cantenna

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toxicmouse

Senior Member
alright, it does not use a picaxe, but i am sure those making 433MHz links would find this interesting. yes, i was thinking of Stans' cotanga.

<A href='http://news.bbc.co.uk/1/hi/programmes/click_online/6646469.stm' Target=_Blank>External Web Link</a>
check about half way down.


Edited by - toxicmouse on 13/06/2007 11:56:35
 
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moxhamj

New Member
Groovy. I presume this is 2.4Ghz? At 433Mhz the can is about 50cm wide, but still, waveguides and parabolic reflectors are possible at this frequency. But Yagi's are a bit easier to build at 433Mhz.

This is our local version of a city wide 2.4Ghz wifi network <A href='http://www.air-stream.org/' Target=_Blank>External Web Link</a>. There is a lot of info in the technical section about waveguides and different antennas.
 
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c6jones720

Member
Theres something like that in Bristol UK. The Bristol wireless guys used to use cantennas for WAN/MAN coverage in the area

http://www.bristolwireless.net/
 
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manuka

Senior Member
Hark- did someone mention 2.4 GHz? In mid 2004,after much past hands on microwave experimentation, (which included ham,sat.TV, WiFi, Bluetooth &amp; video links etc) I flagged away cantenna &amp; the like in favour of arriving USB WLAN adapters,&amp; STILL STRONGLY recommend this approach (for WiFi &amp; BT anyway).

Inbuilt WLAN adapters in most PCs/laptops are OK only when very near an AP,&amp; simply instead using an external cabled USB adapter,placed above head/partition height or near a window etc, can improve coverage enormously. Recently more powerful &amp; sensitive USB client adapters like the Senao/Engenius &quot;362&quot;<A href='http://www.usbwifi.orcon.net.nz/senaousb.jpg' Target=_Blank>External Web Link</a> &amp; Alfa AWUS036H <A href='http://www.usbwifi.orcon.net.nz/alfa.jpg' Target=_Blank>External Web Link</a>have become available,making LOS links over many km a breeze.

USB suits &quot;poor man&quot; &amp; roving WiFi setups,as the dirt cheap &amp; lossless cabling can readily be extended (by at least 5m)into signal sweet spots. Best of all,placement of a USB WLAN adapter at the FP of elevated &amp; directed parabolic reflectors can GREATLY boost signals. Asian mesh cookware scoops have been celebrated top performers, &amp; these were also used for 2.4GHz ZigBee range trials <A href='http://www.picaxe.orcon.net.nz/zigscoop.jpg ' Target=_Blank>External Web Link</a>,with flea powered 1 mW Picaxe XBee units successfully then linking up to 3km LOS over water.

Results &amp; diverse evolving designs are hosted at my near infamous &quot;wokfi&quot; site =&gt; <b>www.usbwifi.orcon.net.nz </b> <A href='http://www.usbwifi.orcon.net.nz ' Target=_Blank>External Web Link</a>. Feedback has been highly satisfying, especially from folks in downtrodden &quot;$1 a day&quot; regions. It was really intended as my bit for global altruism,but my sense of humour is continually being tickled by mega budget skeptics reporting &quot;Gawd-it works! Stan



Edited by - manuka on 16/06/2007 00:48:33
 
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BrendanP

Senior Member
I did a bit of experimentation at 2.4ghz for video TX. I used the pringle can which is a very similar idea to the can in the article. It worked well. Stan is an expert in this area and you would be hard pressed to find anywhere in the world someone with the combination of practical experience and academic trainning.

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Edited by - BrendanP on 16/06/2007 05:52:06
 
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manuka

Senior Member
Modest blush- I'm really just a big kid who learned to improvise when raised in the rural NZ back blocks!
 
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BrendanP

Senior Member
Ha! A lot of academics couldn't solder two wires together. My father is ham like Manuka, he mentioned to me that a lot of the break throughs in RF technology were made by amatuer radio enthusiats.

 
 
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andrewpro

New Member
Our understanding of the universe as it is now would not be where it is without radio amateurs <img src="smile.gif" width=15 height=15 align=middle> Grote Reber (ex-W9GFZ, call now held by the NRAO amateur radio club) pretty much launched modern radio astronomy with a parabolic dish in his back yard.

For those interested:

<A href='http://www.nrao.edu/whatisra/hist_reber.shtml' Target=_Blank>External Web Link</a>
 
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BrendanP

Senior Member
Great link Andy. Just building that dish is a great engineering accomplishment. I was interested to read Mr.Reber lived/died in Tassie. My father told me that it was amatuers who opened up UHF frequencies to common use. Prior to hams experimenting at high frequenceys it was thought that they were useless for communications.

I just read on wiki that Mr. Rebbe lived in Tassie from the 1950's on. He moved there because of the lack of RF interference.

Stan, did you meet him or know him?

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Edited by - BrendanP on 17/06/2007 01:57:27
 
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