Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 17-03-2017, 20:52   #31
Senior Cruiser
 
roverhi's Avatar

Cruisers Forum Supporter

Join Date: Aug 2005
Location: Kona, Hawaii, Carlsbad, CA
Boat: 1969 Pearson 35 #108 & 1976 Sabre 28
Posts: 5,753
Send a message via Yahoo to roverhi
Re: AIS Transceiver in VHF

If the 6500 is like the 2200 it probably doesn't need an antenna splitter as conflicts between the VHF voice and AIS data would be handled internally in the radio. If it didn't there would little reason to combine the two types of trasmissions in one package.
__________________

__________________
Peter O.
'Ae'a Pearson 35
roverhi is offline   Reply With Quote
Old 17-03-2017, 22:18   #32
Moderator
 
Don C L's Avatar

Join Date: Sep 2014
Location: Channel Islands, CA
Boat: 1962 Columbia 29 MK 1 #37
Posts: 3,279
Images: 27
Re: AIS Transceiver in VHF

I'm still waiting on this question of splitter from WM. NMEA 2000 too. If this really is a complete package for 800 I wonder how Vesper will compete? Around here, regularly crossing a very active shipping lane, this is a pretty amazing little radio/transponder for $800 to me having grown up with ded. reckoning and the most advanced stuff on a little boat was an RDF and LORAN.
__________________

__________________
DL
Pythagoras
1962 Columbia 29 MKI #37
Don C L is offline   Reply With Quote
Old 18-03-2017, 05:46   #33
Senior Cruiser

Cruisers Forum Supporter

Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 16,588
Re: AIS Transceiver in VHF

Quote:
Originally Posted by roverhi View Post
If the 6500 is like the 2200 it probably doesn't need an antenna splitter as conflicts between the VHF voice and AIS data would be handled internally in the radio. If it didn't there would little reason to combine the two types of trasmissions in one package.
I think it uses two antennas.

It is a transceiver AIS so it would not access DSC on the VHF with a splitter. Probably not legal as DSC is obligatory on new VHF radios.

http://www.panbo.com/assets_c/2016/1...auto-14331.jpg

I think the image is the connector side of the 6500.

Cheers,
b.
__________________
barnakiel is offline   Reply With Quote
Old 18-03-2017, 16:31   #34
Registered User
 
PassportJoy's Avatar

Join Date: Mar 2014
Location: San Diego
Boat: Passport 43
Posts: 21
Re: AIS Transceiver in VHF

Vespar makes a splitter & AIS/VHF antenna. With it on the masthead my AIS reception and signal are much stronger than a rail mount AIS antenna.
__________________
PassportJoy is offline   Reply With Quote
Old 18-03-2017, 17:16   #35
Registered User

Join Date: Jan 2012
Boat: Catalina 470
Posts: 1,157
Re: AIS Transceiver in VHF

I justed fitted the vesper ais with their splitter, im picking up ships 22nm away. Its not cheap though..ouch!

Sent from my vivo Y35 using Cruisers Sailing Forum mobile app
__________________
daletournier is offline   Reply With Quote
Old 18-03-2017, 18:59   #36
Registered User

Join Date: Jun 2012
Location: Port Aransas, Texas
Boat: 2002 Seawind 1000 (33 ft) Cat
Posts: 767
Re: AIS Transceiver in VHF

Is the SH unit going to have an integrated splitter, or require either an external splitter or a separate antenna? I would be concerned about a single unit/box doing VHF and AIS transponder/transceiver and splitter all together. Frankly, I prefer separate units. To me, best in class is Icom VHF and Vesper AIS and splitter. Plus, I can look at the diagnostic lights on my Vesper XB8000 and the antenna splitter, and it should provide insight if either of those are not working properly. What's SH going to have to do same?

Oh, and if you have a NMEA2000 compatible VHF radio (like my Icom M506, without AIS), and a Vesper AIS on the NMEA network, you can select AIS targets on the Icom screen to make a direct DSC call. But honestly, I've had better luck just getting the target info off of the chartplotter, and hailing them by name on the working channel. A lot of ships do not answer DSC, in my experience. They almost always answer a hail on working channel.

