Omni Antenna question

Walter · EVDO Junkie Joined: 14 Sep 2005 Posts: 307

RG6 is 75 Ohm. EVDO antennas are 50 Ohm.

Back to bcsman... Even getting closer to LOS could likely improve your signal significantly. I went from a small booster antenna in the window with an 18 inch cable at -75 dBm to an omni on the roof with 27 ft. of cable total and now have -67 dBm. I still don't have true LOS, though I'm close now, and I have a huge pine tree between me and the tower.

I tested my location by taking a laptop outside, mounting the omni on a 6ft wooden dowel, and having my son climb a ladder with it. Signal got better the higher he went, so I mounted the antenna as high as cheaply practical at the peak of my roof.

HTH
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Reach, Connect, Celebrate, Grow, Serve.

bcsman · Posted: Fri Jul 20, 2007 6:46 pm Post subject:

thebubbleboy · Posted: Sat Jul 21, 2007 2:07 pm Post subject: Sorry

Mooch, you can't use RG-6 or RG-58. They are 75 ohm. You must get the good stuff....I have the Wilson 9913. Bubble

bcsman · Posted: Sat Jul 21, 2007 9:53 pm Post subject:

Took a climb on my 2 story farmhouse roof today to check things out. Looks like even up there I still won't have LOS as I've got a couple pretty tall trees south of my house! Did some measuring and looks like I would need less than 40' of cable to run down from my peak to my computer. Is that approaching the distance I should look into low loss cable?? And does the 3Gstore sell that?? Can't find it anywhere on their website.

Joe C · EVDO User Joined: 05 Dec 2006 Posts: 76

bcsman,

Just an idea but, couldn't you buy the OMNI antenna with the stock length cable and instead of trying to run 40 additional feet, put a Linksys or KR1 router at the end of it and send the signal wirelessly to your desktop?

If need be you could probably build a small enclosure for the router and keep it on the roof.

mooch · Posted: Sun Jul 22, 2007 6:59 am Post subject:

The router on the roof plan might not work due to high summer temps, same goes for putting the router in a hot attic. The max operating temps are about 135 degrees and the summer heat added on to any heat created by the unit would put it over that at some point.

I'm a bit torn between a router and cabling at this point. Either way I do it is going to cause some loss in speed but not certain how much loss would be involved with each. With a router, I'd need about 20 feet of cable and without a router I could change my antenna location and would need about 40 feet.

bcsman · Posted: Sun Jul 22, 2007 7:12 am Post subject:

n6gn · Posted: Sun Jul 22, 2007 10:39 am Post subject:

Walter · EVDO Junkie Joined: 14 Sep 2005 Posts: 307

I have to agree with n6gn here (not surprising since he's more knowledgeable about RF stuff than I am). The gain from getting the antenna in a better position is likely going to dwarf the cable loss. 40 ft. really isn't that long of a run all in all. Plus, if money is not an issue, you can always add an amp up by the antenna later to compensate for the cable run loss.
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Reach, Connect, Celebrate, Grow, Serve.

Alex · Posted: Sun Jul 22, 2007 4:17 pm Post subject:

bcsman · Posted: Tue Jul 24, 2007 10:06 am Post subject:

Alex · Posted: Tue Jul 24, 2007 12:50 pm Post subject:

interesting. so you speculate you will need external omni and our doing research even before you know for sure you need it?

before you spend the money on custom cabling, i'd make sure omni was even needed. (maybe thats just cuz i'm cheap?)

did you get 3gstore to look at your address for coverage? if not, and you'd like us to, send the full address and zip to sales@ 3gstore.com

oh. the 12ft of cable on our omni is permanently attached, but can be cut/shortened to as little as a foot. all our antennas except marine use FME connectors.

i don't remember what custom LMR400 is per foot, but i'll find out.

[warning: blatant plug follows]
don't forget that if you get your Sprint card/service from 3gstore, you'll get $10 off an omni or half off our 'booster' anntena (and expert support too!)

bcsman · Posted: Wed Jul 25, 2007 8:19 am Post subject:

Alex,
I'm sorry but I guess I thought you knew I had already contacted you at your sales address. But that was using my e-mail address not this bcsman name! I apologize!! My e-mail is brians@basicisp.net and my city is Capac, MI. I won't give you the street address here, but I'm sure with that you can figure out who I am.

Yes I am going to order, just trying to get my best gameplan on before I do. I like to be as educated as possible before jumping into something I know little about. And I am getting my education here thanks to all posters.

Also have a friend who is going to loan me his laptop and Verizon PCMCIA card to try. I know you recommended Sprint to me because of the mapping, but I figured I would see if Verizon would show anything here. Besides with the laptop I can try inside my house as well as around my yard. And according to the cell tower website the Verizon tower is only 1.9 miles from my house as opposed to Sprint being 3+ miles. Just figured an experiment would be worthwhile. He also has a small antenna to plug in to try and pull a little more signal. I'll report back with any results.

Again sorry about the mixup but I will be ordering soon!!

Alex · Posted: Wed Jul 25, 2007 8:41 am Post subject:

no need to apologize, i just wanted to make sure you knew we could map coverage and offer our opinion, if we hadn't already done so. Cool

McFly · EVDO Newbie Joined: 20 Jul 2007 Posts: 4 Location: WA