I purchased an AIS 650 unit last June and had a certified installer/boatyard put it in. I have recently realized that only vessels within 1/2 mile can see our AIS signal. We have no trouble seeing anyone else but vessels have to be way too close in order to see us. I am wondering if there is a low/high power setting somewhere that I can adjust although I looked at the software interface that came with the unit and didn't see those options. The unit is connected to a new E7 that we bought at the same time I am assuming via sea talk. Any thoughts?
Welcome to the Raymarine Technical Forum Brian,
Class B AIS transceivers transmission power is limited to 2W. This is essentially a VHF signal and one may typically assume a range of 1 nm/W of transmission power. As VHF signal transmissions are line of sight, antenna height will also have an affect upon range. It is recommended that the VHF antenna w/any extension may be tested with a VSWR meter or with the ProAIS2 application. With a good antenna, cable, coupler assembly, the measured VSWR should be in the range 0.8:1 - 2.0:1. Should the antenna's VSWR be within this range, then it is recommended that AIS650 be sent to Raymarine's Product Repair Center to be tested/serviced.
Ok, I think I have found the problem. The installer apparently used a receive only antenna splitter made by Glomex. The AIS receives great but as stated above we get very short transmit range. My question to you is this - is the Raymarine AIS 100 antenna splitter appropriate for use with the AIS 650 transceiver?
Thanks for your time.
Use of a VHF antenna splitter which is not designed for use with CLASS B AIS transceivers may result in damage to the receiver section of the Class B AIS (ex. AIS650) and/or VHF radio. Class B AIS antenna splitters such as the A80190 AIS100 Active Antenna Splitter are designed to support interfacing a Class B AIS transceiver and a VHF radio to a single VHF antenna. Class B AIS antenna splitters are designed to protect the receiver of each device from the other devices transmissions.