There are several approaches for this. But if you have a class A
DSC (that has separate antenna for DSC reception), a passive splitter
would work fine with the DSC (receiving) antenna and a AIS receiver.

If you can and will install the system yourself (only pay for material)
it is probably cheaper to get a separate antenna for your AIS.

But if someone is going to install it for you the extra antenna will
probably
be more costly than the filter, as the filter requires less work.
(others peoples time=big ???/$$$)

Regards, TomS

"You" wrote in message
...
In article ,
"Gordon" wrote:

Smart Radio (Milltech Marine) offers an active splitter so you can use
the
same antenna for both vhf and ais.
However, it seems expensive. So what is an active splitter? (Does it
turn
flips to or just splits?) Why so expensive? Is there a substitute?
Thanks
Gordon

Probubly an RF Activated Antenna Switch with internal 1/4 Wave Stub
Grounding on both radio ports, if it is designed for full AIS
Transponder operation. Seems kind of a stupid idea, if it costs more
than a second antenna would cost. But hey, what ever blows youe skirt
up......