Cell phone booster on the boat..?

[CSY Man]

Got another Gizzmo in the mail today:

A Cell phone booster with an antenna and adapters, cable and all that.

Going to install it tomorrow, but the company that made 'em swore up and down ya can't use a VHF antenna on the system..Looks like I have to buy a 9 something gain marine antenna made especially for cell phone boosters.
($140.00)

Does anybody else on this here board have any experience installing and using these boosters?

I am hoping to save on SSB phone patches and roaming close to Nasseu in the Bahamas: Cost me severeal hundred $$ last year @ 3.00 per minutte.

With this system and a local SIM card, I could talk to the US for $0.51 per minutte.

The savings should pay for the system in a few months of talking.

The booster was $200.00 plus a little extra for an adapter for my phone.

Guess I should be doubling my range without putting the remote antenna on top of the mast.
If I did that, the tech-rep promised me a 50 NM range.

On the rail, 15 to 20 NM.

Any personal experience with this set-up...?

[Harriet]

For a lot less $$, go to Batelco in Nassau when you get there and buy a Bahamian cell phone for about $120. It will come complete with a starter pack of minutes, and you buy phone cards as you need them. I believe the cost to phone the U.S. is around $0.56/min. If you get a GSM phone, you will be able to change the chips for whatever area you choose.

[Doghouse]

the problem with using the same antenna is that it is not harmonically resonate. The frequency's used for vhf are 156-162 MHz (including ais). Cell phones use 850 MHz (824.2 - 848.8 MHz Tx; 869.2 - 893.8 MHz Rx)900 MHz (880-2 - 914.8 MHz Tx; 925.2 - 959.8 MHz Rx) 1800 MHz (1710.2 - 1784.8 MHz Tx; 1805.2 - 1879.8 MHz Rx) and 1900 MHz (1850.2 - 1909.8 MHz Tx; 1930.2 - 1989.8 MHz Rx).

The antenna, if made correctly, will be a dual if not quad band antenna, resonate at the required frequency lengths. This is why it is important to get the proper antenna.

That being said as you increase your DB rating of an antenna you flatten out the RF dough nut that it projects. So as you raise it up your mast you may lose range with a higher gain antenna. Why? as the boat heals over you will be pushing the RF into the ocean rather than out twords the horizon. One of the magazines had a great picture last month of the differences in the RF dough nut that was created by different gain antenna's. Wish I could remember which one.

[CSY Man]

For a lot less $$, go to Batelco in Nassau when you get there and buy a Bahamian cell phone for about $120. It will come complete with a starter pack of minutes, and you buy phone cards as you need them. I believe the cost to phone the U.S. is around $0.56/min. If you get a GSM phone, you will be able to change the chips for whatever area you choose.

Well, not sure I need a Bahamian cell phone, my US phone will work just fine over there and I plan to get a local SIM card to put in it. The cost for calling the US will then be $0.51 per minutte, off-peak.

The booster is for better reception so I won't have to be close to Nassau...Hoping for a 20 NM range with the booster and I could be sitting for anchor in the Nortern Exumas using the phone.

the problem with using the same antenna is that it is not harmonically resonate. The frequency's used for vhf are 156-162 MHz (including ais). Cell phones use 850 MHz (824.2 - 848.8 MHz Tx; 869.2 - 893.8 MHz Rx)900 MHz (880-2 - 914.8 MHz Tx; 925.2 - 959.8 MHz Rx) 1800 MHz (1710.2 - 1784.8 MHz Tx; 1805.2 - 1879.8 MHz Rx) and 1900 MHz (1850.2 - 1909.8 MHz Tx; 1930.2 - 1989.8 MHz Rx).

Yeah, that is what the tech people at the cell phone place said as well: Need a special cell phone antenna and will look for one today, but they are pricey compared to a VHF antenna, $130.00 for the cell ant, and $50.00 for a basic VHF antenna.

Don't think I will bring it up the mast, but rather find a place on the antenna farm in the back of the boat where I already have antennas for VHF, NAVTEX, AIS and GPS.

The poor ship is already looking like a Russian spy trawler from the Cold war....

