I've build a lot of cantenna type antennas. I changed the position of the 1/4 lambda element and it really make no big difference. I also verified the 8-10 dB calculated with real life and it is almost the same.
So, yes it is worth spending the money for an N-connector. What's wrong with your prototype ? I do not know. /Lars ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, November 11, 2003 7:58 PM Subject: [BAWUG] Trouble building a cantenna > Hi, > > I am trying to build an antenna by following the directions on > http://www.turnpoint.net/wireless/cantennahowto.html . I am using a > Linksys WUSB11 v2.5 (the one with an MMCX connector on it). The can I am > using has a diameter of 3.94 in, and the length is between 5.5 - 6.0 > inches. Before I spend $20 on an N connector/pigtail and more for > shipping, I want to make sure the thing works. > > I drilled a small hole 1.75 in from the bottom. I found some thick copper > wire, and stripped the covering off of the last 1.21" part. I cut the > wire to about 2" length. Next, I set up my D-Link DI-614+ router in the > same room. When I remove the default Linksys antenna, I get a very poor > signal-to-noise ratio on Netstumbler (as predicted). Attaching the > Linksys antenna greatly improves this (as predicted). Next, I had a > friend take one end of the copper wire and stick it into the internal MMCX > connector on the Linksys. I held the other end 1.21" into the can. The > effect of all this is that I had the copper wire sticking into the can > exactly as the web site at Turnpoint describes. The can was pointed > directly at the router - no more than 5 feet. The SNR I measured was not > much better than with no antenna at all. No amount of wiggling, etc. of > the copper wire could rectify this. Obviously if this thing can be made > to work I will spend the money on the pigtail/N connector, but I will feel > very stupid if I spend $30 on these two things if the entire setup doesn't > work. > > My questions are: > > 1. The inside of the can is coated with some kind of white lining - could > this be the problem? Scratching this off with my key reveals a silver > metallic can (predictably). > > 2. The length of copper wire outside the can which extends to the MMCX > connector is only about 1". This shouldn't make any difference - right? > Or is it required to use the N connector/pigtail before the setup will > even begin to work? > > 3. Are the Super Cantennas at www.cantenna.com any good? Are they worth > the extra money when (theoritically) you can build one out of the garbage? > > 4. Any other ideas on why this isn't working? I've measured things like > 10 times and tried to get a decent signal numerous times - all without > good results. > > My intent (once I get the thing to work with an AP in the same room) is to > reach an AP across the street. I don't think I need to amplify the signal > much, because the builtin Linksys antenna seems to pick up a trace signal > every few minutes. And I don't need full 11 MBPS bandwidth - just 1 or 2. > > Thank you! > > Best Regards, > > James Johnston > E-mail: [EMAIL PROTECTED] > > -- > general wireless list, a bawug thing <http://www.bawug.org/> > [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless > > -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
