cell phone signal amplifier

[kjango]

Where I'm docked I have no cell phone signal in the boat cabin , but if I go up on deck I can somewhat get a signal . This is problematic for me as I use a cell phone device on my computer to go online . I was looking through a West Marine catalog & saw a device called a cell phone signal amplifier . It has an external antenna they advise you mount as high as you can & a second antenna that mounts in the cabin . Electronics are pretty much " white man's magic " to me , but could this device possibly be the solution to my problem ???

[KindOfBlue]

Call your cell provider. They can recommend an antenna that will work best with your specific cellular modem card.

[noreault]

The device wasn't listed in their online catalog so I couldn't check the particulars of this device.

But, yes in principle this type of system should work given the right conditions. Essentially what it is a repeater. It receives the signal inside the boat and rebroadcasts it on the outside antenna. It will work in the condition you describe. Inside a boat or house that has no signal and outside the structure the signal is serviceable. Either because the interference of the structure is removed or the external antenna is higher.

The condition you describe where the phone works on the deck is a very strong indication of success. You may also want to check with your carrier since they may provide a solution.

As with all cell phones, until you test the specific device at a specific location, results may vary.

[N0NJY]

Let me cut through the magic for you.

There is no such thing as a "cell phone amplifier".

There is, however a device (and I haven't looked at this one specifically so I can't be sure) that is a passive device.

Basically what they do is simple. You put up an antenna high enough up in the air and that antenna at the bottom, collects your signal and is actually tuned to the band the cell phones are in (800-900 MHZ very wide bandwidth by the way!) and essentially "rebroadcasts" your signal at the top of the antenna.

With LUCK that small amount of signal at the top will make it to the nearest cell tower.

With LUCK the signal coming back will trigger your phone circuits to see good cellular reception.

That's the theory behind it.

I don't know how that particular one works.

These devices really don't amplify anything though - they are passive devices, and sometimes they work, sometimes they don't.

HONESTLY - if you stand near any sort of wire going up in the air (shroud, backstay for example) you ought to see some increase in received signal strength. This is because the RF way up above you is hitting that wire and can be conducted down.

I won't say you're better off doing that, but you should be able to see if such a thing would work simply by standing near a backstay on your boat and holding your cell phone near it.


Ok - I just looked at this device. It is a type of a repeater. (Go back up and read what I said before about passive devices, that is still correct. When you go up on deck you're getting the signal because the stays and shrouds will tend to act as little antennas redirecting some of the signal from up higher.)

This thing.... appears to be a real amplifier system and uses an antenna at both ends. One at the top transmits and receives the signal from the tower.

The one in the cabin picks up your cell phone signal and then rebroadcasts the tower's transmitted signal to your phone.

And the price is almost 500 bucks. For that it better do something!

[N0NJY]

One other thing.

Don't pay any attention to things that say "Receives up to 20 miles" or some other such crap.

A signal can be received much further than that - under certain conditions, BUT, it's not how distant the signal is, but how much MAKES it to your antenna.

(I say this because people ask, "How far away can you hear on that shortwave" and this doesn't make logical sense. If you can hear a signal, that means it arrived at your antenna - and distance isn't the issue, the SENSITIVITY of the front end of the receiver is the issue!)

[CaptKermie]

I remembered this site and product promotion after reading the above posts and thought I should pass it along. I am not promoting the product or site just passing intel.
ActiveCaptain - Going Mobile - Cell Ranger

[Deadeye]

I've installed some of the DA4000 listed in the ad on this page (well...the heatsink was white not black, otherwise the same unit!)

To be honest, I wasn't that impressed with them, especially for the money. I've heard that they work ok out in the straight but we're in an area where the geography makes reception tricky in general.

Bear in mind that you do need a minimum separation distance between the antennae (shouldn't be hard with a mast though). At any rate, the LED changes color if they're too close together.

IIRC, the radar's beam will interfere as well so the external ant needs to be above it. I'd have to check again to be sure though.

Oh, and the number of 'bars' on your phone doesn't increase when it's on - it either works or it doesn't.

[xort]

jeff seigel of active captain has been doing a lot of cell phone testing for a number of years. I recommend reading the link posted by Kermie

[kjango]

Thanks everyone for your input . That cell ranger from active captain looks interesting & for a fraction of the cost . I especially like the idea of being able to return it if itdoesn't work . The circumstances they tested it under are very similiar to mine . Thanks again for the advise .

[xort]

let us know if you return it!