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Old 06 June 2012, 11:41   #11
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Originally Posted by Erin View Post
GPS should not be to the side of the VHF, it should be either above or below it.
Might want to look at a drawing of what your VHF antenna actually has inside. I believe that the actual radiating elements are contained in the upper third to half of the mast. Mounting the GPS and VHF antennae on the same level will keep the GPS out of the VHF radiation.

jky
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Old 06 June 2012, 11:55   #12
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leave the GPS where it is, low down is good, it gives a more stable reading.
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Room for one more in pedants corner


What you got on board? A survey quality reciever???

short version:

GPS antenna height effect on position in a rib is negligible - The s*dding machine can't pin you down to much better than a couple of boat lengths on a good day anyway.


The stoopid thing is - we all agree the console is fine!!!!!!
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Old 06 June 2012, 12:39   #13
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Quote:
Originally Posted by jyasaki View Post
Might want to look at a drawing of what your VHF antenna actually has inside. I believe that the actual radiating elements are contained in the upper third to half of the mast. Mounting the GPS and VHF antennae on the same level will keep the GPS out of the VHF radiation.

jky
I'm sure you're right. I was just going by what the manual says. I suppose a metal whip aerial will be radiating along most of its length.
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Old 06 June 2012, 12:51   #14
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I believe the reason for not mounting a gps antenna too high is because it can pick up signals reflected off the water. I'm not sure if the problem is that an antenna mounted high is more susceptible to reflected signals or because there's more time delay in a reflected signal reaching a high mounted antenna.

Either way it's got bugger all to do with your a frame rolling about!
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Old 06 June 2012, 14:24   #15
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Console mounted AM/FM aerial is fine, inside the console works fine and picks up anything you wish to hear.
I have a GPS mounted on the a Frame. mainly to ensure the transducer and GPS position are as acccurate as possible and I don't automatically introduce a couple of meters of error automatically.
This is for wreck finding and searching purposes and probably doesn't matter otherwise.
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Old 07 June 2012, 07:23   #16
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Just a thought - surely you want the GPS aerial as close to the middle of the boat as possible as in theory if you stick it at the back then on a 7m boat you have just put yourself 3.5m out of position ?(if you want to be really really accurate )
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Old 07 June 2012, 08:22   #17
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Like I keep saying - you'l be lucky if the machine actually puts you less than a boat's length from reality anyway....

- At 20+ knots, a couple of metres shouldn't be a problem.
- At super close range I'd be relying more on my eyesight or an oar over the bow!
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Old 07 June 2012, 08:38   #18
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I'm not going to bother commenting on the GPS debate other than I've never heard so much ..................



Anyway get yourself a VHF/FM splitter to reduce the number of antennas.
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Originally Posted by Zippy
When a boat looks that good who needs tubes!!!
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