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  Topic Review (Newest First)
01-11-2016 02:03 PM
SVAuspicious
Re: AIS Unit for Raymarine Chartplotter System

Quote:
Originally Posted by E38 View Post
Right, I don't know what is connected to the E80 NMEA 0183 and will find out this weekend. As I understand it, I can take anything connected there and move to the NMEA 0183 4800 baud connection on the AIS650 with the 38400 baud NMEA 018 connection on the AIS650 going to the E80 NMEA 0183.
That is supposed to work. If it does not update the firmware in the AIS650. That works much more easily if you have Internet at the dock.

Quote:
Originally Posted by E38 View Post
Can't argue with your experience...why does Raymarine suggest the splitter for AIS install on a sailboat?
Because they sell more AIS receivers and transponders if the make it appear easier.

Quote:
Originally Posted by E38 View Post
A friend recommended the wirie. After doing some checking into options, I decided to go with it. I saw where I could same some money by assembling something similar from components, but the wirie seems pretty turnkey.
Best of luck. In side by side comparisons, even with the Wirie/Bullet performance is better with the two part systems. Your mileage will not vary.
01-11-2016 09:42 AM
E38
Re: AIS Unit for Raymarine Chartplotter System

Quote:
Originally Posted by SVAuspicious View Post
You may already have something hooked up at 4800 bps (VHF DSC radios for exampls) in which chase you'll have to make a decision. You can add a multiplexer like the Actisense NDC-4-AIS to provide data rates suitable for all your NMEA 0183 inputs and outputs.
Right, I don't know what is connected to the E80 NMEA 0183 and will find out this weekend. As I understand it, I can take anything connected there and move to the NMEA 0183 4800 baud connection on the AIS650 with the 38400 baud NMEA 018 connection on the AIS650 going to the E80 NMEA 0183.

Quote:
Originally Posted by SVAuspicious View Post
Please please PLEASE hook up a silent switch so you can run your electronics without transmitting. Don't be a lid transmitting from the dock.
Definitely.

Quote:
Originally Posted by SVAuspicious View Post
I think I've been pretty clear I don't think much of splitters and why. VHF and AIS performance deteriorates. You can't beat physics.
Can't argue with your experience...why does Raymarine suggest the splitter for AIS install on a sailboat?

Quote:
Originally Posted by SVAuspicious View Post
What WiFi range extender did you choose?
A friend recommended the wirie. After doing some checking into options, I decided to go with it. I saw where I could same some money by assembling something similar from components, but the wirie seems pretty turnkey.

Thanks for you comments.
01-09-2016 08:54 AM
SVAuspicious
Re: AIS Unit for Raymarine Chartplotter System

Quote:
Originally Posted by E38 View Post
I have a Raymarine E80 with GPS, radar, and autopilot and would like to add AIS. With the range of options out there, I decided to keep it simple as a DIY project and stick with Raymarine (not as simple as I thought because it turns out the E80 SeaTalk is not compatible with the AIS650 SeaTalk-ng and I have to use the NMEA 0183 connection between the AIS and E80).
I quite like the Raymarine E80 - it is a good plotter. Remember you'll have to use the setup menus to change the E80 NMEA 0183 interface from 4800 bps to 36400 bps for AIS. You may already have something hooked up at 4800 bps (VHF DSC radios for exampls) in which chase you'll have to make a decision. You can add a multiplexer like the Actisense NDC-4-AIS to provide data rates suitable for all your NMEA 0183 inputs and outputs. You might also build a small network segment (either NMEA 2000 or SeaTalkng for future "someday" upgrades and do one conversion to SeaTalk or SeaTalkhs; in future new equipment will be added to the new segment and older equipment will be retired from the old segment(s).

If you are fortunate, nothing is connected to the NMEA 0183 interface on the E80 and you can just hook things up.

Please please PLEASE hook up a silent switch so you can run your electronics without transmitting. Don't be a lid transmitting from the dock.

Quote:
Originally Posted by E38 View Post
I have an arch with two solar panels, a wind generator, radar, and GPS antenna. I am adding an antenna for Wi-Fi boosting and now another GPS antenna for AIS. I decided that will all that on the arch, I would go with a splitter for the VHF and purchased the Raymarine AIS100 splitter and I have the Raymarine AIS650 transponder. I hope this was not a big mistake…planning on installing next weekend.
I think I've been pretty clear I don't think much of splitters and why. VHF and AIS performance deteriorates. You can't beat physics. In the grand scheme of everything we can do on and to our boats I don't think I would call it a big mistake: no one will die and your boat won't sink. I think it is not well advised.

