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+--- Thread: How does the AIS acquire a Signal? (/showthread.php?tid=4095)
How does the AIS acquire a Signal? - DRFASailboater - 10-09-17 05:48 PM
If i have a Axiom installed with a internal GPS and a Quantum Radome. How does the AIS650 transceiver acquire a signal for transmissions and broadcasts? Does the AIS650 come with a Antenna or a internal function to provide others and myself with AIS information? Or do i require a seperate attachment onboard to enable acquisition of these sources for display on a Axiom MFD?   Â
RE: How does the AIS acquire a Signal? - Chuck - Raymarine - Moderator - 10-10-17 10:23 AM
Welcome to the Raymarine Forum DRFASailboater,
In order for a MFD to support plotting and displaying AIS data, the MFD must be interfaced to an AIS receiver (ex. AIS350, AIS250 (retired), or third party AIS receiver), AIS transceiver (AIS650, AIS950, or third party AIS transceiver), VHF radio / AIS receiver/transceiver combination device (ex. Ray70 w/AIS receiver option, Ray260 w/AIS receiver option, third party VHF radio w/AIS receiver) which in turn will be interfaced to a VHF antenna having a maximum gain of -3dB. AIS transceivers must additionally be interfaced to a passive GPS antenna which is typically supplied with the AIS receiver. Should the AIS receiving device be equipped with a SeaTalkng / NMEA 2000 communications interface, then it will be interfaced as a spur to a powered and properly terminated SeaTalkng / NMEA 2000 backbone to which the MFD has also been interface. Should the AIS receiving device not be equipped with a NMEA 2000 communications interface and instead be equipped with a NMEA 0183 communications interface, then the AIS receiving device would be interfaced to a 38400 BAUD NMEA 0183 to NMEA 2000 data bridging device (ex. Actisense NGW-1-ISO-AIS, etc). which in turn will be interfaced as a spur to the aforementioned SeaTalkng / NMEA 2000 backbone.
While it is considered to be a best installation practice to install dedicated VHF antennas for the AIS receiver/transceiver and VHF radio, Raymarine offers the AIS100 Class B AIS Antenna Splitter to support the needs of those seeking to utilize a single VHF antenna to support the AIS receiver/transceiver and VHF radio.
RE: How does the AIS acquire a Signal? - DRFASailboater - 10-10-17 01:48 PM
I also have a Ray260 VHF onboard that doesn' come supplied with a Antenna. If you missed it before i was using the AIS650 of which is a "Transceiver"and comes with a external GPS according to the manual, A Axiom MFD, one Quantum Radome. Axiom has its own internal GPS. I don't see any Antenna's listed or provided with the purchase of a AIS650. Networking options claim it can be connected to a external GPS. Nor do a see a list of purchasable Antenna listed in a section. Which Antenna's are you refering to?
RE: How does the AIS acquire a Signal? - Chuck - Raymarine - Moderator - 10-11-17 07:56 AM
DRFASailboater,
AIS transmissions are broadcast/received via the VHF antenna which will be interfaced to the AIS receiver/transceiver. The Ray260 may be purchased with and without AIS receiver (not transceiver) circuitry. The AIS650 must not only be interfaced to the supplied passive GPS antenna (required for the AIS650 to determine the vessel's position, SOG and COG ... the AIS650 is not designed to utilize GPS data from other marine electronics products), but must also be interfaced to a VHF antenna. The part number for the passive GPS antenna included within the AIS650's package is R62241. Raymarine neither manufactures nor sell VHF antennas. Typically, VHF antennas will be sourced by the customer or installer from a dealer of Shakespeare, Digital, etc. Per my prior response and the AIS650's manual, it is recommended that the VHF antenna have a gain of no more than -3dB.