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View Full Version : AIS + GPS combo units - Recommendations?



Samuel Burns
03-21-2010, 03:49 PM
Is anyone else shopping for AIS? Separate receivers for VHF, GPS, AIS, etc. is expen$ive! The Standard Horizon GX2100 VHF receiver includes AIS [ they both use VHF band], but I don't want to upgrade my current VHF radio, which isn't much use anyway on an open ocean. Since Southernaire needs both AIS and another GPS, the COMAR AIS-MULTI receiver/splitter for $399 looks like a good option. It has the active splitter built-in which allows use of existing VHF antenna; it interfaces w/Raymarine or other NMEA0183 plotters, and has USB capability for simultaneous monitoring on a PC running either Windows or MAC nav software.
There's also the AMEC cypho-101G with similar multiple interface capabilities for $439, viewing software included; but this one needs either an active splitter [ another $139 ] or a separate antenna, consumes 3 watts compared to only 1.3 watts for the COMAR unit.

Recommendations, anyone?

Alchera
03-21-2010, 05:25 PM
Comar system doesn't receive GPS data, you will still need to get that in addition. Too bad it has the internal VHF splitter, because I would rather make my own decision on that - run a second VHF antenna to the stern pushpit and have my emergency backup VHF antenna ready to go. Plus I've heard that with the splitter arrangement, if you are trying to communicate with a closing ship, you are disabling the AIS updating at the time you need it the most. Don't know how much of a problem that really is, it's just something that I've heard. Lots of folks go the splitter route.

AMEC system has the GPS, but did you see that crappy nonstandard combination power cord and USB plug? What a hack. At least that's what it looked like from what I could see. Also, since you should figure that the AIS is on pretty much the whole time, the additional power consumption over the Comar is not good. Then again, it's powering a GPS receiver in addtion and the Comar is not, so it's not really comparing apples and oranges.

If you are counting on the GPS function, It would seem you would have to go with the AMEC because I didn't see that functionality in the COMAR. Everything else I think is a matter of individual preference, either one would work just fine. They both produce both USB and NMEA, that's the main thing.

My 2cents
- Mark/Alchera

Culebra
03-24-2010, 11:23 PM
I really prefer using a splitter, but one that is separate (not integrated into the receiver). Also, how about opting for a transponder? I use a Comar AST-100 splitter along with the Comar CSB-200 transponder, with internal GPS. The transponder interfaces with the PC, so if need be, the internal GPS becomes a backup. Most of all, having a transponder brings the assurance that ships will see me (I have no radar). I installed mine just before the Long Pac last year and wow, it really works! I've had numerous conversations with ships who, after being hailed by me, acknowledge that they see me and then alter their course accordingly... I was impressed they would do this. I use the splitter to get the benefit of the height of the masthead antenna. The splitter gives priority to voice, so Mark raises an interesting dilemma. Nevertheless, I think the height of the antenna, and therefore the range, which is like an early warning to counter the speed of these beasts, is critical. And you don't get the range if you don't have a splitter (unless you mount a second antenna up top and run another coax). My std (and quite old) VHF antenna works great... I see ships 90 nm away! I keep a spare aft-mounted antenna ready to swap in if I lose the masthead, so I lose neither AIS nor VHF, thanks to the splitter. And actually, because the splitter is a separate device, I can plug the spare antenna into either the VHF or the AIS directly if I need to. So, lots of built-in redundancy/options along with early warning thanks to antenna height.

Paul
Culebra/Olson 34

Samuel Burns
03-28-2010, 10:53 AM
I really prefer using a splitter, but one that is separate (not integrated into the receiver). Also, how about opting for a transponder? I use a Comar AST-100 splitter along with the Comar CSB-200 transponder, with internal GPS. The transponder interfaces with the PC, so if need be, the internal GPS becomes a backup. Most of all, having a transponder brings the assurance that ships will see me (I have no radar). ships 90 nm away! .......

Paul
Culebra/Olson 34

http://www.comarsystems.com/brochures/comar_ASR_AST_splitters.pdf

Are you sure your splitter is the AST-100? Mfg's website, link above, says the AST-200 splitter is for transponder AIS, while AST-100 is for receiver-only AIS.

Another question: Do you have a separate GPS antenna, or share GPS signal?
Quoting from mfg's website, below link........"The CSB 200 must use its own internal GPS receiver and a compatible external powered LNA (Low Noise Amplifier) GPS antenna (such as the AMEC AGGRESSOR-111-C ). "

http://www.milltechmarine.com/Class-B-AIS-FAQs_ep_62.html

- Sam / C309 S'aire

Culebra
03-30-2010, 11:55 PM
Hi Sam,

Yep, I have the AST-100, purchased a year ago ('T' for transponder, 100 for product release I assume). Looks like Comar has updated their product line since now they offer the AST-200. It is the AS'R'-100 that is for receivers only.

I have a dedicated GPS antenna for the CSB-200 transponder, per their recommendation, and a separate antenna for the ship's primary GPS.

The folks at Milltech Marine are great, by the way. I picked up my AIS components from them and they helped me think through the redundancy design I wanted for certain systems. I can post more about that if you're interested.

Paul
Culebra/Olson 34

BobJ
03-31-2010, 08:50 AM
I have the NASA AIS "Radar" receiver I bought in 2005 but have found the AIS to be so valuable that I'm thinking about moving the NASA unit to backup status and getting a new "primary" AIS.

Also, I'd like to get the second VHF antenna off the stern pulpit, except when installed as the emergency back-up, so I'm thinking about an antenna splitter to use with the masthead antenna for both VHF and AIS.

The new Standard Horizon unit (Sam mentions up top) is appealing but reminds me of the old integrated stereos - if the turntable or eight-track craps out you have to throw out the whole system! (Come on, you had one of those - I KNOW you did.)

Finally, if the prices come down a bit more, having a transponder as the new "primary" AIS is appealing. So it sounds like a good strategy would be to get that AST-200 now, then figure out what I want to do for a second AIS when my wallet stops making that sucking sound.

John Hayward
04-01-2010, 05:13 PM
I have both a Miltech AIS receiver that I use with the computer and the Nobeltech program and the standalone AIS Radar (thanks to Mark Deppe :-)) I almost never use the Miltech unit because of the associated current draw of the laptop computer. I almost never turn off the AIS Radar because it draws 100 ma and is a great nightlight on the ocean and has a much better alarm than the Nobeltech software. I love my AIS radar unit. Having said that, the only thing that might supplant it in first place is a Class B AIS so ships can *see* me too. I don't know how they do on power consumption, so that might temper how much I want one and if they need the laptop running, then that would be the kiss of death for me. If it's not out already, there will someday be a reasonably power efficient Class B AIS radar type unit and then I will need one. For this year, the kitty has been hit hard enough.

John
Dream Chaser

Samuel Burns
04-01-2010, 08:37 PM
Thanks for the inputs Paul, BobJ, John. Took the plunge with the COMAR CSB200 transponder, and will install a toggle to disable the TX transmit function when I am on watch to save power, flip it back on when down below. It has separate outputs for the PC and Raymarine chartplotter so I should be able to run one or the other to monitor incoming AIS.

Sam Burns, C309 S'aire