SGC SG-230 Operating Manual

SG-230

®

S m a r t u n e r

Microprocessor Controlled Automatic Antenna Coupler

Installation and Operations Manual

Getting the most from every watt of HF-SSB Power

Globally, HF-SSB has literally changed the world. For a minimal investment, it has allowed millions of people - often in
amazingly remote settings, often in emergency conditions - to reliably bounce clear voice and data signals across a state,
across a continent, over an ocean, or around the world. Without satellites, relay stations, cellular nets, stadium sized anten­nas or huge user fees. Just some fine equipment, a smart operator and nature's own ionosphere make this possible.

For nearly 30 years, the perfection of HF SSB has been the focus and the life of our company. Our efforts have not gone
unnoticed. Today, SGC is a prominent choice of leading corporations, governments, relief agencies, paramilitary organiza-

tions, mariners, aviators, explorers, and
scientists - all over the world. They trust
our engineering and they value our expe­rience.

A vital part of our company's strate­gy centers around new product develop­ment, with an emphasis on providing
quality equipment which remains rugged,
reliable and competitively priced. We are
focused on providing customer service of
the highest standard. Our commitment is
to product training and comprehensive
after sales support. Today, SGC is recog-

nized as a world class designer and manufacturer of HF SSB communications products.

At SGC we build communications power tools. Next generation HF-SSB radios, antennas, amplifiers and coupler sys­tems that squeeze more range and clarity out of every watt of HF SSB communications power, are the technology and innova­tions that have helped SGC emerge as a cutting edge player in the expanding world of HF-SSB.

Actually, SGC was the first company to perfect and mass produce solid-state HF SSB radios, almost 30 years ago.
Today, our focus is an ever higher level of HF SSB refinement and performance. All focused on creating HF SSB voice and
data communications systems that are so user friendly
and so powerful, they allow every SGC user to easily
lock in the world.

Pierre B. Goral, President

SMARTUNER MANUAL

SG-230

SMARTUNER

ANTENNA

COUPLER

Installation and Operations Manual

Revised: November 2000

Caution:

and all pertinent sections of this manual prior to operating your
Smartuner for the first time. This unit will provide outstanding
service if you follow the detailed recommendations within this
manual.

Carefully read the “Quick Start” on the following page

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SMARTUNER MANUAL ii

)

Quick Start Guide

To quickly install your antenna coupler you will need the following:

1. An HF radio with 10 to 150 watts output.

2. An HF antenna with a single wire feed (not coax fed).
Minimum length of 8 feet (to 3.5 MHz) or 23 feet (1.8 MHz).

3. A good ground or counterpoise for the antenna and coupler

4. +12 VDC and ground for the coupler.

5. An LED or other indicating device. (Optional)

Connections:

Connect the Smartuner as shown in the following diagram:

TO TRANSMITTER (10-200 w

Single wire

Black: DC Ground

AN TEN NA

GROUND (Counterpoise)

Red: +12 VDC coupler power

Red/ White: Optional SmartLock lock/ reset line. (+12 VDC locks,
momentary ground reset s)

Black/ White: Optional remote tuned indicator. Goes low when coupler is tuned

Operation:

1. Turn on Radio. Apply 12 VDC power to the coupler.

2. As power is applied, coupler should make one "click" sound.

3. Coupler should come up in the bypass (untuned) state.

4. To tune, speak normally, whistle or use CW.

5. Tuning should be done at full power. Clicking is heard.

6. When tuned, clicking stops and Black/White wire goes low.

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SMARTUNER MANUAL iii

Table of Contents

Quick Start Guide .......................................................................................................ii

1.0 General Information............................................................................................. 1

1.1 Experience Levels of Users .......................................................................1

1.2 What Is an Antenna Coupler?..................................................................1

1.3 Overall Description.................................................................................... 3

1.4 Coupler Network Configuration.............................................................4

1.5 Operation Indicators..................................................................................4

1.6 Mechanical Design.....................................................................................5

1.6.1 Marine Mounting........................................................................ 6

1.6.2 Desert and High Temperature Installations............................7

1.6.3 Extremely Cold Temperature Installations............................. 7

1.7 Remote Installations...................................................................................7

1.8 Upgrade Sequence......................................................................................8

2.0 Specifications.........................................................................................................8

2.1 Accessories..................................................................................................9

2.2 Recommended Antennas..........................................................................9

3.0 Parts and Technical Support............................................................................... 9

3.1 Parts Furnished...........................................................................................9

3.2 User Supplied Items...................................................................................10

3.3 Technical Support.......................................................................................11

4.0 Antenna Types....................................................................................................... 11

4.1 Antenna Selection.......................................................................................11

4.3 Longwire Antenna.....................................................................................12

4.4 Backstay Antennas.....................................................................................12

4.5 Typical Installations...................................................................................12

4.5.1 Jeep installation ...........................................................................12

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SMARTUNER MANUAL iv

4.5.2 Vehicle installation......................................................................13

4.5.3 Motor Vessel installation............................................................14

4.5.4 Base installation...........................................................................14

4.5.5 Base installation with ground wire radials..............................15

4.5.6 Base dipole....................................................................................16

4.5.7 Base Quadra Loop....................................................................... 16

4.5.8 Delta Loop....................................................................................17

4.5.9 Vessel Groundless Loop.............................................................18

4.5.10 Vessel insulated backstay.........................................................19

4.6 Apartment Loop Antenna.........................................................................19

4.7 Recreational Vehicle (RV) Antennas .......................................................20

4.8 Aircraft Antennas....................................................................................... 21

4.9 Low Profile, Hidden...................................................................................22

4.10 Emergency Antennas...............................................................................24

4.10.1 Kite Antenna..............................................................................24

4.10.2 Tactical Installations..................................................................25

4.11 Five Golden Rules of HF Installation………………………………….26

5.0 General Notes on Antennas ................................................................................27

5.1 Steps to Antenna Installation....................................................................28

5.2 Antenna Location.......................................................................................28

5.3 Ground Systems—General .......................................................................29

5.3.1 Vehicle Grounds..........................................................................29

5.3.2 Marine Grounds..........................................................................30

5.3.3 Base Station Grounds.................................................................. 31

5.4 Corrosion.....................................................................................................32

5.5 Antenna Coupler Mounting..................................................................... 32

5.6 Antenna Connection..................................................................................32

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SMARTUNER MANUAL v

6.0 Installation Procedures.........................................................................................33

6.1 Installation with SG-2000.......................................................................... 33

6.2 Installation on all Radios...........................................................................33

6.3 Smartlock Installation................................................................................ 34

6.4 Weatherdeck Mounting.............................................................................35

6.5 Electrical Checkout.....................................................................................35

6.6 Do-It-Yourself Light-Bulb Dummy Load……………………………….36

7.0 Coupler Configuration......................................................................................... 38

7.1 Schematic Diagrams................................................................................... 38

7.2 Tuning Process............................................................................................ 39

7.3 Impedance Detector...................................................................................39

7.4 VSWR Detector...........................................................................................39

7.5 Phase Detector ............................................................................................40

7.6 Central Processing Unit (CPU).................................................................40

7.7 Initialization................................................................................................40

8.0 Tuning Processes and Options........................................................................... 41

8.1 Program Description..................................................................................42

8.2 Tuning Paths...............................................................................................43

9.0 Smartlock Operation.............................................................................................46

9.1 Tune, Tune Lock, and Reset......................................................................46

9.2 Smartlock Notes..........................................................................................46

10.0 Receiving Antenna
Systems…………………………………………………...47

11.0 Troubleshooting the SMARTUNER................................................................47

11.1 Ground Faults...........................................................................................48

11.2 Antenna Faults.......................................................................................... 49

11.3 Transmitter Faults....................................................................................50

11.4 A Final Pointer on Troubleshooting......................................................50

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SMARTUNER MANUAL vi

12.0 Further Reading…………………………………………………………………51

SUBJECT INDEX......................................................................................................... 52

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SMARTUNER MANUAL 1

1.0 General Information

The Smartuner™ reputation has grown to legend status because it is simple to use and a
highly reliable piece of electronic equipment. A SMARTUNER will provide maximum
transfer of radio energy from any HF transmitter to any end-fed HF antenna within the
frequency and power limits of its specifications. The SMARTUNER builds upon the
renowned reputation of the SG-230 by adding many advanced features, among them: a
new, highly technological microcontroller that has built in A/D functio ns, non-volatile
memory, and serial communications capabilities.

This document is designed to guide the SMARTUNER user through installation and
operation of the unit. This document will also recommend various steps that may be
undertaken in the field to provide correct operation of the SMARTUNER should
difficulty be encountered. Smartuners are extraordinarily reliable. But you should be
aware that there are scores of fine points to any HF installation that are easily
overlooked and may cause difficulty. Our goal in this manual is to help you quickly
obtain the best possible performance from your HF radio installation. By reading this
manual carefully, you can avoid most of the pitfalls that can degrade the performance
of your HF system.

1.1 Experience Levels of Users

The Smartuner may be installed successfully by anyone with the help of this manual.
However, if you ar e inexperienced in HF radio installation and o peration, do not be shy
about seeking advice from people with more experience than yourself. They will help
you achieve good results quickly and with minimum frustration. Even the most
experienced professional HF users will occasionally run into difficulty.

Regardless of the level of your experience, SGC stands ready to offer you installation
suggestions and help you resolve any aspect of Smartuner operation that is not entirely
satisfactory. If you have a specific question, please send us an email or fax at our
Bellevue, WA headquarters on the bottom of this page. If you require telephone
assistance, please call us between 8:00 A.M. to 5:00 P.M. Pacific Time.

1.2 What Is an Antenna Coupler

Antenna “couplers” are placed at the antenna and precisely match conditions of the
antenna to the feed line. Antenna “tuners,” on the other hand, are generally located at
the transmitter output at the radio end of the coaxial feed line. Do not be confused by
the term “coupler” or “tuner.”

• A tuner placed at the transmitter fools a transmitter into working correctly.

• A coupler installed at the antenna eliminates feed line losses by providing a

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SMARTUNER MANUAL 2

proper match of the antenna to the feed line. The Smartuner is a true antenna
coupler.

The several key points, which we will emphasize throughout this manual, will result in
the best possible operation of your Smartuner. These include:

• The coupler must be located at the antenna.

• No coax may be connected to the coupler output.

• The coupler must have clean +12 VDC power supplied to it.

• The ground system must always be larger than the antenna.

• The antenna wire should be of the largest gauge practical.

• Capacitance at the coupler output must be minimal.

• The antenna should be of sufficient length for your lowest operating
frequency.

Strictly observing these basic rules will insure good operations under the widest range
of conditions.

This manual should be thoroughly studied if you plan t o have the best possible signal
and most reliable operation of your HF system.

Please make note of the following information for your records:

Date unit was purchased:

Dealer from whom purchased:

Date installed:

Type of antenna used:

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SMARTUNER MANUAL 3

R

)

(

1.3 Overall Description

The SMARTUNER is a general-purpose coupler that can operate with any type of radio
and almost any type of antenna configuration. The coupler network con-figuration is of
a pi or L type; sensors continually monitor the state of the tuning and relay this
information to the processor.

The initial (first time) tuning may take several milliseconds to a few seconds de-pending
on the complexity of the tuning process for a specific antenna configuration. After
tuning the first time for a specific frequency and antenna, this information is entered in
the non-volatile computer memory that will store up to 170 tuning solutions.

When the same conditions are encountered again, re-tuning is accomplished within 20
milliseconds by recalling the information from the non-volatile memory. Special
software has been designed by SGC to allow accurate and fine-tuning of the coupler.

™

For software description, refer to the MicroTune

SG-230 SMARTUNE

side view)

section of the manual.

To Tra nsmitter

PL-259

Wire antenna

Large Ground or counterpoise system

DIAGRAM OF SMARTUNER INSTALLATION

9 feet (2.8 mtr

Blk - Gr ound

Red +12 VD C

Red/ Wht - SmartLock
control line

Blk/ W ht - Remote
Tuned Indicator

If antenna or transmitter conditions have changed since the information was stored in
memory, the coupler retunes and a new tuning solution is achieved. This new
information is stored to memory for future reference. The Smartuner will always look
for the best possible tuning solution and will impr ove existing tuning solutions whenever
possible.

The SMARTUNER may be bypassed and your antenna used as a broadband receiving
antenna. To do this, turn off the power to the coupler for two seconds and then turn it
back on, or simply press the reset button on the SmartLock. In this situation, the coupler
is reset to stand-by waiting for the first RF power to be transmitted before providing a
tuning solution. In the stand-by mode, the antenna bypasses tuning elements and
connects the antenna directly to the receiver with no tuning elements engaged. This
allows for receiving signals throughout the HF range.

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SMARTUNER MANUAL 4

The coupler will cease to operate normally if input voltage drops below 10.5v DC. This
situation may occur if a marginal battery is used or if you are transmitting at high
power with an inadequate po wer supply or batte ry. Batteries must be fully char ged for
proper operation. Large gauge wiring to the transmitter and coupler must be used to
avoid retuning.

If broadband operation is required during scanning operations, jumper JP-1 on the
printed circuit board inside the coupler may be set to the “YES” mode. This will bypass
tuning elements on receive. Jumper JP-1 is located near U1.

In some cases, it may be desirable to re-tune the coupler and bypass the memory
information. If yo u wish to bypass t he r ecalled tuning solut io ns, place jumper JP-2, also
located near U1, to the “NO” position.

1.4 Coupler Network Configuration

The coupler network configuration is designed with 64 different input capacitor v alues,
32 output capacitor values, and 256 inductor values, thus providing about a half million
different pi or L configurations. The coupler requires an input of 3 to 200 watts to
operate. The unit operates on +12 VDC and can be optionally supplied to operate at +24
VDC. The +24 VDC option may be installed in the field. Please contact your dealer or
SGC and order Part Number 54-52.

1.5 OPERATION INDICATORS

Operational status of the coupler and the onboard computer’s tuning decisions is
displayed by five LEDs, which are located on the main printed circuit board (PCB).
These indicators are only visible when the cover of the coupler is removed. These five
LEDs are not designed to be interpreted by other than factory and trained service
personnel.

CAUTION: Dangerous high voltages exist inside the Smartuner

when it is operated with an HF transmitter. High RF voltages in excess
of 10kv may be expected in normal operation of this unit. In addition
to shock hazard, these RF voltages may produce burns that are very
painful if you come in contact with exposed components. Therefore,
DO NOT operate without the cover secured in place unless you are a
well experienced radio technician or engineer.

As a matter of good installation and engineering practice, exposed
metal antenna elements should be located in such a manner as to
prevent accidental contact with people (especially young children),
pets, and small animals.

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SMARTUNER MANUAL 5

1.6 Mechanical Design

The SMARTUNER is supplied in a weatherproof case with two mounting brackets. RF
and DC power are supplied to the unit through the same cable. This special cable
consists of a 50-ohm coaxial cable and four conductors. The four conductor wires are
for the ground, the positive power lead, the optional SmartLock control, and optional
LED indicator.

