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02-24-2004
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#1 (permalink) |
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Registered Member
Join Date: Feb 2004
Posts: 17
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How Many dBi?
After doing a bunch of reading on this forum, I'm thinking about picking up an Orinoco card and an omnidirectional antenna to play with. Looking on netstumbler.com, fab-corp, ebay, etc, I see antennas from 5dBi on up. I would've thought the more gain the better, but I read about higher dBi giving a "flatter" range. Can someone give me a reccomendation for how many dBi I need? This won't be for anything serious, just toying around with WiFi and wardriving.
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02-24-2004
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#3 (permalink) |
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Alien Paranoid Stumbler
Join Date: May 2003
Location: WI
Posts: 2,688
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5.5 db seems to optimal. The problems with running higher gain amps are that they will be affected by altitude, and also, your maps will not be accurate.
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"Yeah," said a voice from under the table, "you go to pieces so fast people get hit by the shrapnel." |
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02-24-2004
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#5 (permalink) |
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Alien Paranoid Stumbler
Join Date: May 2003
Location: WI
Posts: 2,688
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Just make sure you find one with a built in ground plane. You will see a metal disk that makes the thing look like a UFO if you found a good one. You probably won't see much difference in APs discovered using a higher gain antenna.
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"Yeah," said a voice from under the table, "you go to pieces so fast people get hit by the shrapnel." |
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02-24-2004
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#6 (permalink) |
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Registered Member
Join Date: Jan 2004
Location: remote scottish highlands (after leaving therpalm trees of torquay in the english rivierra Brrr chilly man!
Posts: 149
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I believe the difference between a lot of the omnis is the quality of the coax, short runs of high quality coax are the best, the fab corp antenna is highly praised on this forum and is usually about twice the price of an ebay omni and will I think give you an extra 1 or 2 db gain over the cheaper ones. If you have limited funds though do not despair, the ebay antenna will still improve your station count due to the nature of it having a better line of site to APs than an antenna inside a pcmcia card bulge shielded by the metal of the car you are sitting in. As you can see TthreePts is very pleased with his and I too use an ebay special which does give me a better signal than the internal.
cheers..paul
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'We havent had that spirit here since 1969' |
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02-24-2004
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#8 (permalink) |
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Registered Member
Join Date: Jan 2004
Location: remote scottish highlands (after leaving therpalm trees of torquay in the english rivierra Brrr chilly man!
Posts: 149
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No worries, Im a relative newbie too, I bought the ebay antenna as It was all I could afford to spend but will give me a better chance of pickin up an AP that I might otherwise miss if I am sat inside the car with the antenna inside the PCMCIA card. The very least effective of the antennas will probably not give much more gain than the pc card antenna but being located in a prime spot on top of your car roof will be able to see more RF. The better antenna after deducting the inevitable loss will probably still give you a gain of 3db making it nearly twice as effective if i remeber what I read in the forums.
Do a search and check out some of the threads as there have been some great discussions on this subject covering radiation patterns, the relationship of decibels and gain, ground planes etc. I usually save my favourie threads to my HD/sony pda so I can read em anytime trouble is I have a list as long as my arm now hehe. I also just bought jeff Duntemanns "Drive by wi-fi" off amazon, which is a wi-fi bible and covers wardriving with netstumbler as well as everything else about wi-fi you need to know. between it and these forums search engine you cant go wrong. all the best...paul
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'We havent had that spirit here since 1969' |
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02-24-2004
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#9 (permalink) |
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Registered Member
Join Date: Feb 2004
Posts: 17
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Thx, I will look at picking up a copy of that book. I definitely need to get a better card for my laptop, and I know the ORINiCO Classic Gold comes highly reccommended. Is the CLassic Silver good too? I'm not sure of the difference.
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02-24-2004
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#10 (permalink) |
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Alien Paranoid Stumbler
Join Date: May 2003
Location: WI
Posts: 2,688
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The silver will work just fine with NS. The only difference is that the silver can't connect to a network using 128 bit WEP, however it works just fine using 40 bit WEP.
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"Yeah," said a voice from under the table, "you go to pieces so fast people get hit by the shrapnel." Last edited by King_Ice_Flash : 02-24-2004 at 03:41 PM. |
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02-24-2004
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#11 (permalink) |
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Registered Member
Join Date: Feb 2004
Posts: 17
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Ok I think I'll get the Silver instead, as I don't use 128 bit on my home network. Now, I am looking at fab-corp antennas and I know this one has what I need:
"5 dBi Magnetic Mount Omni Antenna" for $59.99 But, whats the big difference between that one and this? "5.5dBi Magnetic Mount" for $15 They seem very similar. |
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02-24-2004
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#12 (permalink) |
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Registered Member
Join Date: Feb 2004
Posts: 17
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And while I'm already annoying you with questions....I'll throw in one more. Whats the big difference between those and the "5 dBi Desktop Omni Antenna"? All these antennas have ~ the same dBi, and they are all omnis, and they all include pigtail. There must be something I'm missing. What I'm really asking is, which of these antennas will be best for wardriving?
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02-24-2004
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#13 (permalink) | |
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Umm Smells like kim chee
Join Date: Jun 2002
Location: South Korea
Posts: 139
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Quote:
Orinoco Silver Mag-Mount from FAb-Corp. (still going strong). Had bought 2 Lucent/Avaya/Orinoco desktop antenna's both are now trash. And with the Mag-mount I picked a lot more AP's driving the same area with the desktops. Both outside the vehicle. Maui
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Minister of the Church of WiFi Far Eastern Chapter NEMA |
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02-25-2004
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#15 (permalink) | |
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Tropical Stumbler
Join Date: Apr 2002
Posts: 575
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Quote:
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Linear Mode
