Are My Radar and AIS Antenna Too Close Together?

Question:

I just bought a 20 years old Nauticat 331 ketch sailboat, and I want to upgrade the electronics. I have VHF antenna on the main mast, and I want to install the AIS antenna on the main mast. If I also install a Garmin GMR Fantom radar on the main mast, I will not have a one meter distance between the radar and the AIS antenna cable as it is recommanded (I understant AIS is a kind of VHF device). Is that a problem ? Best regards from France. – Leon

Answer:

Great question, yes the AIS antenna is effectively a VHF antenna with a very specific VHF frequency range. Unfortunately, I don't know what will happen when the Fathom radar and AIS antenna are so close. Why not use a really good AIS splitter and have a VHF/AIS antenna at the top of your mast instead? -Jeff