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"Super Cantenna"
Has anyone had any luck with these? the ones from Wireless Garden
I got one, and no matter how i turn it, I get very weak signal. my target is about 400' away line of sight, except my friends ap is not right in the window (i can see the window from my window). I'm using an ALFA AWUS036H 500mW usb adaper with a RP-SMA. the cantenna claims 12 dBi, and has a 3' cable with RP-SMA the ap, has just the built in antennas (belkin) I can get a week signal, but I get just as good or better with my 2 dBi omni! do to the card being hi power the ap can hear everything but the ALPA Rx SNR must be very low. thanks in advance -Jason |
#2
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"Super Cantenna"
On Mar 12, 12:19*am, Jason wrote:
Has anyone had any luck with these? the ones from Wireless Garden I got one, and no matter how i turn it, I get very weak signal. my target is about 400' away line of sight, except my friends ap is not right in the window (i can see the window from my window). I'm using an ALFA AWUS036H 500mW usb adaper with a RP-SMA. the cantenna claims 12 dBi, and has a 3' cable with RP-SMA the ap, has just the built in antennas (belkin) I can get a week signal, but I get just as good or better with my 2 dBi omni! do to the card being hi power the ap can hear everything but the ALPA Rx SNR must be very low. thanks in advance -Jason A lot of the new double pane windows have a metalize layer in them that blocks RF very effectivly. Raising my window and removing the screen is requiire for me acces my AP from outdoors. Jimmie |
#3
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"Super Cantenna"
On Mar 12, 12:19*am, Jason wrote:
Has anyone had any luck with these? the ones from Wireless Garden I got one, and no matter how i turn it, I get very weak signal. my target is about 400' away line of sight, except my friends ap is not right in the window (i can see the window from my window). I'm using an ALFA AWUS036H 500mW usb adaper with a RP-SMA. the cantenna claims 12 dBi, and has a 3' cable with RP-SMA the ap, has just the built in antennas (belkin) I can get a week signal, but I get just as good or better with my 2 dBi omni! do to the card being hi power the ap can hear everything but the ALPA Rx SNR must be very low. I'm sorry, no answer to your question, I just think it's funny, remembering the Heath Cantenna, that someone expects a Cantenna to actually radiate a signal. Back 30 years ago when I was a novice, I remember accidentally leaving my Cantenna hooked up instead of my real antenna and working a couple of JA's with it. 15M really was wide-open to Japan every afternoon back then! Tim. |
#4
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"Super Cantenna"
On Mar 12, 11:57*am, Tim Shoppa wrote:
I'm sorry, no answer to your question, I just think it's funny, remembering the Heath Cantenna, that someone expects a Cantenna to actually radiate a signal. I have a Heath Cantenna too, but the WiFi folks mean a different thing with that term -- a 2.4 GHz waveguide antenna made from a Pringles (tm) can. Unfortunately, that cantenna of the second kind has almost no gain. It needs a much larger aperture to make that gain than the 3-inch diameter of a foil- covered paper tube. That can be had by attaching a larger, metallic funnel to the mouth of the antenna to form the typical microwave horn antenna. See any reputable antenna text book for design details. Jim, K7JEB, Glendale, AZ |
#5
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"Super Cantenna"
a much larger aperture to make that gain than the 3-inch diameter of a
foil- covered paper tube. *That can be had by attaching a larger, metallic funnel Its odd because the dia. is only 85mm where the homemade ones say 100mm +/- 10mm. also the 3' wire is very skinny (don't know what one it is). About a thin as a pencil lead. and also there's a tripod mount that has a bolt inside that blocks the lower 7-8mm of the antenna. as for the windows, tested (on my end), there not making any difference. Kismet & Netstumbler don't seem to report noise level with this card, just rx level. but the app that came with the Alfa shows "Signal Str" and "Link Quality". No differnce betewen a 2 dBi omni and the cantenna. |
#6
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"Super Cantenna"
On Mar 12, 6:39*pm, "Jim, K7JEB" wrote:
