Hi Etoile,
Thanks for your information. You’d better to contact us before ordering the protocol bridge. Your issue isn’t related to the protocol bridge.
You probably know that AIS messages have to be runing at 38400bps, not 4800. So the NMEA output of A028 has been fixed setting as 34800bps. If your vhf radio can only accept 4800, I believe you need a NMEA buffer.
I am sorry for this. If you don’t want to keep the protocol bridge, you can contact our customer department to return it.