The SMARTUNER antenna coupler’s weatherproof case is designed to withstand the
environmental conditions encountered aboard ship when mounted on the
weatherdecks. The internal construction is designed to withstand the shock and
vibration of marine service. Corrosion-resistant hardware and passive alloys are
employed throughout.

We do not recommend o pening the SMARTUNER case unless it is necessary. For 99%
of installations, the factory settings for jumpers will be correct. Should you have
occasion to open the case, use care to ensur e the gasket that seals the unit is relocated
properly to maintain watertight integrity of the unit.

Although the SMARTUNER is built very solidly, it is good installation practice to
provide additional protection from the elements. SGC makes the following
recommendations:

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SMARTUNER MANUAL 6

1.6.1 Marine Mounting

The SMARTUNER should be located inside the house or under the aft lazaret on a
sailboat. On powerboats, the coupler may be mounted outside, but an addition
protective housing is recommended. The preferred installation if vertical is with the
standoff insulator pointing upward.

A stuffing gland for the RF and DC cables is pro vided on the lo wer edge o f the weather
housing, along with a 1/4-20 stainless steel ground stud. The antenna connects to the
ceramic insulator on the top of the weather housing.

The SMARTUNER may be mounted in any position including inverted without any
degradation of performance. If the coupler is to be exposed to long periods of high
vibration, such as aboard helicopters or tug boats, installation of the optional shock
mounting is recommended.

1.6.2 Desert and High Temperature Installations

The SMARTUNER may be used in very hot climates on a continuous basis if some
additional protection from direct sunlight is provided. The best protection for a mobile
installation is provided by the QMS (Quick Mounting System) that keeps the antenna
coupler outside of a vehicle. Temperatures inside a vehicle may exceed 212°F (100°C). If
a QMS is not used, it is desirable to keep the coupler in the shade if possible. Please
refer to the diagram in the following section.

1.6.3 Extremely Cold Temperature Installations

Your SMARTUNER will operate down to specified temperatures. We recommend
placing the SMARTUNER under some kind of housing other than the case to prevent
heavy build up of ice. If you are mounting on a tower in a hot or cold climate, a plastic
wastebasket (such as those made by Rubbermaid™) makes an excellent weather cove r
and costs only a few dollars.

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SMARTUNER MANUAL 7

Long wire antenna

Smartuner mounted inside a plastic waste
basket to protect it from extreme heat and
heavy icing. This type of enclosure is widely
available in all countries.

1.6.4 Warranty Note

It is important to have protection from the elements as common weather conditions can
reach beyond the capabilities of the coupler. Although the SG-230 coupler is fully
waterproof and was created to withstand normal weather conditions, warranty will be
voided if left exposed directly to extreme weather such as snow, rain, and ice or prolonged
sun exposure. Even in milder climates, direct and constant sunlight can exceed the safe
operating temperature and can shorten the lifespan of your coupler.

1.7 Remote Installations

The SMARTUNER is supplied with 9 feet of cable standar d. SGC has two standard lengt hs
of antenna extension cable available in the event you need to mount the cable farther than 9
feet from the transmitter. A 25-foot extension cable is available (SGC Part Number 54-65) as
is a 50-foot cable (SGC Part Number 54-66).

If you need to install the antenna coupler more than 50 feet from the transmitter site, up to
two extension cables may be used for a total of 75 or 100 feet. However, SGC does not
recommend installing the Smartuner more than 100 feet from the transmitter because two
losses must be considered.

• The first loss in long distance installations is normal attenuation of the radio signal
coming from the antenna to the radio via the coax. As you may be aware, the longer
the coaxial cable run, the higher the loss will be. The amount of loss is dependent on
frequency. At 2 MHz, the loss is approximately .5 dB, while at 30 MHz the loss in
100 feet of coaxial cable is over 2 dB. This means that a 100-watt transmitter would
actually deliver about 70 watts to the antenna after running through 100 feet of coax
at 30 MHz.

If you are seeking the utmost performance at 30 MHz and you cannot avoid a run of
100 feet, or longer, we recommend using a larger low loss type of coax such as RG-8

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SMARTUNER MANUAL 8

(foam dielectric) or Belden type 9943 coax. Both of these will reduce attenuation to
less than 1 dB per hundred feet. You should be aware that this heavier cable is less
easy to work and may be quite expensive.

• The second loss which must be co nsidered is the losses in the DC po wer and reset
control line. At any distance other than the 9-foot cable that is supplied by SGC, we
recommend that the DC voltage at the antenna coupler be measured because if the
coupler voltage drops below 10 volts, the coupler may not operate properly.

For this reason, SGC recommends that if distances are great, the input DC voltage at
the transmitter site be adjusted to provide for +12 to +14 volts at the coupler site.

We do specifically advise against use of a different power supply than the one used to
power the radio because of the danger of creating ground loops which may cause
oscillation of the final amplifiers or other undesired side effects. If you decide to use a
separate power supply mounted at the antenna coupler location, please be advised that
SGC does not provide technical support in this area.

1.8 Upgrade Sequence

The current version of the SMARTUNER coupler will have a revision letter lo cated on
the printed circuit board. To continue moving forward in coupler design, the
SMARTUNER may be revised as needed. Later revisions of the coupler will be denoted
by the subsequent letters of the alphabet.

SGC will continue making incremental improvements in the SMARTUNER product.
When you buy your product today and a new feature is added, you can always
upgrade for modest fees to the latest version of the unit. If you would like to upgrade to
the latest version of the unit, contact SGC because special discounts are always
provided to our valued customers.

2.0 SPECIFICATIONS - SMARTUNER

HF Frequency Range: 1.8 to 30.0 MHz

Note: The SMARTUNER may be operated as low as

1.6 MHz and is commonly used as an antenna­matching unit for differential GPS transmitter site
antennas. However, when operated under these
conditions, a longer antenna is re commended, such
as a 60-foot tower section for operation in the 1700­1710 kHz band and an appropriately larger
counterpoise. In addition, inductor heating may
become pronounced at high power levels in the
SMARTUNER's inductors, which are commonly
used at these frequencies. For this reason, we

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SMARTUNER MANUAL 9

recommend 70 watts at 1700 kHz and 50 watts at
1600 kHz on a continuous basis.

Power Input Range: 3 to 200 watts (PEP)
Input Impedance Range: 45 to 55 ohms
VSWR: (Typical) Typically less than 1.4:1
DC Input Requirement: +13.8 VDC
DC Operating Range +10.5 to 15 VDC
Input Current: Average: .9 amps
Random set time: Typical: less than 2 seconds
Recurrent set time: Typical: less than 10 milliseconds
Non volatile memory address: 170
Antenna Length: Minimum length of 8 ft. —3.5 to 30 MHz
Minimum length of 23 ft. —1.8 to 30 MHz
Installation: Any position
Operating Temperature: -35° to +70°C
Size: 16 x 12 x 3 inches
Weight: 8 pounds (3.5 kilos)
Case Construction: Plastic ABS wea t he rproof case
Control Cable: SGC special cable, 9 feet coaxial and two power

Input wires (plus remote tune LED wire replaceable
by any standard cable)

2.1 Accessories

Shock Mounting Tray. SGC Part Number 54-50
+24 VDC Power option. SGC Part Number 54-52
25-foot extension cable. SGC Part Number 54-61
50-foot extension cable. SGC Part number 55-62

2.2 Recommended Antennas

SG-105 Marine and Base station antenna. This is a

60 foot end fed long wire type antenna. SGC Part
Number 55-10.

SG-107 Delta Loop Antenna. This is a delta loop 11

meters high by 11 meters wide at the base. SGC Part
Number 55-12.

SG-203 Marine 28 foot whip antenna. This antenna

is used for most powerboat installations. SGC Part
Number 55-24.

SG-303 High performance 9-foot whip antenna.

This dual element antenna is designed for severe

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SMARTUNER MANUAL 10

marine and land mobile service. SGC Part Number
55-27.

QMS - Quick Mounting System that houses

SMARTUNER Smartuner and also provides a sturdy
mounting platform for the SG-303 antenna system.
Designed for fly away installations requiring no
holes installation of high performance HF antenna
system. SGC Part Number 55-45.

3.0 Parts and Technical Support

SGC supplies SMARTUNER equipment; the user supplies suitable radio and antenna.

3.1 Parts Furnished

1. Antenna Coupler

2. 9 foot special cable (RG-58 plus 4 conductors in a single jacket.)

3. Instruction Manual

3.2 User Supplied Items

The user of the SMARTUNER will need to supply a suitable HF radio antenna. Such an
antenna may be as simple as an 8-foot-long piece of wire and several ground/
counterpoise radials of 8 feet or longer. The longer the antenna, up to about 80 feet, the
better all around performance will be. Longer antennas may be used, but please refer to
the sections on antennas for discussion of limitations.

The user will also have to supply a good counterpoise. Such a counterpoise is a large
metal surface (much larger electrically than the antenna). Generally, the bigger the
counterpoise, the better your signal will be.

3.3 Technical Support

Before contacting SGC for technical support, please take a few minutes to think through
your installation and ask if there is anything obvious that you have o verlooked in the
installation. Check to make sure your ground system is both adequate and tight and
that proper voltage is supplied to the coupler.

In the event you experience difficulty with your SMARTUNER antenna coupler, you
should contact SGC for technical advise. Before calling, we ask you to have the
following information ready so that we may readily assist you.

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SMARTUNER MANUAL 11

Coupler Information. Please have the serial number of your coupler, the name of

the dealer from whom the unit was purchased, and the approximate date of
purchase.

Antenna Information. Please be ready to describe your antenna installation.

You will need to advise us whether the antenna is a wire type, a dipole, V,
vertical, long wire, or whip antenna.

Ground System. You should be ready to describe yo ur ground system in detail.

If you are dealing with a marine installation, you should have a description of
the vessel's bonding system. If you are using the coupler in a mo bile setting, you
should be able to describe bonding of the hood, trunk, and other vehicle parts
that may have been done. In an aircraft, you should be able to describe location
of the coupler and type of ground connection used.

Power supply voltage. One of the common mistakes made when installing

couplers is to assume that a connection is go od when it hasn't been measured. If
you experience any type of erratic or intermittent operation, please measure the
power supply voltage inside the coupler.

. Describe Coupler behavior. If you are having a problem, determine if it is

happening all the time or only part of the time. Does the problem occur only on
certain frequencies? Does the problem happen only in certain modes?

. Be patient. Finding the reason for less than ideal system operation may take one

telephone call or it may take several calls. Regardless of how complex the
problem is, your SGC representative will be able to walk you through the
process of solving your problem in a logical step-by-step manner. The Smartuner

and accessories will always give top performance when carefully installed.

4.0

Antenna Types

The automatic antenna coupler is designed for use wit h end-fed unbalanced antennas
such as whips and long wires. The radiating portion of the antenna is connected
directly to the coupler through a high voltage insulator. It is extremely important that
the antenna type, site location, and grounding technique be correctly chosen so that the
system will radiate effectively.

Wideband antennas (e.g., log periodic) that cover the full range of the system may be
used with the coupler if desired. Narro w band resonant antennas, such as dipoles, Vs,
and inverted Vs may only be used if the antenna VSWR (including coaxial feeder) is less
than, or equal to 3:1 at the operating frequency.

Note that if a dipole or V type antenna is used, the antenna may be operated at any
frequency within the range of the coupler if each side of the V or dipole is 23 feet or

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SMARTUNER MANUAL 12

longer. In addition, the SMARTUNER is just as happy feeding a conventional V antenna
as an inverted V. The coupler is flexible in this regard.

4.1 Antenna Selection

The automatic antenna coupler will operate into almost any end-fed antenna with a
length of 2.5 meters or more, provided an effective ground is used. The antenna
efficiency will generally be proportional to length and in most applications will be
maximum at a length of 1/4 wavelength. This means that the longest possible antenna
should be selected for each installation.

Very short antennas are only recommended when there is no other alternative such as
in a vehicular mobile installation. The performance of short whip antennas is usually
very poor, par ticularly at the lower frequencies, and radiation efficiency will be only a
few percent of a full sized antenna. However, a special electrically long antenna such as
the SG-303 9-foot antenna overcomes the radiation problem.

4.2 Whip Antennas

This antenna is recommended only for vehicular mobile installations. The short length
will result in poorer performance compared with the longer antennas. A special high
performance 9-foot antenna, the SG-303, is manufactured by SGC specifically for this
problem. (SGC Part Number 55-27.)

This antenna is recommended fo r marine installation o n smaller vessels. It may also be
used in base stations if there is no way of using a longer antenna. The SG-203 is this
type of antenna. (SGC Part Number 55-23.)

This is the preferred antenna for marine installation when there is no room for a
longwire antenna. It will also provide reasonable efficiency for base station use and is
the shortest recommended base antenna. (SGC Part Number 55-24 for the SG-204 35
foot whip antenna.)

2.5 to 3.0 Meters (8 to 9 feet)

7.0 to 8.5 Meters (28 feet)

10.7 Meters (35 feet)

4.3 Longwire Antenna—23 Meters (75 feet); 46 Meters (150 feet)

For most applications, the longwire antenna will give the best results and is
recommended when practical. The diagrams at the end of this section show some
recommended methods of installation. These are only a few of the many possible
methods of installation, and frequently a different configuration will be the best at a

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SMARTUNER MANUAL 13

particular site. SGC’s long wire antenna, 60 feet in length, provides efficient operation
on low frequencies and high frequencies alike. (SGC Part Number 55-10.)

4.4 Backstay Antennas —8 Meters (28 feet) and Longer

Although we would lov e to sell ever yo ne a high per for mance marine whip ant enna, the
backstay of a sailboat is almost impossible to improve upon in most installations.

4.5 Typical Installations

Figures 4.5.1 through 4.5.11 show some typical installations for the automatic antenna
coupler.

