hardtop antenna layout

bud wasierski

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I just had a factory hard top added to my Seafarer 228. I am going to move my VHF and GPS the new top and will be adding radar and three other antenna to the top. I want to have a layout before I start drilling, can anyone give me a recommended layout?
 
radar in front, gps up out of the radar beam, vhf, and Uhf as far away from each other a space permittes. and talk to the antenna people they have more on best ways to set up spaceing. I set up my boat with all the antenna that I needed and it all works great, just don't look the best, as you can see in my pic.
 
Bud,

Just as the other guy said..radar in the front. I made my own mount one time out of two pvc toilt flanges and a 6" piece of 3" pvc pipe that I drilled a hole in and was able to run the cable down into the inside of the pipe and down through the roof of my first 26 Shamrock hardtop..nice and neat and water tight. GPS antenna needs to be at least 1 foot above the radar antenna..depending on what you travel under, it could be higher. The VHF antenna should be close to the outside of the hardtop where it is easy to tilt it down if you need to go under bridges, etc.
 
We installed a Furuno NavNet system three years ago. We used the short, mushroom GPS antenna that is mounted just outside the swing of the open-array antenna and on the port side of the hardtop and we have traveled 250 miles into the Bahamas with the GPS spot on.

If your new top has the "hump" on it, mount the front edge of your antenna a few inches back from the front edge of the hardtop if it will fit. On my boat, that part of the hardtop was about 1 inch thick. Watch for the tube/frame underneath before you drill any holes!

I agree with the VHF antenna being a foot or so behind the radar antenna and a foot or so in from the side/edge to help with lowering.... You can see all three mounted on my Marlin here.....

Boat020.jpg
 
when i bought my boat (used), it had 2 gps sensors, 4kw radome, and a vhf whip on the hardtop.
the gps sensors were mounted on extensions and mounts and just off center and behind the radome, the whip was also on a ratchet mount and IMO too far center.
here's a pic of the old set-up:
GW%20282%20Dockside%20Resized.jpg


i upgraded my chartplotter and when doing so, replaced both gps mushroom sensors with the newer and flush mountable 330B sensors which eliminated any mount or extension and got them under and out of the path of the radome signal. mounts tend to loosen up, rattle and fall down and even potentially damage an expensive sensor, so eliminating a few mounts, improving to a cleaner look and eliminating the need to raise and lower the gps mounts for towing was a much needed win win situation.
I also added another 8' vhf whip for my second radio, new stylish HD shakespeare 5187 ratchet mounts, and moved the whips closer the sides of the hard top which made lowering or raising the whips much much easier. if you choose to mount the whip closer to the center line of the hard top, you'll literally need to climb the top to adjust the whip. mine are now far enough to the side to allow for easier access but still mounting close enough to the center to allow the wires and fastening hardware to be accessed from inside the overhead elect. box.
the only thing i may do is add a wedge for the radome as i feel it needs to be angled down a bit as targets (boats) do not show up well on the radar until they are beside or behind me.

wish i took a pic of the final look of the hard top after i moved the sensor and removed the extensions to share with you, but no dice.
if you can flush mount the gps sensors, you can avoid having to add a strut for the radar.