Author Topic: Ideal wifi aerial length (Read 18058 times)

Simon · « **Reply #25 on:** December 28, 2011, 08:58:09 am »

Nice, I guess Tenda routers cannot be hacked ?

Sionyn · « **Reply #26 on:** December 28, 2011, 10:16:38 am »

try these guys
http://www.alfa.com.tw/in/front/bin/home.phtml

sonicj · « **Reply #27 on:** December 28, 2011, 02:07:53 pm »

Quote from: Simon on December 28, 2011, 08:58:09 am

Nice, I guess Tenda routers cannot be hacked ?

looks like some models are hackable. http://www.dd-wrt.com/wiki/index.php/Supported_Devices#Tenda

openwrt is the bare bones linux kit, dd-wrt is much easier for the uninitiated, gargoyle is the best open firmware available imo. not as many supported models though....
-sj

Simon · « **Reply #28 on:** December 28, 2011, 02:48:34 pm »

oh good, mine might be one, will check later, the router is shit and often looses connection, The dongles for it also only work with a tenda router.... Never buy tenda guys, I've never had such a piece of crap: you get what you pay for !

Simon · « **Reply #29 on:** December 28, 2011, 04:07:08 pm »

yay mine is supported, one of the first to be supported, I'll have a read around and give it a go

edit: actually it is not supported, or at least not directly

ipman · « **Reply #30 on:** December 28, 2011, 05:46:56 pm »

Altough great softwares, Xwrt will not modify your RF hardware, which is the most important factor.
Great routers do not come cheap.
Anyway, try to select a lower modulation or speed, it will improve things a bit.

Simon · « **Reply #31 on:** December 28, 2011, 05:59:25 pm »

well problem with my router is i keep loosing wifi link to the PC, strangely with the Tenda dongle all other dongles work fine - like you say: pay for shit: get shit. I'll probably buy a decent router soon and chuck out the stupid dongles with it

ipman · « **Reply #32 on:** December 28, 2011, 06:14:42 pm »

Take a look at Ubiquiti. I have two of them outside and they work for two years without any problems. They are based on Atheros SOC's and they can also run DD-WRT, having 16M flash and 32M RAM.
The Bullet type mounts directly on a N-type antenna connector, and that let you choose the antenna of your choice.
Nice and cheap antennas are from Interline.

sonicj · « **Reply #33 on:** December 28, 2011, 10:29:35 pm »

the ubiquiti stuff looks like a great deal. i just find their lineup a little hard to decipher. is the airrouter the most up to date "pro-sumer" router/switch type unit? according to their forum, its a AR71xx series @ 400 Mhz 32 Mb SDRAM 8 Mb Flash.

i am very pleased with my Buffalo WZR-HP-G300NH running Gargoyle. it uses a AR9132 @ 400 MHz 64Mb of SD 32 Mb of Flash, 2x2 external antennas. probably old news by now..... i have a 8dB collinear antenna attached to a u.fl to sma pigtail which replaces one of the stock antennas. this router/firmware combo has been my most reliable setup to date.
-sj

Simon · « **Reply #34 on:** December 28, 2011, 11:58:30 pm »

well I'm just after something decent to work around my house. I'll probably get a midrange router of reputable make and toss the whole tenda kit on ebay for some other poor bugga to play with.

gregariz · « **Reply #35 on:** December 29, 2011, 12:09:38 am »

Quote from: Simon on December 28, 2011, 11:58:30 pm

well I'm just after something decent to work around my house. I'll probably get a midrange router of reputable make and toss the whole tenda kit on ebay for some other poor bugga to play with.

One quick and simple antenna would just be the quarter wave vertical. (btw due to reflection it theoretically will have the same gain as the longer half wave, however the half wave is somewhat more complicated to match and tune). If you have a signal strength indicator in your software, just cut about a 4cm length of tinned copper wire and attach to whatever mounting connection you have ie sma connection. Make sure the whole concoction is mounted on a metal plane. Then cut down the wire 1mm at a time until your signal strength is maximum. At maximum your antenna will be roughly matched and tuned.

Simon · « **Reply #36 on:** December 29, 2011, 09:04:19 am »

well the tenda dongles have no antenna, I bought a realtek adapter off ebay with an antenna. I think the issue will connection loss is just crap quality tenda gear, probably a bug in the firmware or something

ipman · « **Reply #37 on:** December 30, 2011, 01:09:49 pm »

They do have an antenna, altough is a very small one, SMD-style mounted on PCB or even made from traces on PCB itself.
Not the best option, but this is to comply to UE directives about non-removable antennas.

Simon · « **Reply #38 on:** December 30, 2011, 01:43:54 pm »

Quote from: ipman on December 30, 2011, 01:09:49 pm

They do have an antenna, altough is a very small one, SMD-style mounted on PCB or even made from traces on PCB itself.
Not the best option, but this is to comply to UE directives about non-removable antennas.

well I meant no external antenna. Signal strength is fine I think it is a firmware issue, a bug or something. The dongles will only connect to the tenda router and often the connection locks up although at full strength, no other dongle has a problem. I think the dongles are more of a problem than the router and I'l probably get another dongle for the pc first and see if things improve

clonecrp · « **Reply #39 on:** December 30, 2011, 03:32:06 pm »

I also would think you have to measure WSWR, or reflected power. Wrong antenna could wipe-out the transmitter chip ..

Happy New Year...

Doug

Simon · « **Reply #40 on:** December 30, 2011, 06:41:21 pm »

Quote from: clonecrp on December 30, 2011, 03:32:06 pm

I also would think you have to measure WSWR, or reflected power. Wrong antenna could wipe-out the transmitter chip ..

Happy New Year...

Doug

yea, one good reason I may just leave well alone, it works pretty well out of the box so I'll leave it at that

ipman · « **Reply #41 on:** December 30, 2011, 06:44:18 pm »

There's no point in measuring reflected power in that USB dongle, and very hard to accomplish. You have to desolder the SMD antenna from PCB or cut the PCB trace before antenna ...
On the router side it's another story, but the tools required are expensive.

clonecrp · « **Reply #42 on:** January 02, 2012, 08:18:40 pm »

I'd say U are right ... so... why not create a field strength meter (or use an android app) use a hunk-o-wire & tune with a variable condenser for max output ... Done !

ARRL.org or equiv...?

Doug

ipman · « **Reply #43 on:** January 03, 2012, 09:02:36 am »

And if you find out that you have a huge value, then what? I mean, what can you do?


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Author Topic: Ideal wifi aerial length (Read 18058 times)

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