Figure 4.5.1 Jeep installation

Jeep Installation
for Automatic
Antenna Coupler

Feed-through
insulator

Figure 4.5.2 Vehicle installation

3.0 M whip

Detail

Transceiver

Coupler

GTO cable
(as short as possible)

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SMARTUNER MANUAL 14

Ground

3.0 M whip

coupler
securely
to truck

Feed through insulator

Coupler

Transceiver

Vehicle Installation

Figure 4.5.3 Motor Vessel installation

Feed through insulator

Coupler

Suitable stay cable

Ground to
steel bulkhead
or overhead

Motor Vessel Installation

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Figure 4.5.4 Base installation

SMARTUNER MANUAL 15

COUPLER

Figure 4.5.5 Base ladder installation

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SMARTUNER MANUAL 16

up to 300 feet

up to 40 feet

Balanced Line Feeders
300-600 Ohms

GND

Hot

Coupler

RF cable

DC Control cable

Base Ladder Installation

Figure 4.5.6 Base installation with ground wire radials

Insulator

30°

GTO cable

Coupler

2M

Insulator

Ground cable No. 4 AWG
(150 cm maximum)

Conduit for
control cable
and coax

Figure 4.5.7 Base dipole installation

11M

30°

Radial wires
buried in soil

Base Installation with
Ground Wire Radials

2M

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SMARTUNER MANUAL 17

Hot

Coupler

RF Cable

Base Dipole Installation

Figure 4.5.8 Base Quadra Loop Horizontal

Porcelain
isolators
with tie rope

1 meter

3 meters

E66 insulators
(x8)

GND

7 to 25 meters

DC Supply Line

Radiation

3 meters

Ground
bolt
terminal

50 ohm
coax from
transmitter

Base Quadra
Loop Horizontal

Coupler

Antenna
terminal

The horizontal quad loop is a groundless antenna for high angle radiation and is ideal
for HF communications up to 500 miles in the frequency range of 2 to 10 MHz. This
configuration prov ides optimum near-right ang le reflection to the ionosphere fo r short­range communications.

A square base can be from 8 to 15 meters long and can be configured to the shape of the
structure as necessary, to provide the best arrangement. The height of the supporting
poles should be 20 to 40 feet. Supporting poles should be as tall as possible to prov ide
the antenna with the greatest isolation from industrial noise generated by the building,
such as fluorescent lights and electrical moto rs. Loop antennas are also less susceptible
to industrial RF noise generated by the building, because they are isolated from the
ground system of the building.

Loop wires are attached at one end on the high voltage active side of the coupler and on
the other end at the ground side of the coupler.

Figure 4.5.9 Base Delta Loop

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SMARTUNER MANUAL 18

Radiation

Coupler

Base Delta Loop

The delta loop antennas are ideally suited to long range communications due to their
low angle. This configuration is best for communications ranging from 500 to 5000
miles in the HF frequency range of 4 to 22 MHz. Noise rejection is excellent, as stated
for the quad loop antenna. Because the antenna system is not connected to a ground,
noise rejection is enhanced. If mounted on the rooftop of the building, it is further
isolated from the building, which generates RF noise.

The supporting mast should be 8 to 14 meters tall to provide good overall HF
performance.

Note that with this type of antenna, the coupler may be mounted in the middle of the
horizontal portion of the loop or it may be mounted at the corner. If mounted at the
corner and the lead from the coupler attached to the vertical leg, the polarization of the
loop tends to be vertical and is slightly better for low angle long distance
communications.

Loops in the horizontal plane may also be used. This type of antenna provides
exceptionally good performance on the low frequency bands for short to intermediate
range communications.

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SMARTUNER MANUAL 19

Figure 4.5.10 Vessel Groundless Loop

Radiation

75 feet

Vessel
Groundless
Loop

Lower mast connection

to coupler RF ground

Coupler

Porcelain
isolator

The triangular loop antenna for sailboats is designed to operate in a groundless
environment and still provide high performance. This type of installation will re quire
only one insulator point on the bottom back stay and an electrical connection on top of
the mast and the stay. The grounded side of the coupler should be connected to the
bottom of the mast. Although not our best r ecommendation, this antenna will provide
a workable solution in some installations.

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SMARTUNER MANUAL 20

Figure 4.5.11 Vessel insulated back stay

Porcelain
isolator

Radiation

75 feet

Vessel
insulated
Backstay

connection

The insulated back stay antenna requires two porcelains isolator s. The coupler must be
placed as close as possible to the base of the back stay antenna. Proper grounding of the
coupler is very impo rtant. Connect the RF ground terminal of the coupler to all of the
metal parts or structures of the boat (keel, engine, etc.).

Coupler

Porcelain
isolator

Ground

4.6 Apartment Loop Antenna

Loop antennas can be used very effectively in small apartments, offices, and rooms.
Radiation for a loop antenna is always efficient but highly directive. Therefore, the
orientation of the loop is very important. Generally, the vertical loop antenna with
horizontal radiation is much preferred for a general application throughout the 1.8 to 30
MHz band. However, loo p antennas can be effect iv e when mount ed hor izo ntally to the
ground to radiate vertically and provide efficient short-range communications on
higher frequencies. Generally HF connections ar e difficult to establish in the distance
range of 50 to 250 miles. In a large room (such as 20 x 30), we would recommend the
installation of a single wire loop antenna mounted on the ceiling with the coupler
against the wall directly below the antenna. The wire gauge should not be less than 16
AWG with insulation.

When operating in a small room, install a small multiple wire loop (six loops) on a
rectangular configuration three by four feet (as illustrated in Figure 4.6.1). This
configuration allows operation from 1.8 to 60 MHz, and the SG-231 will tune and load

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SMARTUNER MANUAL 21

all frequencies well below a ratio of 1.4:1 VSWR. Directivity will be high from 3 to 12
dB depending upon the frequency. If this is a problem, two loops at 90 degrees can be
installed to communicate at 90 degrees off direction of the first loop antenna. Loop
antennas are low noise antennas. However, because they are used in apartments and
crowded cities, high industrial noise can be expect ed. Avoid using neon or fluor escent
lights within 50 feet of the loop antenna, as they may completely jam one or several
frequency bands.

Figure 4.6.1 Small loop antenna (3x4 feet)

Pegs or Nails

Building wall

Loop antennas of much larger sizes can be used; however, while the low frequency
operation of such antennas may be quite goo d, the larger antennas may not work well
at very high frequencies when located in a plane parallel to the earth. This is because
large loop antennas generally radiate their maximum lobe (field strength) at right
angles to their plane.

This means that a large loop, say 60 feet on a side, mounted 20 feet above the ground,
would radiate much of its energy upward. While during the day this would work well
for close in communications, longer distances would be achieved with the loop
mounted vertically. The vertical loop antenna of 1/4 wavelength is the basis of the
“quad” type directional antenna.

Use 6-8 turns of #16 or larger wire which is
insulated for high voltages. No spacing
between turns. Use a total of 70-90 feet of
wire.

Cable to Radio

Smartuner

Loop antennas repr esent a clo sed circuit and fo r this r easo n are much less suscept ible to
noise or RF contamination than other kinds of antennas. In certain residential and
industrial areas where high noise levels occur, the loop antenna may provide a
substantial improvement in receiving and transmitting performance at very little cost.

4.7 Recreational Vehicle (RV) Antennas

RVs or trailers provide an excellent base to install effective low cost antennas, and in
both configurations, end feed or loop antennas can be used.

An end-fed antenna could be effectively used if a metal cabin structure is available.
Loop antennas have the advantage of not requiring a ground system but are highly

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SMARTUNER MANUAL 22

directive. The antenna can be mounted simply on short (18” long by .5” diameter)
plastic plumbing pipes. Make the end-fed antenna as long as possible in an “L” shaped
configuration, as illustrated in Figure 4.7.1.

Figure 4.7.1 Recreational vehicle, bus, or truck detail

18" PVC
pipe
standoffs

Coupler mounted

inside coach

Use a separate ground strap or wire for the body
and the chassis to the ground of the coupler.

Recreational Vehicle
Antenna Installation

Antenna wire

Metal roof
of vehicle

4.8 Aircraft Antennas

When installed in high performance turboprop or jet aircraft, the Smartuner will
operate well with a shunt-fed antenna.

This is generally a 13-foot piece of metal that mounts on the fuselage of the aircraft and
is grounded to the aircraft at one end. The device looks something like a towel bar on
the underside of the aircraft.

The Smartuner will also match well the more common wire antenna from fuselage to
vertical stabilizer (and continuing to a wing tip, if desired) and a long wire antenna
under the tail rotor of helicopters. This long wire appro ach has proven effectiv e on Bell
Jet Rangers and Long Rangers in particular.

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SMARTUNER MANUAL 23

Figure 4.8.1 Aircraft installation detail

Rotary Aircraft

Isolator

Wire antenna

Strut to space out
antenna with plastic
tubing or fiberglass
rod

Figure 4.8.2 Aircraft Installation Detail

Aviation
control
head

Ground

Radio

Coupler

Fixed Wing Aircraft

Wire goes to
the coupler

Wire antenna

Coupler

Isolator

Wire antenna

Isolator

4.9 Low Profile, Hidden and Covert Antennas

There are two users of low profile, hidden, and covert antennas:

• The paramilitary user who will wish to operate from a residence or commercial
building without drawing attention to long range HF communication in
progress.

• Commercial building without drawing attention to the fact that long range HF
communication is in process.

• The amateur radio community (a larger group) finds itself more restricted by
covenants, building codes, and tenant requirements.

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SMARTUNER MANUAL 24

g

ge gaug

g

g

y

y

y

y

y

g

In a typical residential building, covert antennas have been used successfully for
intercontinental communications. The antennas used include both groundless loop
type antennas and those that require a counterpoise (ground).

A. If a fla
it is easy to tape a lar

pole is made of PVC pipe,

e wire

to the inside of the pipe and use a

ood counterpoise. Typical flagpoles

are 25 to 35 feet in hei

ht and offer

excellent performance on all bands.

B. Masonr

chimneys are visuall
“busy.” You can run a #10 copper
wire parallel to the chimne

with
little risk of detection. Some short
standoffs and

ou have a support for
a vertical dipole type antenna.
C. Along the edge of the roof, held
off by some inexpensive TV twin­lead standoffs, you can hide 25 to 40
feet of antenna on virtually any
house.
D. The Inverted “L” antenna may
work slightly better if it is installed
clear of a building, but for covert
operations, this t

pe of installation is
a favorite. If the feed-point is at
ground level adjacent to an iron or
copper water line enterin

the house
that could provide an excellent
counterpoise but it is not
recommended as radials. Ground
wire will always insure proper and
better grounding.

B

COUPLER

Coupler

At least three ground radials
longer than the flag pole

C

COUPLER

D

COUPLER

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SMARTUNER MANUAL 25

g

E. Under the roof overhang, all
kinds of wire antennas may be
installed.
F. All types of antennas may be
hidden inside the roof of a building
that uses non-metallic roofing
materials.
G. The downspout, rain gutter
antenna works well if the pipin

and

gutter are aluminum. You may wish

Coupler

E

Coupler

F

G

Coupler

to assure low electrical resistance
connections between gutter sections
with hose clamps or plumber’s tape.

4.10 Emergency Antennas

There are a couple of antennas which don't fit into any category in particular, but which
should be mentioned because when used with a Smartuner, they will deliver
spectacular results.

4.10.1 Kite Antenna

Figure 4.10.1 Kite Antenna

Use string to post for strain relief—do not tie

Box, delta, or conventional kite

100 feet of
string

30 to 70 feet of wire
ground conductor (counterpoise)

Note: The counterpoise may be underwater if installed on a beach or from
a vessel at sea. If an underwater counterpoise is used, tuning may change
with tide changes in shallow waters. This type of antenna has been run for
hours in tropical trade winds with excellent results.

30 to 70 feet of wire

kite wie to coupler without strain relief

String

Jumper

Coupler

Post or stake

This is our recommended antenna to be carried aboard all types of vessels. This is
because when a wind strong enough to damage a boat occurs, it is easy to fly a kite and
this may lift fifty to one hundred feet of antenna wire. For good emergency
communications, you will only need 30-70 feet of antenna and a strongly built (Mylar or
nylon) kite.

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SMARTUNER MANUAL 26

Remember that when a mast comes down, you have easy access to the high voltage feed
line which may be secured to a kite antenna. Offshore power boats can use this antenna
as well, since 10-20 knot winds are almost always available when underway at sea.

4.10.2 Tactical Installations

Over the course of nearly 25 years of HF communications, SGC equipment has been
used everywhere from camel back in the desert to Antarctic expeditions. Along the
way we have collected a number of tips to get maximum system performance from
your radio system when you are operating in a tactical or disaster situation. These tips,
by the way, also apply when you go camping or are involved in amateur radio Field
Day activities:

Tactical Antenna Supports. Except for a barren desert, just about all landscapes have
structures (natural and man made) t hat can be used for ante nna suppor ts. A ll it usually
takes is several hundred feet of rope and some creativity. Here are some examples to
consider. If you wonder which structure would work best remember the one with the
greatest height and greatest distance from grounded metal will generally give the best
performance.

Natural rock formations such as cliffs and bluffs.
Tall trees.
Water towers.
Church spires and minarets of mosques.
Rooftops of buildings—strung between.
Sign posts such as for banks and gasoline stations.
Telephone (not power) poles. There's no power line noise on

telephone poles.
Railroad trestles
Highway structures: signs, overpasses, and bridges.
Flag poles at public buildings, schools, and hospitals.

Tactical Grounds And Counterpoises. Just as antenna opportunities abound, so do
ground and counterpoise opportunities to the professional eye. Some of our favorite
examples which correspond to the antennas above include:

Cross country water and petroleum transmission pipes (e.g., as it passes

under a bluff)
Long steel cables along a mountain highway (e.g., one with nearby trees)
Chain link fencing (e.g., around a water tower)

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SMARTUNER MANUAL 27

Metal lawn sprinkler piping (e.g., in a church yard)
Fire department standpipes (required in most big city building codes)
Underground metal petroleum storage tanks (e.g., at a gasoline station)
Metal fencing of any type (e.g., a barbed wire fence along a pasture or

under telephone pole)
One hundred feet of wire thrown into a river or sea (e.g., under a

trestle)
Metal drain culverts (e.g., along a highway)
Four to five cars parked with their metal bumpers touching
A sheet metal roof (e.g., hospital or public building)

As you can see from this list, there are an almost limitless number of options available
to install a high performance antenna system with only a small amount of wire and a
SMARTUNER.

4.11 FIVE GOLDEN RULES OF HF INSTALLATION

These rules apply to all types of stations, including base, mobile, airborne and marine.
They are very important for planning and installing your HF system if you want to
achieve good communications.

1. Install transceiver as close to yo ur operat ion site and t o the power supply system
as possible (whether it is an external power supply or battery system).

2. The antenna must be installed in an open space and as far as possible from your
operating point. As an example, on a sailboat, use the backstay as the antenna,
since it is the farthest point away from the rest of the vessel.

3. The antenna coupler must be installed at the base of the antenna.

4. Always create your own ground with radial wire or copper straps. They are the
only ones that will guarantee a solid and proper ground system.

5. All cables
and/or necessary. Any excess cable should be shortened to the proper length
never coiled.

Following these rules will minimize marginal installations and problem sources such as
RF feedback in the radio, power supply or cables and "hot" or RF burning microphones.
If all 5 above points are follo wed during the design and installation of your HF system,
the operator can expect top performance.

- power supply, cont rol or co axial - must always be as short as possible

-

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SMARTUNER MANUAL 28

5.0 General Notes on Antennas and Couplers

1. The longer the antenna, the generally better the antenna performance. By

doubling the length of the antenna, an improvement of 3 to 6 dB can be
expected in your radiation or receiving characteristics. This is the equivalent of
transmitting with 400 watts, when actually you are using only 100 watts.

