Reply
 
Thread Tools Search this Thread Display Modes
 
Old 12-30-2018, 02:08 PM   #1
Senior Member
 
City: Norfolk, VA
Country: USA
Vessel Name: Slow Bells
Vessel Model: Marine Trader 38
Join Date: Nov 2013
Posts: 270
em-trak B300 AIS

I noticed today that the em-trak B300 AIS transponder might not need an external antenna. They say...


"The internal high-performance GPS with advanced redundancy
is complemented by a unique internal GPS antenna which means
that in certain installations no external GPS antenna is
needed."

Any idea which "certain installations" can skip the external
antenna?
__________________
Advertisement

seattleboatguy is offline   Reply With Quote
Old 12-30-2018, 03:27 PM   #2
Guru
 
kchace's Avatar
 
City: Brookline, NH
Country: USA
Vessel Name: Blue Heaven
Vessel Model: Albin 43 classic double cabin, twin 135 Lehmans
Join Date: Sep 2013
Posts: 1,319
Quote:
Originally Posted by seattleboatguy View Post
I noticed today that the em-trak B300 AIS transponder might not need an external antenna. They say...


"The internal high-performance GPS with advanced redundancy
is complemented by a unique internal GPS antenna which means
that in certain installations no external GPS antenna is
needed."

Any idea which "certain installations" can skip the external
antenna?
A guess would be installations that put little between the device and a clear view of the sky. Usually, GPS signals go through fiberglass pretty well. So if the device was placed high up on the boat with not much more than a thin fiberglass skin between it and the sky it should probably work ok. But one would have to test to be sure.

Ken
__________________

kchace is offline   Reply With Quote
Old 12-30-2018, 03:44 PM   #3
Guru
 
Cigatoo's Avatar
 
City: Narragansett Bay
Country: New England
Vessel Model: Grand Banks 36
Join Date: Sep 2016
Posts: 632
I believe you will still need a VHF antenna or minimally a splitter and an existing VHF antenna. The new GPS units seem to work fine under fiberglass as stated above.
Cigatoo is offline   Reply With Quote
Old 12-30-2018, 04:38 PM   #4
Senior Member
 
City: Norfolk, VA
Country: USA
Vessel Name: Slow Bells
Vessel Model: Marine Trader 38
Join Date: Nov 2013
Posts: 270
Quote:
Originally Posted by kchace View Post
A guess would be installations that put little between the device and a clear view of the sky. Usually, GPS signals go through fiberglass pretty well...
Ken

I confess I'm a little ignorant concerning AIS. When your chart plotter tells you there is a tugboat 2 miles ahead beyond a blind turn, is your AIS receiver getting that information directly from the tug's AIS transmitter, or does all the data come and go via the satellite?
seattleboatguy is offline   Reply With Quote
Old 12-30-2018, 04:43 PM   #5
Guru
 
kchace's Avatar
 
City: Brookline, NH
Country: USA
Vessel Name: Blue Heaven
Vessel Model: Albin 43 classic double cabin, twin 135 Lehmans
Join Date: Sep 2013
Posts: 1,319
Quote:
Originally Posted by seattleboatguy View Post
I confess I'm a little ignorant concerning AIS. When your chart plotter tells you there is a tugboat 2 miles ahead beyond a blind turn, is your AIS receiver getting that information directly from the tug's AIS transmitter, or does all the data come and go via the satellite?
The data is encoded in the Tug's AIS transmission which is a VHF transmission.

https://www.navcen.uscg.gov/?pageName=AISworks

Ken
kchace is offline   Reply With Quote
Old 12-30-2018, 05:01 PM   #6
Guru
 
Fletcher500's Avatar
 
City: So-Cal
Country: USA
Vessel Model: Helmsman 43 PH
Join Date: May 2016
Posts: 979
That link provides a good summary. Wiki also has some details, including the differences of Class A and B systems. AIS is worth the investment, you will like it.
Fletcher500 is offline   Reply With Quote
Old 12-30-2018, 05:47 PM   #7
Guru
 
drb1025's Avatar
 
City: Bellevue, WA
Country: USA
Vessel Name: Fiddler
Vessel Model: DeFever 46
Join Date: Oct 2012
Posts: 581
em-trak B300 AIS

I mounted my AIS in a cabinet in the pilot house and itís gps works very well without an external gps antenna.
drb1025 is offline   Reply With Quote
Old 12-30-2018, 05:53 PM   #8
Guru
 
South of Heaven's Avatar
 
City: Sharon, Ma
Country: USA
Vessel Name: Slow Lane
Vessel Model: 2005 Silverton 35 Motoryacht
Join Date: May 2017
Posts: 747
We installed an emTrak AIS transceiver last summer ( I can't remember if its the B100 or B300). We DID install a separate VHF antenna for it.

I love the emTrak. It works perfectly and was easy to set up. The bang for your buck is amazing too.
__________________
2000 Camano 31 (SOLD 2/19)
South of Heaven is offline   Reply With Quote
Old 12-30-2018, 07:07 PM   #9
Guru
 
Cigatoo's Avatar
 
City: Narragansett Bay
Country: New England
Vessel Model: Grand Banks 36
Join Date: Sep 2016
Posts: 632
Quote:
Originally Posted by seattleboatguy View Post
I confess I'm a little ignorant concerning AIS. When your chart plotter tells you there is a tugboat 2 miles ahead beyond a blind turn, is your AIS receiver getting that information directly from the tug's AIS transmitter, or does all the data come and go via the satellite?
In short your AIS (transceiver) is downloading your GPS position and transmitting it out to others over VHF. It is also receiving other AIS transmissions through VHF from other vessels.
Cigatoo is offline   Reply With Quote
Old 12-30-2018, 10:00 PM   #10
Guru
 
City: Doha
Country: Qatar
Join Date: Jun 2012
Posts: 1,037
I installed an Emtrak B100 in my boat (required by law here) and it was self contained and battery operated. Unfortunately it was transmit only. But it seemed to work adequately.

The one thing about an internal antenna is that it's not going to have the same range as with a traditional external high gain whip. Of course in local situations that is not really a big issue, and I would think that AIS is most useful in close situations anyway.
__________________

makobuilders is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 05:39 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012