Re: Too many VHF aerials?
Scott SV Tengah
I just replaced my main mast VHF antenna and traced all the other ones. On our A54 main mast, there are two Banten aerials, one for the VHF and the other for the FM/AM radio.
On the mizzen, we have the AIS antenna, connected to our Furuno FA-50. As you may know, AIS transmits on VHF frequencies. The second antenna on the mizzen is the weather fax, which I don't really use. Based on my understanding, it's important that the VHF and AIS antennas are at least half a wavelength (a meter) apart horizontally and ideally on a different vertical plane. That's how Amel installed it on my A54. So if you're going to add an AIS antenna, put it on the mizzen, which it seems you're planning on doing.
Having VHF and AIS on the same mast will negatively impact both. That said, in reality, Class B AIS doesn't transmit that often and we don't blabber that much on VHF that I'd be too worried about that affecting AIS that often. :)
2007 A54 #69