Mounting distance from radar to gps/light/ante.

[protozo1]

I'm getting ready to mount a 18"radar dome on the hardtop of my power boat. I've read a bunch of stuff about where and how to mount. Here are my questions:

How close can I mount my radar dome to my anten./ gps anten./ light pole or mast? (Manual says 3 feet, but I see pictures with them all together on same short mast)

How do I determine if I need a wedge to help with the radar cone angle when under way? (The boat clearly has a higher angle when under way on plane as a pose to headway speed)

If I have to much angle will my radar preform poorly at headway speed?

 

[Texasmark]

Re: Mounting distance from radar to gps/light/ante.

Probably 3' is just a guess. Frequencies are significantly different which would normally keep you from worrying about interference......like if 3' is tolerable, there is not much difference in 6" in terms of signal strength change. Just so that you have no mechanical interference.

On antenna pitch, depends upon beam width of the antenna. Easy to determine that.

Have the boat at rest in totally calm water.

Have the radome sitting on the mounting surface but not attached.

Point the antenna forward and you get aft of it....you don't want to be in front of it while it is radiating (microwave oven type thing).

Find a target at maximum range or as far out from the boat as possible. A channel marker buoy would be great.

Crank up the radar and monitor the display.

By hand, move the antenna around till you get maximum return from the target....that's your focus point...peak of the beam.

Now move the antenna up and down (no sideways movement) and pay attention to the pitch of the antenna where the return disappears....probably 15 degrees or thereabouts. There's your answer. Set your pitch (including the boat's) to half that and you should be good to go.

Mark

 

[protozo1]

Re: Mounting distance from radar to gps/light/ante.

Thanks, I went to a marina today and looked at about 20 different setups. About 15 of them had dome, gps, and radio ante. about 10" away from each other on the same post. The other 5 had them seperated as much as they could, on a hardtop that is (`3 feet). Many had no wedge but the post had an angle to it and some were mounted directly to the hardtop. Of these a couple had an angle integrated into the hardtop while the others were just sitting flat.

 

[protozo1]

Re: Mounting distance from radar to gps/light/ante.

anyone else?

 

[dingbat]

Re: Mounting distance from radar to gps/light/ante.

I’ve got everything mounted on my hardtop. My VHF and Am/Fm antennas are roughly 3 ft away from the dome. No problems at all.

Now the GPS antenna is a different story. The distance you mount the GPS from the radar isn’t as important. What is important is that the antenna is not in the path of the radar beam. The radar will fry a GPS antenna in a heart beat

I flush mounted the GPS roughly a 10” in front dome and have no problems with it. I’ve also seen dome brackets with an integrated GPS mount above the dome as well.

As for the wedge it depnds on your boats running angle. I made my own mounting bracket and made it adjustable so I could play with it a bit.

 

[Aficionado]

Re: Mounting distance from radar to gps/light/ante.

I agree; it is most important to keep other antenna's out of the beam of the radar. 1 to protect the antenna from the beam and 2 to prevent blind spots in your radar field of visibility. Many mount the GPS above or below the radar antenna without consequence. www.battlewagonmounts.com has links for each radar manufacturer's owners manuals. That should provide any guidelines that may be specific to you radar.

 

[Pez Vela]

Re: Mounting distance from radar to gps/light/ante.

As you are probably already aware, Seaview has some mounting solutions to consider, for antenna separation and dome tilting.

http://www.seaviewglobal.com/en/categories

I just completed my 18" dome install and used a Seaview mount with the light bar attachment to solve a mounting issue. Most radars have a 25? vertical beamwidth, and the tilting issue may not be an issue for you. I would say that any problem in that regard may be addressed after the initial installation.

 

[Pez Vela]

Re: Mounting distance from radar to gps/light/ante.

I agree; it is most important to keep other antenna's out of the beam of the radar. 1 to protect the antenna from the beam and 2 to prevent blind spots in your radar field of visibility. Many mount the GPS above or below the radar antenna without consequence. www.battlewagonmounts.com has links for each radar manufacturer's owners manuals. That should provide any guidelines that may be specific to you radar.

You just sucked me in to a two year old post ... my bad!