AIS Antenna VSWR Fault

[Starscream]

I need some advice, please. I recently added a Raymarine AIS transmitter to my network, and it works great as a receiver. Problem is that I get a VSWR fault when I installed it.

So, I replaced the entire antenna system with the following parts:

• Masthead antenna with a Shakespeare combination AIS/VHF antenna. https://ca.binnacle.com/p7502/Shakespea ... _info.html

• Ancor Marine RG8X Coax, 47 ft total run back to the AIS receiver, with one split at the mast foot. https://ca.binnacle.com/product_info.ph ... cts_id=582

• All PL59 connectors replaced with Shakespeare Solderless, and continuity checked from the top of the mast to the AIS receiver. https://ca.binnacle.com/product_info.ph ... ts_id=5669

The AIS has a coax output to share the signal with the radio, and that is a short loop from the AIS to the radio right beside it, that should have nothing to do with the AIS transmission.

And I STILL get the VSWR Fault. Well, 3 out of 4 times that I start the network I'll get the fault, and 1 out of 4 it'll just boot right up. I haven't checked on the shiptracker website to see if I'm transmitting or not, yet. Any help or advice would be much appreciated.

[Hamin' X]

What is the model number of your AIS unit?

[Starscream]

What is the model number of your AIS unit?

It's the Raymarine AIS700

[Hamin' X]

I would first check the software version on your unit. Latest version is: v01.17.01, available HERE. Next, I would check all your grounds. Antenna mount to mast, etc. If you know any ham radio operators, have them run an SWR check on your system. All manuals and guides are available HERE.

From the AIS700 trouble shooting guide:

3.3 VSWR Alarm troubleshooting
If you experience regular VSWR alarms try the troubleshooting guidance below.

Incorrect antenna in use.
Check that your antenna meets the required VHF antenna specification that can be found in the product documentation.

Antenna short or open circuit.
Check antenna for short or open circuit, repair or replace as necessary.

Product running an older version of software
Software version 1.09 included Improvements to Antenna fault detection (VSWR alarm).

[Starscream]

Happy to report that the VSWR fault has entirely gone away, and I can see my boat on Shiptracker. I don't know what changed to get rid of the error, but it's been functioning perfectly for weeks now.