2. A ground for end-fed antennas can be effectively created by running radial

wires from the coupler point and burying them in the ground. We re commend
for a good ground that 12 radials should be used and they be about 1/3 longer
than the antenna length. The number of radials can be reduced; however, you
need at least one. Efficiency pattern and radiation will decrease in proportion.

3. Antennas will always perform better if the wire is of a large gauge. Never use

anything less than gauge 16. If gauge 6 is used, an improvement of 6 dB can be
expected over the 16 gauge. The radial ground wire should be at least the same
size as of the antenna wire.

4. The SMARTUNER coupler can handle antennas beyond the specified mini-

mum range of 8 to 80 feet and should be extended as much as possible. In some
cases, the antenna can be 300 feet or longer. In this situation, you may find
some tuning holes. The antenna can be made a little shorter or longer to
overcome the tuning hole on the frequency band you may have wanted to use.

5. Always install the antenna system as far away as possible from any electrical or

industrial noise source. Electrical appliance, electric motor, or fluorescent
lighting noise may cover up weak or even strong signals.

6. A remarkable antenna coupler, the SMARTUNER will tune practically any an-

tenna—good or bad. Keep in mind that it is not the coupler that will radiate the
RF energy, it is the antenna. Therefore, use only good size wire and long
antennas.

7. Never use a feed line or coaxial cable at the output of the antenna coupler. The

coupler functions to couple the radio to the antenna, not to act as a mid point
connector. Because the antenna system star ts at the output of the coupler, the
lead end from the coupler to the hypothetical antenna is part of the antenna
system. Avoid having the lead end wire touch any o ther metal structure: it will
capacitively short your antenna to ground.

8. The backstay of your mast is the only viable antenna on a sailboat. The

SMARTUNER coupler is specifically designed to be used for such applications.

9. For vehicular installation, do not use any inexpensive CB antennas and/or

mounts. These antennas will not perform well from 1.8 to 10 MHz even though

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SMARTUNER MANUAL 29

the coupler will load and tune the antenna whip. A high voltage of 15,000 to
30,000 volts RF will be applied to the antenna depending on the RF power lev el
and frequency. The inexpensive ball mounts for CB antennas are not designed
for so string ent a purpose. We recommend the use of an antenna system such
as the SG-303: it was specifically designed for such extreme applications.

5.1 Steps to Antenna Installation

System installation is a three-part process covering the following steps:

1. Selection and installation of the antenna

2. Mounting the antenna coupler

3. Connecting the appropriate interface cables between the coupler and the

transceiver

This manual section will discuss the three steps mentioned above in detail and will
provide sufficient information to enable the user to confidently install a complete
system properly.

The antenna system is a key part of the communication system. For satisfactory
operation the system must be carefully selected and then installed correctly. The
unbalanced antennas used with the automatic antenna coupler use the ground
(counterpoise) as half of the antenna system. The ground forms an “image” antenna and
is a critical part of the system. It is essential to consider both the ground and the
antenna when designing the system installation.

5.2 Antenna Location

The figures in Section 4.0 illustrate several different antenna installations. The following
points should be carefully considered when designing the antenna system.

a) The antenna should be located in a position free of obstructions, particularly in

the desired direction of communication.

b) The antenna should be kept as far away as possible from buildings, trees, and

vegetation. If metallic masts or supports are used, arrange the insulator s so that
the antenna is spaced at least 2 meters from the mast.

c) Remember that the radiating part of the antenna starts at the coupler. The

location of the bottom portion of the antenna is important.

d) Vertical antennas have an omni-directional radiation pattern, providing equal

performance in all directions.

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SMARTUNER MANUAL 30

e) Horizontal wire antennas have maximum radiation broadside to the antenna

when the frequency is less than 1/4 wavelength. As the frequency increases
beyond 1/4 wavelength, lobes will appear in the radiation pattern with the
principal lobes becoming closer to the plane of the antenna as the length
increases. At all times, radiation will be minimal at the end of the antenna;
therefore, it should be located so that the ends point in directions where
communications are not required.

f) The V antenna construction minimizes the directivity of the ho rizontal antenna

and is recommended for all around coverage. In addition, the V antenna is a
compromise between vertical and horizontal polarization and will give good
results for communications with land or marine mobiles using vertical whip
antennas.

g) High voltages (sometimes exceeding 30,000v RF) are present on the antenna.

All parts of the antenna and coupler must be located or protected so that there

is no possibility of accidental contact.
h) Do not locate the antenna close to other antenna systems.
i) Make sure that the antenna is rigidly supported. The antenna will de-tune if it

sags or sways.
j) The connection from the coupler to the ground must be a small percentage of

the total length of the antenna. Do not let the length of the ground strap exceed

1.5 meters. Use heavy gauge wire or strap for ground connection.

k) Whip antennas should be connected with the minimum length of wire. (Do not

exceed 0.6 meters).
l) Do not locate the coupler farther from the transceiver than necessary. If the

distance exceeds 10 meters (30 feet), we recommend you use low loss coaxial

cable, such as RG-8 or Belden type 9943.

5.3 Ground Systems—General

The ground system (also called a counterpoise) is a key part of the overall antenna
system and is the primary cause of poor performance and the difficulty of adjusting the
coupler. A good ground is essential.

5.3.1 Vehicle Grounds

Connect the coupler directly to the frame of the vehicle. Ensure that a heavy strap is
used from the coupler ground lug and that the connections are cleared of all paint and
dirt so that the shiny metal is exposed. SGC always recommends that two grounding
bolts with star washers be used to ensure no ground resistance is encountered. Make

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SMARTUNER MANUAL 31

sure that the grounding point is not insulated from other parts of the vehicle by non­metallic couplings, bushings, fiberglass panels, etc. Modern vehicle assembly techniques
that use spot welding may not always adequately connect various body parts. Use an
ohmmeter and insure your vehicle is electrically bonded.

Another area to watch is trunk lids and hoods. Because many body parts are dip
painted, they may float above the RF ground when assembled. Use of short heavy braid
to insure all doors and hatches are grounded is good installation practice. Although
this is tedious work, the benefit is that once completed you will have a much superior
radiated signal and lower noise floor on receive.

5.3.2 Marine Grounds

A metal-hulled vessel in salt water provides an almost ideal ground. The coupler
should be connected directly to the hull using the sho rt est possible ground strap or 2- to
3-inch wide 2 mil copper foil. Make sure that the contact point is free from paint and
dirt. Ensure a good contact area for minimum resistance.

Wooden and fiberglass hulled vessels present more of a grounding problem. It is
normally necessary to bond all large metallic part s such as the stove, fuel tanks, engine,
and propeller shaft; so metimes an external g rounding plate should be connected to t he
hull. The bonding and grounding plate should be chosen with consideration for the
problems of electrolysis. Severe damage may result if dissimilar metals are connected
together.

Our experience is that sacrificial zincs, which double as radio grounds, may help, but
are not by themselves a complete solution. If you use one (or more) of these devices,
remember to provide for a large physical counterpoise in addition.

In a sailboat installation, we generally place the SMARTUNER in the aft lazaret and
then run at least three runs of foil forward. One runs up the port chine, just below the
waterline, another up the starboard chine below the waterline, and the third up the
center of the vessel.

The center foil is gener ally connected to the rudder post, tr ansmission, engine, and keel
bolts. The chine foils are attached to through hulls, the stove, tankage and so forth. The
idea is to get as much metal inside the vessel connected as possible. Metal toe r ails and
life lines work well as do keel coolers on motorized craft.

Here is a neat trick for attaching foil to keel bolts. When a large keel bolt is exposed,
drill into the keel bolt and tap the hole for a suitable stainless steel machine screw.
Attach with suitable copper washers for a solid electrical connection.

Although it is not mandatory that ground foil be glued into place, we consider it a goo d
idea to keep the space below decks neat and orderly under all conditions.

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SMARTUNER MANUAL 32

If you are using a backstay antenna, try to visualize your ground as you look down
from the top of the mast. Ask yourself if you see 100 square feet of metal below you.
The closer to this figure you can get, the better your radiated signal will be. What you
are trying to do is make a large capacitor to the seawater. Consider the salt water of the
sea to be one plate of a capacitor, the ground system the other, and the hull to be the
dielectric.

On marine installations, you should also be aware of potential noise so urces that may
need to be bypassed to ground. We have encounter ed just about every source of noise
imaginable in vessel installations. The best time to track down annoying noise sources is
when you are laying in a ground system. Not only will you get much better voice
communications, but Weatherfax, Navtex, and Loran reception will impro ve as well if
they are also tied into the ground system.

Particular attention should be paid to any device that uses an electric motor. This means
to turn on the water pressure pump, bilge pump, hot water forced air heater fans,
refrigeration, and auto pilot motors. A few small capacitors to ground (.01 microfarads
at 100 VDC) can resolve many issues. Bypassing of the vessel's alternator is also a good
idea.

5.3.3 Base Station Grounds

In areas of high ground conductivity, an effective ground can be made through a
grounding rod. The rod should be approximately 3 meters in length and should be
installed as close as possible to the coupler . It may be necessary to use several ground
rods bonded together to improve the ground contact. Water pipes are sometimes
recommended as grounds and may be used provided plastic pipe is not buried as part
of the system and the following conditions are met:

a) The water pipe is close to the coupler.
b) The water pipe enters the ground close to the coupler bonding point.
c) There are no joints or couplings in the pipe that will increase the resistance path

to ground.
d) The water pipe enters soil with good conductivity.
e) A low resistance contact is made to the water pipe.

Earth requiring a counterpoise. Frequently the ground conductiv ity will not suffice to
provide satisfactory operation of the coupler—almost certainly the case with well
drained sandy, rocky, or loamy soils. Therefore, a co unterpoise (artificial ground) must
be used as the ground system.

Rooftop installation requiring a counterpoise. In a rooftop installation where there is
no existing ground plane, the ideal ground would be a conducting surface ex-tending
several wavelengths in all directions around the antenna. On a rooftop, this situation

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SMARTUNER MANUAL 33

may be approximated by placing a screen of chicken mesh, copper hardware cloth, or
similar material over the roof of the building. More frequently, a counterpoise system of
radial wires must be used. SGC recommends the use of at least 8 to 12 radials bonded
together in the center. If the antenna is at ground level, the radials should be buried a
few inches below the surface.

5.4 Corrosion

Ground connections are subject to co rrosion and o xidation. All jo ints must be clean and
the hardware adequately tightened. Joints should be well soldered wherever possible.
The joints may be protected by an application of silicon grease and, under severe
conditions, covered with electrical tape and waterproof varnish or a durable brand of
silicon caulking.

If you are mounting your SMARTUNER on a vessel where a lot of salt spray is en­countered, it is a good idea to put the wire connections that are exposed to weather on
your six-month periodic maintenance plan. Then, every six months, you will be
reminded to undo each of the connections, clean, retighten, and reseal.

Use jumpers around metal backstay triangles on split backstay antennas. Corrosion may
cause up to several hundred ohms of resistance to occur even though you may think
that a metal-to-metal connection would be a good one.

5.5 Antenna Coupler Mounting

The coupler is mounted using the proper mounting ears on the case. Choose a location
immediately adjacent to the antenna feed point. In trunk-mounted mobile installations,
locate the coupler so that the antenna insulator is within a few centimeters of the
antenna exit hole. Note also that the antenna lead must pass through an insulated
bushing. High voltage connecting cable must be used. (RG-8U cable with solid
insulation may be used if the outer shielding is removed). When the coupler is installed
on the outside, or on the deck, we recommend a protective housing.

5.6 Antenna Connection

The antenna lead is connected to the high voltage insulator. During operation, use two
wrenches when tightening the nut to prevent the stud rotating. A potential of several
thousand volts may be present at the antenna terminal and adequate protection must be
made against accidental contact. It is also necessary that the antenna be spaced at least 3
centimeters from the conducting surface. Sharp points in the lead-in wire should be
avoided to prevent corona discharges.

6.0 Installation Procedures

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SMARTUNER MANUAL 34

J

J

J

J

J

The following diagrams will assist you with installing the SMARTUNER with SGC
equipment.

6.1 Installation with SG-2000

The SG-2000 is shipped with all necessary connectors for installation of a
SMARTUNER™ and for installation of peripherals by means of the audio input/output
jack on the rear panel. You will see the connectors when you remove the Philips head
screws that hold the protective sheet metal cover over the rear panel connectors.

From left to right, these jacks provide the following:

J-502 SMARTUNER connections
J-301 Aux. Audio input/output and PTT line
J-503 Remote control head or multiple head junction box
J-504 Remote control head or multiple head junction box (Head mounted

on radio is normally connected here.)

Ext. SPK External Speaker
Oven Turns oven On-Off (Shipped with oven ON as default)

SG-2000 to Smartuner Coupler Connections

SG - 2000

502 -1 B lack wire of coupler cable (Ground)

­502 -2 Red wire of coupler cable (+12 VDC)

­502 -3 Wht/ Blk wire of coupler cable (TND)

-

SG - 2000 Rear

Panel view

502

-

- 30 1

6.2 INSTALLATION ON ALL RADIOS

The SMARTUNER requires only a source of +12 VDC (optional: +24 VDC), an RF
transmission line (RG-58/U up to 30 ft., RG-8 OR RG-213/U if over 30 ft.), plus suitable
ground and antenna systems. No band switch information, low power tuning, or
handshake is required, since the coupler tunes on RF voice or carrier. Power
consumption is normally less than 1 amp, allowing for use of small gauge wire. The
PCB is fully protected against power reversal. The output for a remote mounted tune
indicator, if desired, is strictly optional.

SG - 230 Wire

When installing your SMARTUNER, remember to allow for the power to be
disconnected from the battery during periods when equipment is not being used. This
will prevent draining the battery unnecessarily.

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SMARTUNER MANUAL 35

6.3 Smartlock Installation

The SmartLock is an optional accessory with the SMARTUNER. This gives the user
additional control over the coupler. It is not required for normal operation of the
coupler and does not need to be installed. It allows the coupler settings to be held in
place so no tuning or retuning will occur, and has an LED indicator which will light
when the coupler is tuned, and provides a manual reset of the coupler without turning
the power off and on.

Connections:

SG-230 Smartlock
Red wire (+12VDC) red wire
Black wire (Ground) black wire
White/Black wire (TND) green

White/Red (Reset/Lock) white
We recommend soldering the wires together and insulating the exposed wires with heat
shrink or electrical tape; howev er, ot her metho ds may suffice as long as t he connectio ns
are firm and there is no exposed wiring. A schematic drawing is provided as an aid to
understanding the operation of the SmartLock.

Smartlock Schematic Diagram

6.4 Weatherdeck Mounting

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SMARTUNER MANUAL 36

Weatherdeck mounting can be used. Years of experience have sho wn that inside mounting or
even splash-proof mounting is preferred, particular ly in cold, damp environments. In tropical
use, shielding from direct sunlight is desirable.

