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res0kkw
EVDO User
Joined: 16 Apr 2008
Posts: 69
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 Posted: Wed Apr 23, 2008 7:55 pm Post subject: Another antenna question. |
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Im gonna go ahead and order a antenna.
And need to know what would be the best for in the house? |
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tz1
EVDO Junkie
Joined: 29 Sep 2005
Posts: 434
Location: http://kr1gps.dyndns.org:8888/
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| Posted: Thu Apr 24, 2008 5:45 am Post subject: |
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Generally you can't do much better than a trucker style antenna (which is larger) and tends to have a long cable.
This assumes you don't already have a good signal.
If you are getting full speed, you don't need one.
If you are about 3/4 speed, a smaller booster should be enough to get you full speed if it is placed right.
If you are at 1/2 or less, the trucker or larger should be better (do use a lightening arrestor if it is outside).
If you are using the router as a car - mobile, a magnetic roof antenna might be best. |
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res0kkw
EVDO User
Joined: 16 Apr 2008
Posts: 69
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SlyFerret
EVDO User
Joined: 19 Mar 2007
Posts: 87
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| Posted: Thu Apr 24, 2008 9:19 am Post subject: |
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I've got the Wilson Trucker Antenna (the vertical omni that you linked to) and it works great for me.
I mounted the antenna on a 1.25" diameter dowel rod. I put the dowel rod in a patio umbrella stand in the corner behind my desk, and cut it to length so that the tip of the antenna is about half an inch from the ceiling.
-SF |
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res0kkw
EVDO User
Joined: 16 Apr 2008
Posts: 69
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xrayman
EVDO Junkie
Joined: 23 Feb 2007
Posts: 293
Location: Kansas City
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| Posted: Thu Apr 24, 2008 1:43 pm Post subject: |
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res0kkw,
After you receive the antenna please let us know what dB gain you get? |
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res0kkw
EVDO User
Joined: 16 Apr 2008
Posts: 69
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| Posted: Thu Apr 24, 2008 1:57 pm Post subject: |
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| xrayman wrote: | res0kkw,
After you receive the antenna please let us know what dB gain you get? |
No problem will do.Should have it monday hopefully.
By the way soemone needs to explain what the db is because ims till new to this.
Only thing i know so far is bar signals and speed tests tell me. |
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res0kkw
EVDO User
Joined: 16 Apr 2008
Posts: 69
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| Posted: Sat Apr 26, 2008 1:58 pm Post subject: |
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Hey just given you all the review.
It didnt do much in the house but as soon as i stretched that baby out my window.
Bars went from a 1 to a 3 and download speeds went from 100 to over 300.
Defently give it a thumbs up.And its a good price. |
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Jim_in_VA
EVDO Junkie
Joined: 09 Apr 2007
Posts: 479
Location: On the Chesapeake Bay, Virginia
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| Posted: Sat Apr 26, 2008 4:17 pm Post subject: |
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dBm scale:
Simply put, the closer you are to the tower, the lower the dBm.
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res0kkw
EVDO User
Joined: 16 Apr 2008
Posts: 69
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| Posted: Sat Apr 26, 2008 5:43 pm Post subject: |
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| where would the dbm be? |
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n6gn
EVDO Junkie
Joined: 22 Aug 2006
Posts: 384
Location: Northern California
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| Posted: Sat Apr 26, 2008 5:44 pm Post subject: |
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| Jim_in_VA wrote: |
Simply put, the closer you are to the tower, the lower the dBm. |
I didn't put it on that chart but (in case you're a glutton for detail  )
dBm is "dB, relative to a (m)illiwatt" - an absolute power level
dB is "deci-Bel" - a relative term and equal to 10*log(Power2/Power1)
some "interesting" dB values are:
20 dB Power2 = 100 times Power1
10 dB Power2 = 10 times Power1
6 dB Power2 = 4 times Power1
3 dB Power2 = twice Power1
Thus an antenna with 6 dB more gain than another antenna would produce 4 times as much signal power.
Also, because signal strength follows an "inverse-square law" in free space, doubling your distance to the
cell site will cause received power to drop by four times or by 6 dB. Over typical radio paths it will probably
drop a good deal more than this, perhaps by 12 dB or more depending upon terrain, foliage etc.
So if your signal level was, say, -90 dBm at a first location and you then experienced a 6 dB drop, to -96 dBm,
because of changing your location, replacing your antenna with one having 6 dB more gain could restore
signal level to -90 dBm.
n6gn |
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Jim_in_VA
EVDO Junkie
Joined: 09 Apr 2007
Posts: 479
Location: On the Chesapeake Bay, Virginia
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| Posted: Sun Apr 27, 2008 5:25 am Post subject: |
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Sorry Glenn, I couldn't remember where that chart came from. It must have been from one of your papers. Well done.
So in your example above I assume you could only maintain that signal strength with the antenna, provided the location change did not also incur a change in path interference as well.
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n6gn
EVDO Junkie
Joined: 22 Aug 2006
Posts: 384
Location: Northern California
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| Posted: Sun Apr 27, 2008 10:18 am Post subject: |
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| Jim_in_VA wrote: | | Sorry Glenn, I couldn't remember where that chart came from. It must have been from one of your papers. Well done. |
No problem at all, it was just part of more idle banter here on this forum.
Thanks for taking the time and effort to put EVDO details together in one place. That seems
to be one of the problems - new folks ask perfectly reasonable questions that have already been answered but don't know where to go to find the answers.
| Jim_in_VA wrote: | | So in your example above I assume you could only maintain that signal strength with the antenna, provided the location change did not also incur a change in path interference as well. |
Yes. That assumes the incremental path is all free space (not likely for most paths, but possible).
n6gn |
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res0kkw
EVDO User
Joined: 16 Apr 2008
Posts: 69
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| Posted: Sun Apr 27, 2008 8:36 pm Post subject: |
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Just wanted to add about the antenna.
B4 i got it the router would keep losing connection because of teh weak connection.
Since ive had the antenna it hasnt lost it one time.Speeds defently have doubled.
Worth the $$$ |
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