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Old 03-04-2015, 11:43   #16
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Re: AIS Antenna Splitter

Thank you John. This is mostly for satisfying my curiosity/nerdiness for a longer term plan in maybe 10+ years (or who knows if ever). I just would like to play with different systems and tools and increase my overall knowledge. So in that regard, Vesper is above my intended budget for a splitter.

I found a Glomex for $60 with free shipment and already ordered it. I don't expect it to be anywhere near a higher end splitter and that is fine. As long as it works and I can manage to plot a couple of ships on my iPad and iPhone (I am using iAIS) I will be a happy sailor in the Bay. If that works, my next technical adventure will be to integrate NMEA into the mix but that is for another post.

I will report back with my experiences with the unit.
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Old 03-04-2015, 12:25   #17
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Re: AIS Antenna Splitter

Quote:
Originally Posted by ka4wja View Post
Tenedos,
I realize you are asking about a AIS/VHF splitter (splitter/relay), for your VHF radio and AIS receiver....and would probably consider $250 for the Vesper SP-160 splitter/relay to be out-of-the-question, but the fact is that the Vesper SP-160 is a GREAT piece of gear, works VERY well, meets/exceed its advertised specs, AND will work well for you when you upgrade to an AIS transponder in the future...
http://www.vespermarine.com/antenna-splitter-sp160.html

Vesper AIS SP-160 "relay/splitter" test results

Vesper AIS SP-160 "relay/splitter" test results, lab/real world



Sorry, I do not have any experience with the Glomex splitter...
The Glomex splitter is about $90, but I do NOT know what its specs are, what its losses are, etc....and it will only work for a VHF radio and AIS receiver ONLY....

I'm not telling you that the Glomex is bad, 'cause I don't know....just letting you know about your other options...



I hope this helps...

Fair winds...

John
Another vote for the Vesper unit. Cost $$$ but it works great!
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Old 09-04-2015, 18:40   #18
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Re: AIS Antenna Splitter

The vesper equipment is great. I have the watch mate. Use on night trips all the time. I have found there service is great. Email them a question and you get a response in a day. It might be a bit more $ but I never have questioned the price after their service and quality of equipment.



Sent from my iPad using Cruisers Sailing Forum
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Old 12-04-2015, 21:02   #19
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Re: AIS Antenna Splitter

Thanks for all the feedback. I have bought the Glomex and installed it over the weekend. I wanted to close the thread with my experiences.

In short, it works great for my purposes.

I replaced my existing VHF and FM radio splitter with Glomex and installed Digital Yacht iAIS along the process. It worked like a charm.

I did notice some degradation on the VHF radio performance but it is hard to quantify how much. AIS did pick some targets from about 8nms, that was pretty much the limit. I could see targets within 5nm radius easily, that is what I needed.

This is an iNavx screenshot from my phone (I am the blue one):



I linked the iAIS to my iPhone and iPad with iNavx (native app didn't work for some reason). I also linked it to my OpenCPN running on OS X both with wireless and USB cable. All of them worked very nicely.

The Glomex unit did the job for me for a mere $60 and I am very happy about it.

There is one thing I somewhat regretted though. The moment I started seeing AIS targets on my navigation software, I wanted to have a trasponder. It is clearly very beneficial to see what is around you but also to be seen.

iAIS is not the cheapest unit and is a receiver only. I bought it mainly for integrating to my iPad and iPhone. Looking around, I could find wireless enabled Class B transponders that pretty much could do the same job for the same price and additionally support NMEA 2000 (iAIS is NMEA 0183 only). That would require a more expensive splitter but I think with a few hundred extra dollars, I could get a working transponder and NMEA 2k too. One thing that wasn't clear to me during the buying process was iOS integration. Clearly, all communication is taking place over TCP/IP over standard protocols so any wireless unit should support pretty much what iAIS supports (maybe with a bit of troubleshooting) for iOS integration.

But as I mentioned in one of earlier posts, I am not a cruiser (yet). I am poking at these things to learn how things work and I certainly did achieve that goal. I have a working AIS setup that I can use the next time fog comes to San Francisco Bay.

My next adventure will be trying to hook my laptop running OpenCPN into my auto pilot ;-)

Once again, thanks for all the inputs, I may come back with more questions down the road.
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Old 13-04-2015, 03:04   #20
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Re: AIS Antenna Splitter

Job well done. Enjoy
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Old 13-04-2015, 06:50   #21
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Re: AIS Antenna Splitter

Tenedos,
You're very welcome!
(And, thank you for returning here and letting us know how it all worked out for you...many do not do this, and it's nice to see!)

