GPS Antenna Location

[dsiekman]

Hey guys,

I have a 29' Cobalt (Express Crusier) with a Garmin 4208. The boat came without a VHF. I have an Icom 422 VHF I picked up at the boat show last year and am in the process of finding the best place to install the new antenna. The GPS puck is mounted to a small pole - about 18" long - on a ratchet mount midship. It does not clear the top of the windshield. I am considering moving the puck up to the front of the bow and using the existing ratchet mount for a 3' VHF antenna. I boat in the Chesapeake and I am never out of site of land - no need for a REALLY powerful VHF antenna. Do you think I will have issues with the GPS or VHF with this setup?

 

[Fireman431]

Re: GPS Antenna Location

Your GPS antenna needs a clear, uninterrupted view of the sky. At the front of the bow, top of a radar arch, whatever...as long as it's not obstructed. The VHF antenna gets it'v view by being the highest point on the boat. As long as the antenna gets pointed straight up, you should be fine. More than likely, the rachet mount was there for a VHF antenna, and since the boat didn't have one, the PO used it for a GPS.

 

[dsiekman]

Re: GPS Antenna Location

Thanks, Fireman! No arch - wish I had one - so bow it is.

 

[Jlawsen]

Re: GPS Antenna Location

Hey guys,

I have a 29' Cobalt (Express Crusier) with a Garmin 4208. The boat came without a VHF. I have an Icom 422 VHF I picked up at the boat show last year and am in the process of finding the best place to install the new antenna. The GPS puck is mounted to a small pole - about 18" long - on a ratchet mount midship. It does not clear the top of the windshield. I am considering moving the puck up to the front of the bow and using the existing ratchet mount for a 3' VHF antenna. I boat in the Chesapeake and I am never out of site of land - no need for a REALLY powerful VHF antenna. Do you think I will have issues with the GPS or VHF with this setup?

Probably not. The GPS Puck can be mounted just about anywhere flat as long as it isn't completely blocked from a overhead view. On my fhishin boat, I run a 8' Shakespear whip for my Lowrance VHF and a 4' Shakespear for my AM/FM Radio. The VHF gets it's GPS data from the Lowrance 4000 GPS puck mounted back by the stern. Just about everything I have is on a NEMA 2000 network including my SmartCraft system.

Unless I'm running with my buddies, my VHF whip is layed down on top of the Gunwale and I get out about a mile or so. With it up I'm good for 20 miles if the propagation is right.

 

[dingbat]

Re: GPS Antenna Location

A 3' lg. VHF antenna mounted 2' above the waterline you give you a transmisson range of roughly 2.5 miles. Throw in the effects of pitch and roll and you could probably yell further than you could broadcast on any given day.