel Tent Stakes is available from Chameleon Antenna TM.
n.
Strain Relief Hole
The two Strain Relief Holes are used to provide mechanical strain relief for the Antenna and Counterpoise Wires.
Initial Assembly
Prior to first use, perform the following initial assembly procedure to prepare the EMCOMM III for field
deployment. Refer to plates (2) and (3) during assembly.
1.
Attach the Carabiner (j) which is fastened to
the Antenna Wire (g) to the Strain Relief
Hole (n) on the left side of the Line Winder
EMCOMM III Portable
2.
(b). The Antenna Wire is the longer of the
two coils of wire.
Connect the Wire Connector (i) at the end
of the Antenna Wire to the Antenna
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3.
4.
5.
6.
Connection (c) on the left side of the
Matching Transformer (a). Tighten the wing
nut finger tight. The Antenna Connection is
marked with an “A”.
Attach the Carabiner which is fastened to
the Counterpoise Wire (m) to the Strain
Relief Hole on the right side of the Line
Winder. The Counterpoise Wire is the
shorter of the two coils of wire.
Connect the Wire Connector at the end of
the Counterpoise Wire to the Counterpoise
Connection (d) on the right side of the
Matching Transformer. Tighten the wing
nut finger tight.
Wrap the Antenna Wire around the left side
of the Line Winder using the grooves at the
top and bottom of the Line Winder.
Wrap the Counterpoise Wire around the
right side of the Line Winder using the groves
at the top and bottom of the Line Winder.
Plate (3). Antenna Wire Connection.
The completed assembly should look similar to
that pictured in plate (1). Once assembled it is
not necessary to completely disassemble the
antenna after use.
Antenna Configurations
Using the supplied components, the EMCOMM III Portable antenna can be deployed into a number of useful
configurations. Three basic 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
↑
Omnidirectional
Deliberate /
Hasty
Bidirectional
Bidirectional
Hasty
Deliberate
Inverted “L” / Sloping Wire
↕
↕
End-Fed Inverted “V”
Horizontal End-Fed (NVIS)
↕
↕
↑
↓
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 EMCOMM III Portable configuration with the corresponding symbol in the appropriate distance column. All
EMCOMM III Portable 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.
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To operate efficiently, all EMCOMM III Portable antenna end-fed configurations need one or more counterpoise
wires. The single non-resonant counterpoise with a length of 25 feet, which is supplied, will provide satisfactory
performance on most frequencies. However, increasing the number of counterpoise wires will increase the
efficiency of the antenna, with four being a good compromise between performance and practicality. Chameleon
AntennaTM offers a counterpoise kit (CHA COUNTERPOISE KIT), which consists of four 25 ft radials and Tent Stakes.
Contact Chameleon AntennaTM for availability and price.
An antenna tuner or coupler may be required with some configurations and frequencies to obtain a suitable
transmitter match.
Inverted “L” / Sloping Wire Configurations
The EMCOMM III Portable antenna, Inverted “L” and Sloping Wire configurations, see figure (1), are medium to long
range HF antennas. They should provide acceptable ground wave and sky wave propagation. The Inverted “L” and
Sloping Wire configurations are excellent general-purpose antennas and are a good choice when two supports are
available (for the Inverted “L”) or one support (for the Sloping Wire) and there is sufficient time for site selection
and installation. Installing the antenna at a height of around 25 feet or higher will provide good performance. These
configurations are predominately omnidirectional on lower frequencies, slightly favoring the end of the antenna on
upper frequencies.
Figure 1. Inverted “L” and Sloping Wire (inset) Configurations.
Site Selection and Preparation.
1. Select a site to deploy the EMCOMM III Portable
antenna Inverted “L” configuration, see figure
(1). The best site should have two trees or other
supports where the height of the supports and
the distance between the supports equal the
length of the of the Antenna Wire. In the
example configuration shown in figure (4), the
height is 25 feet and the distance between the
supports is 48 feet for a total of 73 feet. The
Sloping Wire configuration requires only one
EMCOMM III Portable
2.
3.
4.
support and is the easiest configuration to install.
If tall supports are unavailable, any convenient
object, such as fence posts or the top of vehicles,
may be used as a field expedient supports with
reduced performance.
Unwind the Antenna Wire (g) from the Line
Winder (b).
Unwind the Counterpoise Wire (m) from the Line
Winder.
Using a Bowline or similar knot, tie one end of a
short length of Paracord through the Suspension
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Attachment Point (f). This will be used to anchor
the bottom end of the antenna to the ground.
Extend the Antenna Wire.
5. Secure the Line Winder to the ground with the
short length of Paracord and a Tent Stake (not
supplied) or base of a small tree.
6. Extend the Antenna Wire to its full length to a
position near the desired end point of the
antenna.
Raise the antenna.
Inverted “L” only, perform steps 7 through 9. Sloping
Wire, skip to step 10.
7. Using a Bowline or similar knot, tie a long length
of Paracord to the floating Isolation Ring on the
Antenna Wire.
8. Using a throw weight or some other method,
loop the free end of the Paracord from the
floating Isolation Loop on the Antenna Wire over
the near end support.
