www.seacas.com

>Sounds to me like your AIS problem is really an antenna problem. All of these potential antenna connection problems provide a great argument for the SeaCAS AIS 300. It has a GPS and AIS receiver built inside of the antenna housing and the whole unit talks to your computer by USB. No antenna connections to go sour. I have one of these and it has been ticking along without problems for a couple of years. Fred Pot, the developer, is a very nice guy and a big mucky muck in AIS circles. www.seacas.com Best, Steve Steve Dubnoff 1966 Willard Pilothouse www.mvnereid.com sdubnoff@circlesys.com

      www.seacas.com

Except if the antenna goes bad on that unit, you're really of out luck. The AIS and GPS electronics are integrated with the antenna. Antennas fail more often than electronics -- joys of wind, saltwater and weather -- and ordinary antennas are relatively cheap to replace. I've got a 16' 10db antenna on my AIS, and I routinely pick up commercial Class A units beyond 50 miles, sometimes out to 70 miles. Albeit I usually only get the rapidly transmitted portion of the data (MMSI, COG, SOG and position data) that far out. That says that most packets are getting lost and the 6 minute packages aren't getting through as the repeat rate isn't high enough. I use a Furuno Class A transceiver unit, but the receivers in my FA150 are nothing special. I think my range advantage over most setups is all antenna. Of course, 50-70 miles range is useless for collision avoidance. But the extra margin ensures that a ship preparing to come around the end of an island 10 to 20 miles away (or go through a pass in the San Juans) is visible on my AIS long before I can see him. The nice thing about the 160Mhz frequency range is that its a bit better than line- of-sight, unlike our radar and eyeballs. But only if your receiver sensitivity is good enough. John Marshall N55-Serendipity Sequim Bay, WA On Nov 10, 2007, at 6:40 PM, Steven Dubnoff wrote: >> Sounds to me like your AIS problem is really an antenna problem. > > All of these potential antenna connection problems provide a great > argument for the SeaCAS AIS 300. It has a GPS and AIS receiver built > inside of the antenna housing and the whole unit talks to your > computer by USB. No antenna connections to go sour. > > I have one of these and it has been ticking along without problems > for a couple of years. Fred Pot, the developer, is a very nice guy > and a big mucky muck in AIS circles. > > www.seacas.com > > Best, > > Steve > > > > Steve Dubnoff > 1966 Willard Pilothouse > www.mvnereid.com > sdubnoff@circlesys.com > _______________________________________________ > http://lists.samurai.com/mailman/listinfo/passagemaking-under-power > > To unsubscribe send email to > passagemaking-under-power-request@lists.samurai.com with the word > UNSUBSCRIBE and nothing else in the subject or body of the message. > > Passagemaking Under Power and PUP are trademarks of Water World > Productions, formerly known as Trawler World Productions.