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cellphones
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#3
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cellphones
On 27 Oct 2003 15:39:00 -0800, (Parallax) wrote
(with possible editing): My posts havent been gittin through fer some reason so I'm gonna repost this one. For ppl who really want to stay connected while afloat ( I dunno why but they do). Useless Idea #3734 Put a T in the output of your VHF so your cellphone can be connected to your VHF antenna waaaaaaaaay up thar on your mast. Since your 900 Mhz cellphone is even more line-of-sight than vhf, this will give you more more coverage when you are a few miles out. In this case, I expect coverage will then be limited by cellphone power instead of by not being able to see a tower. I would expect to be able to get coverage from 15 miles out. I once experimented, while standing on my cabin top, I was able to use my cell phone while being 6 miles offshore. Would a cell phone booster be illegal? NO! Don't do it! 1. VHF radio WILL destroy cell phone receiver. 2. Cell phone transmitter WILL NOT match the VHF antenna resulting in mostly reflected power. That could damage the cellular phone. 3. If you COULD use the same antenna (which you can't), the only safe way would be to switch it to the transceiver in use while applying a dummy load to the unused transceiver. 4. Some cellular phones are analog which uses the 800 mhz band, and others are digital which uses the 1900 mhz band. Still others work on both bands. Also, don't use marine radar antenna. Radar operates at different frequency than cell phones. They are not harmonically related. You CAN legally use a booster amplifier (they are manufactured typically for installation in a car. That can boost the 0.10 - 0.15 or so watts from the typical cell phone to 3 watts. Mount the antenna as high up as you can, but do not extend the feedline from what is supplied with the kit. The reason is twofold: 1) the amp is based on effective radiated power which includes the loss on a feedline, and 2) unless you get very good cable, you will lose more in feedline loss than you gain from height, particularly on the 1900 mhz band. You could use a directional antenna, but, so far as I know, they are not legal for that type use. That's worth a check, though, as I believe they are considered legal for use in security systems and it's been a while since I looked at those regulations. http://www.fcc.gov -- Larry W1HJF Email to rapp at lmr dot com |
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cellphones
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#5
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cellphones
Come on, Bruce, lighten up. Of course it's a really dumb idea -- many
of Parallax's ideas are dumb and he says so. Occasionally, though, he gets me thinking along unconventional lines, so I go along with the gag on some of his dumbest ones.... Jim Woodward www.mvFintry.com Bruce in Alaska wrote in message ... In article , (Parallax) wrote: For ppl who really want to stay connected while afloat ( I dunno why but they do). Useless Idea #3734 snipped for being "to Stupid to Republish" I never said I had good ideas. However, I realize that somehow you better disconnect the connection when the VHF or radar is used. I also forgot about impedance matching (my god, alzheimers, I taught an engineering lab on impedance matching once). I really don't know how a radar antenna works on small boats. If it is just a rotating dish, it oughta work with the right transducer. OK, an even worse idea.......Use your radar (I dont have one) as a high gain antenna to point toward a cell tower. It ought to work for 900 Mhz. Some electronics could figger out the direction to the best tower. would be nice if folks who don't have a clue would just say they 'Don't have a clue" From Jim Woodward 3) The radar antenna idea actually has some technical merit, and this "technical merit" would be????? Cellphone 800Mhz xBand radar 10Ghz Bzzzt, Try again....... Well not that the "Moorons" have finished lets hope Sanity wins out..... Bruce in alaska |
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#6
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cellphones
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1 On 27 Oct 2003 15:39:00 -0800, Parallax wrote: My posts havent been gittin through fer some reason so I'm gonna repost this one. For ppl who really want to stay connected while afloat ( I dunno why but they do). Useless Idea #3734 Put a T in the output of your VHF so your cellphone can be connected to your VHF antenna waaaaaaaaay up thar on your mast. Since your 900 Mhz cellphone is even more line-of-sight than vhf, this will give you more more coverage when you are a few miles out. In this case, I expect coverage will then be limited by cellphone power instead of by not being able to see a tower. I would expect to be able to get coverage from 15 miles out. I once experimented, while standing on my cabin top, I was able to use my cell phone while being 6 miles offshore. Would a cell phone booster be illegal? Wrong kind of antenna, most Cell phones are 800-900MHz, PCS is around 1.2GHz IIRC, and some are 1.8GHz. The VHF antenna, is expecting to see about 150MHz. Bast case scenario, it simply doesn't work. If you were so unfortunate as to key up the VHF while it was connected, that acrid smell you'd experience, would be the death throes of the the cell phone. THat's without getting into the whole issue of impedence mismatch. In short, don't even go there. Get a booster, buy a type approved one, and you'll be fine. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (GNU/Linux) iD8DBQE/n1DVd90bcYOAWPYRAn0iAJwPNTQnx9XhdNIMNlp9SxalrnzQPw Cg5kam yLS6xkLP/nF3mQkEm83+kz0= =cnWj -----END PGP SIGNATURE----- -- Jim Richardson http://www.eskimo.com/~warlock If ignorance is bliss, why aren't more people happy? |
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