Its time to upgrade the old VHF radio with the new type DSC and since my helm and radio are in two different locations I am thinking of getting the Standard Horizon GX 1700 that has GPS that way I don't have to run a wire from my Garmin to my radio. I am a little concerned since my radio is down below in the cockpit. I don't want top have to put in a separate antenna. Anyone have experience with this unit?