[hellosailor]

CSY-
It's all physics, you know that.<G>

A VHF antenna is resonant at around 150MHz. Cell phones use four bands, roughly 800-900-1800-1900 MHz. Which band they use depends on your provider and what country you are in, and what your phone supports, so you need to tell us that.

If the radio (cell phone) and antenna aren't resonant three bad things happen. You can burn out the radio from excess power being reflected back in during transmissions (fast) and you don't put any signal out into the air, so no one hears you either. Last, you don't get good reception.

I wouldn't say you need a $140 special marine cellular antenna...it ain't rocket science. But if you want a high-gain antenna in a sturdy marine fiberglass pole, yeah, that's gonna carry a marine price tag. There should be other alternatives.

A good "booster" is a bi-drectional amplifier. It amplifies signals coming it, and passes them down the cable to your cell phone so you can receive calls. And, it boosts the 600mW maximum power of your cell phone up to about 3W (3000mW) so the towers can hear you. The old analog bag phones had that high power rating--handhelds don't.

The booster will roughly double or triple your power into the tower when used with a 'zero gain" antenna, and the antenna will double your signal for every 3db of gain it has. So, the booster itself is similar to a 6db-9db gain antenna, and when used with another 6-9db gain antenna, that's a lot of extra power.

Just running an antenna up the mast wouldn't be the same--you also have power loss in the cable, and with cellular frequencies, top quality cable is a MUST.

A 50nm range is terribly unlikely, because the cellular system software is set up to prevent it. You remember the old Apollo broadcasts from the moon, and the signal lag between each side of the conversation? Well, all radios have signal lag. The cell system uses that lag time to determine how far away from the towers you are, and the tower with the shortest signal lag gets "voted" to carry your call. And...when the lag gets too large, the system simply will not accept your call. I'm told that in the US the software generally rejects call calls from 32 miles (statute miles) maximum range, no matter how much power you use. That's to prevent the towers from going nuts trying to figure out how many of their best friends might have to route your call.

Which also means that if you do a line-of-sight distance range, figuring any cellular tower is at least 50' above sea level, you can figure out just how high up to mount your own antenna for the 32 mile maximum line-of-sight to the towers. A 50' tower gets 8nm, a 100' tower 11nm (roughly) so in theory, you'll get some real benefit from putting the antenna at the mast truck and adding another 8nm (?) to your side of the range, probably combining for a maximum 20nm range unless those towers are on seaside mountaintops.<G>

[CSY Man]

I wouldn't say you need a $140 special marine cellular antenna...it ain't rocket science. But if you want a high-gain antenna in a sturdy marine fiberglass pole, yeah, that's gonna carry a marine price tag. There should be other alternatives.

Roger on that Mr. Hello.

I did luck out today: West Marine had 2 Marine Cellular antennas left . One was the Shakespare 5411-TX with a price of $149.95...I got it for $37.50...Not because of my premium personality or classic good looks, but rather because some chap had ordered it but never picked it up.

That kind of thing does not happen all to often, but I deserve it

I will mount it on the rail in the back and the top will probably be 9 to 10' above the water.

Now I am trying to figure out how to connect the coax from the antenna to the booster. The connectors of course does not match as the booster has a male mini-uhf and the coax cable a 259 or some such big fat connector with a big fat cable (Guessing it is an 8X or something, which is good, less signal loss)

At any rate, been to Radio shack and a couple of marine stores, they don't havy anything that will make the connection, so I will have to jury rig something.

As I said earlier, I plan to use this booster gizzmo in the islands where the cell towers are far apart so I probably won't interfee with nuthing.

[hellosailor]

CSY-
WEST?! Knocked a hundred bucks off the antenna because someone didn't pick it up?! This is obviously a drug problem, they're bogarting the joints.<G>

Connectors never match, that's a corollary of the basic laws of physics. What you call a mini-UHF is probably a "Type N" and the PL-259 aka "UHF" would be the standard kind used on CB's and shortwave radios, roughly as thick as your thumb?

If you could post pix I could tell you the right names for them and maybe give you a hint on where to find adapters. FWIW, if there's really a PL-259 conector there--it doesn't belong anywhere in cell phone antenna lines. They are horribly lossy over 300MHz and "never" intentionally used over 1GHz. Never. (Never say never, yeah, I know.)

