NAIS400 says transmitting but can't be seen

[Neptune's Gear]

Its almost certainly an antenna fault. Get a decent (new) antenna with good coax and crimped plugs and try again. I have seen this fault quite a few times, often with new units and old antennas or coax. AIS class B is only a small (2w) compared to your base VHF at 25w (normally) and will highlight issues with your antenna first. The SWR does not tell you how efficient the antenna or actual transmission is.

[torrmundi]

Yes, it is. And the AIVDO reports show correct position.

[torrmundi]

NG: I'm leaning towards that or some hidden Simrad thing.

For instance, in my RS35 VHF, if you set GPS source to any GPS other than the chartplotter, DSC is disabled and the menu item "DSC Func" is removed! Now you cannot enable DSC, and nowhere is this documented. Even customer support didn't tell me.

Originally Posted by Neptune's Gear

Its almost certainly an antenna fault. Get a decent (new) antenna with good coax and crimped plugs and try again. I have seen this fault quite a few times, often with new units and old antennas or coax. AIS class B is only a small (2w) compared to your base VHF at 25w (normally) and will highlight issues with your antenna first. The SWR does not tell you how efficient the antenna or actual transmission is.

[Neptune's Gear]

That’s interesting on the rs35. The chart plotter likely has a 10hz gps, (which model?) the NAIS 400 has 1 hz, but I’ve not noticed that issue before. Change the antenna as above, and you’ll be good to go. By the way, I’m a certified Navico tech - early next week I’m fitting a couple of rs35s to a boat, I’ll see if they do the same.

[smac999]

Originally Posted by torrmundi

NG: I'm leaning towards that or some hidden Simrad thing.

For instance, in my RS35 VHF, if you set GPS source to any GPS other than the chartplotter, DSC is disabled and the menu item "DSC Func" is removed! Now you cannot enable DSC, and nowhere is this documented. Even customer support didn't tell me.

that doesn't make sense. the radio should be getting gps from say a point 1. that way the vhf and n2k buss are left on 24/7 and the plotters turn off when anchored. if its' required from a plotter that is horrible programming error.

[torrmundi]

I attached a new Tram VHF antenna and confirmed transmissions via AISPro. It showed the usual array of targets received, on my chartplotter. However, as before, MarineTraffic.com and local receivers did not show any target for my boat. I conclude that my NAIS-400 is only a receiver, for whatever reason.

Time to replace, I think!

[clownfishsydney]

NAIS-400 is a transponder, not just a receiver. Still think it is probably something in settings or connections.

[torrmundi]

Still a possibility that it's a setting, yes, but no one has identified anything beyond silent mode, which is off. So I'm going with "no transmitter output" given a new antenna failed to produce measurable results.

And yes, I know it's supposed to be a transponder. Mine isn't.

By the way, many thanks to all who gave me ideas and suggestions. Much appreciated!

Now, time for a replacement. Simrad says the NAIS-400 has been out of production for over a year. NAIS-500 is the replacement device.

[Jim Cate]

Now, time for a replacement. Simrad says the NAIS-400 has been out of production for over a year. NAIS-500 is the replacement device.

With all the vendors now supplying AiS equipment, why would you go back to a vendor whose product failed you so badly?

Especially when Vesper has such a great track record, both for customer service and quality of product...

Jim

[torrmundi]

Jim, great question. I guess because if I to a fixed-fee repair with Simrad ($360) they'll end up replacing the obsolete NAIS-400 with a new NAIS-500. That compares favorably to the cost of a new Vesper unit ($799 msrp, $555 discounted). Otherwise, you are correct!

[Jim Cate]

Originally Posted by torrmundi

Jim, great question. I guess because if I to a fixed-fee repair with Simrad ($360) they'll end up replacing the obsolete NAIS-400 with a new NAIS-500. That compares favorably to the cost of a new Vesper unit ($799 msrp, $555 discounted). Otherwise, you are correct!

Yeah, I can see the attraction of that deal,so lets hope that they've raised their game a bit with the new unit!

Jim

[torrmundi]

All,
After complaining again to Simrad (someone actually closed my ticket), they finally agreed to replace the unit under warranty! Yay Simrad! So I sent in the old NAIS-400, which they claimed passed all functional checks (yes, that is what ProAIS shows), but they said it had a loose part inside. Probably not, I didn't when I sent it.

With that finding, they sent me a new NAIS-500 (which replaces the fault-prone NAIS-400 design), a new antenna splitter, new N2K cable and Tee.

Upon installing with all original cables and doing the configuration, I was seeing boats 44 nm away, and for the first time other boats can see me.

Nothing was wrong on the boat, it was the lousy NAIS-400 the whole time.

Thanks for all the advice! CF is a great resource ☺.

John

[Fearnow]

I wish I had read all of this a week ago! Same problems with NAIS 400. Pulling my hair out using the Pro AIS, which is showing that all is wonderful, but can't see my boat. Worse yet, the electronic compass stopped working. Not sure what that is all about.

[torrmundi]

Originally Posted by Fearnow

I wish I had read all of this a week ago! Same problems with NAIS 400. Pulling my hair out using the Pro AIS, which is showing that all is wonderful, but can't see my boat. Worse yet, the electronic compass stopped working. Not sure what that is all about.

Yup, same experience with NAIS-400; Pro-AIS showed no faults, but no one could see me. Got an RMA from Simrad after a LOT of fussing and the new NAIS-500 worked fine in the current setup. Because the AIS transmission is bursty you cannot use a VSWR meter to measure the performance; the only thing you can try is measuring the AIS antenna VSWR when attached to the VHF radio.



My RC42 rate compass also failed. I had to pay for the Precision-9 replacement.

[Fearnow]

Haha my RC 42 failed also. No warrantee, but they are agreeing to sell me new equipment at 1/2 price.