On Mar 12, 11:57*am, Tim Shoppa wrote: I'm sorry, no answer to your question, I just think it's funny, remembering the Heath Cantenna, that someone expects a Cantenna to actually radiate a signal. I have a Heath Cantenna too, but the WiFi folks mean a different thing with that term -- a 2.4 GHz waveguide antenna made from a Pringles (tm) can. Unfortunately, that cantenna of the second kind has almost no gain. It needs a much larger aperture to make that gain than the 3-inch diameter of a foil- covered paper tube. *That can be had by attaching a larger, metallic funnel to the mouth of the antenna to form the typical microwave horn antenna. See any reputable antenna text book for design details. Jim, K7JEB, Glendale, AZ Just about anything works better than the Pringles(tm) can that made the antennas famous. I made one with a large fruit juice can and it worked fairly decent. I picked up about 10 db compared to the stock antenna. Jimmie |
#7
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"Super Cantenna"
Just about anything works better than the Pringles(tm) can that made the antennas famous. I made one with a large fruit juice can and it worked fairly decent. I picked up about 10 db compared to the stock antenna. Jimmie Ditto,but mine was a clam-chowder can,IIRC. Got funny looks walking down the soup aisle with a tape measure..but I found a can with nearly-perfect diameter. |
#8
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"Super Cantenna"
"PhattyMo" wrote in message ... Just about anything works better than the Pringles(tm) can that made the antennas famous. I made one with a large fruit juice can and it worked fairly decent. I picked up about 10 db compared to the stock antenna. Jimmie Ditto,but mine was a clam-chowder can,IIRC. Got funny looks walking down the soup aisle with a tape measure..but I found a can with nearly-perfect diameter. The 2.4 GHz Multipoint Distribution System (MDS) pirate receivers from the 1980's used a coffee can. The circuit board parts kit was sized to fit inside the standard 1-lb coffee can, so you knew (without the tape measure ;-). I still have one overhead in the garage. It worked much better with a big cone of screenwire out in front. Maybe the experimentors should work in that direction. The cone acted just like a funnel. Since the MDS signals are/were NTSC television, improvements could be evaluated real-time. "Sal" |
#9
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"Super Cantenna"
On Wed, 11 Mar 2009 21:19:18 -0700 (PDT), Jason
wrote: Has anyone had any luck with these? the ones from Wireless Garden I got one, and no matter how i turn it, I get very weak signal. my target is about 400' away line of sight, except my friends ap is not right in the window (i can see the window from my window). Any coating on the window? If either window is a Low-E window, you will have problems passing RF. Similarly, if the wall at your friends end is full of chicken wire, concrete, or foil backed insulation, RF is not going to penetrate. Line of sight means the antennas can see each other with NOTHING in between. Get line of sight and it will probably work. I'm using an ALFA AWUS036H 500mW usb adaper with a RP-SMA. the cantenna claims 12 dBi, and has a 3' cable with RP-SMA the ap, has just the built in antennas (belkin) Ummm.... methinks perhaps 9 dBi on a good day. I ran a model sometime back. No guarantee mine is the same size can as yours: http://802.11junk.com/jeffl/antennas/coffee2400/index.html Note that the driven element is not a 1/4 wave wire, but is slightly conical for better bandwidth. I can get a week signal, but I get just as good or better with my 2 dBi omni! Ummm... there's probably something wrong with the Super Cantenna or your coax cable and connector arrangement. Start with a continuity check using an ohms guesser. Also look for shorts. Beyond that, you'll need a pile of test equipment. If the Super Cantenna uses a type N connector, you might be able to substitute another external antenna to test the coax cables and pigtail. Incidentally, my father once warned me about products with amazing, magic, miracle, super, and other superlatives in the name. Few come even close. do to the card being hi power the ap can hear everything but the ALPA Rx SNR must be very low. Don't assume the card is the problem, especially if the 2dBi omni works as expected. I would investigate the antenna first. thanks in advance -Jason -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#10
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"Super Cantenna"
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