NorthStar GM1708 961X User manual

961X/XD
GPS CHART NAVIGATOR
INSTALLATION MANUAL
Revision A
Part Number GM1708
Northstar Technologies
30 Sudbury Road
Acton, Massachusetts 01720
www.northstarcmc.com
Service: 978/897-0770
Sales: 978/897-6600

Limited warranty policy
Northstar Technologies warrants the Northstar 961 to be free from defects
in materials and workmanship for a period of two (2) years. This warranty
applies to the original purchaser and to any subsequent owner during the
warranty period, which begins on the date of shipment of the unit, F.O.B.
Acton, Massachusetts, to an authorized Northstar dealer.
Systems may not be returned to Northstar without a Returned Materials
Authorization (RMA) number. Call the Northstar dealer or Northstar for
instructions.
During the unit’s warranty period, Northstar will repair or replace, at its
option, any part of the unit it finds to be defective due to faulty mate-
rial(s) or workmanship. All such repairs and/or replacements will be
promptly performed by Northstar free-of-charge to the owner, excluding
freight costs incurred in shipping to the factory. Return shipments from
Northstar to points within the United States are made via ground trans-
portation, freight prepaid. Special shipping charges (overnight, two-day,
and so on) are the responsibility of the owner.
To be covered by this warranty, the Northstar equipment must have been
in normal use. This warranty does not apply to units with defects caused
by improper installation, physical damage, abuse, tampering, lightning or
other abnormal electrical discharge, or to units with defaced or altered
serial numbers, or to units repaired by unauthorized persons or repaired
in a manner that violates Northstar’s recommended service procedures.
All repairs and/or replacements made under this warranty must be per-
formed at Northstar’s facilities in Acton, Massachusetts. Performance of
warranty work elsewhere will not be authorized, and Northstar will not
pay for any charges for such work. Northstar will not be responsible for
payment of any charges imposed by a Northstar dealer or other party for
services requested by and/or performed for a unit’s owner in connection
with this warranty. Such services might include removal of the unit from
a vessel, inspection, packaging, handling, reinstallation, and the like.
Northstar Technologies assumes no responsibility for any consequential
losses of any nature with respect to any of its products or services sold,
rendered, or delivered. The foregoing is the only warranty expressed or
implied. No other warranty exists.

961 INSTALLATION MANUAL Revision A Page i
Contents
SECTION ONE - Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Welcome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Who should read this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Scope of this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Getting technical support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Servicing the unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Returning a unit for service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
SECTION TWO - Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Safety considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
System overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Installation considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Choosing a system location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Wiring the 961 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Installing the antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Turning the unit on and off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Testing and troubleshooting the 961 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
SECTION THREE - Interfacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Interfacing the unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Configuring the NMEA output ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Setting the auxiliary port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Setting PPNM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Using VGA output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
SECTION FOUR - Service/Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Service functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Maintenance functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
APPENDIX A - Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Northstar 961 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
Physical features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70
Internal beacon receiver specifications (961XD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
AN150 Active GPS Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
8410 Antenna Coupling Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
AN205-P GPS/DGPS antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

Page ii 961 INSTALLATION MANUAL Revision A

961 INSTALLATION MANUAL Revision A Page iii
Figures
Figure 1: 961 control head yoke-mount dimensions (side) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Figure 2: 961 control head yoke-mount dimensions (front) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Figure 3: 961 control head flush-mount drilling dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Figure 4: Processor connectors (back of unit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Figure 5: Separation distances between antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Figure 6: GPS-only antenna (AN150) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Figure 7: Stripping the coax cable jacket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Figure 8: Flared cable braid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Figure 9: Completed BNC connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Figure 10: Combo GPS/DGPS antenna (AN205-P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Figure 11: Correct AN205-P (combo antenna) splitter wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Figure 12: Stripping the coax cable jacket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Figure 13: Flared cable braid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Figure 14: Completed TNC connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Figure 15: ACU assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Figure 16: Correct AN150 and 8410 wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Figure 17: PL-259 (UHF) connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Figure 18: Initial startup screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Figure 19: System test screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Figure 20: Owner’s message screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Figure 21: Advisory message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Figure 22: GPS satellite status screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Figure 23: Interface cabling wiring screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Figure 24: Port 1 output setup screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

Page iv 961 INSTALLATION MANUAL Revision A
Figure 25: Port 1 output setup (sentences) screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Figure 26: Port 1 output setup screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
Figure 27: Auxiliary port setup screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Figure 28: PPNM output setup screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Figure 29: Product information screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Figure 30: Receiver information screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
Figure 31: GPS satellite status screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
Figure 32: Database function screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
Figure 33: Select database to save dialog box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
Figure 34: Select database to restore dialog box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
Figure 35: Select a restored database to undo dialog box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
Figure 36: Save log data dialog box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

