SGC STEALTH Kit Quick Start Guide

The STEALTH Kit

Thank you for choosing the American made, SGC STEALTH
Kit. We are confident that you will be happy with your purchase and
assure you of our full commitment to customer service. Since 1971,
SGC has been designing and manufacturing a wide range of HF SSB
communications products. Our goal is to provide reliable equipment,
which is competitively priced and which fits the need of the radio user.
With the STEALTH Kit, SGC has provided an all-in-one,
convenient antenna solution. The STEALTH Kit is perfect for emer­gency use, when an urgent communications command center must be
setup in minutes. The STEALTH Kit contains everything a novice or
professional needs to erect an antenna in any location—and provides
performance equivalent to most dipole antennas!
And, in keeping with its’ name, the STEALTH Kit is an ideal
antenna solution for restricted areas, such as condominiums and gated
communities where dipoles and towers are forbidden. Or, use the
STEALTH in city apartments where access to roofs or large open areas
is restricted. The STEALTH Kit is also a great antenna solution when
you are on vacation. Whether in an RV or a hotel room, the STEALTH
Kit is a “Grab and Go” box - filled with everything you need to com­plete your communications center.
We are proud of the STEALTH Kit as it provides an antenna
system that is automatic, easy to install and easy to use. Any location,
any radio and any situation - the STEALTH Kit is the perfect choice
for a quick and convenient antenna solution.

Pierre Goral
President
KI7UA

Table of Contents

Quick Start.............................................................4

1.0 Introductio n.......................................................5

2.0 Specifications....................................................6

3.0 Supplied Items..................................................7

4.0 Installatio n.........................................................7

4.1 Advance preparation for emergency use...........7

4.1 Antenna Installation ..........................................8

4.1.1 Antenna Orientation.......................................8

4.1.1.1 Horizontal - for less than 500 miles.............9

4.1.1.2 Vertical - for more than 500 miles..............10

4.1.2 Shape of the antenna loop...........................10

4.1.3 Antenna Directivity.......................................10

4.1.4 Height of antenna.........................................11

4.1.5 Inside or outside...........................................11

4.1.6 Environment.................................................11

4.2 So what should I do?.......................................11

4.2.1 One Loop Configurations .............................12

4.2.2 Two Loop Configurations .............................13

4.2.3 Three Loop Configurations ...........................14

4.2.4 Four Loop Configurations.............................14

4.2.5 Coupler Connection Point ............................14

4.3 Sample Installation..........................................15

4.4 SG-237 Smartuner Coupler Installation...........19

4.5 Tips: Do’s & Don’ts .........................................19

5.0 Adjustable Directive Loop Antenna .................21

5.1 Antenna Setup with Four Brooms....................25

5.2 General Appl ications.......................................27

6.0 SGC Limited Product Warranty.......................29

7.0 Appendix.........................................................30

8.0 Global Reference Database............................38

9.0 Conclusion......................................................38

10.0 Further Reading............................................39

11.0 Special Thanks .............................................39

Mailing: PO Box 3526, Bellevue, WA 98009

Shipping: 13737 SE 26th St., Bellevue, WA 98005

Toll-Free: 800-259-7331 • Phone [phone] • Fax: [phone]

www.sgcworld.com • Email: [e-mail]

3

Quick Start

1. Locate a proper area where you would like to erect your loop
antenna. Initially the system could b e o perated with the antenna
lying on the floor.

2. Connect your coupler to the transceiver and a suitable 12VDC
power supply. This can be the same source as the power supply to
the radio if it is a 12VDC unit. Avoid regulated linear or switch­ing power supplies as they may be susceptible to RF radi ation
and may lose regulation and apply higher voltage than permissi­ble. Power supplies may also lose regulation at peak modulation
and cause intermittent operation.

3. Connect your loop antenna to the two terminals of the coupler;
one hot side, one ground side. Both have a wing nut terminal to
allow easy attachment.

4. If urgent operation is required, transmit on an emergency fre­quency with the antenna on the ground. Although this setup is not
efficient, it will allow you to easily establish a communication
link in an emergency.

