wrote in
ups.com:

Hi,

AIS operates on 162MHz which is in the maritime VHF band, I think. Can
I split the VHF aerial line to feed both a DSC VHF set and a stand
alone AIS receiver??? - this receiver in particular
http://www.allgadgets.co.uk/ag/produ...pf%5Fid=AG3933

TVMIA




Think, think, THINK~! What do you suppose will happen to the poor AIS
receiver when you go keying 25 watts DIRECTLY into it from the VHF
TRANSMITTER?.....

Answer - The magic smoke will escape, rendering it BURNED TO HELL.

NEVER CONNECT TWO RADIOS TO THE SAME ANTENNA IF ONE OF THEM INCLUDES A
TRANSMITTER!

The device which DOES allow you to connect two (or even more) radios to one
antenna is called a ferromagnetic circulator. It isolates the other radios
connected to it from the one that's transmitting.
http://www.repeater-builder.com/rbtip/circulator.html
http://www.wa8dbw.ifip.com/Circulator.html
http://www.macom.com/parametric/para...tors_Isolators

If you have to ask the price, you can't afford it.....They're not cheap.