It looks like all VHF/AIS units are receivers only yes? Would there be a conflict of any kind by buying a transmitter only and installing that separately? If you put a splitter in the line with the VHF/AIS-receiver would it all go haywire? I'm not averse at all to a 2 antenna solution (after all, the good boats have 2 masts
) for redundancy.
To my knowledge the integrated VHF/AIS units are all receive only.
To my knowledge there are no transmitter-only units available -- given the timing mechanism to avoid transmission conflicts I don't see any way to build such a unit.
The setup I am imagining is the standard horizon VHF/AIS-receiver attached to the mainmast VHF antenna and either a transmitter only, or a transceiver separately on the mizzen mast antenna. Would the mizzen antenna transmitting cause confusion for the main mast antenna receiver?
No problem with VHF antennas on main mast and mizzen mast. If you have a metal triatic stay I would expect some directionality but likely not enough to be noticeable.
I understand you want an entry level machine but the receiver only in the VHF doesnt send the AIS information to the chartplotter. All you get, as I understand it, is the tiny VHF screen.
The integrated VHF/AIS units I have seen all have 38.4kbps NMEA 0183 outputs to pass AIS and GPS information to other devices.
For those of us limited to one mast, is there any problem with two two VHF/AIS antennas being in close proximity at the masthead? Any interference issues?
Yes. Don't put two VHF antennas on the same masthead. Your options, in no particular order, are to put the second antenna on a spreader, on a bimini, on a pushpit, on the backstay, on a radar pole, or on an arch.
Yes. I thought the splitter was ****.
I agree for a reason you did not list. Splitters insert a signal loss of 2.5 - 3 dB. That is equivalent to reducing power for both the AIS and the VHF by half in both transmit and receive.
The other reasons Mark lists are good reasons to avoid a splitter also, but the power loss is a good enough reason for me all by itself.
Raymarine removed its internal splitter from its earlier version WHY?
Are you talking about the older AIS 500 and the current AIS 650? You're correct. I don't know why they did that but I'm glad they did.