Re: Information on Raytheon RL70 and Raymarine 2kw Dome
I have a similar set up.
Skip the Raystar 120, buy the 125 instead. The 120s were built with a battery hardwired into the GPS. These batteries have a life and expiration date that based on the production date of the 120 has since passed. Yes, there is new old stock on Ebay, but even if you get one that works it will die soon. You have to replace the whole thing with a 125 and that means running a new wire from the display to the arch.
The 125 can be set up as either NMEA0183, or SeaTalk, use SeaTalk. It will come with the cable.
You will need:
Power cable for the RL70
RL70 mounting trunion
Radar Cable
You will also need ether 4 degree mount wedge, or tower for the radar scanner, depending on whether you have a fiberglass arch, or metal tube arch.
To add the GPS, and any other SeaTalk accessories, depth, fish finder,
SeaTalk Cable
SeaTalk junction box, or 3 buss bars to create a junction point (power, shield, and data). I'd suggest the Blue Sea Systems 5 point buss bars, will cost the same as the RM junction box and is a heck of a lot easier to work with.
The radar is going to be a little wonky without a course compass when you try to overlay radar and GPS. The course compass input syncs the two displays. I bought the RM Smart heading POS. Biggest waste of $800 there ever was. You can also use a KVH electronic compass with NMEA 0183 output to feed the RL70 with course data. Its about $ 300. NMEA input for the RL70 is via the power cord cable.
You would also need a NMEA out cable if you planned to take the course data to feed something like the Mercury Smartcraft SC1000 tach or SC5000 System view display