Yes, and I see AIS targets over 20 nm miles away too. I have a combination VHF/AIS antenna is at the top of the mast. I know its a risk using a splitter, but if I put a separate AIS antenna on the stern rail, I'm sure the AIS target distance would be significantly less. If the splitter craps out, its easy to delete it and screw the VHF antenna cable directly to the radio. It's only been a couple of years of use, but the Vesper unit and splitter have been flawless so far.
__________________
sailjumanji is offline   Reply With Quote
Old 18-03-2017, 19:12   #37
Registered User

Join Date: Jun 2007
Location: SW Florida
Boat: FP Belize, 43' - Dot Dun
Posts: 3,250
Re: AIS Transceiver in VHF

Quote:
Originally Posted by sailjumanji View Post
Yes, and I see AIS targets over 20 nm miles away too. I have a combination VHF/AIS antenna is at the top of the mast. I know its a risk using a splitter, but if I put a separate AIS antenna on the stern rail, I'm sure the AIS target distance would be significantly less.
I have to ask as I've seen more than you stating seeing AIS targets over 20nm away.

What navigational value is there is seeing a target 20nm away on a vessel doing <10kts?
__________________
DotDun is online now   Reply With Quote
Old 18-03-2017, 21:37   #38
Registered User

Join Date: Jun 2012
Location: Port Aransas, Texas
Boat: 2002 Seawind 1000 (33 ft) Cat
Posts: 767
Re: AIS Transceiver in VHF

Quote:
Originally Posted by DotDun View Post
I have to ask as I've seen more than you stating seeing AIS targets over 20nm away.

What navigational value is there is seeing a target 20nm away on a vessel doing <10kts?
If you are traveling at the ais target, it's nice to have as much advance warning as possible. You get sport fishers crossing to Bahamas that travel pretty fast and are not always best at keeping watch.

I've also used ais to identify boat to call at an anchorage and ask about crowd and entry conditions. If no room, we would have diverted.

But otoh if you want an ais system with limited range, I suspect there are plenty available.
__________________
sailjumanji is offline   Reply With Quote
Old 19-03-2017, 07:18   #39
Registered User

Join Date: Jun 2007
Location: SW Florida
Boat: FP Belize, 43' - Dot Dun
Posts: 3,250
Re: AIS Transceiver in VHF

Quote:
Originally Posted by sailjumanji View Post
If you are traveling at the ais target, it's nice to have as much advance warning as possible. You get sport fishers crossing to Bahamas that travel pretty fast and are not always best at keeping watch.

I've also used ais to identify boat to call at an anchorage and ask about crowd and entry conditions. If no room, we would have diverted.

But otoh if you want an ais system with limited range, I suspect there are plenty available.
So you don't actually do anything with the data, it's just nice to know.

My point is that a splitter adds failure points to your VHF comms so you can see AIS targets at distances that don't matter. There is nothing you are going to do navigation-wise 30 minutes TCPA from a recreational vessel. I'd be surprised if you altered course before 10 minutes TCPA. Hence, a rail mount AIS antenna provides all the navigation data needed for collision avoidance.
__________________
DotDun is online now   Reply With Quote
Old 19-03-2017, 07:58   #40
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,164
Re: AIS Transceiver in VHF

Quote:
Originally Posted by DotDun View Post
So you don't actually do anything with the data, it's just nice to know.

My point is that a splitter adds failure points to your VHF comms so you can see AIS targets at distances that don't matter. There is nothing you are going to do navigation-wise 30 minutes TCPA from a recreational vessel. I'd be surprised if you altered course before 10 minutes TCPA. Hence, a rail mount AIS antenna provides all the navigation data needed for collision avoidance.
I agree with you that a splitter adds a point of failure, but so does an extra antenna and, more negatively, an extra coax cable.

If you add sensors to your electronics then it makes sense to make them as good as possible. Why not receive AIS targets 50nm away? Why would that hurt you when you can simply reduce the range on your plotting device?

Let me give the reason why you want AIS to use your masthead antenna: The targets you see very far away are probably big ships that have their antennas at high elevation as well. But not everybody has that. If you would use an antenna attached to your rail, do you think that you are the only one doing that? Have you calculated the range between two class-B AIS transceivers with their antennas 4 feet above sea level? (it is only 4nm) Having your antenna at the masthead, you can see all targets. If your antenna is at 50' elevation and the other station is at 4' elevation, the maximum range of detection is 10nm which is a solid, workable situation.

Now let's say the antenna switch fails. You can simply install a manual switch if you don't want to carry a spare automatic switch. Or you connect the antenna directly to the AIS transponder and connect an emergency antenna to the VHF. This is an easy failure to deal with.