5. Configure your antenna in single or multiple loops (not to exceed
four loops).

6. Elevate your system to any surrounding high points such as a
tree, roof, top of car, ceiling, mast, etc. Attach with 4 ropes and
clips provided. The coupler can also be elevated using the fifth
piece of rope.

7. After your initial contact, you may improve your antenna ins talla­tion following the guidelines in this manual.

Mailing: PO Box 3526, Bellevue, WA 98009

Shipping: 13737 SE 26th St., Bellevue, WA 98005

4

Toll-Free: 800-259-7331 • Phone [phone] • Fax: [phone]

www.sgcworld.com • Email: [e-mail]

© March 2002 - SGC, Inc.

1.0 Introduction

The Smart Tuning, Emergency Antenna Loop, Tactical HF Kit ­STEALTH - antenna kit is a high-freque ncy antenna for situations
where a full size antenna is not possible. Its main features are:

•

Easily configured to the space available

•

Groundless - no RF ground re quired

•

Easy to install - kit contains all necessary items

•

Automatic operation

•

Easy to use - no meters or lights to watch, no buttons to
push

•

Wide bandwidth - 2.5 (and lower for non-amateur radio
usage) to 30 MHz

•

High performance - can match the performance of a full
size dipole

STEALTH is a loop antenna chosen for its radiation efficiency and
because it does not require an electrical ground. It can be horizontal or
vertical mounted for short and long range communications needs.

An important use of STEALTH is as an emergency antenna.
STEALTH is easy to install and easy to operate. Its small size makes
it easy to transport and quick to install.

But STEALTH was also designed for...
The amateur radio user who is struggling with Homeowners’

“Covenants, Conditions & Restrictions”. A stealth antenna can be
installed with no visible signs of its presence, in developments where
erected antennas are forbidden.

Those living in an apartment or similar limited environment.
STEALTH provides an effective antenna in small spaces. It can be
installed in an area as small as 5 feet by 5 feet.

Use as an effective, ready to go, compact vacation antenna.

Offices, farms, etc. It can be used where other antennas are not practi­cal.

Mailing: PO Box 3526, Bellevue, WA 98009

Shipping: 13737 SE 26th St., Bellevue, WA 98005

Toll-Free: 800-259-7331 • Phone [phone] • Fax: [phone]

www.sgcworld.com • Email: [e-mail]

5

1.1 Disclaimers

RF Burns can occur if the output terminals or antenna wire of the SG­237 are touched while transmitting. Use caution to avoid injury and
burns.

Prolonged exposure to RF should be avoided. Those persons using
heart pacemaker devices should avoid RF exposure.

To avoid injury and damage to equipment: Whenever possible, we
strongly recommend reducing transmit power. Preferably, 10 to 25
watts should be used and will generally provide good communica­tions. If using an outside antenna, 100 watts can be used without any
harmful consequences.

If for any reason a particular setup or frequency does not provide the
expected results, minor changes can significantly improve perform­ance. For example: move the radio as far away as possible from the
coupler or antenna; avoid coiled power or coaxial feed cables; recon­figure setup, etc.

SGC accepts no responsibility for performance or results from the
STEALTH Kit. SGC accepts no responsibility for any unlikely dam­age or injury resulting from the use of the STEALTH Kit.

2.0 Specifications

• Antenna loop perimeter: 80’ (24m)

• Maximum square configuration - 20’ (6.1m)

• Minimum squa re configuration - 5’ (1.5m)

• Number of turns - 1 to 4

• HF frequency range - 2.5 to 60 MHz.

• Maximum power - 100 watts

• Package size 3.5” x 10” x 15” (8.9cm x 25.4cm x 38.1cm)

• Package Weight 5lbs. (2.3kg)

Mailing: PO Box 3526, Bellevue, WA 98009

Shipping: 13737 SE 26th St., Bellevue, WA 98005

6

Toll-Free: 800-259-7331 • Phone [phone] • Fax: [phone]

www.sgcworld.com • Email: [e-mail]

© March 2002 - SGC, Inc.

