Chameleon Antenna CHA LEFS User manual

Lightweight End Fed
Halfwave Sloper
(CHA LEFS)
Operator’s Manual
Nevada - 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.................................................................................................................................5
Antenna Configurations............................................................................................................................6
Antenna Installation..................................................................................................................................7
Recovery Procedure..................................................................................................................................8
Troubleshooting........................................................................................................................................8
Specifications ............................................................................................................................................8
Warranty.................................................................................................................................................10
Accessories..............................................................................................................................................10
Chameleon AntennaTM Products............................................................................................................11
References ..............................................................................................................................................11
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.
Photographs and diagrams in this manual may vary slightly from current production units due to manufacturing
changes that do not affect the form, fit, or function of the product.
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 Lightweight End Fed Half Wave Sloper (CHA LEFS).
The CHA LEFS is a six-band, no-tuner, High Frequency (HF) antenna for use on the 40, 20, 17, 15, 12, and 10 meter
Amateur Radio Service (ham) bands. Its’ minimalistic design and lightweight components, shown in plate (1), are
intended for the serious backpacker and outdoor adventurer use. Leave the tuner and SWR meter at home –just
bring a radio and a pair of boots!
Plate 1. CHA LEFS Antenna.
The CHA LEFS is designed for the trail. The sturdy line
winder with integral high-efficiency impedance
matching network transformer, ultra-thin 20 gauge
PTFE antenna wire, and Micro 90 paracord enables
highly portable six band operation without the extra
bulk of an antenna tuner. Setup is quick and easy and
the antenna will operate without a tuner or
adjustment on the entire 40, 20, 17, 15, 12, and 10
meter ham bands. The antenna can also be used on
30 meters with an antenna tuner. When ready to be
packed, the CHA LEFS doesn’t take up much space in
your backpack –it is only eight inches long, four
inches wide, and weighs only 1.5 pounds. The CHA
LEFS is perfect for backpackers, hikers, bikers,
campers, and survival communication. The CHA LEFS
is also configurable to facilitate Near-Vertical Incident
Sky wave (NVIS) communication. 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 LEFS.
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 LEFS 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

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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 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.

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Parts of the Antenna
The CHA LEFS is comprised of the following components, see plate (2):
a. Line Winder Assembly
The Line Winder Assembly is a unitary assembly comprised of the components and sub-components that
make up the Lightweight End Fed Half Wave Sloper antenna. It functions as the suspension and feed point of
the antenna when erected and convenient storage for the Antenna Wire and Paracord when not in use.
b. Suspension Point
The Suspension Point is the large hole, in the top of the Line Winder Assembly, used to enable attachment of
Paracord for suspending the feed point of the antenna.
c. Antenna Wire
The Antenna Wire is permanently attached to Line Winder Assembly. It is comprised of 63 feet of strong,
lightweight 20-gauge copper-clad Kevlar PTFE wire and a small loading coil.
Plate 2. CHA LEFS Details.

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d. Insulator Loop
Two Insulator Loops are permanently installed on the Antenna Wire. One at the end for suspension of the far
end of the Antenna Wire and one floating along the length of the Antenna Wire for erection of the antenna in
other configurations.
e. UHF Connector Socket
The UHF Connector Socket (SO-239) is located on the back of the Line Winder Assembly and is used to connect
the Coaxial Cable to the antenna.
f. Paracord
The Paracord is a 50-foot length of lightweight Micro 90 paracord used to suspend the antenna.
g. Coaxial Cable
The Coaxial Cable (not supplied) is used to connect the antenna to the radio set. RG-58 with an integrated RFI
Choke, such as that sold by Chameleon AntennaTM, is recommended.
Antenna Configurations
The two basic configurations for the CHA LEFS are as an End Fed Sloper and an End Fed Horizontal antenna. Figure
(1) shows the Sloper configuration, which is the normal configuration. When installed at around 25 feet, this antenna
will provide good general-purpose communication. There is some directivity broadside to the antenna on 40 meters
and towards the ends of the antenna on 20 meters and above. The main advantage of the Sloper for portable
operation is that it requires only one end support and is fast and easy to setup.
Figure 1. CHA LEFS Sloper Configuration.

