Which antenna for AIS transponder/receiver

slawosz

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Hi,
I aquired an AIS transponder (Onwa Chartplotter). I need to buy an antenna. What is the best (or best budget) choice?
 
Forgive me stupid question - does it matter if I will install the antenna on the rail instead on the mast even though it says in the description 'top mast antenna'?
It will just limit the range from perhaps 20-40 miles to 10-20, which may be adequate for most conditions.
 
Slawosz

I forgot to tell you it is better to have the right antenna. It needs a diffferent range of frequencies to a standard VHF.
AIS frequencies are at the top end of VHF marine frequencies. A normal VHF aerial will have a length suited to the middle of the VHF frequencies which extend from 156 to about 157.4Mhz. AIS runs at 161-162 Mhz approx which is a slightly shorter wavelength hence the optimum AIS antenna would be slightly shorter. Without doing the calculations a standard marine VHF antenna would not be optimum but practically good enough.
 
Out of curiosity, could I use my AIS antenna for a VHF radio (R1, 2, 3,4, etc)? Would either signal suffer noticeably?

I do just that. In fact my Vesper AIS splitter has a dedicated FM connector which is connected to the car type radio. Works really well.
 
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