ICOM M330G- Ground; GPS Antenna

VHF Marine Band radios, protocol, radio communication theory, practical advice; AIS; DSC; MMSI; EPIRB.
Don SSDD
Posts: 291
Joined: Fri Oct 23, 2015 6:58 am
Location: Nova Scotia

ICOM M330G- Ground; GPS Antenna

Postby Don SSDD » Sun May 08, 2022 8:19 am

I'm installing a new fixed-mount [ICOM M330G] VHF Marine Band radio on my 1986 Outrage 18.

GROUND CONNECTION.
The [ICOM M330G] as a red and black [power]. I will connect the black conductor to the battery negative post. In addition, there is a ground screw post connector. The [installation] instructions say to bond the ground post on the radio to "vessel ground". The only grounding on my Outrage is via the battery.

Q1: Do I need to add an additional ground wire from the VHF screw ground connection to the negative battery post?

Q2: Is "vessel ground" more applicable to a larger vessel where you may have a large grounding system separate from the vessel connected to anodes?

GNSS ANTENNA:
The [ICOM M330G] radio its own GNSS receiver. There is a connector on rear panel of the ICM M330G radio for a GNSS antenna. The GNSS antenna is a square puck that comes with 3M double-sided tape to fasten it to the boat. The instructions give no rules for where the puck should be installed or not installed.

Q3: should the GNSS antenna be installed inside the console?

Q4: would a line-of-sight skyward placement be best?

Thanks for any help.

Don

ASIDE: I rarely go out of sight of land in Mahone Bay. I have never lost no cellular telephone service [while in Mahone Bay]. [Mahone Bay] has almost no commercial traffic and not a huge amount of pleasure vessels. Mahone Bay is a huge bay full of islands. With the lack of people and boats, Mahone Bay is a wonderful and relaxing area to boat.

Our spring weather has been cool but we are getting some high air temperatures of 70-degrees-F later this week. We had frost this morning.
1986 Outrage 18 with 2001 Honda 130 HP
Former Owner 1991 Guardian 19 with 1994 Evinrude V4 140HP
Former owner 1987 Montauk with 1998 Mercury 90HP
Nova Scotia

jimh
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Location: Michigan, Lower Peninsula
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Re: ICOM M330G- Ground; GPS Antenna

Postby jimh » Mon May 09, 2022 6:55 am

On a small fiberglass boat there is really no "vessel ground" system in terms of a radio-frequency ground. If the ICOM M330G radio were being installed on a boat with a metal hull and superstructure, you would bond the radio ground post to the metal hull using a wide copper braided conductor or a copper strap. But that is not practical on a small fiberglass boat

If you want to install a "ground" conductor to the radio ground post, use a 10-AWG wire with green insulation. Run that conductor to the battery negative primary power distribution bus. I would not bond the radio ground post to any part of the metal fuel components bonding system.

jimh
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Location: Michigan, Lower Peninsula
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Re: ICOM M330G- Ground; GPS Antenna

Postby jimh » Mon May 09, 2022 7:06 am

I infer from your narrative that the ICOM M330G radio has an internal GNSS receiver with its own antenna, but that internal GNSS receiver can also be connected to an external antenna. Using an external antenna is a good idea. The external antenna for the internal GNSS receiver should be positioned so that it has a unobstructed clear view of the sky. The antenna should not be close to the radio transmitting antenna or close to a RADAR antenna. You can temporarily place the antenna in a location, and then check to see how well it works. Typically dry fiberglass will not attenuate radio signals significantly, and that property of fiberglass may allow the GNSS antenna to be placed below a fiberglass component, out of view, and out of the weather.

Read the radio instruction manual to find where you can see information about the signals being received by the GNSS receiver. Typically a GNSS receiver will provide information about the number of satellites "in view." That means satellites which the receiver has been able to capture information from.

The satellites-in-view page will also show a metric indicating the strength of the signal. The higher the signal strength number, the stronger the signal.

If the antenna is in a good location, you should be able to have at least six to possible eight or more satellites in view at any moment. Typically a GNSS receiver has an almanac that predicts which satellites should be in view at your location and time, and it will show those satellites with an indicator if they are being properly received or not, and the receiver will show the relative signal strength of each satellite signal.

The satellites are typically identified by a number in a range from 1 to about 256. Satellites in the U.S. Space Force Global Positioning System use ID numbers in the 1 to 128-range. Other constellations use other numbers. For more background on satellite identification numbers is this article

Satellite Identification Numbers
https://continuouswave.com/forum/viewto ... =12&t=1696

Typically an external GNSS antenna will have an attached small-diameter coaxial transmission line cable should be easy to route back to the ICOM M330G radio. The antenna typically has a built-in preamplifier and down-convertor, so signal loss in the coaxial transmission line cable will not be a concern. A small coaxial transmission line cable connector is typically used, often an SMA connector.

Don SSDD
Posts: 291
Joined: Fri Oct 23, 2015 6:58 am
Location: Nova Scotia

Re: ICOM M330G- Ground; GPS Antenna

Postby Don SSDD » Mon May 09, 2022 1:51 pm

Thanks Jim.
1986 Outrage 18 with 2001 Honda 130 HP
Former Owner 1991 Guardian 19 with 1994 Evinrude V4 140HP
Former owner 1987 Montauk with 1998 Mercury 90HP
Nova Scotia