AIS Problem

[Pdemajo]

Hi All,

I have a true heading Carbon x + AIS system which has a splitter inbuilt, separate GPS, and connects to my VHF antenna.
I have checked all the connections of the antenna, and they are all good and soldered properly.
When i look at the information I receive I only see "some" boats, maybe 5 boats within a 10 mile radius, whilst from the boat next to me i can see around 30 boats in the same area. The ones I see are a mix of class A and B.
Also Marine traffic is reporting my boat to be still in Malta, whilst i am in Greece.
The Diagnostic software (ProAis) reports every thing to be fine.

Any thoughts on what may be going wrong?

[Brian.D]

Not an AIS expert, but a few things I would look at.

Is your AIS getting its clock information from the GPS? Not sure if AIS is precision timed, probably is, but if the timing is wrong so will be the messages for decode.

You have several devices all talking to each other? Is there a proper start up sequence that must be followed when turning on your devices? I would think in some cases this might be important.

If the ProAIS is saying all is good, then it might be an external influence. I would test by making sure the GPS is giving the correct information to the AIS and the AIS connected only to the antenna. No VHF or anything else connected. Narrow it down.

JMHO

[capn_billl]

I believe most AIS systems have their OWN GPS, this requires plain line of sight, (nothing solid) between unit, and satellites.

IF it's under the instrument panel, I would suspect interference, or a solid object placed on top blocking signal.

Should not use the same antenna as VHF, even with splitter only ONE can talk at a time.

Like above. Turn everything off, turn on AIS, wait to boot, then screen, wait to boot, and lock, and see if it works.

[capn_billl]

Update.

If it is seeing SOME targets, but not ALL targets.

It either didn't have time to receive all the targets, (it takes several seconds each).

Antenna is dropping out, or not picking up weaker signals.

Settings are screening out some boats, (size, distance, speed)???

[smac999]

Probably a bad antenna

Assuming you have left it on long enough. Most boats only send every 5 mins. So leave it for 10-15m. Before checking.

[bstreep]

Buy an antenna that's tuned for AIS rather than VHF. It makes a difference.



These folks are great:


https://www.morad.com/collections/fr...nna-162-hd-ais

[LoudMusic]

Originally Posted by Pdemajo

Hi All,

I have a true heading Carbon x + AIS system which has a splitter inbuilt, separate GPS, and connects to my VHF antenna.
I have checked all the connections of the antenna, and they are all good and soldered properly.
When i look at the information I receive I only see "some" boats, maybe 5 boats within a 10 mile radius, whilst from the boat next to me i can see around 30 boats in the same area. The ones I see are a mix of class A and B.
Also Marine traffic is reporting my boat to be still in Malta, whilst i am in Greece.
The Diagnostic software (ProAis) reports every thing to be fine.

Any thoughts on what may be going wrong?

How's your VHF audio range?