961 INSTALLATION MANUAL Revision A Page v
Tables
Table 1: Contacting Northstar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Table 2: Troubleshooting the installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 3: Troubleshooting the GPS/DGPS antenna installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Table 4: Troubleshooting the radar interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Table 5: Interface cable wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Table 6: Port setup options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Table 7: NMEA 0183 sentence identifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Table 8: Aux port setup parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Table 9: PPNM output setup parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Page vi 961 INSTALLATION MANUAL Revision A

SECTION ONE - Introduction
961 INSTALLATION MANUAL Revision A Page 1
SECTION ONE - Introduction
Welcome The Northstar 961 Installation Manual describes how to install the entire
961 system (control head, processor, and antenna). It describes the physi-
cal, mechanical, and electrical characteristics of the unit, as well as how to
select the right location, and mount and wire the system. This manual
also describes how to interface, troubleshoot, and maintain the Northstar
961 GPS chart navigator. For complete details on operating the unit, see
the Northstar 961 Operations and Reference Manual (part number
GM1700).
The terms “unit” and “961” are used throughout this manual to refer to
the 961 GPS chart navigator. The 961X is differential-ready so you can
interface it to an external differential receiver. The 961XD has a built-in
differential receiver. Unless specifically indicated, all information in this
manual refers to both the X (non-differential) and XD (differential) ver-
sions of the unit.
Who should read this manual
The Northstar 961 Installation Manual is intended for marine technicians
who are configuring and installing the 961 GPS chart navigator.
Scope of this manual
In this manual, you’ll find information on the following procedures:
•choosing a location
•mounting and wiring the unit
•installing the antenna
•testing the unit
•interfacing the 961 to other instruments
•troubleshooting the unit
•configuring the NMEA output ports
•setting the auxiliary port
CAUTION!
To obtain the best performance from your 961, Northstar
strongly recommends that you have an authorized Northstar
dealer perform the installation. Proper installation of the North-
star 961 is of utmost importance to accurately receive and
effectively use GPS signals under a variety of weather condi-
tions.

SECTION ONE - Introduction
Page 2 961 INSTALLATION MANUAL Revision A
•setting pulses per nautical mile (PPNM)
•service functions
•maintaining the unit
•installing software updates and saving and restoring the database
The unit’s technical specifications can be found in Appendix A at the back
of this manual.
The rest of this section explains how to obtain technical support and how
to return a unit for service.
Getting technical support
After you’ve followed the instructions in this installation guide, if you
require additional technical support or have any other service-related
questions, you can contact either your dealer or the Northstar Service
Department. Northstar’s Service Department can be reached by email, fax,
U.S. mail, or phone as described in the table below. Whether you send an
email or fax, or write or phone, please have the unit’s serial number avail-
able, and be as complete and accurate as possible when describing the
problem so that a service technician can research the problem and pro-
vide the quickest possible response.
Northstar’s Service Department is available between 9:00 AM and 5:00
PM Eastern Time, Monday through Friday, excluding major holidays.
Table 1: Contacting Northstar
Hearing from you Your feedback is important and helps ensure that this manual is a valu-
able resource for all marine technicians. Send your questions, comments,
or suggestions about this manual to:
Email:
Service: [e-mail]
Sales: [e-mail]
Fax:
Service: 978/897-1595
Sales: 978/897-7241
Telephone:
Main number: 978/897-6600 or 800/628-4487
Sales: 978/897-0770
Service: 978/897-6600
U.S. mail:
30 Sudbury Road
Acton, MA 01720
Website:
www.northstarcmc.com (you can send email to
Northstar directly from this site)
You can email the Ser-
vice Department directly
from Northstar’s website.
The address is
www.northstarcmc.com.
From here, you also can
access additional techni-
cal information under
either the Manuals or
Support links.

SECTION ONE - Introduction
961 INSTALLATION MANUAL Revision A Page 3
[email protected]
Servicing the unit
Repair of the unit is performed only at the Northstar factory. Service
includes a complete hardware and software check-out.
For a system under warranty, shipping charges to the factory are the only
cost for factory repair. Repaired units will be returned via prepaid econ-
omy ground freight (units returned overseas are chargeable).
Units and accessories returned for warranty repair that are determined to
be without fault are subject to a handling charge.
Returning a unit for service
The unit is covered by a two-year hardware-only warranty, which, in
summary, states that if the unit is returned to the factory by the owner or
dealer during the warranty period, Northstar will repair or replace, free of
charge, any part found to be defective due to faulty materials or work-
manship, if the system has been properly installed and hasn’t been
abused. See the Limited Warranty Policy at the front of this manual for
further details. The only cost to the owner will be the one-way shipping
charges and any associated charges that may be imposed by the dealer. If
you have overnight or second-day shipping requirements, before ship-
ping the unit, please call the factory for turnaround time, freight charges,
and payment arrangements.
The unit should be shipped only in a properly designed carton with pack-
ing material. Shipments to the Northstar factory should be made to the
following address:
Northstar Technologies
Service Department
30 Sudbury Road
Acton, MA 01720 USA
NOTE:
Field repairs are not authorized and will void the warranty!
CAUTION!
You may want to ensure that the user has backed-up any of
their waypoints and routes before returning the unit for repair;
see “Saving and restoring databases and system logs” begin-
ning on page 63 for information on backing up waypoints and
routes.
Before returning the unit
to the Northstar factory,
to prevent delays it is
critical that you first
obtain a Return Materi-
als Authorization (RMA)
number from the North-
star Service Department.
If you purchased your
unit through a dealer,
call the dealer and pro-
vide your serial number
so they can get you an
RMA number.
Shipments without a
proper RMA number will
not be accepted!

