Raymarine AIS problem

[Ric]

I have a Raymarine AIS transceiver which is connected to my masthead VHF antenna via a Raymarine active splitter. All has worked perfectly for a couple of years. Suddenly I am now getting VSWR failure warnings which annoyingly repeat themselves on the chart plotter every few minutes.

Strangely, the performance of the AIS (and VHF which works through the same splitter) seem to be completely unaffected and I can see absolutely no degradation.

I connected my emergency antenna and the problem disappears (albeit now with reduced AIS performance due to siting of the antenna under the deck).

So the problem would appear to be with the antenna and coax cable - but having visually examined it all seems fine. Does anybody have any suggestions?

 

[MikeCC]

What happens if you connect the AIS directly to the masthead antenna without the splitter (leaving VHF on emergency antenna)? Do you still get the errors?

After than only real option is to get hold of a VSWR meter and see what that comes up with.

First test just the main lead to the antenna without the splitter using the meter's lead to the radio. Then test with each of the splitter flyleads connected on the antenna side of the meter (again without splitter). You may need some BNC/PL-259 adapters for that depending on the connections. Assuming all that checks out with acceptable values, reinsert the splitter and try again on the VHF side.

The only thing I would not recommend is using the VHF to test the AIS side of the splitter as it will be expecting a low power digital transmission. Hopefully you'll have found the fault before that.

 

[sdeti]

Same issue here. I went up the mast found the antenna unscrewed, the VSWR reading was excellent (like 1.1).

The error kept going.

Did some more work to no avail.

After finding multiple errors I think the unit is bad.

One minute you get great vswr and the next nothing with nothing changed.

 

[Martin_J]

Whereabouts are you (or more importantly the boat) located? Somebody on the forum might be nearby and have a power/VWSR meter and be able to test out the antenna system.

Using one of those is the quickest/ simplest way to fault find

 

[sdeti]

Martin,
Thanks for your note!

I am in Alameda, CA.

Yes, i bought a VSWR meter for this purpose.
Also, updated the AIS software successfully.

We replaced PL295 connectors, inspected the antenna (which was found to be loose, that would explain the initial VSRW fault).
But now, the proAIS2 monitoring software diagnostics shows
- one minute a great VSWR close to 1.0 !
- another minute it is back to super high VSWR.

In above I am linking to images...hope you can see

Contacting the RM mothership support line to get guidance on what to do next.

 

[SaltIre]

Martin,
Thanks for your note!

I am in Alameda, CA.

Yes, i bought a VSWR meter for this purpose.
Also, updated the AIS software successfully.

We replaced PL295 connectors, inspected the antenna (which was found to be loose, that would explain the initial VSRW fault).
But now, the proAIS2 monitoring software diagnostics shows
- one minute a great VSWR close to 1.0 !
- another minute it is back to super high VSWR.

In above I am linking to images...hope you can see

Contacting the RM mothership support line to get guidance on what to do next.

These links are to your Cloud storage. Only you can access them...

 

[sdeti]

These links are to your Cloud storage. Only you can access them...

Sorry about that,- I set the pics on google drive to "Anyone on the internet with the link can view"

 

[SaltIre]

Sorry about that,- I set the pics on google drive to "Anyone on the internet with the link can view"

They are visible now.

 

[sdeti]

They are visible now.

Thanks.

Is tricky.
I am thinking to replace the antenna itself. Perhaps the antenna if it is causes the signal to be good in one minute, bad in another?

 

[david_bagshaw]

Got some damp in there somewhere or a dry joint. / loose connection etc.