Most arches leave plenty of room for an antenna farm. Your biggest issue is shading - not nearly so big a problem with VHF as your wind generator.

Good luck with your project.

What WiFi range extender did you choose?
01-08-2016 06:23 PM
alctel
Re: AIS Unit for Raymarine Chartplotter System

I've got my VHF antenna on my masthead and my AIS antenna mounted on the back of my spreader.

The AIS transponder and the VHF unit are next to each other, so if I lost one of the antennas I could easily switch to using the other one in a matter of seconds.

IMO, having that redundancy is worth the extra hassle.
01-08-2016 03:41 PM
E38
Re: AIS Unit for Raymarine Chartplotter System

SVA,
Timely discussion for me (although maybe I’m coming to it a bit late). I am about to undertake a similar project. I have a Raymarine E80 with GPS, radar, and autopilot and would like to add AIS. With the range of options out there, I decided to keep it simple as a DIY project and stick with Raymarine (not as simple as I thought because it turns out the E80 SeaTalk is not compatible with the AIS650 SeaTalk-ng and I have to use the NMEA 0183 connection between the AIS and E80). I have an arch with two solar panels, a wind generator, radar, and GPS antenna. I am adding an antenna for Wi-Fi boosting and now another GPS antenna for AIS. I decided that will all that on the arch, I would go with a splitter for the VHF and purchased the Raymarine AIS100 splitter and I have the Raymarine AIS650 transponder. I hope this was not a big mistake…planning on installing next weekend.
John
01-07-2016 07:20 PM
SVAuspicious
Re: AIS Unit for Raymarine Chartplotter System

Quote:
Originally Posted by WoobaGooba View Post
I'm most likely headed towards Vesper kit (splitter and AIS unit).

Hope it interops OK with the rest of the Zeus/Triton kit. One way to find out.
I still strongly recommend separate antennas. You won't be sorry.

Regardless, if you have interface questions the time to work them out is before you spend money and open boxes.

Post what you are considering and when I have a chance I'll look through the manuals.
01-07-2016 04:19 PM
WoobaGooba
Re: AIS Unit for Raymarine Chartplotter System

Quote:
Originally Posted by SVAuspicious View Post
Not worse, and neglects the loss in VHF range...
Quote:
Originally Posted by SVAuspicious View Post
I've worked with the Vespar splitter in the past. It is the one I referred to above as not so bad. Insertion loss is specified as 1 dB, plus of course the additional ~1 dB from two extra connectors. That's roughly 40% reduction on both radios in both directions.



I haven't touched the Simrad splitter. The spec is 0 dB insertion loss on receive (1 dB on transmit). I don't believe it. I would want to know the measurement points. With all the connections even if there is a high quality low noise amplifier (LNA) inside the signal to noise ratio (SNR) will deteriorate. I don't think Simrad is accounting for the whole signal path.

Both are expensive splitters and not what most people purchase. Those are worse and result in the 3-4 dB loss that is common.

Note that "active" doesn't mean there is an LNA. It just means the box does something, like switch a relay. If you're lucky it will have a small dummy load on the switched off transmit side rather than depending on the AIS or VHF foldback circuitry to protect the radios.
The Simrad kit has me concerned. Within their NAIS 400 manual is the following ...

"Warning: If using a VHF Antenna Splitter, you must use the
NSPL-400 as it is specifically designed to work with the NAIS-400
transceiver. The use of third party antenna splitters may result in
malfunction or permanent damage to the NAIS-400 transceiver".

I'm most likely headed towards Vesper kit (splitter and AIS unit).

Hope it interops OK with the rest of the Zeus/Triton kit. One way to find out.
01-07-2016 04:09 PM
SVAuspicious
Re: AIS Unit for Raymarine Chartplotter System

Quote:
Originally Posted by IStream View Post
Yes, I saw that in the spec sheet I linked to. Cost is not the question here as the cost of the splitter is partly or largely offset by obviating the need for a second AIS antenna and cable run.
So the question is whether any degradation is acceptable to you as a trade-off to adding another antenna.

Quote:
Originally Posted by IStream View Post
The Vesper unit does have an LNA on the AIS side and they quote a receive gain of 12dB and a net sensitivity increase of 6dB. You don't get a sensitivity increase by amplifying both signal and noise to the same degree.
Not that simple. In fact you can get a sensitivity improvement by amplifying signal and noise. Recognize that even an LNA has a noise floor. Still, this is why satellite TV systems put an LNA at the feed point - amplify everything before the losses associated with transmission lines and connectors on the way to demodulation, accepting that SNR will deteriorate in the LNA.

