On 08/07/2010 08:30 PM, Bob Goodwin wrote: <snip> > G, I have antennas all over, but these two boxes I am messing with have no > connectors. hello bob, no connectors? usb or cheap cards? some usb wifi have a hidden connector. i have never seen a wifi card that you could not change antenna or remove and connect a coax cable. and yes, i know i have not seen all cards. ;) if cheap cards and you are handy with a soldering iron, cut the antennas out at mount bracket and solder coax direct to pcb. :) > Not only that but cable losses are very high at these frequencies and more > than a few inches of cable will cost you more in loss than you can gain > with directivity. yes, the higher the frequency, the greater the loss. but there is 'low loss' coax for vhf and micro freqs. do not know off hand, but will have a quick look at belden wire; http://www.belden.com/ selecting 'ecatalog' brings up; https://edeskv2.belden.com/Products/ entering 'wireless' in search produces, https://edeskv2.belden.com/Products/#s=wireless&r=0 double clicking 1st in list of coax cables, 1671a, produces spec sheet; https://edeskv2.belden.com/Products/index.cfm?event=showproductdetail&partid=3462 scrolling down page shows table; Nom. Attenuation: Freq. (MHz) Attenuation (dB/100 ft.) 500 15.0 1000 22.2 2000 32.8 3000 41.2 5000 54.9 which would be 0.549 per foot or, 0.04575 per inch. i do not know what you consider 'losses are very high at these frequencies', but i would call it *not much loss*. ;) i would imagine if i checked specs on some other low loss cables, loss may very well be less. if you want to know what they are, have a look. just follow above link. > 5 gHz probably wants wave guide ... lower loss, yes. but coax is cheaper. :^P some more info i found while waiting for your reply; google, diy "5gh" "wifi+antenna"; http://www.google.com/search?num=100&hl=en&lr=&as_qdr=all&&sa=X&ei=YdVdTOH8N4WglAf1vcSpCA&ved=0CBwQBSgA&q=diy+"5gh"+"wifi%2Bantenna"&spell=1 diy video; http://www.5min.com/Tag/wifi antenna?CategoryID=0 diy yagi; http://www.k7mem.150m.com/Electronic_Notebook/antennas/yagi_vhf.html commercial; http://www.alternativewireless.com/ http://www.alternativewireless.com/cellular-antennas/building-cellular-repeater-systems.html?gclid=CL-zxMO5qKMCFRRsswod6Bb45g http://www.wifi-link.com/ be aware that in all of links i am feeding you, they are all for 'high gain' directional antennas. this may not be acceptable. if not, there are also omni directional antennas that can be use, but they only have 8db to 10db gains. if you have to have omni direction, i suggest using an inline amp to boost signal to and from wifi card. hth. -- peace out. tc,hago. g . **** in a free world without fences, who needs gates. ** help microsoft stamp out piracy - give linux to a friend today. ** to mess up a linux box, you need to work at it. to mess up an ms windows box, you just need to *look* at it. ** learn linux: 'Rute User's Tutorial and Exposition' http://rute.2038bug.com/index.html 'The Linux Documentation Project' http://www.tldp.org/ 'LDP HOWTO-index' http://www.tldp.org/HOWTO/HOWTO-INDEX/index.html 'HowtoForge' http://howtoforge.com/ ****
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