Where to put AIS antenna?
- Thread starter arcadiahunter28
- Start date
AIS is line of sight and low wattage, for the best reception and transmission the antenna needs to be as high as possible. This means the masthead.
Bot the AIS transceiver and the VHF can use the same antenna and cabling, but there must be an active splitter. This blocks transmission from one device blasting directly into the other when transmitting, i.e., only one device can transmit at a time.
The big advantage of AIS is that it allows you to see and be seen in poor visibility conditions, this only happens with a transceiver. The receive only units really aren't worth much, because they don't let others know where you are.
Bot the AIS transceiver and the VHF can use the same antenna and cabling, but there must be an active splitter. This blocks transmission from one device blasting directly into the other when transmitting, i.e., only one device can transmit at a time.
The big advantage of AIS is that it allows you to see and be seen in poor visibility conditions, this only happens with a transceiver. The receive only units really aren't worth much, because they don't let others know where you are.
For me, it's more important to be seen by large vessels than to see them! Since class B transponders have come way down in price, it's tough to rationalize not having one if you sail in places with serious shipping and pretty regular fog, as I do.
I tend to agree, at least for the type of sailing I do on the Chesapeake. I don’t expect the ships in the channels to avoid me even if they see me. I just want to see them and get the CPA calculations so I can avoid them.
Edit: Evidently I was replying too early in the morning. I tend to *dis*agree.
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My AIS transmitter/receiver is mounted near my Radar tower at 10ft from WL and has integrated GPS. I get 17NM to a high powered base station receive and over 10NM receive on most ships (class A). Prior to this, I used a splitter and found I was getting around 5miles receive max and that the poor quality of the splitter was negatively affecting the VHF transmit/receive distance and that was not desirable - do not buy the Glomex splitter. Also, having a second antenna away from the mast is desirable if you get dismasted.
the AIS is shown on my Chartplotter as well as my VHF via USB and NMEA0183 respectively. Connecting Chartplotter/MFD, VHF/DSC and AIS together gives you the best chance to see and be seen in the event of an incident
2 wks ago during the Lake Michigan Clipper cup we reacted to an Active DSC MOB alarm, which was displayed on my Chartplotter screen while 20 miles outside of Port Washington, WI. The Info I had in front of me was the distance, direction, point on the map, last report age and MMSI. It was a false alarm but having that info straight away was pretty much enough convincing that my team will probably install an MOB1 in their Life jackets - I already have one.
the AIS is shown on my Chartplotter as well as my VHF via USB and NMEA0183 respectively. Connecting Chartplotter/MFD, VHF/DSC and AIS together gives you the best chance to see and be seen in the event of an incident
2 wks ago during the Lake Michigan Clipper cup we reacted to an Active DSC MOB alarm, which was displayed on my Chartplotter screen while 20 miles outside of Port Washington, WI. The Info I had in front of me was the distance, direction, point on the map, last report age and MMSI. It was a false alarm but having that info straight away was pretty much enough convincing that my team will probably install an MOB1 in their Life jackets - I already have one.