For AIS and VHF things are easier but frankly 12 dB amplification and "6 dB net sensitivity increase" is a pretty noisy front end. SNR which correlates to demodulation (voice clarity and demodulating AIS sentences) takes a hit.

Quote:
Originally Posted by IStream View Post
are you better off with this splitter on the masthead with +6dB receive / -1dB transmit AIS performance and -1.5db receive / -1dB transmit VHF performance or are you better off with a 0/0 dB VHF hit and a stern mounted AIS antenna which, I'm guessing, would cut your AIS range in both transmit and receive equivalent to -6dB or more?
Well the +6 dB number doesn't include an extra dB of attenuation from the extra connectors. Even my 1 dB number assumes good connectors well installed. Shakespeare crimp connectors are 1. much worse and 2. really expensive.

I'd love to run some math for you on gain and attenuation but the big deal is geometry (trigonometry is beautiful). Accordingly the difference of masthead from pushpit (or radar pole or backstay) is line of sight. In simple terms line of sight (LOS) (nm) is about 1.41 x sqrt of height (ft); this number accounts for ray bending at VHF.

So a sailboat with a mast 55' above the water and pushpit 10' above the water receiving an AIS signal from a commercial ship whose AIS is 100' above the water (Class A AIS requires an independent AIS antenna - think about that) is as follows:

LOS masthead = 1.41 ( sqrt(55) + sqrt(100) ) = 24.6 nm
LOS pushpit = 1.41 ( sqrt(10) + sqrt(100) ) = 18.6 nm

The math does not account for network congestion (trivial) or for reflection or refraction (not dependable and net increases).

In the real world my experience is that the worst thing you can do is put two antennas at the masthead. From the perspective of AIS performance I just can't tell the difference between masthead through a splitter and pushpit mounting locations. I can tell the difference between voice VHF through a splitter and not.

I have had customers complain of poor VHF performance and moved the AIS to known-good suction cup mounted VHF antenna on the cabin top with no discernible degradation and solved the voice VHF problem. Net-net moving to a good quality installation (note tirade above about Shakespeare crimp connectors) makes everything better.
01-07-2016 10:36 AM
IStream
Re: AIS Unit for Raymarine Chartplotter System

Yes, I saw that in the spec sheet I linked to. Cost is not the question here as the cost of the splitter is partly or largely offset by obviating the need for a second AIS antenna and cable run.

The Vesper unit does have an LNA on the AIS side and they quote a receive gain of 12dB and a net sensitivity increase of 6dB. You don't get a sensitivity increase by amplifying both signal and noise to the same degree. You can't do anything about environmental noise at the limit of detection but the additional gain stage does help in overcoming the noise in their AIS receiver at the limit of detection.

Granted, the splitter costs you 1dB on the transmit side for both VHF and AIS but my question still stands: are you better off with this splitter on the masthead with +6dB receive / -1dB transmit AIS performance and -1.5db receive / -1dB transmit VHF performance or are you better off with a 0/0 dB VHF hit and a stern mounted AIS antenna which, I'm guessing, would cut your AIS range in both transmit and receive equivalent to -6dB or more?
01-07-2016 09:22 AM
SVAuspicious
Re: AIS Unit for Raymarine Chartplotter System

Quote:
Originally Posted by IStream View Post
I've worked with the Vespar splitter in the past. It is the one I referred to above as not so bad. Insertion loss is specified as 1 dB, plus of course the additional ~1 dB from two extra connectors. That's roughly 40% reduction on both radios in both directions.

Quote:
Originally Posted by WoobaGooba View Post
I haven't touched the Simrad splitter. The spec is 0 dB insertion loss on receive (1 dB on transmit). I don't believe it. I would want to know the measurement points. With all the connections even if there is a high quality low noise amplifier (LNA) inside the signal to noise ratio (SNR) will deteriorate. I don't think Simrad is accounting for the whole signal path.

Both are expensive splitters and not what most people purchase. Those are worse and result in the 3-4 dB loss that is common.

Note that "active" doesn't mean there is an LNA. It just means the box does something, like switch a relay. If you're lucky it will have a small dummy load on the switched off transmit side rather than depending on the AIS or VHF foldback circuitry to protect the radios.
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