Avoiding Antenna Interference

[alessandra]

My masthead has a VHF antenna (GAM can with whip and windex) mounted 4 inches VHF top bracket of lopolight (LED) which is mounted on two one inch spacers above mast top plate. 12 inches forward and 26 inches up (Lopolight VHF top bracket and glomex aluminum extension tube makes the base of Maretron WS100 stand 28 inches above mast top plate.

I have not had any interference notable between sensors and radio - however VHF is not constantly broadcasting. If I add AIS with a splitter to this antenna I will have a lot of broadcasting.

First alternative:

I have a radar pole at stern. Put AIS here? will have cell and wifi antennas relatively near it. What interference here?

Second alternative. Put 48 inch Glomex extension tube. Issues with this are mechanical right off the bat: Is cable long enough? Is mount strong enough?

[s/v Jedi]

How about the AIS antenna on a lower spreader? If radar is about the same height, move AIS antenna to upper spreader.

ciao!
Nick.

[alessandra]

i had vhf antenna near radar with no issue - will check if new broadband antenna needs distance.

[silverheels3]

Our AIS whip is on the bimini. We see ships at 25 miles and our AIS signal can be picked up by ships at the same distance away, cruising sailboats see our transmitted AIS signal within 5-7 miles. In my view the extra expense of a specially tuned AIS whip isn't worth it. A base loaded Metz, Shakespeare or other metal antenna is broad banded enuff to work beautifully. Any small amount of impedance mismatch will not be detrimental and is barely measurable. We use a similar marine whip for 2M amateur VHF (146.52 mHz) and it's fine.