erations Manual
Getting the most from every watt of HF-SSB Power S G - 23 1
S p e c i f i c a t i o n s
Frequency
Ranges:
1 to 60MHz
Power Input
Range:
3 to 100 watts (PEP)
Input Impedence
Range:
45 to 55ohms
VSWR:
Typical -
less than 1:1.4
DC Input
Requirement:
+13.6VDC
Input Current:
Average-.9 amps
Random Set
Times:
Typical- less than
4 seconds
Recurrent Set
Times:
Typical-less than 10
milliseconds
Non-volatile
Memory
Addresses:
170 BINS
Antenna
Length:
Min. length 8 ft.,
3.5 to 60 MHz
Min. length 23 ft.,
1 to 60 MHz
Installation:
Any position
Operating
Temperature:
-35° to +70° C
Environmental:
Waterproof at
immersion of 1
meter for 24 hours
Size Overall:
11.5D x 9.5W x 1.7H
29.2D x 24.1W x
4.32 H centimeters
Weight:
3.8 pounds
(1.6 kilos)
Case
Construcion:
Plastic ABS
weatherproof case
Cable:
10 ft. Power Cable
10 ft. RG-58 coax
cable with PL259
connectors
Slim Design with Simple Mounting
The SG-231 is a slim design that
will easily fit in the most compact
installations. The unit measures only
11.5D x 9.5W x 1.7H inches,
and weighs 3.8 lbs. The SG-231 is
waterproof and is designed to be
mounted at the antenna feed point for
maximum efficiency. Easily config-
ured for tower mounting.
The SGC Building, 13737 S.E. 26th Street,
P.O. Box 3526, Bellevue, WA 98009 USA
Phone: 425-746-6310 1-800-259-7331 FAX: 425-746-6384 425-746-7173
E-mail: sgc@sgcworld.com www.sgcworld.com
No Compromise
Communications
SG-231 Smartuner
TM
SG-230
SG-237
SG-235
SG-231
SGC SMARTUNER
TM
Family
SG-230
1.6 - 30 MHz
3 to 200watts
SG-231
1 - 60 MHz
3 - 100 watts
Antenna Applications: End-fed wires Center-fed dipoles Inverted Ls Loops Mobile whips Vee Beam Many others
© Copyright November 2000 SGC, Inc.
SG-235
1.6 - 30 MHz
3 to 500watts
SG-237
1.8-60 MHz
3 to 100watts
SG-231
ANTENNA
COUPLER
Installation and Operations Manual
Updated: November 2000

CAUTION: Carefully read the Quick Start on the following page 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. SG-231 MANUAL


SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
© 11/00 SGC, Inc.

P.O. Box 3526, 98009 Fax: (425) 746-6384 Tel: (425) 746-6310
E-Mail: sgc@sgcworld.com Website: www.sgcworld.com

i
Quick Start Guide
To quickly install your antenna coupler you will need the following:
1. An HF/VHF radio with 3 to 100 watts output.
2. An HF antenna with a wire feed (not coax fed).
Minimum length of 7 feet (to 3.5 MHz) or 23 feet (1.8 MHz).
3. A good ground (counterpoise) for the antenna and coupler.
4. +12 VDC and ground for the coupler.
5. SmartLock Pro coupler controller (optional).

Connections:
Connect the Smartuner as shown in the following diagram:


Orange : Option A
Violet : Option B
Brown: Not used
Blue : Reset
White : Hold (Locks coupler settings)
Green : Tuned Indicator
Black : DC Ground
Red : +12 to 15 VDC
To SmartLock
Pro optional
GROUND
(Counterpoise)

TO TRANSMITTER
(3 to 100 w)
ANTENNA
Single Wire
RG-58 COAX


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 (un-tuned) state.
4. To tune, speak normally, whistle or use CW (CW is recommended).
5. Tuning should be done at full power. Clicking is heard.
6. When tuned, clicking stops and Green wire goes low. SG-231 MANUAL


SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
© 11/00 SGC, Inc.

P.O. Box 3526, 98009 Fax: (425) 746-6384 Tel: (425) 746-6310
E-Mail: sgc@sgcworld.com Website: www.sgcworld.com

ii
Table of Contents
Quick Start Guide......................................................................................................... i
1.0 General Information............................................................................................... 1
1.1 Users Experience ........................................................................................ 1
1.2 What Is an Antenna Coupler .................................................................... 1
1.3 Overall Description.................................................................................... 2
1.4 Coupler Network Configuration ............................................................. 3
1.5 Operation Indicators.................................................................................. 4
1.6 Mechanical Design ..................................................................................... 4
1.6.1 Marine Mounting ........................................................................ 5
1.6.2 Desert and High Temperature Installations............................ 5
1.6.3 Direct Weather Protection Installations ................................... 5
1.7 Remote Installations................................................................................... 6
1.8 Upgrade Sequence...................................................................................... 7
2.0 Specifications7
2.1 Accessories .................................................................................................. 7
2.2 Recommended Antennas .......................................................................... 8
3.0 Parts and Technical Support................................................................................. 8
3.1 Parts Furnished........................................................................................... 8
3.2 User Supplied Items................................................................................... 8
3.3 Technical Support....................................................................................... 8
4.0 Antenna Types........................................................................................................ 9
4.1 Antenna Selection....................................................................................... 9
4.2 Whip Antenna............................................................................................. 10
4.3 Long wire Antenna .................................................................................... 10
4.4 Back Stay Antenna ..................................................................................... 11
4.5 Typical Installations................................................................................... 11
4.6 Apartment Loop Antenna......................................................................... 18
4.7 Recreational Vehicle (RV) Antennas ....................................................... 19 SG-231 MANUAL


SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
© 11/00 SGC, Inc.

P.O. Box 3526, 98009 Fax: (425) 746-6384 Tel: (425) 746-6310
E-Mail: sgc@sgcworld.com Website: www.sgcworld.com

iii
4.8 Aircraft Antennas20
4.9 Low Profile, Hidden and Covert Antennas............................................ 21
4.10 Emergency Antennas............................................................................... 23
4.10.1 Kite Antenna .............................................................................. 23
4.10.2 Tactical Installations.................................................................. 23
5.0 General Notes on Antennas and Couplers......................................................... 24
5.1 Steps to Antenna Installation.................................................................... 25
5.2 Antenna Location ....................................................................................... 26
5.3 Ground SystemsGeneral ....................................................................... 27
5.3.1 Vehicle Grounds .......................................................................... 27
5.3.2 Marine Grounds .......................................................................... 27
5.3.3 Base Station Grounds.................................................................. 29
5.4 Corrosion .................................................................................................... 29
5.5 Antenna Coupler Mounting ..................................................................... 30
5.6 Antenna Connection .................................................................................. 30
6.0 Installation Procedures.......................................................................................... 30
6.1 Installation with SG-2000 .......................................................................... 31
6.2 Installation on ALINCO DX-70 ................................................................ 31
6.3 Installation on other Radios...................................................................... 32
6.4 SmartLock Pro Installation ....................................................................... 32
6.5 Weatherdeck Mounting............................................................................. 33
6.6 Electrical Checkout..................................................................................... 34
6.7 Alternate Electrical Checkout................................................................... 35
7.0 Coupler Configuration37
7.1 Schematic Diagrams................................................................................... 37
7.2 Tuning Process.............................................................