SECTION ONE - Introduction
Page 4 961 INSTALLATION MANUAL Revision A
Ordering information
To order spare parts or replacement/missing parts, call the Northstar Sales
Department at 978-897-0770.

SECTION TWO - Installation
961 INSTALLATION MANUAL Revision A Page 5
SECTION TWO - Installation
This chapter includes all the information needed to install the 961. It
begins with a review of the system components and then provides infor-
mation on basic installation and powering on the unit. The rest of the
chapter describes how to wire the unit, install the antenna, and trouble-
shoot. Proper installation of the Northstar 961 is of utmost importance to
accurately receive and effectively use GPS signals under a wide variety of
weather conditions.
Safety considerations
WARNING!
Be sure to turn the power off at the main switchboard
before starting the installation. Further, it is highly
recommended that you post a sign by this switch tell-
ing others to keep power off while you’re performing
the installation. If power is left on or turned on during
the installation, fire, electrical shock, or other serious
injury may occur.
WARNING!
Be sure that the voltage of the power supply is
compatible with the unit’s voltage rating, which
can be found on the label at the rear of the unit.
Connecting to the wrong power supply can
result in fire or damage to the equipment.
Be sure to ground the equipment in order to pre-
vent electrical shock or mutual interference.
WARNING!
Be sure to use the proper fuse. Using the incorrect
fuse can result in fire or damage to the equipment.
CAUTION!
Make sure that the 961 does not interfere with
any of the on-board systems. Check all other
systems to ensure that their performance
doesn’t degrade when the unit is turned on.
CAUTION!
The 961 processor can only be mounted horizontally
due to its rubber vibration mounts.
CAUTION!
If you must cut the processor’s 10-foot power
cord shorter, be sure to keep the external fuse
intact. If the power cable must be longer than 10
feet, use a heavier gauge wire for those applica-
tions and be sure to use an external fuse.

SECTION TWO - Installation
Page 6 961 INSTALLATION MANUAL Revision A
System overview
The unit is shipped ready to install and operate.
It is recommended that you follow the steps below:
1. Check the shipping carton for any damage, and immediately report
any damage to the carrier. Save all packing material in case you have
to return the unit to the factory for repair or evaluation. For return
procedures, see “Returning a unit for service” beginning on page 3.
2. Unpack the cartons. Compare the 961 Packing List (P/N GM1703),
included in the 961’s packaging against the contents in those cartons
and with what you ordered.
3. Make sure you have the tools necessary to complete the installation.
4. After reviewing the components, next, review the components of a
proper installation. For details, see “Installation considerations”
beginning on page 6.
5. Choose the best location to mount the control head(s) and processor.
For suggestions and further information, see “Choosing a system
location” beginning on page 9.
6. Choose the best location to mount the antenna. For suggestions and
further information, see “Installing the antenna” beginning on
page 14.
7. Review the section on wiring the system. For details, see “Wiring the
961” beginning on page 12.
8. Install the control head(s), processor, and antenna. (You may want to
temporally install the antenna, then try operating the 961 to ensure
the antenna location works well before permanently installing the
antenna.)
9. Turn on the unit. For details, see “Turning the unit on and off” begin-
ning on page 26.
10.To ensure that the system is installed correctly and running properly,
perform a functional test. For details, see “Testing and troubleshoot-
ing the 961” beginning on page 32.
11.If desired, interface the NMEA output ports; for details, see “Config-
uring the NMEA output ports” beginning on page 46. If desired,
interface the auxiliary port, see “Setting the auxiliary port” beginning
on page 53.
Installation considerations
CAUTION!
The following basic installation considerations aren’t a substi-
tute for all the details in SECTION TWO. To ensure that you
meet all critical installation parameters, be sure to read and fol-
low everything in this section.

