Another AIS transponder question

[neil1967]

Further to my previous question on AIS transponders, I note there are two types of aerial splitters to allow both the transponder and the VHF to use the same aerial. The Garmin 600 AIS has a built in passive splitter, which presumably introduces some loss into the VHF. On the other hand Digital Yachts splitter uses active technology, which supposedly improves the VHF performance. Both Garmin and Digital Yachts claim that failure of the unit will still allow the VHF to work. The Garmin is attractive as it is a single unit to install and is cheaper than buying a Digital Yacht transponder and separate splitter, but I wonder how much better the DY arrangement actually performs? Grateful for any informed thoughts

Neil

 

[Daydream believer]

If cost is a problem then why not buy an AIS dedicated aerial for less than £ 30-00 & stick it on a pole on the pushpit
would that be cheaper than a splitter- I have never tried to buy one
That way you also get a spare aerial in case of mast failure or failure of the aerial up the mast
Furthermore you do not risk messing up the VHF radio

 

[prv]

If cost is a problem then why not buy an AIS dedicated aerial for less than £ 30-00 & stick it on a pole on the pushpit
would that be cheaper than a splitter- I have never tried to buy one

Splitters are remarkably expensive, so yes, a basic second aerial will be much cheaper. However, lots of us do not want to clutter the stern rails with a thicket of antennae, poles, mushrooms, and other things for mooring lines to snag on. Others struggle to run cables neatly through their boats to new aerial positions. Personally I'm a big fan of the VHF with integrated AIS receiver - it's already pulling data off Ch70 alongside whatever the voice part is doing, so it's not much of a stretch to also monitor the AIS channels 5 or 6 MHz further along. No splitters, no extra aerial cabling. Not much help to the OP though as he wants to transmit (as far as I know, nobody makes a combined AIS transmitter VHF).

Pete

 

[salar]

I have tried both. On my previous boat I had two aerials so no danger of a splitter malfunctioning. On my current one I have the Garmin 600 which does the splitting, I am more comfortable with that form of splitting because it is dedicated and works for the VHF even when the AIS is off.

 

[david_bagshaw]

I have the DY ais and splitter, as extra wiring to the tabernacle is problematical and yes it seems good, may be some loss of reception on long distance vhf ie don't tend to hear the 90 miles + traffic, but no detectable loss of transmission distance.

 

[ghostlymoron]

I would think that some loss of power is inevitable but does it matter? Why would you be interested in shipping 20+ miles away? If they're coming closer, they'll be in range soon enough.

 

[salar]

I don't understand why people are worried about degrating the AIS performance with a splitter. The far bigger worry is introducing a point of failure in your vital, life-saving VHF aerial.

 

[RichardS]

An active splitter works well for me. Vesper Marine rather than DY but same principal. VHF works fine whether splitter is powered on or off and AIS range from masthead antenna is stunning.

Richard