Of-course, the best solution is to buy a ketch and have two mast heads for installing antennas
__________________
s/v Jedi is offline   Reply With Quote
Old 19-03-2017, 08:39   #41
Registered User

Join Date: Jun 2007
Location: SW Florida
Boat: FP Belize, 43' - Dot Dun
Posts: 3,250
Re: AIS Transceiver in VHF

Quote:
Originally Posted by s/v Jedi View Post
I agree with you that a splitter adds a point of failure, but so does an extra antenna and, more negatively, an extra coax cable.
I don't understand how a separate AIS antenna and coax adds more failure points to VHF comms (which was my earlier point).

Quote:
Originally Posted by s/v Jedi View Post
If you add sensors to your electronics then it makes sense to make them as good as possible. Why not receive AIS targets 50nm away? Why would that hurt you when you can simply reduce the range on your plotting device?
Why did the designers make Class B 2 watt? Maybe to limit the distance???

Quote:
Originally Posted by s/v Jedi View Post
Let me give the reason why you want AIS to use your masthead antenna: The targets you see very far away are probably big ships that have their antennas at high elevation as well. But not everybody has that. If you would use an antenna attached to your rail, do you think that you are the only one doing that? Have you calculated the range between two class-B AIS transceivers with their antennas 4 feet above sea level? (it is only 4nm)
No need to calculate, I have real-world experience.

Quote:
Originally Posted by s/v Jedi View Post
Having your antenna at the masthead, you can see all targets. If your antenna is at 50' elevation and the other station is at 4' elevation, the maximum range of detection is 10nm which is a solid, workable situation.
Rail-mount to rail-mount Class B is 4nm to 8nm.

What do you do navigation-wise when you see a Class B vessel at 10nm? The answer is nothing! Hence, my point, for navigation you don't need to see Class B at 10nm nor Class A at 20-50nm.

Quote:
Originally Posted by s/v Jedi View Post
Now let's say the antenna switch fails. You can simply install a manual switch if you don't want to carry a spare automatic switch. Or you connect the antenna directly to the AIS transponder and connect an emergency antenna to the VHF. This is an easy failure to deal with.
It's easy to deal with except during an emergency when you really need the VHF comms...

Quote:
Originally Posted by s/v Jedi View Post
Of-course, the best solution is to buy a ketch and have two mast heads for installing antennas
No arguing with that!

I really don't care if someone adds an antenna splitter to their VHF comms, it's their boat. Plus I believe Vesper has a good unit.

My real point is more for the newbies reading this thread thinking they need to see approaching vessels at 10, 20, 50nm away in order to avoid a collision. That's pure BS!!!

It's like the guy I was talking to and he was complaining the PO of his boat installed a depth sounder that only read to 200'. He said he doesn't fish, I asked him the draft of the boat.....he didn't get it.
__________________
DotDun is online now   Reply With Quote
Old 19-03-2017, 08:54   #42
Registered User

Join Date: Jun 2009
Location: Annapolis, MD
Boat: Sabre 34-1
Posts: 114
Re: AIS Transceiver in VHF

Quote:
Originally Posted by John_Trusty View Post
Ron,
I think that you would be overloaded with hits around any busy port like New York -- it's just too crowded with commercial vessels. For us, AIS has its benefits in the middle ground of crossing commercial traffic where you otherwise do not notice (or can't see) if it is around - a poor man's radar. In busy harbors, we do not turn it on because there are too many close-aboard CPA notices.

Check out this live view of traffic centered on NYC -- MarineTraffic: Global Ship Tracking Intelligence | AIS Marine Traffic
You are right about traffic overload. Unfortunately, it's not the commercial traffic that are the problem -- it's the self-important recreational boats that have destroyed AIS usefulness. Unless you set the alarm range WAAAY down, you'll have dozens of alarms an hour -- every few minutes. And your screen will be so cluttered with contacts that you can't easily tell which one is the tug and tow (without cursoring to each contact). It would make it SO MUCH more useful if you could filter out the AIS-B contacts. At times (night, offshore, etc), Class B is useful -- but where/when I sail, the answer to Class-B "alarm fatigue" is to turn off the radio, a really crappy solution.
__________________
sailingharry is offline   Reply With Quote
Old 19-03-2017, 09:22   #43
Registered User

Join Date: Jun 2012
Location: Port Aransas, Texas
Boat: 2002 Seawind 1000 (33 ft) Cat
Posts: 767
Re: AIS Transceiver in VHF

Quote:
Originally Posted by DotDun View Post
So you don't actually do anything with the data, it's just nice to know. .
Hmm, I don't remember writing that anywhere. I actually gave you one example of what I did with an AIS target exceeding 20 nm distance.

