Problem with Comar CSB200 AIS tranceiver

[Carmel2]

We have just installed a Comar CSB200 AIS transceiver and are experiencing problems. Basically we are only receiving AIS signals from boats within a 2 nm radius or less, even out in the open sea with no obstructions. We are also transmitting at a similar range - we radioed a tanker who was approx 2nm from us and they were not receiving our signal. We have run the computer diagnostics and all is ok. We have a dedicated Glomex standard marine vhf 156-162 mhz antenna for it. Does anyone have any suggestions as to what the problem could be? We are soon to do another long passage in a busy area and so really would like it working properly before then. Thanks very much in advance.

 

[maby]

A problem with the antenna cable would seem to be the most likely. Can you swap the antennae between the AIS Transponder and your VHF and repeat the test?

 

[Salty John]

If you're sure you don't have a corroded, damaged or shorted connector it could just be down to the location of the antenna. You don't say where the antenna is sited, but here are some tips or getting the most out of your antenna:

http://www.saltyjohntheblog.com/2014/04/vhf-antenna-tips.html

A bit further up the blog there's a post on antenna extension poles which you might want to consider. If you are using a masthead antenna then my guess would be you have a connector shorted or corroded somewhere in the line.

 

[Martin_J]

I'd offer to do a power, antenna and SWR test for you but your profile does not include your location.

Those tests would immediately show where the issue lies.

Apart from that - As others have said, it'll be trial and error swapping out with known good parts.

VHF - even if you think it sounds good at a nearby handheld.. might only be putting out a few milliwatts of power if either the transmitter or the antenna/cabling is bad.

Perhaps say where you are and someone nearby might have some test equipment.

 

[Carmel2]

I'd offer to do a power, antenna and SWR test for you but your profile does not include your location.

Those tests would immediately show where the issue lies.

Apart from that - As others have said, it'll be trial and error swapping out with known good parts.

VHF - even if you think it sounds good at a nearby handheld.. might only be putting out a few milliwatts of power if either the transmitter or the antenna/cabling is bad.

Perhaps say where you are and someone nearby might have some test equipment.

If you're sure you don't have a corroded, damaged or shorted connector it could just be down to the location of the antenna. You don't say where the antenna is sited, but here are some tips or getting the most out of your antenna:

http://www.saltyjohntheblog.com/2014/04/vhf-antenna-tips.html

A bit further up the blog there's a post on antenna extension poles which you might want to consider. If you are using a masthead antenna then my guess would be you have a connector shorted or corroded somewhere in the line.

A problem with the antenna cable would seem to be the most likely. Can you swap the antennae between the AIS Transponder and your VHF and repeat the test?

Thank you folks!! Martin J, we are in Milos Greece. I will endeavour to find someone who can do a test. In the meantime I have now swapped the VHF and AIS cables around and we are getting signals from 30 odd miles away on the AIS, so Maby I think you're right. Salty John, it's all new gear so I doubt corrosion is the issue.

Once again thanks.

Cheers
Paul

 

[maby]

Thank you folks!! Martin J, we are in Milos Greece. I will endeavour to find someone who can do a test. In the meantime I have now swapped the VHF and AIS cables around and we are getting signals from 30 odd miles away on the AIS, so Maby I think you're right. Salty John, it's all new gear so I doubt corrosion is the issue.

Once again thanks.

Cheers
Paul

That would seem to be pretty definitive - check every connection in the AIS cable run carefully.

 

[Martin_J]

Have you soldered the connections? i.e. both the center part and the outer within the PL259 plugs...

 

[Martin_J]

Center part definitely can be (and needs to be soldered).

Unfortunately with the outer shield this is not always possible.

Preferable to have the PL259 plugs that allow for a bit of solder through holes to the braid (also helps seal the cable end) but not the end of the world if you have the un-solderable plugs..

 

[Boatman]

Center part definitely can be (and needs to be soldered).

Unfortunately with the outer shield this is not always possible.

Preferable to have the PL259 plugs that allow for a bit of solder through holes to the braid (also helps seal the cable end) but not the end of the world if you have the un-solderable plugs..

I think they are BNCs on the comar, but havn't looked at mine since installation.