The base of the antenna should be connected to the high voltage feed-through insulator on the
housing. Note that this insulator is not designed to support heavy mechanical loads. If such
loading is encountered, use a strain insulator.

The ground system should be connected to the 1/4-inch stainless steel stud protruding from
the bottom of the housing. Connection to the ground system is extremely important to a
successful installation. Ground runs of over a few inches should be made from 4-inch-wide
copper strap or larger. The act ual ground system sho uld be as good as possible, as t he ground
is an integral part of the antenna system. See section 5.3 on grounding. However, couplers in
general require the antenna parameters to be within the range of the tuning parameters or the
coupler will not find a satisfactory match. The computer in the SMARTUNER cannot second­guess the installer.

A proper antenna/ground installation is of great

importance: regardless of whether your station

is a base station, marine, or land mobile.

6.5 Electrical Checkout

After the SMARTUNER antenna coupler has been installed, the SSB transmitter should be
adjusted to the highest frequency desired, and a directional watt meter (e.g., Bird Model 43)
should be inserted into the transmission line. The transmitter should then be powered. The
SMARTUNER will begin to tune when RF power is applied, and you will hear a “clattering” of
PC-mounted relays. If the antenna length and ground parameters are within range, the relay
noises will stop when just a few words are spoken, and the reflected po wer on the watt meter
would indicate a value of better than 2:1 VSWR. The “TUNED” LED, which is mounted on the
PC board, will light, and if there is a remote “TUNED” indicator, it will also light.

12 volt power source

SG-2000 -->SG-230

Black (of coupler cable) = ground - Pin 1
Red (of coupler cable) = +12 VDC - Pin 2
White w/Black = tuned indication - Pin 3

(View: Back panel of unit)

SG–2000 HF radio

Terminal block
for DC power
cable

Watt meter

SG–230

Antenna

Counterpoise

Smartlock

(Optional)

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Next, the SSB transmitter should be adjusted to the lowest desired frequency, and the
test as outlined above should be repeated. The SMARTUNER should immediately sense
the mismatch and switch to the tune mode to retune the antenna system. Since the
algorithm must search through more possible values of L and C to find an appropriate
combination at the lower frequencies, the tune cycle may take longer. A few spoken
words should achieve an “all tuned” indication. The SMARTUNER installation and
tune-up are considered complete if the above tests have been successfully performed.

The SMARTUNER will probably not be supplied from SGC with memory data
appropriate to your installation, and the memory feature may not seem impressive at
first. Allow the SMARTUNER to “learn” your antenna’s requirements by proceeding
from frequency to frequency and allowing the normal tune-up to occur. As the
SMARTUNER computer memorizes more and more frequencies, you should then be
able to return to a previously tuned frequency and find that the coupler immediately
responds “ALL TUNED,” even before the first word is completed.

The memory system is capable of storing hundreds of individual frequency/relay
combinations, mostly in the lower operating frequencies, providing better memory
resolution at lower frequencies where antenna systems are inherently narrow band.
Usually, only one or two memory positions are needed to provide satisfactory coverage
at higher frequency bands.

6.6 Do-It-Yourself Light-Bulb Dummy Load

Any time that a transmitter is used, it must be outputting into a load. A load is anything
that the output power can be pumped into. If the transmitter is operated without any
sort of load connected, the final amplifier stage could become severely damaged. The
problem is that you should never test a transmitter on the air for the first time, if you
are unsure about how to operate it, and if you are unsure whether it is working
properly. You could create harmful interference to other stations.

To test transmitters without actually operating into an antenna, dummy loads were
created. A dummy load is a load that will dissipate the energy from the transmitter
instead of emanating it into the ionosphere. Nearly all commercial dummy loads are
large oil-filled cans. These dummy loads change the transmitted energy into heat, which
is absorbed by the oil. Because different transmitters output different amounts of
power, different sizes of dummy loads must be used. Dummy loads for typical amateur
powers (under 500 watts) are relatively inexpensive and are readily available.

Unfortunately, when you use a can-type dummy load, you can't see "what's happening"
with your transmitter. In this case, you can use a light-bulb dummy load to test your
transmitter. Here, the light bulb is directly connected to the output of the transmitter
and it dissipates the RF energy as light. The light bulb dummy load is more useful than

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SMARTUNER MANUAL 38

the oil-can type because you can g uess how much power is being output, you can see
the voice modulate the SSB (the light will flicker with your voice peaks), and you can
tune the transmitter for maximum output (if the transmitter is an older model that
requires tuning).

Before building or using the light-bulb dummy load, remember that these models
typically don't dissipate the transmitter's output as well as an oil-can dummy load. The
result is that RF will "leak" out; I have heard a few stories of amateurs who were heard
around town while operating their transmitters into a light-bulb dummy load. If you
use this system, make sure that you test the equipment on a clear, harmless frequency
(NEVER test with the transmitter set on an emergency frequency, such as 2182 KHz).

SGC recommends that you build the light-bulb dummy load with the following parts
(although I have made one with an ol d light fixture and a makeshift version with just
alligator clip leads and a light bulb):
* AC socket to cable with a PL-259 connector (for transceiver)
* AC socket to cable with alligator clips (needed with coupler)
* Light bulb to AC adapter
* 75 to 125 watt light bulb, 120 to 220 VAC
* 100 watt radio transceiver
* SG-230 coupler (optional)

f

For transceiver

For coupler

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SMARTUNER MANUAL 39

Antenna Jack

GND

Radio HF/VHF

RF GND

RF IN-OUT

Antenna Coupler

RADIO TEST PROCEDURE

1. Connect the transceiver light bulb load to the radio RF in/out jack.

2. Turn on the radio and set the CW mode.

3. Key the PTT switch on the microphone and look at the light bulb. If the light bulb
load is connected and the radio is transmitting, the light should turn on.

4. Set the power to LO.

5. Set the radio to SSB mode.

6. Key the PTT switch on the microphone and talk into the microphone. Notice that the
light turns on when you talk.

COUPLER TEST PROCEDURE

1. Connect the coupler to the radio.

2. Connect the coupler light bulb load to the SG-230 antenna jack.

3. Turn on the radio and the SG-230.

4. Set the radio to the CW mode.

5. Key the PTT switch on the microphone and look at the light bulb. The light should
turn on if the coupler has completed its' tuning cycle and if the radio is transmitting.

6. For further testing, follow steps 5-6 of the radio test procedure.
Note: The light bulb might not turn on immediately if the coupler has not yet been
tuned for the frequency of the transmitter. The output power (light-bulb brightness) is
greatest when the coupler is properly tuned.
This test will ensure that the radio and coupler are working properly.

7.0 Coupler Configuration

Schematic Q30102000, sheet 4 is the schematic diagram of the two basic coupler
networks. Note that the L network as viewed from the generator, may be configured as
either “C in” or “C out,” whichever is required by the load. In either case, the end of the
network containing the shunt C element will be the higher impedance end of the
network.

7.1 Schematic Diagrams

Schematic Q30102000, sheets 1 thru 6, are schematic diagrams of antenna coupler.
Connections to Smartuner

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RF Input ST-1
RF GND Input ST-1

13.6 (24) VDC ST-7
DC GND ST-8
RF Output ST-9
RF GND Output ST-3, ST-4
TND ST-6
Reset/Hold ST-5
The TND line cannot be connected to the SG-2000 and SmartLock units simultaneously.

7.2 Tuning Process

An array of detector devices in the SMARTUNER monitor the antenna system
impedance, reactance signal, and the VSWR load when RF power is applied to the unit.
The coupler also monitors forward power, since the control computer requires an
indication of both forward and reflected power in order to allow tuning to proceed. The
computer uses the forward power detector as a check to ensure that the measurements
made are applied RF and are not spurious levels from the data conversion system. The
SMARTUNER will proceed to tune only when enough forward power is present to
confirm this check.

After RF is applied to the coupler array, it then passes through the detector system. The
detector system consists of six capacito r s in shunt o n the input ar m of network, eight inductors
in the series arm, and five more capacitors in shunt on output arm, all arranged in binary
increments. Relays are provided in conjunctio n with each lumped constant and allow removal
or entry as desired. A network having 64 values on input shunt C, 32 values of output shunt C,
and up to 256 values of series L is possible with the manipulation of these 26 relays.

7.3 Impedance Detector

RF transformers T1 and T2 drive the impedance bridge that is balanced at 50 ohms. T2 samples
the line current and thus D5 outputs a negative DC level proportional to line current. A
tertiary winding on transformer T1 provides a line voltage sample to D10 that provides a
positive voltage proportional to line v oltage. R49 and R50 act as a summing network for the
current and voltage signals, with ratios chosen, such that at 50 ohms, the summed signals
result in a balanced or zero voltage condition.

If the line impedance goes to high, the signal from the voltage sensor will be relatively higher
than the current sensor, which will result in a net positive output voltag e from the summing

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network. Similarly, a low line impedance will result in more output from the current sensor,
resulting in a net negative output voltage from the summing network which is shifted to a 0 to
5v range, then fed to processor's A to D converter ports, and used within microcontroller.

7.4 VSWR Detector

A directional coupler is made up of a current transformer T3 and a voltage transformer T1, in
conjunction with termination resistors R31 and R32. The coupler is inserted in the 50-ohm
transmission line between the input connector and the tuning network. The forward power is
measured across termination R32 and reflected power is measured across termination R31.
Diode D4 generates a positive DC voltage proportional to forward power and D9 generates a
positive DC voltage proportional to reflected power. The forward DC output is fed to a voltage
divider consisting of R58 and R48. These voltages are input to the RF power detector and to an
A to D converter port of the processor. The reflected DC output passes through a voltage
divider consisting of R53 and R54, and then it also goes to an A to D converter port of the
processor.

7.5 Phase Detector

A phase detector is formed by T2, A1, and their associated components. This detector
indicates the state of any reactance associated with the antenna coupler as noted from the
generator. A line current sample is compared in phase with a voltage sample in a double
balanced mixer. The output of the phase detector A1 is shifted to a 0 to 5v range, then fed to
the processor’s A to D converter ports and used within the microcontroller.

7.6 Central Processing Unit (CPU)

A tune-up algorithm, which is contained in the memory of the microprocessor, actually
implements the antenna matching. It is designed around the MC 68HC711E9 CPU which
features a versatile instruction set, RAM, and EEPROM (memory which is saved after the
coupler is turned off). The antenna coupler relay s are controlled by latches U7, U8, and U9,
which receive serial data input directly from the CPU.

During operation, data is transferred into the CPU from the A to D ports and Input Capture
port (measures RF frequency). Basically, t he program monito rs the status of the input sensors
and—starting from a preset condition—uses a built-in algorithm to achieve a tuned condition.
When the tuning algorithm is complete, the CPU saves the settings in its EEPROM, which is
addressed by the applied RF frequency.

This non-volatile memory table is the basis of the exclusive learning feature of the
SMARTUNER. After it has stored and latched the network status, the CPU waits for RF to
cease transmitting and returns to the Stop mode. When RF is retransmitted, the first step in the
tuning algorithm is to measure the frequency of the signal passing through the coupler. From
the frequency data, the computer then searchers its EEPROM for previously stored data. If

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SMARTUNER MANUAL 42

data is found, it is tested for validity, and the required “end of tune” conditions will be sensed
by the RF sensors. Then the data will be latched in place, and the CPU will again wait for RF to
cease transmitting and return to the Stop mode. This process takes about 20 milliseconds,
which is the same length of time that is required to close the network relays.

7.7 Initialization

The microcomputer is usually in the Stop mode and requires an interrupt signal (XIRQ) to
start program implementation. The IRQ is obtained from the RF detector circuitry. This line
goes into the XIRQ pin of the CPU and will wake the CPU from the Stop mode.

7.8 Bypass Operation, Jumpers

The SMARTUNER may be bypassed for broadband (untuned antenna) scanning listening. All
you need to do is press the reset button of the SmartLock (if installed) or turn power to the
coupler off and on. When the coupler comes back on, the tuning elements remain out of the
circuit until the Smartuner is activated by a transmitted signal.

If broadband operation is required during receiv e for scan oper ation, jumper JP1 may be set to
the Yes po sition. This will drop the tuning elements out of the circuit on receive only. Jumper
JP1 is located adjacent to U1. If yo u open your SM ARTUNER to access t his jumper, please use
caution to ensure that the waterproof seal is carefully placed prior to refitting the coupler
cover.

Setting JP1 to the Yes position is recommended if you are using a radio for split band
communications, for scanning selective calling protocols, or for Automatic Link Establishment
(ALE). The default is: Tuning Out In Rcv: [no].

Jumper JP2 bypasses the coupler's memories. This means that each time the coupler is
used on a different frequency, it will retune rather than use previously stored
information. The default is: Tune From Memory: [yes].

SMARTUNER

™

MicroTune

Software

8.0 Tuning Processes and Options

The SMARTUNER MicroTune™ Software is unique software that allows precise tuning
of the digitally controlled

pi and L network to tune a wide variety of antennas.

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SMARTUNER MANUAL 43

Antenna

L1

50 ohms

C

in

C

out

The versatile MicroTune

™ software offers its user these special functions:

1. The coupler is activated whenever forward power is present.

2. In addition to sampling VSWR to determine if the coupler should retune,
frequency comparison is employed. This causes the coupler to tune whenever
the transmit frequency changes independent of the VSWR reading.

3. Extensive tuning paths are used to test different antenna situations. The initial
tuning of a new frequency (or switched antenna) may require a few seconds.
Any further tuning is accomplished in a matter of milliseconds if jumper JP2
(Tune From Memory) is in its default position.

4. Facilities and algorithms are used which enable accurate tuning at the low end
of the frequency band—even on shorter antennas than previously possible.

5. The BITE (Built-In-Test-Equipment) Indicator Tune LED includes a safety
feature that alerts the operator to a mismatched condition, with blinking
indicators, when proper t uning conditions have not been met. In this situation,
the software will “time out” within 10 seconds unless a new frequency is
sensed, which will cause an immediate time out, and the coupler will attempt
to match the new frequency.

The microprocessor of the coupler “wakes up” every time the coupler has forward
power. However, re-tuning tak es place only if the frequency has changed or the VSWR
exceeds 2:1.

8.1 Program Description

When DC power is applied, the computer initializes the processor registers in
accordance with the hardware. All tuning elements are then removed and the 'tune'
indicators are turned off. At this time the computer reverts to a "sleep" mode awaiting
RF power.

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SMARTUNER MANUAL 44

Detecting no forward power. When RF power is detected, the CPU will perform a test

to verify forward power is present. If no forward po wer is detected, the computer will
revert to the Stop mode. If forward power is detected, the CPU next checks the Hold
signal from the SmartLock. If the user has switched on the Tuned Lock function of the
SmartLock, the Hold line will be low and the CPU will not proceed with the tuning
algorithm. It will wait for forward power to be shut off and return to Stop mode.