Quote:
Originally Posted by DotDun View Post
I'd be surprised if you altered course before 10 minutes TCPA. Hence, a rail mount AIS antenna provides all the navigation data needed for collision avoidance.
Altered course before 10 nm TCPA - yeah, not likely. But probably contact the AIS target. Which my far-reaching AIS setup allows me to do - to identify the target by name.

I'll give an example. We were crossing Gulf Stream heading to Bahamas last March. Night crossing. A cruise ship was coming from port side. We had AIS transponder and radar. A buddy of mine was traveling on same catamaran model about 300 yds behind us. No AIS on his boat. We were sailing, beating, and holding a pretty solid course. Cruise ship was motoring at good clip and holding course. AIS prediction for a long time was crossing at distance of about 200 feet. (Too close) I hailed ship by name, and had a short conversation just to make sure he was aware. He saw us, but did not see buddy boat on radar until we pointed him out. Cruise ship altered course to pass no closer than a mile from us. Nice guy - good communication.

You can put your AIS antenna wherever you want. And as you point out, a ship 20 nm away is not as threatening as one 2 nm distance, and closing on a collision course. But there are instances where it is nice to be able to hail another cruiser by name at a destination, that AIS allows you to get the boat info to call. Or when you're 20 nm out from the Port of Galveston and see there are over 50 ships anchored out, and very few moving in the channel, that something is amiss.

And if the splitter fails, it takes less than a minute to bypass it. In the meantime, there is a handheld VHF within reach.

Ok, so my original point was that, many people have issues with splitters, and extoll the virtues of separate antennas and redundancy. But OTOH, they are getting so excited about an all-in-one VHF and AIS transponder. If I lose a VHF or the AIS, I only lose that one unit. If I lose a powered splitter, then I delete the AIS. But I still have a powerful VHF with masthead antenna. But maybe it makes sense to buy another Vesper splitter and throw it in the spares box before leaving on the next cruise.
__________________
sailjumanji is offline   Reply With Quote
Old 19-03-2017, 09:30   #44
Registered User
 
moniia's Avatar

Join Date: Oct 2012
Location: all over the place. Now Wales, UK
Boat: Westsail/Eric copy
Posts: 65
Re: AIS Transceiver in VHF

My AIS (Vesper) picks up ships from about ninety miles. Pretty useless for collision avoidance, granted. Unless, like me, you sail alone, and that gives you peace of mind for longer (than five minutes ) nap. And because I know, that it does pick it up sometimes from such a distance (I wouldn't count on that) so I know that it should get everything on AIS from half of that.
It still doesn't mean I can sleep for hours, plenty of stuff does not have AIS - but there is a better chance of 30 minute nap...

Using splitter would probably half that. Don't know, small antenna on upper spreader (40' above water) is not a problem and works, as proved - brilliantly.
__________________
--
Kind regards, Monika Matis
www.seawitch-sailing.co.uk
moniia is offline   Reply With Quote
Old 19-03-2017, 09:31   #45
Registered User

Join Date: Jun 2012
Location: Port Aransas, Texas
Boat: 2002 Seawind 1000 (33 ft) Cat
Posts: 767
Re: AIS Transceiver in VHF

Quote:
Originally Posted by sailingharry View Post
You are right about traffic overload. At times (night, offshore, etc), Class B is useful -- but where/when I sail, the answer to Class-B "alarm fatigue" is to turn off the radio, a really crappy solution.
Cant you turn off the alarm feature? (I don't have the alarm turned on for either the VHF - that sees the AIS targets as well - or the chartplotter.) Or just turn off the AIS in a crowded port. Can't you do that without turning off the radio?
__________________

__________________
sailjumanji is offline   Reply With Quote
Reply

Tags
ais, vhf

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
VHF With AIS Transceiver, not just receiver? OrangeCrush Marine Electronics 59 04-04-2017 22:23
VHF and AIS Radiowave Propagation and VHF and AIS Radio Range ka4wja Marine Electronics 21 13-12-2015 18:20
For Sale: ICOM IC-M422 VHF Marine Transceiver FloridianLady Classifieds Archive 0 28-08-2013 08:06
Can You Get Radar & AIS Overlay on Laptop ? AIS Transceiver Recommendations ? lunasea.ds Marine Electronics 22 27-12-2010 13:06


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 18:58.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.