Another AIS Question

[Marc14857]

Getting ready to purchase a Digital Yacht ATI 1500 or 2000 transceiver. The 1500 has an internal GPS antenna and the 2000 has an external antenna. My plan is to mount the unit behind some panels near the Nav station. I know the AIS signal is not effected by glass or plastic but I am wondering about wood as the unit would effectively below a shelf that is ~ 3/8 inch thick. My preference is to go with the internal antenna if possible.

Second question relates to the 12V power supply for both the AIS unit and the VHF splitter. I don't have any available space on the existing 12 volt distribution panel and rather than install a new panel, I was thinking of tapping into the 12V feed to the VHF which is on its own circuit and very close to where the AIS components will go. I was wondering if having the VHF, AIS and VHF Splitter on the same power supply would impact VHF performance. At least this way whenever I have the VHF on I would know that the VHF antenna splitter was also energized.

Thanks for your response
Marc

 

[Bill Roosa]

Putting the VHF, splitter and AIS on a single breaker is OK as long as you have the proper fuses in-line to protect the individual devices. The breaker then becomes more of a switch as it has to be rated for the full load which may or may not be in line with the fusing requirements of each individual unit.
The GPS is more effected by glass than wood but you really can't tell if location x will work till you try. Lots of reflection-refraction as the radio waves pass through solid objects. This results in nulls in unpredictable places. I'd recommend you get a USB puck GPS for the computer and locate it where you plan to place the unit to see if it can receive a signal. This will not insure that the unit will work but if the GPS puck does not work you can almost guarantee that the units GPS will not either.

 

[Davidasailor26]

Putting the VHF, splitter and AIS on a single breaker is OK as long as you have the proper fuses in-line to protect the individual devices. The breaker then becomes more of a switch as it has to be rated for the full load which may or may not be in line with the fusing requirements of each individual unit.

The breakers are there to protect from overloading the wire in case of a short, not to protect the devices.

Using the exising breaker should be fine, if:

1) You make sure that the wire you use to power the AIS and splitter can carry at least the current that the breaker is rated for. (Or you add separate in line fuses between the breaker and each supply line.)

2) The breaker is rated for at least the max current draw of the vhf, splitter, and AIS. If you up the breaker size, you'll need to make sure that the existing VHF supply wire can carry the new max breaker current. If it doesn't, you could add an inline fuse between the breaker and the VHF supply line.

 

[Ken13559]

Why not try putting a handheld gps at where you intend for the ais and see how good the signal is compare to away from there.

 

[jssailem]

GPS reception is always best when the antenna can see the sky to snatch the signal. Location external is always better than internal. On a sailboat the stern pulpit is good. Antenna gets an uninterrupted view of the sky. It is out of the way from most of the operational lines and activities. You can run the antenna lead down inside the pulpit and into the boat where you can run the antenna wire out of the way to your nav station.

You are going to identify the antenna location in the setup procedure relative to the center of the boat. GPS with a good signal can locate you to within 3 meters.

GPS signal can be affected by weather. That's why you try to get best sky vision so maximum number of satellites can be received for best location identification.