couple of radio/gps questions

[1216bandit]

I have been doing some reading here and have a couple of basic questions. I'm not into electronics and am a bit confused about a few things.

I will be buying a fixed mount radio and wondering what feature the radio has to have to interface with a gps. I would like to be able to send and recieve locations from/to other fishermen.

What feature does the gps need to hook up with the radio? The gps does not need to be a combo fish finder as I already have a decent finder.

The boat is a 19' aluminum starcraft islander. Anything in particular to be aware of when mounting the antenna to an aluminum boat?

thanx for any tips! Dan

 

[jhebert]

Re: couple of radio/gps questions

The usual interconnection of a GPS receiver and a VHF Marine Band radio is:

GPS Receiver ---------> VHF Radio

The GPS receiver sends NMEA coded position information to the radio so the radio can transmit the vessel position using digital selective calling.

VHF Radio ------------> Chart Plotter

The VHF radio receives the position information transmission from another vessel via digital selective calling and passes this information using NMEA coding to the chart plotter.

The typical method of connection is to use a serial digital connection according to NMEA-0183 standards.

The typical NMEA coding used from the GPS receiver for position of your vessel to the radio transmitter is sentence formats RMC, GGA, GNS, or GLL.

The typical NMEA coding used by the radio to send another vessel's position to your chart plotter is with the DSC and DSE sentence formats.

 

[NYBo]

Re: couple of radio/gps questions

All fixed-mount marine VHF radios have been required to have the ability to interface with GPS units for a number of years, so no worries there.

On the GPS/chartplotter side, just be sure it has the NMEA-0183 interface, as Jherbert noted. I think virtually all current fixed-mount marine GPS units have this.

 

[jhebert]

Re: couple of radio/gps questions

All fixed-mount marine VHF radios have been required to have the ability to interface with GPS units for a number of years, so no worries there.

This is a good point.

The requirements for transmitters in the VHF Marine Band are given in Title 47, Telecommunications, Part 80, Stations in the Maritime Services. See:

http://edocket.access.gpo.gov/cfr_2007/octqtr/47cfr80.203.htm

which says, in part,

" Applications for type acceptance of all marine radio
transmitters operating in the 2-27.5 MHz band or the 156-162 MHz band
received on or after June 17, 1999, must have a DSC capability in
accordance with Sec. 80.225. This requirement does not apply to
transmitters used with AMTS or hand-held portable transmitters."