Best wireless card for external antenna

My knowledge in wireless networking is next to nothing, except for what I have read here and from many of the links you have posted. I'm hoping to gain access to the AP at my employer which is located 1/4 mile away from my home. I don't have a clear LOS, but from the attic I should only have to go through a few other houses' attics and one window so maybe it will work.

Here is what I have thought about.

1) Building a biquad antenna like this one:
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and find a good place for it at the attic.

2) Then connecting the antenna to the desktop PC with 25' low loss coax cable, probably LMR-400. 25' should give a signal loss of just


3) Choosing the wireless adapter is the hardest part. I have been browsing through newegg and read many reviews. People seem to have few problems with the D-Link DWL-AG 530, so based on this, it may be a safe buy for a beginner. It has a little external antenna which is detachable. Does anyone know which connector this card has? I have checked D-link's website but they don't seem to tell anything about this.

But would this adapter be the optimal for this setup? Or is there anything better out there, perhaps more suitable for long distance hook-ups? Speed is not the most important but I'll like to have a fairly reliable connection.

And what about lightning storms? Would you protect a network card which has 25' cable mounted? I know how induction from lightning can kill electronics.

I appreciate all your feedback.

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I presume you have permission to do this from the employer.

That will take a major miracle. 2.4GHz does not like obstructions. It really depends on from what the roofs are made. If they're extremely thin shake or shingle, it just might work. Dry wood is fairly opaque to 2.4GHz. However, if it's composition shingle, concrete, rock, or something that will block RF, forget it.

It takes two to tango. If the access point at your employers establishment uses the stock rubber ducky antenna, and is located in a inside office, you don't have a change. Such antennas on access points allegedly have 300ft range, but that's under totally ideal conditions (including no interference). You're trying to go 5 times as far, and through several obstructions. Basically, it's not going to happen unless you have a directional antenna at both ends, and your employer cooperates by installing either a 2nd access point on the roof, or re-locates the existing access point some place that's conveninient for your wireless link.

Lacking any useful models and numbers, I can't do the antenna calcs for you. See:

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try running the link calculations. Figure on a very optimistic 10 loss going through each roof. Aim for 20dB fade margin. If you have problems, post your calcs and equipment list, and I'll see what can be done.

Probably not enough gain.

Ummm.... LMR-400 has a loss of 7.8dB/100ft. 25ft has a loss of

2.0dB. Add 0.5dB of loss for each connector pair, for a loss of 3dB or half your power lost in the coax.

Sorry, not familiar with this device. What you shoudl be looking for is a wireless client bridge or game adapter that allows an external antenna. The radio should be mounted in the attic along with the antenna (which will probably need to be a big dish antenna). That will eliminate the coax cable loss. Setup some kind of power over ethernet system to run the radio. My current favorite is either a Linksys WET54G or WRT54G running DD-WRT firmware.

True. There are CAT5 lightning arrestors. Most cost more than the wireless bridge. See thread: |

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Reply to
Jeff Liebermann

You want to use something like the Buffalo WLI-TX4-G54HP, see "

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" You want this mounted in a weatherproof box, outside, as close to the antenna as possible. You will run power and CAT5 cable to the box. You cannot run an antenna from a PCI wireless adapter to an antenna far from the card, as you'll lose too much signal in the antenna cable.

Of course even will all this, it probably won't work, unless the other side has a similar antenna set-up, and even then it's iffy.

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Thanks for your answers. I better forget the 25 ft antenna cable. I like the idea of running the ethernet up near the antenna and converting it to wireless and just using a short antenna cable. I think I'll try the Buffalo Ethernet Converter that SMS suggested.

Jeff may be right about the attic not going to work. If not I will mount an antenna on the roof. 6 ft. above will give me a LOS to the window where the AP is located.

I forgot to mention that I can connect with a laptop from a few places in the attic if it's not raining. Signal is very poor but it's there, and I can log on to the network.

Thank you for your suggestions.

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On 20 Jun 2006 13:18:38 -0700, "time4me2write" wrote in :

Then a directional antenna in the same location will probably work.

Reply to
John Navas


I'm a little confused about what connecter type there should be on the antenna cable for mounting it on the Buffalo ethernet adapter?

Could you please tell me this?

Thank you in advance.

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