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  • low power in a wifi card?

    so for some reason i have an atheros chipset mini pci wifi card that works fine in every way except for the fact that for some unknown reason it has very low power? no matter what i do im only able to maintain a link quality at something like 40% even when im standing next to my ap at home, this is despite antenna enhancements on both the laptop AND the ap. (i should also note that the shitty brodcom card could at least do the distance from my ap to my living room <_<)

    ideas?

  • #2
    Re: low power in a wifi card?

    Originally posted by Vyrus View Post
    so for some reason i have an atheros chipset mini pci wifi card that works fine in every way except for the fact that for some unknown reason it has very low power? no matter what i do im only able to maintain a link quality at something like 40&#37; even when im standing next to my ap at home, this is despite antenna enhancements on both the laptop AND the ap. (i should also note that the shitty brodcom card could at least do the distance from my ap to my living room <_<)

    ideas?
    What are you trying to do with it? Are there any interferences sources near by; especially microwave ovens? Is this a,b,g, or n you are trying to do? Does the laptop have at least 2 antennas? How are they polarized? Does this condition exist under Windows and Linux? Do you have the latest drivers and firmware installed for your card? Most mini-pci cards are 100mw output power, some are higher however and can go as high as 400mw. What kind of AP, make, model, and compatible 802.11 specification? Is the AP got factory or 3rd party firmware? Does this occur even after you default the factory firmware? Oh did you try reseating the antenna connections and the mini-pci card antenna and board connections? What kind of modifications did you make to allow for external antenna's? How long are your leads? Did you use good quality LMR cable for your modifications as well as connectors? Did you have to solder anything?

    It's early I think that covers it.

    xor
    Last edited by xor; December 27, 2007, 16:07.
    Just because you can doesn't mean you should. This applies to making babies, hacking, and youtube videos.

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    • #3
      Re: low power in a wifi card?

      Originally posted by xor View Post
      What are you trying to do with it?
      at this point, just get it to work at the same strength as the other mini pci cards ive put in this system

      Originally posted by xor View Post
      Are there any interferences sources near by; especially microwave ovens?
      yes but problem persists weather im next to it or not

      Originally posted by xor View Post
      Is this a,b,g, or n you are trying to do?
      its an a b g card but im only using / have tested b and g

      Originally posted by xor View Post
      Does the laptop have at least 2 antennas?
      yes

      Originally posted by xor View Post
      How are they polarized?
      no idea

      Originally posted by xor View Post
      Does this condition exist under Windows and Linux?
      no idea, and frankly im not putting windows on this box so if i cant get it to work under nix ill just get another card -_-

      Originally posted by xor View Post
      Do you have the latest drivers and firmware installed for your card?
      yes, although im not sure about firmware, i know i didn't manually upgrade it

      Originally posted by xor View Post
      Most mini-pci cards are 100mw output power, some are higher however and can go as high as 400mw.
      good to know, im not sure what the specs are on this card

      Originally posted by xor View Post
      What kind of AP, make, model, and compatible 802.11 specification?
      AR5006X 802.11abg, atheros chipset

      Originally posted by xor View Post
      Is the AP got factory or 3rd party firmware?
      i have this problem with all ap's so im quite sure its the card, but for reference its factory.

      Originally posted by xor View Post
      Does this occur even after you default the factory firmware?
      see above ;)

      Originally posted by xor View Post
      Oh did you try reseating the antenna connections and the mini-pci card
      antenna and board connections?
      several times, with both my mod antenna AND the built in internal ones that came with the laptop

      Originally posted by xor View Post
      What kind of modifications did you make to allow for external antenna's?
      i drilled 2 holes for the sma connectors and hooked them up by threading the pigtails around in the system, i should note that i have the same low power issue with the internal antenna that came with the card, my mod antenna are actually allowing me to USE the card a little as apposed to the internal ones where the power is so low the card is practically unusable.

      Originally posted by xor View Post
      How long are your leads?
      19 inch pigtails (if thats what u mean)

      Originally posted by xor View Post
      Did you use good quality LMR cable for your modifications as well as connectors?
      well as im not a total wifi guru im not sure id be a good judge of cable but if i had to answer yes or no id say yes

      Originally posted by xor View Post
      Did you have to solder anything?
      nope


      also, pictures of the mod are posted here

      Comment


      • #4
        Re: low power in a wifi card?

        I'm thinking that it mite be a power saving feature either in the card, the laptop, or the AP. Adjusting the TX power as needed. Linux doesn't have very good features for this. I always turn off power saving when running Linux. I have a dual core dual cpu AMD OPT so 4 cpus and it tries to throttle the cpus up and down based on demand, very annoying and it's not even a laptop. I turn it off and just keep it running on high.

        I've seen my Intel 3945 go as high as 90&#37; when sitting next to a Linksys WRV200 wireless router with built in range extender running under Linux; Open Suse specifically. But I get different values depending on whether it''s windows or Linux. Wireless driver support for Linux is getting better however you will get different results depending on the drivers you use. I use to be a Test Engineer so I actually hate % based scales I want to see decibels which at least is meaningful to me. % of what, and is every one measuring the same % of what?

        If you are seeing it in decibels, Cisco recommends a SNR of at least 35db for a reliable connection. As far as polarization goes it's your antenna orientation. Most PC-Cards have a horizontal polarization where most external antennas have a vertical polarization. It you turn your laptop on the side sometimes you will see some additional gain. In your situation you have internal antennas which usually run up either side of your screen and as long as your lid is open they will be polarized correctly.

        As a TE every measurement I made was traceable back to NIST via calibrated equipment. But in the end gravity is even very slight different depending where you are on the planet. One thing I like about Airmagnet is they have calibration parameters for each card they support, so at least there is an attempt there to get good coherent measurements device to device.

        xor

        PS I'm surprised Thorn hasn't registered in here yet.

        Speaking of gravity. I actually have my own pet theory about the 64 million year mass extinction loop that our world seems to be in. Gravitational anomalies, the moon is pulling away from us at a rate of about 1 to 2 inches a year. Perhaps at some critical mass points the minor changes become made changes. The moon is actually a much better calendar than our current one and could explain the pattern. At some point actually long after our sun goes super nova it will spin off into space and be lost forever. But we won't be around to see it. Though I admit I don't have any evidence of this nor am I looking to prove it. I just go by the assumption that there are very few constants over time in this world, everything changes, therefore why not gravity over time.
        Last edited by xor; December 30, 2007, 18:43.
        Just because you can doesn't mean you should. This applies to making babies, hacking, and youtube videos.

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