Help with directional wifi antenna

[d4mo]

I need to extend my wireless so I can use a outdoor wifi security camera. The distance from the router to the camera will be 150 to 200 feet with direct line of site.

Couple of questions:

1. Would this be a decent antenna:
http://www.amazon.com/Pole-Mount-Yag...5854425&sr=8-8

2. If I were to use something like a WRT54GL with one of these, would I need to directional antennae? 1 for the send antenna and 1 for the receive? Or can you use some type of Y connector and have them both use the same antenna?

3. Any other tips?

 

[bobdole369]

If the antennae are truly in the clear - that is no foliage or water in the fresnel zone - than you will be able to make the connection with very little power indeed, and no antenna other than the one it came with. That antenna is a LOT for a 200 ft distance. Multiply your distance by 10 and then it becomes feasible. You can probably make do with a patch antenna or pringles can style.

How far above ground are either side?

 

[theevilsharpie]

1. That should work. That being said, if I need to bridge two wireless endpoints cheaply, I'd use a patch antenna.

2. The dual antennas on the WRT54GL are diversity antennas. Only one is active at any given time. If you're going to use an external antenna, you'll want to disable the unused antenna in the WRT54GL's configuration.

3. Because of the prevalence of 2.4GHz transmitters, I'd advise using the 5GHz band for anything that requires some degree of stability. As for connecting an outdoor antenna, be advised that the cabling usually requires connectors that are physically larger than what you find on cheap indoor wireless routers.

 

[d4mo]

I also forgot to state the that router will be in a steel sided building. So I figured I would need something external. The actual ground from where the router is maybe 10 feet higher in elevation. I'm not exactly sure.

If this is overkill, could you link me to something that would work better?

Also, if the cables are generally bigger, is there an adapter of some sort I can purchase?

 

[Fardringle]

If you want to test to make sure it will work without spending money on a permanent antenna, try this out first. He also has instructions to permanently install an access point/router outdoors so you can avoid the cost of a commercial outdoor antenna..

edit: I forgot to post a link to the gallery showing lots of different ways (and materials) to make these antennas for just about any environment.

 

[bobdole369]

I also forgot to state the that router will be in a steel sided building. So I figured I would need something external. The actual ground from where the router is maybe 10 feet higher in elevation. I'm not exactly sure.

If this is overkill, could you link me to something that would work better?

Also, if the cables are generally bigger, is there an adapter of some sort I can purchase?

10 feet of wire run at 2.4ghz is unfeasible. Unless you pay for LMR-600+

http://www.nr6ca.org/pdf/LMR600A.pdf

100 foot run at 2.4ghz = -4.4db.
10 foot run at 2.4ghz = -0.44db.


RG-58 (the stuff you can buy at Radio Shack) -

http://www.zcg.com.au/Catalogue/10-RG58_SolidCore.pdf
100 foot run at 2.4ghz = -59db!!!
10 foot run at 2.4ghz = -5.9db.


Add 3db of loss for the connectors. So -3.5db for the 10foot run if you use LMR600.

That LMR600 will cost you $70-$100 in the tools needed to terminate + $9+ each connector, which will only be UHF N-connectors, and you still need to buy pigtails to convert from RP-SMA to UHF N. SO add another 3db of loss for that. So -7db lets say.

So you have to make that up in the antenna, but you can't get much past 8-10db without getting REALLY directive. At close distances this is a problem as even wind will make the thing vibrate throwing the signal all over the place on the other end. The massive swings in signal strength will play havoc with the receiving radio.

So the fix for ALL that? Put the AP you intend to use up on the pole outside. It's far easier to run power and ethernet outside than it is to fit RF cables.

 

[d4mo]

I think I didn't finish my thought when I typed last post. What I meant is the ground elevation is 10feet higher at the location of where the router is, compared to where the camera will be.

The problem with putting a AP outside is weather/temp. This needs to be out year round, so it needs to be rugged. It can get -40F here in the winter and 100F in the summer. I can't image an AP would last long in that.

I should be able to get the cable run pretty short if I mount it on the side of the building.

Also would this work: http://www.amazon.com/LMR-400-Times...2?s=electronics&ie=UTF8&qid=1315928006&sr=1-2

To connect the directional antenna to the router if I go that route?

 

[d4mo]

Can anyone provide some quick insight to my last post? I need to get this stuff ordered soon.