As for wanting a transponder...well, once 'ya see AIS used in the real world, most find that they DO want a transponder, so you're not alone!


I didn't remember that you already had a "splitter" in line....and while the loss of this old FM-VHF splitter is probably not too high, it does have loss....and since you've noticed the loss of your new Glomex AIS-VHF splitter (which is significant), I'd like to remind everyone here that these things DO have loss, and many of them have SIGNIFICANT loss...
And, while use of an "splitter/relay" is simple/easy....it is not without issues....

Sorry about digressing here, but I just wanted to take this opportunity to remind everyone of the potential issues...



And, while for your use, in SF Bay, the added loss/degradation in your VHF Radio system might not be detrimental to you....for most of us it would be....or at least be unacceptable!
And, FYI....most with AIS masthead antennas find Class A AIS targets (commercial vessels) appearing at 15-25 miles out, and smaller Class B targets (most pleasure boats w/ AIS), at 5 - 10 miles....your mention of "some targets from about 8nms, that was pretty much the limit. I could see targets within 5nm radius easily", is telling in this case....
This does not necessarily mean you have a problem, but that you might...
Quote:
Originally Posted by Tenedos View Post
I did notice some degradation on the VHF radio performance but it is hard to quantify how much. AIS did pick some targets from about 8nms, that was pretty much the limit. I could see targets within 5nm radius easily, that is what I needed.




I'm not an "i" user....and I'm not familiar with "iAIS"....so I didn't realize that this costs you money???
If you had mentioned that, I would have strenuously suggested a Vesper Marine AIS transponder (such as their XB-8000), which would have been perfect for your application....
But, please be aware that you CANNOT use that Glomex splitter with a transponder!
Not trying to say "we told you so"....just confirming things with you!
Quote:
Originally Posted by Tenedos View Post
The Glomex unit did the job for me for a mere $60 and I am very happy about it.

There is one thing I somewhat regretted though. The moment I started seeing AIS targets on my navigation software, I wanted to have a trasponder. It is clearly very beneficial to see what is around you but also to be seen.

iAIS is not the cheapest unit and is a receiver only. I bought it mainly for integrating to my iPad and iPhone. Looking around, I could find wireless enabled Class B transponders that pretty much could do the same job for the same price and additionally support NMEA 2000 (iAIS is NMEA 0183 only).
That would require a more expensive splitter but I think with a few hundred extra dollars, I could get a working transponder and NMEA 2k too. One thing that wasn't clear to me during the buying process was iOS integration. Clearly, all communication is taking place over TCP/IP over standard protocols so any wireless unit should support pretty much what iAIS supports (maybe with a bit of troubleshooting) for iOS integration.





As I'm not a SF Bay sailor, nor have I sailed in fog more than a couple dozen hours in my whole life!!!
But, I have sailed in rain / T-storms a LOT...
So, while I'm not sure I have much in the way of advice to offer you here about fog (except for my general knowledge of poor vis sailing), I'd like to caution everyone here to remember:
Not ever vessel has an AIS transponder!
And, you should not assume that if your AIS screen doesn't show any "dangerous" targets, that there aren't any!!
Even if you have an AIS transponder, if sailing in fog, you should use proper fog / poor visibility procedures, and NOT rely on the AIS display to alert you to targets!!
Quote:
Originally Posted by Tenedos View Post
But as I mentioned in one of earlier posts, I am not a cruiser (yet). I am poking at these things to learn how things work and I certainly did achieve that goal. I have a working AIS setup that I can use the next time fog comes to San Francisco Bay.







I hope you don't mind an opinion here??
Here's one that might be "old fashioned" to some....but it makes perfect sense to me!
Do NOT "integrate" your electronic charting to your autopilot!
There is no need to do so....ever...
If you take the "human" out of the loop, you open yourself up to a lot of potential issues....
Besides, how hard is it to steer a course and press "Auto" on the autopilot control?
Quote:
Originally Posted by Tenedos View Post
My next adventure will be trying to hook my laptop running OpenCPN into my auto pilot ;-)
Sorry about the unsolicited advice/opinion, but at least I was brief...




I hope this helps some of you...

Fair winds...

John
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Old 13-04-2015, 15:23   #22
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Re: AIS Antenna Splitter

It's interesting to note that AIS antenna splitters have become a requirement to entry for the RORC offshore (including Fastnet) races:

The AIS Transponder shall share the masthead VHF antenna via a low loss AIS
antenna splitter. An acceptable alternative is a dedicated AIS antenna that is a
minimum of 381mm long, mounted with its base at least 3 meters above the
water, and fed with coax cable that has a maximum 40% power loss.
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