Detecting forward power. Once forward power is detected and the SmartLock is
switched to Normal, the current coupler settings are sent to the relays. Next, the VSWR
is checked and the frequency is measured. If the VSWR is greater than 2:1 or a
difference in frequency is detected, the program branches to the re-tune program. If it is
determined that the VSWR is less than 2:1 and the frequency has not changed, the
computer returns to the Stop mode.

Re-tuning. Once it is determined that re-tuning is necessary, a test is made to see if JP2
is set to tune from memory. If the result is re-tuning from memory, settings are recalled
from the EEPROM based on the frequency measured.

The recalled data is then tested for validity. If the data proves invalid, it is bypassed and
re-tuning is performed. If the data recalled proves valid, the data is sent to the relays
and the VSWR is checked. If the VSWR is less than 2:1, the program branches to the
“OK Tuned” section of the program. If the VSWR is found to be greater than 2:1, the
program branches to the “re-tune” program.

Selecting tuning path. Several tests are made to determine which tuning algorithm or
path should be used to tune the coupler. These tests are based on frequency, antenna
input impedance, antenna phase, and VSWR. Numerous sub-routines are executed
repeatedly, depending on the status of the criteria mentioned above, in order to achieve
proper tuning.

Signaling “no-tune.” Should the initial primary tuning sequence prove unsuccessful,
secondary algorithms are attempted until all possible routines have been exhausted. If,
after the secondary attempts, the coupler still cannot achieve a proper VSWR, the
program branches to a “no-tune” program. Here, the LEDs and remote tune indicator
will blink on and off for about 10 seconds to tell the user a proper VSWR could not be
found. After the indicators stop blinking, the program waits for forward power to cease
(if it has not ceased already) and returns to stop mode. At this point the user should try
several other frequencies. If the “no-tune” condition persists, check the installation of
the antenna, coupler, radio, and ground system for possible problems.

Signaling “OK tune.” If the coupler achieves a good VSWR during the tuning
sequence, the program branches to t he “OK Tune” section of the code. Here, the tune
indicators are engaged. A test is then made to check if JP2 is set to tune from memory. If

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SMARTUNER MANUAL 45

so, the frequency is measured and the tuning elements used are saved in memory
coupled with a verification code.

Once saved, a test is made on JP1 to check if the duplex mode has been selected. If so,
the transmit tuning elements remain in circuit until the receive mode is verified. At this
time, all tuning elements are removed.

The frequency is then saved for future comparison and the CPU reverts back to the
STOP mode.

8.2 Tuning Paths

As mentioned previously, various tests are executed to determine the most logical
tuning sequence to be performed. Dependent on the test results, additional tests and
appropriate sub-routines are executed throughout the tuning process. Following are
examples of the activity that occurs when the coupler must be matched to a frequency
that requires a slightly longer or shorter antenna:

8.2.1 Antenna Too Short

Antenna

L1

50 ohms

C in

Once the coupler has verified RF power, the tuning sequence proceeds as follows:

1. Series inductance is added until the phase is deemed as being inductive. At this
point it is normal for the input impedance to be low.

2. Input capacitance is added until the antenna is no longer inductive.

3. The program will continue to incr ement the series inductance in .25 µH steps—
each time normalizing the input impedance with input capacitance—until a
low VSWR is measured of less than 2:1. This process will continue until the
VSWR has climbed back to higher than 2:1 or the impedance has become high.

4. The settings that gave the lowest VSWR have been kept in memory and are
now recalled to verify it is a low VSWR

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SMARTUNER MANUAL 46

5. At this point the tune indicators are engaged. The current relay data is saved if
JP2 is set to tune from memory; if JP1 is set to the tune elements out during
receive position, the pr ogram waits until forward power is no longer present,
then removes all tuning elements. The frequency is saved for future frequency
comparison, and the computer reverts to the Stop mode.

8.2.2 Antenna Too Long

Antenna

L1

50 ohms

C

out

Once the coupler has verified RF power, the tuning sequence proceeds as follows:

1. Output capacitance is added until the phases switches to capacitive.

2. At this point, series inductance is added until the antenna is no longer
capacitive.

3. Fine tuning is performed by trying a small amount of input capacitance (this
may or may not be required).

4. At this point, the program executes the same as step 5 (above).

The preceding gives a simplified program flow on only two possible antenna
conditions. Much more complex tuning is normally the case. Further detailed
description, however, is beyond the scope of this manual.

8.2.3 JP1—Tuning E l ements Out During R eceive

(Factory Default Setting: No)

YES In this position the software will retain data required in transmit to match

the coupler while removing all tuning elements when no forward power
is detected.

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SMARTUNER MANUAL 47

NO In this position the coupler will retain the required tuning data and will

change nothing whether in receive or transmit.

If typical operation is out of band duplex, Yes would be most likely to give better
performance. If in band o peration is typical and duplex or simplex is the predominant
mode of operation, then No is usually the better choice.

8.2.4 Jp2—Tune From Memory

(Factory Default Setting: Yes)

YES In this position the coupler will recall data previously saved and try this

data before attempting to re-tune. If the data is valid and the VSWR is less
than 2:1 the tune is completed. In this position the coupler will save any
new data in its memory for any frequency. A new frequency must first be
learned, while in this mode, before it can be recalled.

NO In this position, the coupler will not use previously saved tuning data.

Each time a different frequency is selected, the coupler will proceed
through a complete tuning sequence.

Clearly, the advantage of Yes is speed. The coupler will seem to be matched instantly
when in this position, if the frequency being used has previously been saved in
EEPROM. Disadvantages include a difference in frequency t oo small for the computer
to detect. This would result in recall of valid data that may not necessarily present the
best match.

We suggest starting with JP2 in the Yes position. If operation is as expected, don't
change it.

9.0 SMARTLOCK OPERATION

The SmartLock allows the operator to have additional control over the SMARTUNER. It
is not required for normal operation.

9.1 Tune, Tune Lock, and Reset

Tuned (green LED) Turns on when the coupler has successfully tuned.
Normal / Tune Lock Toggle switch that allows user to prevent coupler re-tuning

by switching to the Tune Lock position. When in the Tune
Lock position, the red LED blinks to notify the user that the
coupler is locked on the current setting.

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SMARTUNER MANUAL 48

Reset

Pushing the red reset button allows the coupler to be reset.
This is preferable to the other method of turning the input
power off and on.

9.2 Smartlock Notes

The Tune Lock function is in most cases unneeded. Inadvertent retuning is a rare
occurrence. Retuning may occur when the env ir onment or antenna system has changed.
In this case, retuning is within nor mal operation of the coupler. Howev er, the function
is still provided with the SMARTUNER to be used if desired.

10.0 Receiving Antenna Systems

10.1 Receiving Antenna Systems

Traditionally, receiving systems used transistors and transformers as a means of
matching the antenna impedance to the radio (See Figure 10.1.1.) This is called an
Active Receiving Antenna.

Figure 10.1.1

Antenna

Receiver

When a SMARTUNER is used, the impedance matching is done more directly, giving
greater selectivity to the operator. This system is called an Active Tuned Receiving
Antenna (See Figure 10.1.2.) The advantage here is that more of the actual signal energy
reaches the receiver allowing for a greater SNR to be achieved.

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SMARTUNER MANUAL 49

Figure 10.1.2

Antenna

Receiver

Thus, the SMARTUNER can be used in receiver-only systems to enhance its re ception
capabilities.

11.0 Troubleshooting the SMARTUNER

Only a small number of installation mistakes can be made. These will fall into one of
several categories: ground fault, cable fault, and antenna fault. There is also a slight
chance of an electrical fault in the coupler.

When you are troubleshooting the SMARTUNER and you understand that there are
three variables, you should change each variable, in sequence, to determine where the
problem lies. If you change the ground, antenna, or supply voltage, you are bound to
change the performance of the coupler.

11.1 Ground Faults

Common ground faults include faulty counterpoise, indecisive ground, differing
resistance, improper bonding, and problems resulting from inaccurate assumptions.

Faulty counterpoise. The most common problem encountered here is when an
installation has been made without a proper counterpoise. If the counterpoise is
electrically smaller than the antenna, the system may load “upside down”—where the
antenna acts as the counterpoise and the counterpoise radiates. When this condition
occurs, the operator may encounter “RF Bites” from touching metal objects connected to
the counterpoise.

Indecisive ground. A second kind of ground fault occurs when the decision whether
the ground or the antenna should radiate is difficult. When this condition is
encountered (usually at a frequency where the counterpoise is near resonance), the
coupler may cycle repeatedly. This condition may be addressed as follows:

• You may give short bursts of CW and when the coupler stops in a tuned
condition, as indicated by the remote tuned LED, you may invoke the SmartLock
Tune Lock function, thus forcing the coupler to retain correct settings.

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SMARTUNER MANUAL 50

• You may simply change the ground system so t hat it becomes larger than the
antenna at the problem frequency.

Differing resistance. The third kind of ground fault that we encounter occurs when a
ground system and an antenna have very different electrical r esistance. This happens
when you install a very conductive copper antenna wire in an aircraft. When the
fuselage is used as a counterpoise, the aluminum must be much bigger than would a
copper ground because the int ernal resistance of aluminum is significantly higher t han
copper.

By the way, this is why we don't like to use aluminum ground wires as radials. Just as
when aluminum is used in house wiring, several gauges larger are needed to carry the
same amount of current the same need applies here.

Improper bonding. The fourth kind of ground fault y ou may encounter occurs where
the ground is not properly bonded to the coupler. We go to considerable effort to make
sure the stainless steel ground stud is well connect ed to the coupler. In fact, we go so
far as to use large braid on the inside of the coupler.

Particularly in automobiles and aircraft, a single ground connection will n ot do. It is
mandatory that at least two ground bolt connections be used.

Inaccurate assumptions. The fifth situation to check for is what we call “dangerous
assumptions” about the ground system. When you bond from the antenna coupler to

copper or iron water pipes, you might make an assumption that the water pipes are a
good ground. But in many installations, copper pipes are used in the building but a
plastic main connects to the municipal system just outside the service entrance. So
much for a good ground.

11.2 Antenna Faults

The key to getting the most out of your SMARTUNER is to realize the antenna begins
right at the ceramic feed through insulator on the SMARTUNER case. In other words,
this is the feed point of your antenna system. Failing to install your coupler accor dingly
will result in unsatisfactory operation. With this concept in mind, you can easily avoid
some of the common troubles with a properly planned installation.

Coaxial cable on output. Coax on the output is probably the single most commonly
asked question about the coupler and is the most misunderstood. Let us reiterate: The
SMARTUNER was not designed to feed a piece of coax.

Stray ground capacitance. Stray ground capacitance is the next largest cause of
malfunctioning installations. If you have a long lead wire from the coupler to a feed­through (on a wall or bulkhead), you significantly increase your chance of problems.

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SMARTUNER MANUAL 51

Wire running parallel to a grounded surface may represent a significant capacitance to
ground and, just as with coax, this will cause problems.

To give you an idea how these two points can cause problems, let us relate an incident
that happened in late 1992. A SMARTUNER user had a coupler installed in a mobile
ham radio installation. The coupler could not find a lock on several bands. After going
through his installation carefully, the user called SGC for technical support. This user
was nearing wit’s end.

In working through the logical troubleshooting process with him, we discovered that he
had used coaxial feed line from the insulator on the coupler to the antenna feed point.
Because he had read about the dangers of capacitance to ground in an earlier edition of
this manual, he did not have the coax shield grounded. We had him remove the
ungrounded braid and the installation worked fine.

Experiences like this have taught us to be fanatical about using the shortest possible
wire and no coax on the output of the coupler.

Another key lesson here is that even if you have a low capacitance lead, a high
capacitance antenna will not work well. If you have a whip type antenna, mounted on
the back of a van, you will have a large portion of the antenna running right next to
grounded sheet metal. This causes a high loss to ground, one reason why we do not
recommend CB type whip antennas. The other reason is the base insulation in ball
mounts is inadequate for everything but extremely low power.

Long lead lines. If you have a SMARTUNER feeding a 9-foot antenna with a 1-foot feed
line located inside a hull or inside a v ehicle, you have 10% of the antenna where it will
do you no g ood. If you hav e more t han 5% of the antenna inside a g rounded cabin, yo u
will begin to lose performance.

A good rule of thumb is that under one foot of feed line is a good installation, one to
two feet aren't very good installations, and over two feet means you are asking for
trouble.

“Odd reactance.” The next category of antenna fault is what we call the “odd reactance”
problem. Although the SMARTUNER is an exceptionally well-designed product, you
may from time to time find an antenna length that just won’t quite work right.
Generally this occurs when the SMARTUNER is having a tough time making up its
mind about which of two tuning solutions is better. If it is a very close call, you can
have an antenna which causes cycling and just won't stay locked.

The solution in such cases is to add or subtract a couple of feet of wire from the antenna.
This generally cures the problem.

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SMARTUNER MANUAL 52

As part of your check-out of an HF system, you should operate on all channels and
frequencies which you plan to use on a regular basis t o insure the coupler and antenna
which you have provided work well.

Antenna insulators. Sporadic operation may be caused by poor antenna insulators. We
have seen on sailboats, for example, people trying to save money by expecting the
fiberglass hull to act as an insulator and not using a lower insulator. The hull is not a
good insulator and a thin layer of wet salt water will degrade the ground further.
Similarly, mobile HF users who rely on a poor quality ball-mount find these are
especially prone to arc over inside the ball mount where it is difficult to detect.

The point we are making here is simply this: you should have a leakage path of 2 inches
at all points on your antenna and especially in the area of the feed point: 10,000 to
30,000 volts of RF energy will not be adequately confined by inexpensive insulators.

11.3 Transmitter Faults

Some vexing problems don't relate directly to the antenna or the ground system but
may nonetheless cause difficulties. Here are two of the most common types:

Oscillation. The transmitter may have a tendency to oscillate. The general symptom is
that the coupler will wor k well with another ra dio but will not tune correctly when the
desired radio is in place. The coupler finds a tuning solution, as indicated by the remote
tune indicator going on, but then resumes hunting. In a majority of cases this will be
caused by an overly sensitive transmitter final amplifier section or by inadequate
shielding around the amplifier.

We know of several radios that oscillate relatively easier than most radio s because they
are housed in a plastic case. A plastic case does not provide an adequate shield for
serious RF components. In some o f these cases, putting gr ounded foil around the r adio,
or changing the radio location and orientation, has changed the symptoms. But if you
want quality performance, select a solid radio.

Power supply. Power supplies have been known to cause problems for HF users
because they change voltage when the load on them changes. If the transmitter is
drawing heavy current, as transmitters do when they are running at peak input power,
the voltage to the antenna coupler may change enough to cause the coupler to either
drop into a reset mode (under +11 VDC being present) or, the transmitter final
amplifier impedance may change greatly, thus changing the tuning solution.

To alleviate this condition, remember to use a power supply that has both adequate
current handling capacity and good dynamic regulation. Better yet, use a regulated
power supply of an adequate rating.