Performance and results may vary and SGC does not warrant any in­stallation or any result. SGC reserves the rig ht to change the specifica­tions without notice.

3.0 Supplied Items

•

SG-237 Smartuner HF Antenna coupler and manual.

•

80’ (25m) of loop antenna wire.

•

4 - antenna mounting clips and 20’ (6m) ropes attached

•

30’ (9.14m) of nylon support rope with clip

•

12 - Releasable cable ties

•

2 - spare antenna mounting clips

4.0 Installation

4.1 Advance Preparation for emergency use

Plan your emergency station before you need it! You should consider
things like:

Mailing: PO Box 3526, Bellevue, WA 98009

Shipping: 13737 SE 26th St., Bellevue, WA 98005

Toll-Free: 800-259-7331 • Phone [phone] • Fax: [phone]

www.sgcworld.com • Email: [e-mail]

7

• Equipment - Have you selected the equipment to be used
in an emergency situation? Is that equipment able to
withstand possible abuse? Do you have all power
sources immediately available and, in the case of batter­ies, are they fully charged?

• Cable extensions - Do you have AC cords long enough
for typical situations? Is your coax long enough or
should you have some exten si ons? If your installation
will be battery powered, do you have cables to reach
them and also the cables needed to maintain the charge
on them?

• Connector installation(s) - Have you installed all con­nectors on all the cables which might be needed?

• Where are your emergency supplies - Are they in one,
quickly retrievable location? Or do you have them scat­tered around?

Do not wait for an emergency to happen - be ready. Test
everything including STEALTH. Be fully prepared to react
in the event of an emergency.

4.1 Antenna Installation

There are several factors which need to be considered before install­ing the antenna and some can affect others.

WARNING!

Never mount any antenna near power lines or utility wires. Any

materials, ladders, ropes, feedlines, etc., which come in contact

with power lines can conduct voltages that can be fatal.

Stay away from all power lines.

4.1.1 Antenna Orientation

Because the signal radiation of a loop antenna is perpendicular to the
plane of the loop, how you orient the antenna should be determined
by your communica tio n need s .

Mailing: PO Box 3526, Bellevue, WA 98009

Shipping: 13737 SE 26th St., Bellevue, WA 98005

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Toll-Free: 800-259-7331 • Phone [phone] • Fax: [phone]

www.sgcworld.com • Email: [e-mail]

© March 2002 - SGC, Inc.

This is called polarization. A loop mounted horizontally is considered
to be vertically polarized as the signal is primarily radiated vertically
and will provide more effective short distance communications. Like­wise, a loop mounted vertically is horizontally polarized as its signal
is primarily radiated horizontally and is better for long range commu­nications.

4.1.1.1 Horizontal - for less than 500 miles
(830km)

If your needs are expected to be less than 500 miles (830km), the best
results can be obtained by orienting the antenna so the plane of the
loop is horizontal.

Horizontal triangular plane - f or vertical radiation, the coupler is
supported by rope, approx. 25 ft. in the center of the back segment.

Mailing: PO Box 3526, Bellevue, WA 98009

Shipping: 13737 SE 26th St., Bellevue, WA 98005

Toll-Free: 800-259-7331 • Phone [phone] • Fax: [phone]

www.sgcworld.com • Email: [e-mail]

9

4.1.1.2 Vertical - more than 500 miles
(830km)

Use this type of antenna when you need to maintain long range com­munications of 500 to 5000 miles (830km to 8300km).

Vertically mounted two-turn
loop. The coupler is installed in
center of lower section antenna.

4.1.2 Shape of the an­tenna loop

The ideal shape of the antenna for
this situation would b e a single turn
circle. However, this would require
complicated mounting.

Most needs can be fulfilled with a

one-turn square, rectangle or trian­gle shape. When there are limitations on what the size and shape of
the loop can be, it might be necessary to reduce the size by making
the loop two, three or four turns.