If you can't post pix, you'll have to look online at some web sites and try to match them, for the type and polarity (sex). Adapters ballpark at $5-10 each, roughly, if anyone stocks what you need. Rat Shack...uhuh, not unless you absolutely MUST HAVE IT NOW.

You could try calling antennaworld in Miami, 1-305-471-7973. If Raul Pla is still there, he used to be the top tech and they service marine and other special users. Easy enough to call ahead, walk it in, and I'd bet they have the right stuff on hand.

Might also have LMR400 or other premium rated cable to hook you up, too.

[CSY Man]

Uh, roger on that Mr. Hello.

Well, I may have to follow yer advice and get the good stuff...(I thought they were all the same them connectors.. )

No time to shoot pics and publish..Ended drinking beer with good buds after the sun went down and have to leave for Hong Kong tomorrow so the project is on ice untill I get back. Will do the Miami thing and the picture thing then.

In the meantime I better pack some backs and better spend some time with wife...Time is running out and the clock is ticking fast.

[gegroves]

CSY Man:

What Cell booster did you get? What type of phone - GSM? I've been looking for one for a GSM so I can hook it up to my computer in areas where I have no wifi. I have a Blackberry 8700 with EDGE so it can be used as a modem, but I would like to boost the reception and range. Thx.

[CSY Man]

What Cell booster did you get? What type of phone - GSM?

The booster is a DA4000, ($199.99)

The phone is a Razr V3 with 4 bands, including GSM.
(Had the phone for almost 2 years)

Bought the booster from
CellAntenna Corporation: Building Repeaters, Cellular Antennas, accessories, cellphone products.

[hellosailor]

CSY-
Have a safe and profitable trip.
From the web page you mention, that box uses "mini-UHF" connectors, not PL-259, so there should be no problem getting cables and adapters for it. Just don't scare anyone by calling them 259's.<G>

From the ratings on the box, it is about a 5-6db gain (600mW pushed up to 2W). Actually less boost than the 9db gain antenna alone, but when you add them up...all the better to have both if you're really pushing for range.

[CSY Man]

From the web page you mention, that box uses "mini-UHF" connectors, not PL-259, so there should be no problem getting cables and adapters for it. Just don't scare anyone by calling them 259's.<G>

Yeah Slick, the black box uses mini-UHF, but the antenna cable comes with bigger 'nectors, like the 259s or whatever them full-size coax connectors are called.

Somehow I have to marry this little male with the big shemale..No adapters available in the stores I visited today.
Did something weird to make it work, but not quite finished with the project yet....Ain't that always the case?

[hellosailor]

CSY-
You must be on a later flight out, I thought you were sobering up enough to fly this morning.<G>

If your antenna cable has a PL259 on it...there might be adapters but there are reasons not to use them. They'll create impedance bumps, think of that as the electronic version of kinks in a hose. Not fatal but not optimal either. What does the antenna cable itself say, for the cable type and rating? It might (might, not assuming yet) be better to clip off the wrong connectors and fit on the right ones directly, or to replace the cable with the proper (best) cable type at the same time. Fifty feet of the wrong cable type can UNdo all the good your amplifier is trying to do.

West, or the packaging, is SURE they sold you a cellular antenna, not a VHF one, right?

[Kent&Carol]

I put a cell booster antenna on my boat for the MarbleHead to Halifax race last year. I primarily intended to use it with a cellular modem to get weather and grib charts. It did work well and probably added 10 - 20 miles to my range. I didn't get it mounted on the top of the mast so I didn't get the 40 to 60 miles range some people talk about. I bought everything online from WPS Antenna http://www.wpsantennas.com/ and they were great. Even when I screwed up they helped me get it right. It is not cheap however. By the time I got the antenna, 50’ of cable, a splitter, and pigtails for our 2 phones and the Sierra card it was close to $400! Kent www.saildestiny.com

[hellosailor]

Kent-
40 to 60 miles might not be possible in the US at all. I was told by a cellco engineer that their software is designed to drop all calls with a large latency (signal delay) factor, nominally set for 32 miles. Of course since that's software it is subject to change at any time by any vendor on any tower, but he was under the impression that was "absolute" for them all.