9. Raise the floating Isolation Ring 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.
10. Tie a long length of Paracord to the Isolation Ring
on the end of the Antenna Wire.
11. Using a throw weight or some other method,
loop the free end of the Paracord from the end
Isolation Loop over the far end support.
12. Pull the end Isolation Loop up to the desired
height, such that the Antenna Wire is somewhat
taut, but still has sufficient sag to allow for
swaying. Secure the end of the Paracord to the
end support using a Round Turn and two Half
Hitches or similar knot.
13. Extend the Counterpoise Wire on the ground, in
a mostly straight line, in any convenient
direction. The end of the Counterpoise Wire may
be left free or it can be secured to the ground
using a Tent Stake (not supplied).
14. Connect the Coaxial Cable Assembly (l) to the
UHF Socket (e) on the Matching Transformer.
15. Perform operational test.
End-Fed Inverted “V”
The EMCOMM III Portable antenna End-Fed Inverted “V” configuration, see figure (2), is a medium range HF antenna.
The End-Fed Inverted “V” is a good compromise between performance and ease of installation since it requires only
one center support, has a reasonably small foot-print, and provides good sky wave propagation. The center should
be mounted at a height of around 25 feet and when mounted at this height, the antenna will be omnidirectional at
lower frequencies and predominately bidirectional broadside to the antenna on upper frequencies.
Figure 2. End-Fed Inverted “V” Configuration.
EMCOMM III Portable
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Site Selection and Preparation.
1. Select a site to deploy the EMCOMM III Portable
antenna End-Fed Inverted “V” configuration, see
figure (2). The best site should have a tree or
other support that would enable the center of
the Antenna Wire to be raised to a height of
around 25 feet. If tall supports are unavailable,
any convenient object, such as a fence post or the
top of a vehicle, may be used as field expedient
supports with reduced performance.
2. Unwind the Antenna Wire (g) from the Line
Winder (b).
3. Unwind the Counterpoise Wire (m) from the Line
Winder.
4. Using a Bowline or similar knot, tie one end of a
short length of Paracord through the Suspension
Attachment Point (f). This will be used to anchor
the bottom end of the antenna to the ground.
Extend the Antenna Wire.
5. Secure the Line Winder to the ground with the
short length of Paracord and a Tent Stake (not
supplied) or the base of a small tree.
6. Extend the Antenna Wire to its full length to a
position near the desired end point of the
antenna.
Raise the antenna.
7.
Using a Bowline or similar knot, tie a long length
of Paracord to the floating Isolation Ring on the
Antenna Wire.
8. Using a throw weight or some other method,
loop the free end of the Paracord from the
floating Isolation Ring on the Antenna Wire over
the center support.
9. Raise the floating Isolation Ring 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.
10. Tie a short length of Paracord to the Isolation
Loop on the end of the Antenna Wire.
11. Pull the end Isolation Loop, such that the
Antenna Wire is somewhat taut, but still has
sufficient sag to allow for swaying. Secure the
end of the Paracord to the ground using a Tent
Stake (not supplied) or the base of a small tree.
12. Extend the Counterpoise Wire on the ground, in
a mostly straight line, in any convenient
direction. The end of the Counterpoise Wire may
be left free or it can be secured to the ground
using a Tent Stake (not supplied).
13. Connect the Coaxial Cable Assembly (l) to the
UHF Socket (e) on the Matching Transformer
14. Perform operational test.
Horizontal End-Fed (NVIS)
The EMCOMM III Portable antenna Horizontal End-Fed (NVIS) configuration, see figure (3), is a short to medium
range HF antenna. The Horizontal End-Fed configuration will provide good NVIS propagation on lower frequencies
and medium range sky wave propagation on upper frequencies. It requires two supports and should be mounted at
a height of 25 feet for good overall results. When mounted at this height, the antenna is omni-directional on the
lower frequencies and predominantly bidirectional towards the ends of the antenna on the upper frequencies.
A special variation of this configuration is a high-gain long wire antenna for the 50 MHz (6 Meter) Amateur Radio
Service band. In this configuration, the operator uses a 4 ft 8 in (56 in) wire and an insulator (not supplied) as the
Antenna Wire and the supplied Antenna Wire as the counterpoise, as shown in the inset in figure (3).
EMCOMM III Portable
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Figure 3. Horizontal NVIS Configuration.
Site Selection and Preparation.
1. Select a site to deploy the EMCOMM III Portable
antenna
End-Fed
Horizontal
(NVIS)
configuration, see figure (3). The best site should
have two trees or other supports where the
distance between the supports is at least 73 feet.
If sufficiently tall supports are unavailable, any
convenient object, such as fence posts or the top
of vehicles, may be used as a field expedient
supports with reduced performance.
2. Unwind the Antenna Wire (g) from the Line
Winder (b).
3. Unwind the Counterpoise Wire (m) from the Line
Winder.
4. Using a Bowline or similar loop knot, tie the end
of a long length of Paracord to the Line Winder
through the Suspension Attachment Point (f).
This will be used to suspend the end of the
antenna.
Extend the Antenna Wire.