4.1.3 Antenna directivity

Like any antenna, a loop antenna is directional. As the size of the loop
is reduced, by configuring it as two, three o r four turns, the directivity
becomes more significant.

10

Mailing: PO Box 3526, Bellevue, WA 98009

Shipping: 13737 SE 26th St., Bellevue, WA 98005

Toll-Free: 800-259-7331 • Phone [phone] • Fax: [phone]

www.sgcworld.com • Email: [e-mail]

© March 2002 - SGC, Inc.

4.1.4 Height of antenna

As is the case with all antennas, the rule of thumb is “the higher the
better”. You should attempt to make the lowest point of the loop at
least 10 feet (3mtr) above ground.

4.1.5 Inside or outside

If possible, the antenna should be located outside and clear of any
structures for maximum effectiveness. If you find this impossible, and
you must locate the antenna inside, consider the following:

•

Ensure that the antenna will be at least 4 inches (10cm.)
away from any larger metal objects such as a corner
column or window support.

•

Does the ceiling or roof of the room contain metal mate­rial? This can have a negative effect on the performance
of the antenna.

•

Is there any metal within the outside wall s o f the build­ing? This can also have a negative effect.

4.1.6 Environment

Your physical environment can influence how you mount STEALTH.
For example, in a rainy area, an outside mounted antenna would need
to be mounted as high as possible to avoid interaction with the wet
ground. In a desert, where it is dry, this would be less of a considera­tion.

4.2 So what should I do?

The above descriptions are the ideal situations and may not always be
obtainable. You should make every effort to install the antenna in an
optimum way.

Although a square or rectangular antenna loop is generally more ef­fective, a triangular loop can also be used. If necessary, shape the an­tenna as two-turn or three-turn loop and lay it on an inside floor. It
will not be as efficient as possible but you should be able to conduct
effective communications.

Mailing: PO Box 3526, Bellevue, WA 98009

Shipping: 13737 SE 26th St., Bellevue, WA 98005

Toll-Free: 800-259-7331 • Phone [phone] • Fax: [phone]

www.sgcworld.com • Email: [e-mail]

11

The sketches below show possible shapes.

One Loop Configurations

Configuration 101

Configuration 102

These configurations are the most common and
are used for installations outsid e and away from buildings.

Mailing: PO Box 3526, Bellevue, WA 98009

Shipping: 13737 SE 26th St., Bellevue, WA 98005

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Toll-Free: 800-259-7331 • Phone [phone] • Fax: [phone]

www.sgcworld.com • Email: [e-mail]

Configuration 103

© March 2002 - SGC, Inc.

Two Loop Configurations

Configuration 201

Configuration 202

Configuration 203

The two turn loop is primarily used for inside situations. It is also a
very convenient installation for vacationing, a small patio, or even a
greenhouse.

Mailing: PO Box 3526, Bellevue, WA 98009

Shipping: 13737 SE 26th St., Bellevue, WA 98005

Toll-Free: 800-259-7331 • Phone [phone] • Fax: [phone]

www.sgcworld.com • Email: [e-mail]

13

Three Loop Configurations

Configuration 301

Four Loop Configurations

Configuration 302

Configuration 401

Configuration 402

The three and four turn loops are almost always indoor antennas and
are very convenient for situations where there is a limited amount of
space available. This will be of significant importance for the office or
apartment user where they can be mounted near a window or door.

Coupler Connection Point

In the case of the triangular configurations above, the coupler is
shown connected at a mid point of one of the legs which is the sug­gested point. If necessary, it can also be connected at a corner of the
triangle. Testing has sho wn that the corner connection performs better
when the coupler is connected at a midpoint of one of the legs or seg­ments. (Configurations 501, 502 & 503 will perform better than 302
& 402.)

14

Mailing: PO Box 3526, Bellevue, WA 98009

Shipping: 13737 SE 26th St., Bellevue, WA 98005

Toll-Free: 800-259-7331 • Phone [phone] • Fax: [phone]

www.sgcworld.com • Email: [e-mail]

© March 2002 - SGC, Inc.