11.4 A Final Pointer on Troubleshooting

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SMARTUNER MANUAL 53

Remember that the SMARTUNER is an excellent piece of equipment that will give
outstanding performance. If you have a problem with the coupler finding a tuning
solution, you should change one variable at a time.

12.0 Further Reading

Further information regarding applications, installation and operation can be
downloaded from www.sgcworld.com. These publications include:

• HF User's Guide

• Go Mobile at 500 Watts

• Stealth Antennas

• Smartuner Antenna Coupler Manuals

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SMARTUNER MANUAL

SUBJECT INDEX

Accessories, 9
Aircraft installation, 22
Antenna connection, 32
Antenna coupler—what is it? 1
Antenna coupler mounting, 32
Antenna faults, 49
Antenna installation, 28
Antenna location, 28
Antenna selection, 11
Antenna too long, 45
Antenna too short, 44
Antenna types, 11
Apartment loop antenna, 19
Backstay antennas, 12
Base quadra loop, 16
Base dipole, 16
Base installation, 14
Base station grounds, 31
Caution: high voltages, 4
Cold temperature installations, 6
Corrosion, 32
Coupler configuration, 36
Coupler mounting, 32
Covert antennas, 22
CPU —Central Processing Unit, 40
Delta loop, 17
Electrical checkout, 35
Emergency antennas, 24
Experience levels of users, 1
Final pointer on troubleshooting, 50
Frequency range, 8
General information, 1
General notes on antennas, 27
General notes on couplers, 27
Ground faults, 48
Ground systems —general, 29
High temperature installations, 6
High voltages: Caution, 4
Impedance detector, 37
Indicators, 4
Information, ready, 10
Initialization, 40
Installation with SG-2000, 33
Jeep installation, 12
Kite antenna, 24
LED indicator installation 12 VDC, 34
LED indicator installation 24 VDC, 34
Longwire antenna, 12

Low profile, hidden, 22
Manual coupler software, 43
Manual tuning, 33
Marine grounds, 30
Marine mounting, 5
Mechanical design, 5
Microtune, 41
Motor vessel installation, 14
Network configuration, 4
Overall description, 3
Parts, 9
Phase detector, 40
Program description, 42
QMS, 6
Quick start guide, ii
Recalling settings in memory, 46
Recommended antennas, 9
Recreational vehicle (RV) antennas, 20
Remote installations, 7
Remote manual tuning, 33
Remote tune indicator LED, 33
Schematic diagrams, 36
SG-105 marine and base station antenna, 11
SG-203 marine 28 foot whip, 11
SG-303 high performance 9 foot whip, 11
SG-2000 to Smartuner coupler connections, 33
Small loop, 20
Smartlock, 34
Smartlock installation, 34
Specifications, 8
Storing settings in memory, 36
Table of contents, iii
Tactical antenna supports, 25
Tactical grounds, 25
Tactical installation, 25
Technical support, 9
Transmitter faults, 50
Troubleshooting, 47
Tune from memory, 41
Tuning algorithms, 43
Tuning elements out during receive, 44
Tuning paths, 43
Tuning process, 37
Upgrade sequence, 8
V type antenna, 11
Vehicle grounds, 29
Vehicle installation, 13
Vessel groundless loop, 18
Vessel insulated backstay, 19
VSWR detector, 37

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SG-230 Manual

Notes

SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA 98005 USA

P.O. Box 3526, 98009 Fax: [phone] Tel: [phone] or 1-800-259 7331

© 2000 SGC Inc

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© 1998 SGC Inc

Notes

SG-230 Manual

© 2000 SGC Inc

SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA 98005 USA

P.O. Box 3526, 98009 Fax: [phone] Tel: [phone] or 1-800-259 7331

E-mail: [e-mail] Web site: http://www.sgcworld.com

Qu i c k Mo u n t Sy s te m

for mobile HF and VHF use

QMS-7

Antenna Coupler System

•

QMS-7 offers unsurpassed

frequency agility without
user intervention

•

SG-231 Smartuner

automatic antenna c o u p l e r,
SG-307 extended full-range
antenna, and weather
r e s i s t a n t QMS-7 package

It makes no dif f e rence where you

go or what vehicle you drive, the
QMS-7 will provide exceptional
auto-tuning with any HF and VHF
transceiver.

®

No Compromise Communications

SGC, Inc., P.O. Box 3526 , Bellevue, WA 98009 USA

Tel: [phone] or 1-800-259-7331 Fax: [phone]

E-mail— [e-mail] Web site— http://www.sgcworld.com

SGC reserves the right to modify specifications without notice.

•

1 to 60 MHz —continuous—

instant tuning while you
d r i v e

•

Rated for use on moving

vehicles at up to 75 miles
( 1 2 0 k m ) per hour

The QMS-7 Antenna Coupler System

Q M S - 7 —

Mounting coupler and antenna outside the
vehicle reduces engine noise, interference and
eliminates feed loss. It can be quickly installed
and easily moved from vehicle to vehicle. No
drilling or vehicle modifications are required.
Industrial suction cups secure the QMS-7 to the
vehicle, without damaging the finish, and high
strength straps and buckles complete the job
and give structural integrity.

Antenna Coupler

S G - 2 3 1 —

ing brain inside the QMS-7 system. Use the SG-231 to automati­cally tune just about any antenna (7 feet minimum) to 3 to 100 watt

than 10 ms—each time you transmit on that frequency. It operates
with any HF and VHF transceiver.

S G - 3 0 7 —

mobile applications. It’s a high efficiency radiator, by virtue of
its dual element design. In construction, a single fiberglass whip,
helically wound, has a primary resonance at 8 MHz and a
secondary resonance at 25 MHz. So at lower frequencies—those
under approximately 25 MHz—
the SG-307 will vastly outper­form a conventional 9-foot whip
antenna. The QMS puts the
entire antenna system outside
the vehicle for high efficiency and low noise.

No Compromise Communications

Smartuner HF/VHF antenna coupler is the work-

HF/VHF transceivers from 1 to 60 MHz. It
automatically evaluates and switches over 4
million possible combinations of input
capacitance, output capacitance, and series
inductance to ensure a perfect match
between the transceiver and the antenna.
The SG-231 Smartuner remembers the cho­sen frequency and tuning values and will
automatically reselect these values—in less

Marine and Mobile Antenna

a durable and lightweight antenna designed for

S G - 3 0 7 — industrial strength
spring and rubber booting allow for
90° flexibility of antenna.

SGC reserves the right to modify specifications without notice.

SGC, Inc., P.O. Box 3526 , Bellevue, WA 98009

®

USA Tel: [phone] or 1-800-259-7331

Fax: [phone]

E-mail: [e-mail]

Web site:http://www.sgcworld.com

Specifications:

QMS-7

Total QMS system weight:

12.5lb. (5.6kg)

Overall case dimensions:

13.5 x 10 x 4.3 inches
(34 x 26 x 10 cm)

Housing finish:

Black hard anodized

Maximum strap length: 2 ft.

Maximum

strap tension: 2000 lb.
Strap width: 1 in.
Maximum allowable

vehicle speed: 75 miles

(120 km) per hour

SG-231 Smartuner

Frequency
range: 1 to 60 MHz

Maximum RF
Power: 100 watts

Input Impedance
range: 45 to 55 Ω

VSWR: Typical—

less than 1.4:1

DC input
requirements: 13.6 VDC

Input current: Average

. 9 a m p s

Random set time:

Typical— less

than 2 seconds

Recurrent set time:

Typical— less

than 10 milliseconds

Non-volatile
memory addresses: 170 BIN

SG-307 Antenna

Frequency range: 1 to 60 MHz

Maximum RF Power:

150 watts PEP voice or CW

Length: 7 ft., including

adjustable ratchet

mount and spring

Equivalent:
Design: helically wound

23-foot antenna

Q MS

Antenna

•

QMS offers unsur-

passed frequency

agility needing no

user intervention

Coupler System

The Quick Mount System

for any mobile HF rig

• QMS includes SGC
Smartuner automatic
antenna coupler,

extended full-range
antenna, and weather

resistant QMS
package

QMS Descriptions:

No Compromise

Communications

Q M S - b 2 cat. #55-47

includes the SG-230

( 2 0 0 W )

1.8 to 30 MHz

SG-303 9 ft. antenna

Q M S - b 3 cat. #55-48

includes the SG-235

( 5 0 0 W )

3.0 to 30 MHz

SG-303 9 ft. antenna

Q M S - a 7 cat. #55-49

includes the SG-231

( 1 0 0 W )

1.0 to 60 MHz
Includes VHF bands
SG-307 7 ft. antenna

(QMS-7 not shown)

®

No Compromise Communications

1-800-259-7331

The SGC Building, 13737 S.E. 26th Street, P.O. Box 3526, Bellevue, WA 98009 USA

Phone: [phone] FAX: [phone]

E-mail: [e-mail] Website:http://www.sgcworld.com

© October 2000 SGC, Inc.

The QMS Antenna System

Specifications:

(QMS-7 specifications included on separate brochure.)

S

trap the QMS on your favorite family or business vehicle. You’ll

find it gives any HF-SSB superior frequency agility and
exceptional performance.

The SGC Smartuner automatic antenna coupler, the SG-303
extended full-range antenna, and the special exterior QMS mounting
package comprise the QMS. Mounting coupler and antenna outside
the vehicle reduces engine noise and interference.

It can be quickly installed and easily moved from vehicle to

vehicle). No drilling or vehicle modifications are required. Industrial
suction cups secure the QMS to the vehicle, without damaging the
finish, and high strength straps and buckles complete the job and give
structural integrity.

T

he S G - 3 0 3 is a durable and lightweight antenna designed for

mobile applications. It’s a high efficiency radiator, by virtue of its
dual element design. In construction, a single fiberglass whip, helically
wound, has a primary resonance at 10 MHz and a secondary resonance
at 22 MHz. So at lower frequencies—those under approximately 20
MHz—the SG-303 will vastly outperform a conventional 9-foot whip
antenna. The QMS puts the entire antenna system outside the vehicle
for high efficiency and low noise.

he Smartuner HF antenna coupler is the working brain inside the

T

QMS system. It automatically evaluates and switches 64 input and 32
output capacitance combinations, plus 256 inductance combinations in
a π network. The result is over a half­million different ways to ensure a perfect
match between the transceiver and the
antenna. Smartuner remembers the cho­sen frequency and tuning values and will
automatically reselect these values—in
less than 10 ms—each time you transmit

• microprocessor
controlled

• non-volatile

memory

•

16” D x 12” W x 3” H

• 1.8 to 30MHz range

• water resistant

on that frequency. It operates with any
HF transceiver.

(

See QMS-7 brochure for more options.)

®

The SGC Building, 13737 S.E. 26th Street, P.O. Box 3526,

Bellevue, WA 98009 USA

No Compromise

Communications

Phone: [phone] FAX: [phone]

E-mail: [e-mail] Website:http://www.sgcworld.com

QMS (Quick Mount System)

QMS-b2 cat.# 55-47

QMS-b3 cat.# 55-48

Total QMS system weight:
Overall QMS case dimensions
Housing finish:
Maximum strap length: 5.5 ft.

Maximum strap tension:
Strap width: 1 in.

Maximum allowable vehicle
speed: 75 miles per hour

SMARTUNERS

SG-230 cat. # 54-12
SG-235 cat. # 54-15
SG-231* cat. # 54-17
SG-237 cat # 54-19

HF Frequency range:

SG-230 1.8 to 30 MHz
SG-235 3.5 to 30 MHz
SG-231* 1.0 to 60 MHz
SG-237 1.8 to 60 MHz

Input Impedance range:
VSWR: Typical—less than 2:1

DC input Voltage: 13.8 VDC

(SG-230 only option: 24 VDC)

Input current: Average .9amps
Random set time: Typical—
Recurrent set time: Typical—

less than 10 milliseconds

Non-volatile memory
addresses: SG-230 = 500

SG-303 antenna

Frequency range:
Maximum Power:

500 watts PEP voice or CW

Length: 9 ft., including
adjustable ratchet mount

Equivalent: 23-foot antenna
Design: helically wound

21 lb.

18 x 12 x 5 in.

Black hard anodized

2000 lb.

25 to 100 Ω

SG-235: 1.4 amps

less than 2 seconds

SG-235 & SG-231 = 170

cat. # 55-27

* use with QMS-7

1.8 to 30 MHz

M

SG-303

SG-303 Antenna

• Heavy duty rub­ber encapsulated
spring mount

w i t h

SGC Couplers

The SG-303, a high performance mobile antenna, is designed
and built to operate in rough terrain and extreme climactic
conditions. It has a lifetime warranty.

The SG-303 antenna is a light-weight and low-cost mobile
antenna for operation between 1.8 and 30 MHz. Nine feet in
length overall, it consists of two sections of helically wound
whip, mounted on a sturdy professional weatherproof rubber
spring. Mounts on an adjustable ratchet mechanism:

• the base adjusts for the best attachment to the vehicle.

• the antenna ratchet permits orienting the whip from

vertical to horizontal.
The SG-303 stands up to the wind loading at highway speeds,
as well as to rain, ice, and the occasional tree branch.

• Heavy duty whip
antenna

• Adjustable 4-way
ratchets

Smartuners

• Waterproof for
all weather

• Built-in test
equipment indi­cator

• 1.6 to 30 MHz
range

• 3 to 500 watts

(depending on model)

The SGC line of antenna couplers —the famous SGC
“Smartuners”—packed into a sturdy case, mount on the
vehicle as close as possible to the antenna lead-through. Each
one gives almost any HF-SSB a major boost in range and
c l a r i t y. The Smartuner “intelligently” tunes any length
antenna. No preliminary tuning or adjustment is required, and
the Smartuner operates with any HF transceiver in the 1.6—
30 MHz range and with output power from 3 to 500 watts.

Be sure to see SGC's revolutionary mobile QMS

system for mounting antenna and

coupler outside the vehicle.

®

The SGC Building 13737 S.E. 26th Street, Bellevue, WA 98005 USA

Box 3526, Bellevue, WA 98009 USA 425-746-6310 or 1-800-259-7331

Fax: [phone] E-mail: [e-mail] Web site: http://www.sgcworld.com

SG-303

Combine an

Smartuner

Specifications

HF Frequency
Ranges:

Maximum Output
Power:

Dual Frequency Resonance:

Antenna structure:

Two sections, 50 inches each

Mount:

insulated 4-way stainless

Base:

encapsulated spring mount

Feed-through:

Cable:

No Compromise Communications

1.8 to 30MHz

3 to 500 watts (PEP)

voice or CW

at 12 and 22 MHz

high voltage

steel ratchet mount

heavy duty rubber

high voltage wall

feed-through bushing

(hole = .890 in.)
3 ft. high voltage

wire, one end termin-

ated by a round lug

The SGC Building, 13737 S.E. 26th Street, P.O. Box 3526,

®

Phone: [phone] FAX: [phone]

E-mail: [e-mail] Web site:http://www.sgcworld.com

Specifications

SG-303 with an

SG-230 - 200 watts

SGC coupler for

HF Frequency Range:

HF-SSB mobile

operation with

high radiation

Power Input Range:
VSWR:
DC Input:

SG-231 - 100 watts

HF Frequency Range:
Power Input Range:
VSWR:
DC Input:

performance

SG-237 - 100 watts

Antenna installation. The heavy duty
ratchet mount attaches to a flat surface.
Mount high voltage cable away from
the metal antenna support. Mount the
antenna at the highest point of the
vehicle. The high voltage waterproof
cable feeds through the vehicle body as
close to the base of the antenna as pos­sible.

