Vesper xb-8000 problem

[alctel]

Hi all,

I just bought an XB-8000 with the splitter.

Plugging it all in, I get a warning that the VSWR is too high.

Not super surprising, as the antenna/cabling is super old. I bought a new antenna, a Sharespeare 5215 (non AIS version) and tried plugging it into the AIS directly (not through the splitter), using a new, premade 5 foot VHF cable to test before I went to the trouble of scaling the mast.

It still shows VSWR. I phoned Garmin support and they said it could be the antenna isn't suitable, but I looked up the stats and it shows SWR of under 1.5 at 162MHz. 5215 is such a common antenna I would think that this would have been commented on before!

Does anyone else have any solutions or suggestions, or is it a bad unit?

[Captain Bill]

AIS operates at the upper end of the marine VHF band and requires a slightly shorter antenna for optimum performance. The 5215 is tuned to to the center of the band. The 8000 will operate with an swr of 3 or less but with a bit less range than optimum. I have one operating at just slightly less than 3 and pick up class B signals out to about 8 miles and people report seeing my signal at about the same distance. Class A signals are visible at about 20 miles. I also get a warning about my VSWR being too high. My antenna is mounted on my hard top which is 12ft above the water.

[alctel]

Originally Posted by Captain Bill

AIS operates at the upper end of the marine VHF band and requires a slightly shorter antenna for optimum performance. The 5215 is tuned to to the center of the band. The 8000 will operate with an swr of 3 or less but with a bit less range than optimum. I have one operating at just slightly less than 3 and pick up class B signals out to about 8 miles and people report seeing my signal at about the same distance. Class A signals are visible at about 20 miles. I also get a warning about my VSWR being too high. My antenna is mounted on my hard top which is 12ft above the water.

That's the issue - it's saying the VSWR is over 3, even when plugged into a brand new antenna with a brand new cable

[hjohnson]

Originally Posted by alctel

Hi all,

I just bought an XB-8000 with the splitter.

Plugging it all in, I get a warning that the VSWR is too high.

Not super surprising, as the antenna/cabling is super old. I bought a new antenna, a Sharespeare 5215 (non AIS version) and tried plugging it into the AIS directly (not through the splitter), using a new, premade 5 foot VHF cable to test before I went to the trouble of scaling the mast.

It still shows VSWR. I phoned Garmin support and they said it could be the antenna isn't suitable, but I looked up the stats and it shows SWR of under 1.5 at 162MHz. 5215 is such a common antenna I would think that this would have been commented on before!

Does anyone else have any solutions or suggestions, or is it a bad unit?

Had exactly the same problem back on 2016 with an XB-8000 when we tried to install it on a friend’s boat. In the end, we wound up having to RMA the unit. The internal jumper cable between the circuit board and the external VHF connector has come loose. Given the weather sealing on the unit, and that it was still under warranty, we decided we were not going to crack it open ourselves.

[wholybee]

Even with the sub-optimum non-ais antenna, the VSWR should be well under 2.0. With the same antenna and splitter, I have VSWR of about 1.2, and a range of about 10 miles, which is very good for a class B AIS.

The suggestion that something might be loose inside is a reasonable one, given that you tested it on the ground with a new antenna and cable. I would want to use a power meter/VSWR meter other than what the unit reports to confirm what is going on. If the wire has come loose, then there will be no power output at the connector.

[hjohnson]

Originally Posted by wholybee

Even with the sub-optimum non-ais antenna, the VSWR should be well under 2.0. With the same antenna and splitter, I have VSWR of about 1.2, and a range of about 10 miles, which is very good for a class B AIS.

The suggestion that something might be loose inside is a reasonable one, given that you tested it on the ground with a new antenna and cable. I would want to use a power meter/VSWR meter other than what the unit reports to confirm what is going on. If the wire has come loose, then there will be no power output at the connector.

For better or worse you’re not going to see much coming out of an AIS transponder, especially a pre SO-TDMA class B like the XB-8000 unit. At most it’s going to transmit for a few milliseconds every 30 seconds or so. That’s not going to do much at all to an RF power meter.

[alctel]

Thanks guys, I will try to RMA the unit.

[donradcliffe]

I just delivered a boat with a new Vesper unit and splitter, and they got the same error message. Ignored it. We got reasonable reception, but it seemed that we did not show up on Marine Traffic as much as I would have expected when we were coming down the coast. It does show it in its current location.

[Be Free Sailor]

I had a 100% similar problem with a new XB-8000 back in 2018.
Vesper supported via email, but they did not think the unit was at fault, and would not replace it.
I was underway and solo sailing from Greece to Scandinavia, and I needed a working AIS unit.
So I purchased a Digital Yacht AIS transponder, which worked perfectly well on the same antenna + cable.
The XB-8000 is still lying around, perhaps I should try open it up and check the internal antenna cable?!