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Figure (2) shows the End Fed Horizontal NVIS configuration. By reducing the height of the antenna to around 15
feet, and making the antenna wire horizontal, you can enhance NVIS propagation. You will need another support
and an additional length of paracord for the far end of the antenna.
Figure 2. CHA LEFS Horizontal NVIS Configuration.
Antenna Installation
Use the following procedure to install the Sloper configuration.
Site Selection and Preparation.
1. Select a site to deploy the CHA LEFS Sloper
configuration. The site must have a support that
will position the Line Winder Assembly at a
height of 15 to 25 feet. If the right support is not
available, any available support can be used, such
as a fence post, hiking pole, or fishing pole with
reduced performance.
Raise the Antenna.
2. If not already attached, using a Bowline, or
similar knot, attach the Paracord (f) to the
Suspension Point (b) of the Line Winder Assembly
(a); otherwise unwrap the Paracord from the Line
Winder Assembly.
3. Using a throw weight or some other method,
loop the Paracord over the support.
4. Unwrap the Antenna Wire (c) from the Line
Winder Assembly.
5. Connect the Coaxial Cable to the Line Winder
Assembly UHF Connector Socket (e).
6. Raise the Line Winder Assembly to the desired
height and secure it to the support using a Round
Turn and two Half Hitches, or similar knot.
Finish Installation.
7. Fully extend the Antenna Wire, allowing some
sag in the wire. Do not make the Antenna Wire
taut. The Antenna Wire is made from lightweight
20-gauge copper-clad Kevlar PTFE wire.
Although it is strong, compared to similar gauge
wire, it is not as strong as heavier gauge wire. It
very is important not to over-tension the wire or
it may break.
8. Insert a Tent Peg (not supplied) through the
Insulator Loop (d) and drive the Tent Peg into the
ground to secure the end of the Antenna Wire.
Alternatively, you can attach a short length of
high-stretch rope or shock cord (not supplied) to
the Insulator Loop and tie the end of the Antenna
Wire to a small tree or other fixed object.
9. Connect the Coaxial Cable to the Radio Set and
perform an operational test.

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Recovery Procedure
To recover the CHA LEFS, perform the following steps:
1. Disconnect the Coaxial Cable from the radio set.
2. Lower the Line Winder Assembly to the ground.
3. Disconnect the Coaxial Cable from the Line Winder Assembly.
4. Carefully roll (do not twist) the Coaxial Cable.
5. Unfasten the far end of the Antenna Wire.
6. Wrap the Antenna Wire around the Line Winder Assembly in the area shown in plate (3).
7. Wrap the Paracord around the Line Winder Assembly in the area shown in plate (3).
8. Secure the windings with the attached shock cord.
9. Remove dirt from antenna components and inspect them for signs of wear.
10. Stored antenna and antenna components in your backpack.
Plate 3. Recovered Antenna.
Troubleshooting
1. Inspect the Antenna Wire and Loading Coil for breakage, corrosion, or signs of strain.
2. Ensure the UHF Connector Plugs are securely tightened.
3. Inspect the Coaxial Cable assembly for cuts in insulation or exposed shielding. Replace if damaged.
4. If still not operational, connect a Standing Wave Ratio (SWR) Power Meter and check SWR.
5. If SWR is greater than 3:1 on specified bands, replace Coaxial Cable. Most problems with antenna systems are
caused by the coaxial cables and connectors.
6. If still not operational, contact Chameleon AntennaTM Technical Support. Explain to them what specifically
does not work correctly about the antenna, the steps you have taken during troubleshooting, and those
results.
Specifications
•Frequency:
o7.0 - 7.3 MHz (40m)
o14.1 - 14.35 MHz (20m)
o18.068 - 18.168 MHz (17m)
o21.0 –21.45 MHz (15m)
o24.89 –24.99 MHz (12m)
o28.0 –29.7 MHz (10m)
•SWR (frequency ranges listed above): Less than 2.0:1. SWR chart shown in figure (3).
•Power: 250W CW, 500W SSB

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•RF Connection: UHF Socket (SO-239)
•Length: 63 ft
•Weight: 1.5 lbs
•Personnel Requirements and Setup Time: one operator, around 10 minutes.
•Far Field Plots are shown in figures (4) and (5).
Figure 3. SWR by Frequency Graph.
Figure 4. Sloper Far Field Plot 7 MHz.

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Figure 5. Horizontal NVIS Far Field Plot 7 MHz.
Warranty
The Chameleon AntennaTM Lightweight End Fed Half Wave Sloper (CHA LEFS) is warranted to be free from defects
in materials and workmanship for a period of 12 months from the date of purchase. To obtain warranty service,
return all components of the system to Chameleon Antenna at your expense. Chameleon Antenna will repair or
replace defective components and return the system to you at no charge. We encourage you to call us for
technical support before returning the antenna system. This warranty excludes components that have been
damaged or modified by the customer.
Accessories
The following accessories are available for purchase from Chameleon AntennaTM. Please contact us at
[e-mail] for current prices and availability.
•Coaxial Cable. The CHA 50’ COAX is 50 feet of high-quality RG-58 cable with an integrated RFI Choke and
PL-259 connectors on each end.
Recommended non-supplied accessories:
•Extra Paracord or similar low-stretch synthetic line. (Required for some antenna configurations)
•Tent stake
•Throwing weight and string.
•UHF Male Female Right Angle Elbow Coaxial Adapter SO-239 to PL-259 Coaxial Adapter. This adapter is
used to reduce stress on coaxial cable connected to the CHA LEFS by allowing the cable to drop straight
down instead of bending 90 degrees.

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Chameleon AntennaTM Products
Please go to http://chameleonantenna.com for information about additional quality antenna products available
for purchase from Chameleon AntennaTM –The Portable Antenna Pioneer.
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.