How does this work without blowin' somthin' up?

M

Mike...

New member
Fellow electronics buffs, please check this out

Now I am no expert in antennas. So someone please tell me how does this work without 1) negatively affecting the polar pattern of both radiators, and 2) without messing up the cell amp or the VHF radio.

And yet, it's Digital, and they know antennas. So, I must just need a little enlightenment.

But then why does Wilson insist that their marine cell antenna must be at least 5 ft away from a VHF antenna?
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mike
 
The marine signal is around 150 MHz and the cell signal is up in the GHz rage somewhere. They're so far apart it should be pretty easy to filter one from the other. The combination unit might have filtering built in, or maybe the fact that they're both at the center of their respective radiation pattern helps a lot.

Using the other - two separate units, even with filtering, might be just too much overload if they're not on center, hence the need to keep them some distance apart.

That's my guesstimate, remembering engineering school and Ham licensing from years ago. I'm a mechanical engineer, so I don't keep up on antenna stuff too much.

-Jeff
 
I am not too sure about how the 9 db gain would work out on a small boat either. The highest you would want on something like a C-Dory is 6 db.
Think of 3, 6, and 9 db like this. Imagine a radiation pattern around the axis of the vertical antenna like a really fat donut for the 3 db. As the boat rolls or pitches the fatter donut looking radiation and reception pattern can stay on the signal location. At 6 db the pattern is reduced in size to say a regular donut size and at 9db the pattern looks more like a dinner plate. A larger vessel (100 ft type larger) rolls and/or pitches less and the 9 db will work fine.
 
Have looked over my Motorola Verizon Droid X pretty carefully and I cannot see where an external antenna would hook up to it? Am I missing something. The link at the top of this thread has adapters listed for lots of Motorola models but without anything to plug it into???? This would be a good thing to have as this phone will act as a WiFi hotspot if it can get a Verizon 3G signal. Could provide WiFi to other boats at a CBGT that doesn't have WiFi access of its own...
 
Captains Cat":1zkd6wvw said:
Have looked over my Motorola Verizon Droid X pretty carefully and I cannot see where an external antenna would hook up to it? Am I missing something. The link at the top of this thread has adapters listed for lots of Motorola models but without anything to plug it into????
Click to expand...
Hello Charlie. Check out Wilson's Cradle Plus. The Wilson folks tell me the Droid will work with that, and the chance of feedback is slim, unless you are within a foot or so of the exterior antenna. You have to leave the phone in the cradle at all times, so you would use a bluetooth headset.

If that won't work for you, they also have an antenna that sticks right to the back of the phone.
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mike
 
Captains Cat":rcam940h said:
Thanks Mike, will do. I have a bluetooth headset already, just haven't used it.

Charlie
Click to expand...

I'll second the Wilson recommendation Charlie. Tried it on my Verizon MiFi hotspot and my regular phone and it worked like a charm. It also cuts down on phone battery drain because it only has to transmit 1/4" to the retransmitter in the cradle.

Really looking forward to using the cradle with the phone and my new whiz bang blue tooth hearing aids. Stereo phone calls on the water or most anywhere ....

Going back to the topic subject, I think antennas combine engineering and voodoo, and anybody who is an antenna designer is part geek, part psychic, part artist. The upper cell phone freq is around 1800 mhz, the lower is 800 Mhz and WiFi is around 2000 Mhz. It's the 800/1800 combo that really means Wilson has 4 antennas in one if they include WiFi. Amazing technology.

I'll stick to a 4' Digital VHF antenna and if WiFi is necessary I'll do the KISS route. Buy a Hawkins outdoor antenna, clamp it to a cheap 1 1/4 marine antenna extension screwed into a foldover ratchet mount. Works great on my RV.

Don

Don
 
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