5. Extend the Antenna Wire to its full length to a
position near the desired end point of the
antenna.
6. Using a Bowline or similar knot, tie a long length
of Paracord to the Isolation Ring on the end of
the Antenna Wire.
EMCOMM III Portable
Raise the antenna.
7. Using a throw weight or some other method,
loop the free end of the Paracord from the Line
Winder over the near end support.
8. Connect the Coaxial Cable Assembly (l) to the
UHF Socket (e) on the Matching Transformer.
9. Raise the Line Winder 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.
10. Using a throw weight or some other method,
loop the free end of the Paracord from the end
Isolation Ring over the far end support.
11. Pull the end Isolation Ring up to the desired
height, such that the Antenna Wire is somewhat
taut, but still has sufficient sag to allow for
swaying. Secure the end of the Paracord to the
far end support using a Round Turn and two Half
Hitches or similar knot.
12. Extend the Counterpoise Wire on the ground, in
a mostly straight line, in any convenient
direction. The end of the Counterpoise Wire may
be left free or it can be secured to the ground
using a Tent Stake (not supplied).
13. Perform operational test.
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Recovery Procedure
To recover the EMCOMM III Portable antenna, perform the following steps:
1. Disconnect the Coaxial Cable Assembly from the radio set.
2. Lower the antenna to the ground.
3. Disconnect the Coaxial Cable Assembly from the Matching Transformer.
4. Carefully roll (do not twist) the Coaxial Cable Assembly.
5. Wind the Antenna and Counterpoise Wires onto the Line Winder and secure with attached shock cord.
6. Remove dirt from antenna components and inspect them for signs of wear.
Troubleshooting
1.
2.
3.
4.
5.
6.
Ensure Wire Connectors are securely connected.
Inspect the Antenna and Counterpoise Wires for breakage or signs of strain.
Ensure UHF Plug from the Coaxial Cable Assembly is securely connected to the UHF Socket.
Inspect Coaxial Cable Assembly for cuts in insulation or exposed shielding.
If still not operational, replace Coaxial Cable Assembly. Most problems with antenna systems are caused by
the coaxial cables and connectors.
If still not operational, contact Chameleon AntennaTM at [email protected] for technical
support, be sure to include details on the antenna configuration, symptoms of the problem, and what steps
you have taken.
Accessories
The following accessories are available for purchase from Chameleon AntennaTM.
[email protected] for current prices and availability.
•
•
•
Please contact us at
Counterpoise Kit. The Counterpoise Kit is ideal for portable antenna deployment. The system will create
the ground-plane needed for any EMCOMM III Portable end-fed antenna configuration. It contains four 25foot wire radials secured around plastic wire winders and four steel Tent Stakes.
Coaxial Cable Assembly. 50 feet of RG-58 with integrated RFI Choke. Used to connect the EMCOMM III
Portable to the radio set. This is a highly recommended accessory if you are not using a CHA RFI CHOKE.
RFI Choke. Used in conjunction with user furnished coax. This is a highly recommended accessory if
you are not using the 50 ft. coax w/RFI Choke.
Specifications
•
•
•
•
•
•
Frequency: 1.8 MHz through 55.0 MHz continuous (including all Amateur Radio Service bands 160m to
6m)
Power: 100W SSB Phone, 50W CW, 25W High Duty Cycle Digital Modes
RF Connection: UHF Plug (PL-259)
SWR: Subject to frequency and configuration, as measured see table (4), but typically less than 2.0:1. An
antenna tuner or coupler may be required.
Length: 73 ft/25 ft
Weight: Approximately 1 lbs.
EMCOMM III Portable
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•
•
•
Ingress Protection comparable to IP42 standard (not tested). Ingress protection from most wires, screws
or similar objects and from vertically dripping water when device is tilted at an angle up to 15 degrees
Personnel Requirements and Setup Time: one trained operator, less than 15 minutes
Far Field plots for the three basic and special EMCOMM III Portable antenna configurations are shown in
figures (4) through (7)
FREQUENCY
1.9
3.6
5.4
7.1
10.1
14.1
18.1
21.1
24.9
28.5
SWR
1.9
1.9
1.6
1.4
1.9
2.0
1.6
1.5
1.5
1.3
Table 4. EMCOMM III Portable Antenna Measured SWR.
Figure 4. Inverted “L” Far Field Plot.
EMCOMM III Portable
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Figure 5. End-Fed Inverted “V” Far Field Plot.
Figure 6. Horizontal End-Fed Far Field Plot.
EMCOMM III Portable
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Figure 7. Six Meter Long Wire Far Field Plot.
References:
1.
Silver, H. Ward (editor), 2013, 2014 ARRL Handbook for Radio Communications, 91st Edition, American Radio
Relay League, Newington, CT.
2.
1987, Tactical Single-Channel Radio Communications Techniques (FM 24-18), Department of the Army,
Washington, DC.
3.
Turkes, Gurkan, 1990, Tactical HF Field Expedient Antenna Performance Volume I Thesis, U.S. Naval Post
Graduate School, Monterey, CA.
EMCOMM III Portable
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EMCOMM III Portable
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