GDL 40 Installation Instructions
5
11. Route the NMEA 2000 drop cable away
from sources of electronic interference.
12. Connect the antenna to your
NMEA 2000 network (
).
Connecting the GDL 40
Antenna to a NMEA 2000
Network
If you are unfamiliar with NMEA 2000, see
the “NMEA 2000 Network Fundamentals”
chapter of the
Technical Reference for
Garmin NMEA 2000 Products
for more
/garmin/cms/us/onthewater/nmea2000
, and
click
Manuals
.
1. Create a NMEA 2000 network on your
boat, if you do not have one.
You can purchase required cables and
connectors from
or your local marine dealer.
2. Connect the antenna to your
NMEA 2000 network using the
NMEA 2000 drop cable and a
T-connector.
If the included 19.5 ft. (6 m) drop cable
is not long enough, add an extension to
your NMEA 2000 backbone, based on
the NMEA 2000 guidelines.
Note:
If you have not already
registered your GDL 40 (
you must power-cycle the NMEA
2000 network after you complete the
registration process.
Installing an External
Cellular Antenna
In some instances, you can increase the
reception range of your GDL 40 antenna
by connecting a certified external cellular
antenna (sold separately).
Note:
An external cellular antenna is not
compatible with the pole-mount bracket
(
Certified Cellular Antennas
• Digital Antenna 295-PW (18" white
multiband antenna)
• Digital Antenna 861-CW (30" white
multiband antenna)
• Digital Antenna 861-CB (30" black
multiband antenna)
Certified Cables and Connectors
• Digital Antenna PowerMax™ cable, part
number DA240-30NM
• SubMiniature version A (SMA) male to
Mini UHF female RF connector adapter
◦ Bomar Interconnect part number
9316505
◦ Amphenol
®
Connex part number
242116
Connecting an External Cellular
Antenna to the GDL 40
1. Mount the cellular antenna according to
the manufacturer’s instructions.
2. Connect the antenna cable to the
cellular antenna using the male Type N
connector.
3. Connect the SMA to Mini UHF adapter
to the Mini-UHF connector on the
antenna cable.
4. Connect the antenna cable (with the
adapter installed) to the SMA connector
on the bottom of the GDL 40.
Configuring the GDL 40 for
Use with an External Cellular
Antenna
If you connect an external cellular antenna
to the GDL 40, you must specify that you
want to use the external antenna instead of
the internal antenna on the GDL 40.
1. On a chartplotter connected to the
NMEA 2000 network, select
Configure
>
Communications
>
NMeA2000
Setup
>
Device List
>
GDL 40
>
Configure
>
GSM Antenna
.
2. Select
external
.
Updating the Chartplotter
Software
After installing the GDL 40 antenna,
upgrade your Garmin chartplotter with the
latest software.
1. Go to
2. Select the update package that applies to
your network setup.
3. Follow the on-screen instructions.
