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Old 06-18-2009, 08:20 AM   #11
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Default Re: WiFi Antenna's

Question still stands, does anyone have a formula to calculate the foot print using degrees and distance? I would really appreciate it, I've googled it and can't find it.
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Old 06-18-2009, 05:19 PM   #12
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Default Re: WiFi Antenna's

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Originally Posted by Nateo200 View Post
Well I figure if it's pushing 11dbi it damn well better change my 5.5 mps connection! Funny my laptop gets 54 but my desktop might as well have a lead wall in front of it. If I could buy a 200mw omnidirectional antenna without rapeing the entire neighborhoods cordless phones and frying my brains I so would haha....
At 200mw you don't have anything to worry about. I've transmitted at 1000 Watts on Ham frequencies, now that is something you want to be careful with. RF burns are not nice, you can get a cone shaped burn down to the bone.

With the WiFi your signal purity should prevent any problems with neighboring homes at that power level. Seti could probably elaborate on this much more than I.
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Old 06-19-2009, 11:41 AM   #13
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You won't baked your brain and the max legal output is over 200mw. The feds don't bother unless you roast the paint off your neighbor's siding.
It's odd that TD has the TP Link antennas but nothing else. I have the TL-WR542G router. Now the bang for the buck you just can't beat. And it has a detachable antenna. Running barefoot with this model will net clear line of site about 300 feet. With that TP Link antenna I get over 700 feet.
Is it a problem if I sleep next to my wireless router? Lately I have been feeling stupid... I wouldn't be surprise if years from now they released a research study that says wireless router causes brain cancer.
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Old 06-19-2009, 11:47 AM   #14
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Default Re: WiFi Antenna's

I like the old cartoon that I saw years ago. There were a bunch of scientists sitting around a table with frowns. I guy walks in and asks "why the long faces." One of the scientist look up and says: "We just got the results: everything causes cancer!"
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Old 06-20-2009, 09:48 AM   #15
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Default Re: WiFi Antenna's

I had to deal with white pages here last night so I went on to bed. Sorry.

Most instructions for wireless network devices suggest to keep the antenna above your head. I personally follow this guideline even though it would take a life time of exposure to give you a tingle. Besides as Russel can tell you the higher the antenna the greater distance you can cover.

Ok on to figuring out the size of the footprint.
http://www.easycalculation.com/trigo...gle-angles.php

Set it for opposite side and hypotenuse side. In adjacent side put the distance from your antenna to the wall of the school. Keeping in mind that that only figures 1/2 of the beam angle put in 15 for angle. Take the figure for opposite side, multiply it by 2 and that's the beam spread at the target end.
If you figure the distance is 100 feet at 1/2 of the beam angle 15 (half of the lobe) at that distance you'd have a 1/2 beam spread of just over 26 feet. Take 26 multiply by 2 and you get 52 feet. However since the lobe is teardrop shaped, the optimum spread would actually occur at roughly 90 feet. Gets complicated from there.
At any rate, if you need a wider footprint at the target end you'll need to look for a directional antenna that has a wider beam angle. But the wider the angle the less RF energy will arrive at the target. Directional antennas work by focusing the RF energy in one direction. They don't amplify the signal just point it one direction. Where as omni's like what comes on most home wireless wastes the RF energy by radiating in all directions.
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Old 06-26-2009, 06:49 PM   #16
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Default Re: WiFi Antenna's

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I had to deal with white pages here last night so I went on to bed. Sorry.

Most instructions for wireless network devices suggest to keep the antenna above your head. I personally follow this guideline even though it would take a life time of exposure to give you a tingle. Besides as Russel can tell you the higher the antenna the greater distance you can cover.

Ok on to figuring out the size of the footprint.
http://www.easycalculation.com/trigo...gle-angles.php

Set it for opposite side and hypotenuse side. In adjacent side put the distance from your antenna to the wall of the school. Keeping in mind that that only figures 1/2 of the beam angle put in 15 for angle. Take the figure for opposite side, multiply it by 2 and that's the beam spread at the target end.
If you figure the distance is 100 feet at 1/2 of the beam angle 15 (half of the lobe) at that distance you'd have a 1/2 beam spread of just over 26 feet. Take 26 multiply by 2 and you get 52 feet. However since the lobe is teardrop shaped, the optimum spread would actually occur at roughly 90 feet. Gets complicated from there.
At any rate, if you need a wider footprint at the target end you'll need to look for a directional antenna that has a wider beam angle. But the wider the angle the less RF energy will arrive at the target. Directional antennas work by focusing the RF energy in one direction. They don't amplify the signal just point it one direction. Where as omni's like what comes on most home wireless wastes the RF energy by radiating in all directions.
Sorry for the late response. Thanks for the response. So for actual signal amplification you would need an amp connected to the antenna? Wow this certainly gets interesting.
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