Coupler Installation. The coupler
mounts inside the vehicle and close to
the base of the antenna. Braided straps
make a good ground.

Antenna ratchet mount. The four­way ratchet mount allows the antenna
to be adjusted for operation when the
vehicle is in motion.

Excellent communication under even
adverse weather conditions can be
achieved when the vehicle is moving.

Reclining the antenna. When the
vehicle is travelling, this will avoid
unnecessary exposure to objects like
bridges or trees.

Bellevue, WA 98009 USA

HF Frequency Range:

Power Input Range:
VSWR:
DC Input:

SG-235 - 500 watts

HF Frequency Range
Power Input Range:
VSWR:
DC Input:

General Specifications

Input Impedance Range:
DC OperatingRange:

Input Current:
Random Set

Times:

Recurrent Set
Times:

Non-volatile Memory
Addresses:

Installation:
Operating

Temperature:
Environmental:

Size Overall:

Weight:
Case
Construction:

1.6 to 30MHz

3 to 200watts(PEP)

Typical—less than 2:1

+13.6 VDC (24 VDC optional)

1-60 MHz

3 to 100watts(PEP)

Typical—less than 1.4:1

+13.6 VDC (24 VDC optional)

1.8-60 MHz

100watts (PEP)

Typical—less than 1.4:1

+13.8 VDC (24 VDC optional)

1.8 to 30MHz

3 to 500 watts(PEP)

Typical—less than 2:1

+13.6VDC

45 to 55 Ω

+10.5 to 15 VDC

(24 VDC optional)

Average—.9 amps

Typical—less than
2 seconds

Typical— less than
10 milliseconds

500
Any position

-35° to +70°C
Waterproof at

immersion of half
meter, half hour
16 D x 12 W x 3H inches

40.6Dx 30.5W x 7.6H
centimeters

8 pounds (3.5 kilos)

Plastic ABS
weatherproof case

(Cat.#55-28)

(coupler required*)

The SG-307 is designed and built to operate in rough
terrain and extreme climactic conditions. The SG-307 antenna
is a light-weight and low-cost mobile antenna for operation
between 1.8 to 60 MHz.

At only seven feet in length overall,
the SG-307 is mounted on a sturdy

professional weatherproof rubber encapsulated

stainless steel spring.

Mounts on an adjustable ratch­et mechanism:

• the base adjusts for the best
attachment to the vehicle.

• the antenna ratchet permits
orienting the whip from
vertical to horizontal.

The SG-307 stands up to the
wind loading at highway
speeds, as well as to rain, ice,
and the occasional tree branch.

Accompanying SGC's dedica­tion to customer service and
guaranteed product reliability a
lifetime warranty is provided
with the SG-307 antenna.

SG-307 stainless steel ratchet mount with

rubber encapsulated spring mount

• Heavy duty rubber

• Adjustable 4-way

• Heavy Duty Whip

• Waterproof for all

• 1.6 to 60 MHz

• 3 to 100 watts

• Built-in test

FOR MOBILE
HF AND VHF

U S E

SG-307

encapsulated
spring mount

ratchets

Antenna

SG-231 Smartuner

(recommended)

weather

range

equipment
indicator

®

No Compromise Communications

E-mail: [e-mail] Web site: http://www.sgcworld.com

*Antenna must be used with an antenna coupler such as the SG-231

SGC, Inc., P.O. Box 3526 , Bellevue, WA 98009 USA

Tel: [phone] or 1-800-259-7331 Fax: [phone]

SGC reserves the right to modify specifications without notice.

SG-307 Specifications

SG-231 Smartuner

Use the SG-231 to automatically tune just about any antenna
(7 feet minimum) to HF/VHF transceivers from 1 to 60 MHz.
It automatically evaluates and switches over
4 million possible combina­tions of input

HF Frequency Ranges: 1.8 to 60MHz
Maximum Output

Power: 150 watts PEP voice or

Dual Frequency
Resonance: at 8 and 25 MHz

Radiation: Omnidirectional
Mount: 90º stainless steel base

c a p a c i t a n c e ,
o u t p u t
c a p a c i t a n c e ,

Base: Heavy duty stainless

and series
inductance to
ensure a perfect
match between the
transceiver and the

Feed-through: high voltage wall feed-

antenna. The SG-231 Smartuner remembers the chosen frequency
and tuning values and will automatically reselect these values—in

Cable: 3ft. high voltage wire,

less than 10 ms—each time you transmit on that frequency. It oper­ates with any HF and VHF transceiver. (Cat. #54-17)

Catalog Number: 55-28

Antenna must be used with an antenna coupler such as the SG-231

CW

mount rotator and
threaded male stud 3/8-24

steel base spring with
rubber boot, Supplied
with high voltage isolated
mounting base size
10x7x.5 inches

through bushing (hole =
.890 in.)

one end terminated by a
round lug

Q M S

(Universal Quick Mount HF Antenna System)

Mounting coupler and antenna outside the vehicle reduces
engine noise, interference and eliminates feed loss. It can be
quickly installed and easily moved from vehicle to vehicle. No
drilling or vehicle modifications are required. Industrial suction
cups secure the QMS-7 to the vehicle, without damaging
the finish, and high strength straps and buckles complete the
job and give structural integrity. (Cat. #55-49)

SG-231 Specifications

Frequency Range: 1 to 60MHz
Power Input

Range: 3 to 100 watts (PEP)
Input Impedence

Range: 45 to 55ohms
VSWR: Typical - less than 1.4:1

DC Input
Requirement: +13.6VDC

Input Current: Average-.9 amps
Random Set

Times: Typical- less than
Recurrent Set

Times: Typical-less than 10
Non-volatile Memory

Addresses: 170 BINS
Size Overall: 11.5D x 9.5W x 1.7H

Weight: 3.8 pounds (1.6 kilos)
Case Construction: Plastic ABS weatherproof

Catalog Number: 54-17

4 seconds

milliseconds

29.2D x 24.1W x

4.32 H centimeters

case

®

No Compromise Communications

1-800-259-7331

SGC, Inc., P.O. Box 3526 , Bellevue, WA 98009 USA

Tel: [phone] Fax: [phone]

E-mail: [e-mail] Web site: http://www.sgcworld.com

®

Intelligent Tuning

Smartuner®is designed for maximum flexibility.

RF π “pi” network with over a half million
microprocessor combinations.

SmartLock®Option.

Provides two external controls for the SG-230
S m a r t u n e r®: Locking function prevents retuning
despite changing antenna loads (e.g., from passing
trucks, or from driving beneath an overpass);
Reset function forces the Smartuner®into the
retune cycle until the signal is transmitted again,
or allows receiver/scan operation in a broadband
antenna mode. (Smartuner®is bypassed).
Cat. #54-63

QMSTMAutomatic Antenna Coupler System.

Special external mounting system for Smartuner.
Gives an incredible boost in receiving and
transmitting range-between 3 and 20 db gain!
Cat. #55-47.

SG-303 Marine and Mobile Antenna – 8 ft.

(shown installed on QMS box) A high-efficiency­radiator, dual element design. Vastly outperforms a
conventional 9 foot whip antenna. Radiation
omnidirectional. Cat. # 55-27.

SGC SMARTUNER Family

SG-230

SG-237

SG-231

SG-230

1.6 - 30 MHz

3 to 200watts

Cat. # 54-12

SG-237

1.8-60 MHz
100watts

Cat. #54-19

®

No Compromise

SG-235

1.6 - 30 MHz

3 to 500watts

Cat. #54-15

Communications

The SGC Building 13737 S.E. 26th Street, Bellevue, WA 98005 USA

Box 3526, Bellevue, WA 98009 USA 425-746-6310 or 1-800-259-7331

FAX: [phone] E-mail: [e-mail] Web site: http://www.sgcworld.com

SG-235

3 - 100 watts

Cat. #54-17

1-800-259-7331

SG-231

1 - 60 MHz

HF Frequency
Ranges

Power
Input Range:

Input Impedance
Range:

VSWR:
DC Input

Requirement:

DC Operating
Range:

Input Current:
Random Set

Times:
Recurrent Set

Times:
Non-volatile

Memory
Addresses:

Antenna
Length:

Installation:
Operating

Temperature:
Environmental:

Size Overall:

Weight:
Case

Construction:

Cable:

Catalog Number: 54-14

1.6 to 30MHz

3 to 200 watts (PEP)

45 to 55 ohms
Typical—less than

2:1
+13.8VDC

(24 VDC optional)

10 to 15 VDC
(24 VDC optional)

Average—.9 amps

Typical—less than
2 seconds

Typical— less than
10 milliseconds

170

8 to 80 feet,

3.3 to 30 MHz

25 to 80 feet,

1.6 to 30 MHz
Random lengths up to
300 feet can be used.*

Any position

-35° to +70°C
Waterproof at

immersion of half
meter, half hour

16 D x 12 W x 3H inches

40.6Dx 30.5W x 7.6H
centimeters

8 pounds (3.5 kilos)

Plastic ABS
weatherproof case
(optional shock­mount tray)

SGC special cable, 9
feet coaxial and two
power wire input
wires, (replaceable
by any standard
cable), RMT tune
and Smartlock®wire

*Under certain limitations.

SG-230 Manual

SGC Equipment Standard Warranty

SGC wishes you to be satisfied with your new equipment purchase. Most SGC products
are therefore warranted to be without defect in workmanship or materials for a period of one
year from the date of purchase. Proof of a date of purchase is required when requesting warranty
service.

The warranty registration card which is furnished with this product should be returned
immediately to provide evidence of purchase and to assure receipt of important notices regard­ing your SGC equipment and related services.

In the event of a defect as defined above, SGC shall, at its option, either repair or replace
the product free of charge to the purchaser, provided that:

1. The warranty is limited to the original purchaser and is not assignable.

2. As a condition to obtaining warranty services, purchaser must at its own expense deliver the
product to SGC’s facility in King County, Washington. If purchaser returns a model that is no
longer in stock, SGC reserves the option to replace that unit with another model with comparable
capabilities. SGC may choose the carrier for return of the unit, provided that purchaser may
request an alternative method of shipment.

3. This warranty is void if your SGC product:

a) has not been operated in accordance with all procedures described in the operating

instructions;

b) has been serviced, adapted or modified without written approval by SGC; or

c) is improperly installed, used, or otherwise damaged (including without limitation any

damage by fire, smoke or water).

4. There is no warranty coverage for any of the following:

a) costs of removing or reinstalling the product when submitted for warranty service;

b) incidental, consequential or exemplary damages arising from any defect or failure of

the product (except to the extent that applicable state law may not allow exclusions or

limitations on such damages, in which case this exclusion may not apply to you);

c) any non-performance of the product due to an inadequate or improperly tuned

antenna or grounding system;

d) transmission range or geographical coverage of the product, which are highly variable

in each application;

e) routine maintenance, periodic adjustment or performance testing of the product as

recommended in the operating instructions;

f) normal wear and tear on the product.

5. THIS LIMITED WARRANTY SHALL CONSTITUTE THE SOLE AND EXCLUSIVE WAR­RANTY FOR YOUR PRODUCT. SGC DISCLAIMS ANY OTHER EXPRESS OR IMPLIED WAR­RANTY, INCLUDING WITHOUT LIMITATION ANY WARRANTY OF MERCHANTABILITY
OR FITNESS FOR ANY PARTICULAR PURPOSE.

6. This limited warranty contains the complete obligations of SGC to purchaser in connection
with this product, and it shall supersede all previous oral or written statements or agreements
concerning such obligations. This warranty may only be amended by a writing signed by an
authorized officer of SGC.

7. After expiration of the warranty herein, SGC may continue to offer repair services to keep your
equipment operational. Please inquire as to the prevailing charges for such service.

20

© 2000 SGC Inc

SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA 98005 USA

P.O. Box 3526, 98009 Fax: [phone] Tel: [phone] or 1-800-259 7331

E-mail: [e-mail] Web site: http://www.sgcworld.com

million precision matches. Smartuner
remembers the chosen frequency and tuning

Automatic Antenna Coupler for all
HF-SSB Bands and Modes

values and automatically reselects those
values - in less than 10 ms, each time
you select that frequency.

Flexibility is a key Smartuner

It is available with a number of attractive

options, including a shock mount for

your smartest choice.

• Micro p rocessor Controlled, Precision,
Automatic Antenna Tu n i n g

• Non-Volatile Memory (170 Addre s s e s )

• Wa t e r p roof for All We a t h e r

• B.I.T.E. (Built In Test Equipment)
I n d i c a t o r

GIVES ALMOST ANY HF-SSB A

MAJOR BOOST IN RANGE AND CLARITY.

I d e a l l y, your HF-SSB radio would always be
perfectly tuned to your antenna – for
maximum range and clarity. It’s a goal that’s
been easy to wish for, but not so easy to

• 1.6 to 30 MHz Range

• 3 to 200 Watts Input Power

• 10 ms Retuning Ti m e

• Tunes from 8 to 80 ft. Antennas

• For Marine, Aviation, Ham and
Para- Military Applications

achieve. Until SGC developed the intelligent,
m i c ro - p ro c e s s o r- c o n t rolled, SG-230
Smartuner

®

.

The SG-230 Smartuner®– intelligently –
tunes any length antenna from 8-80 ft! No
preliminary tuning or adjustment is required,
and the Smartuner will operate with any HF
transceiver in the 1.6-30 MHz range and
output power from 3 to 200 watts.

S m a r t u n e r

®

automatically evaluates and
switches 64 input and 32 output capacitance
combinations, plus 256 inductance
combinations in a “pi” network—over a half-

®

A seven LED B.I.T.E. (Built-in Test Equipment) status display
indicates DC power, forward power, phase, two VSWR levels,
low impedance and tuned conditions.

®

t h e n

®

feature.

military and extreme applications, plus

a 24 VDC option.

For maximum range, clarity and

f l e x i b i l i t y, with just about any

HF-SSB, the SG-230 Smartuner

®

i s

No Compromise Communications

The SGC Building 13737 S.E. 26th Street, Bellevue, WA 98005 USA

Box 3526, Bellevue, WA 98009 USA 425-746-6310 or 1-800-259-7331

FAX: [phone] E-mail: [e-mail] Web site: www.sgcworld.com