Which AIS ?

[adrianb]

Brian - I didn't think Raymarine had shipped product yet of the 250 unit.

Do you have a secret source ?


I've gone for the NASA unit anyway now! Separate multiplexor and NASA unit were much more competitively priced !



Adrian
www.cleanandshiny.co.uk

 

[pappaecho]

Followingthe Ouzo disaster last year, I fitted a Nasa unit to the Garmin 230 without problem, and the Nmea worked straight away, using a single wire between the two units. Return is obviously 12 volt minus rail.
More recently fitted a Cobra DSC radio, which stated in the instructions that "all Nmea + wires are coded red", which they arn't cos the Garmin is blue. I connected the whole lot together, using -12volts as the Nmea minus for the Cobra, and worked first time. The default settings on each unit worked perfectly, and there was no need to alter the baud rate.
As one poster has indicated the NASA unit uses a BNC connector for the VHF radio aerial. I fitted a second VHF aerial to the Mizzen for the AIS unit, which also doubles for the Lw/Mw/VHF car radio for weather forecasts etc.
When on the Solent we watch the screen and plot the ships going up and down. Beware however some ships which appear to be over 300 tonnes, either dont have a transponder, or it is switched off. When crossing shipping lanes, we find it easy to contact passing ships, to ensure that they see us, via the MMSI number and the DSC radio

 

[MikeJones]

NASA unit is great value, just remember that you miss 50% of all the information as it flops between Class A & B.

 

[pvb]

[ QUOTE ]
NASA unit is great value, just remember that you miss 50% of all the information as it flops between Class A & B.

[/ QUOTE ]Most AIS receivers do - you've got to pay £300 or so to get one which has simultaneous receive.

 

[DaveS]

I noticed that the setup instructions allow either A, B, or A / B alternating to be selected. I left it at A / B (as I suspect most do) but could there be an argument for taking a different approach?

 

[Talulah]

The AIS250 started shipping a couple of weeks ago. We received ours two weeks ago.

 

[pvb]

Theoretically, the same information is transmitted on both frequencies, so it shouldn't make a difference. The reason the data is transmitted on 2 frequencies is to avoid problems due to interference, so setting your receiver to alternate between A & B might be the best compromise.