SECTION TWO - Installation
961 INSTALLATION MANUAL Revision A Page 7
Ensuring a proper
961 installation
To ensure a proper installation, it is highly recommended that you per-
form all of the following activities before starting the installation:
•preview/survey the vessel’s layout and existing equipment
•review all the installation materials
•review all the installation requirements, including:
- the physical requirements (spacing, location with regard to other
equipment, etc.)
- the electrical and electronic requirements (interference between
other pieces of equipment, power requirements, etc.)
Although the unit itself is very straightforward and easy-to-understand, it
has a few basic requirements that must be met before safe and proper
operation can be assured. The major parts of the rest of this section
address several topics regarding the minimum installation requirements
for the unit to:
•minimize electrical wiring hazards
•be mounted correctly
•accurately receive GPS and DGPS signals
•navigate safely
Avoiding
shortcuts
The majority of installation problems are caused by shortcuts taken with
system cables. When installing your 961, be sure to:
•assemble the connectors carefully
•don’t make sharp bends in the cables
•leave service and drip loops
•tie-wrap all cables to keep them secure
•if cables are lengthened, seal all wiring splices
Using the GPS
antenna (AN150)
The “active” GPS antenna is best mounted in the clear, and low on the
vessel to avoid extra motion from pitching and rolling. It should be
mounted lower than directional high-power transmitting antennas such
as radar or satcom. The length of coaxial cable to the “active” AN150
antenna (supplied with the unit) must be a minimum of 20 feet, but not
more than 100 feet. Coil up any unused length of cable; do not cut it to
less than 20 feet! Be sure that all cable connectors are securely fastened,
and that the cable itself is not subject to any tight bends.
For complete details about installing the AN150, see “Installing the
antenna” beginning on page 14.

SECTION TWO - Installation
Page 8 961 INSTALLATION MANUAL Revision A
Using DGPS with
an AN150 and
8410 ACU
If the unit is equipped with a differential receiver (and you’re using the
AN150 GPS antenna, not the AN205-P GPS/DGPS combo antenna), this
receiver must be connected to a Northstar 8410 differential Antenna
Coupling Unit (ACU). The ACU’s four-foot whip antenna should be
mounted as high as conveniently possible (but not at the highest point)
and as far away as possible from other antennas. The ACU can be
mounted on a standard marine antenna mount (1" diameter, 14 threads
per inch).
For complete details about installing the AN150/8410 ACU, see “Install-
ing an 8410 ACU (for use with the AN150 only)” beginning on page 22.
Using the DGPS
antenna
(AN205-P)
For complete details about installing the AN205-P, see “Installing the
antenna” beginning on page 14.
Bench-testing the
961
It is recommended that you bench-test the unit before installing it on the
vessel. Bench testing ensures that the equipment is fully operational, and
allows the GPS receiver to collect its almanac and ephemeris data for the
installed location, which results in less on-board installation time.

SECTION TWO - Installation
961 INSTALLATION MANUAL Revision A Page 9
Choosing a system location
The 961 consists of two major parts—a processor and a control head. The
961 supports two fully functional control heads (the second head is
optional). The 961 system comprises the processor and control head, GPS
receiver, optional differential receiver, controls, and the specially-coated
display screen.
Mounting the
control head
You can either yoke- or flush-mount the control head: Use the
yoke-mount kit as a framework for holding the control head, or
flush-mount the control head directly onto a flat surface of your choice.
Using the Northstar-supplied yoke mounting kit usually provides a
quicker and less expensive installation than a flush-mount installation.
Regardless of the type of mount, here are a few helpful hints about where
to mount the control head. Choose the mounting location care-
fully—before any drilling or cutting takes place. Choose a location that:
•is convenient, accessible, and within comfortable reach
•gives you easy access to the function keys
•is where you can clearly see the display screen from your normal
vantage point when navigating
•for best display contrast, is viewed from below, looking up at the
display screen
•provides a reasonably direct path for running the required electrical
cables
•has minimal glare from windows or other bright objects (even
though the unit has a high-contrast, anti-reflective LCD screen
that’s specially coated and readable in direct sunlight, you’ll want to
make the screen as visible as possible)
•if flush-mounting the head, make sure you choose an area that’s
well-ventilated; poor ventilation may cause overheating, resulting
in potential backlighting problems
Yoke mounting
For yoke mounts, leave ample room—usually two inches—all around the
sides and top to avoid crowding the unit. Also allow a clearance of at least
2½ inches in the rear just for the cables and connectors. For the recom-
mended yoke-mount installation dimensions, see Figure 1, and Figure 2.
Before drilling holes, rotate the unit to the desired angle to ensure proper
clearance for cables and operation of the unit.

SECTION TWO - Installation
Page 10 961 INSTALLATION MANUAL Revision A
Figure 1: 961 control head yoke-mount dimensions (side)
Figure 2: 961 control head yoke-mount dimensions (front)
6.1
12.4
1.9
8.2
2.5
13.5
12.4
11.6