awus036h minimum working dbm value

Discussion in 'Wireless Networking Cards' started by vinnie, 16 Jan 2014.

  1. vinnie

    vinnie Member

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    Hi guys,
    I'm having problems with my awus036h.
    I can't have a stable connection with networks with -65, -70dbm (measured with airodump), internet is very very slow and with ping packetloss is 80-90%.
    So my question is: is it normal? what's the minimum dbm value to a stable connection with a AWUS036H?


    I think my Alfa is not a fake, the pcb is blue, here it is:
    [​IMG]
     
  2. kevsamiga

    kevsamiga Well-Known Member
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    There is only one way in my experience to spot a fake ALFA...

    Not checking the hologram because they can easily be copied. No need even to email off the MAC address to ALFA. It's actually a 2 second job...

    Every single ALFA produced whatever the model has an imperfect smudge in the plastic near the RP-SMA connector (like someone accidentally slipped with a soldering iron tip). Maybe it was an accident in design, but the fakes do not copy this flaw in the ALFA adapter plastic.

    All the fake adapters have this section of plastic around the SMA connector perfect with no imperfections. Shhhh... don't tell the clone makers.

    Check yours around the SMA connector and you'll see exactly what I'm talking about. And most fakes don't even go to the bother of installing an RF shield anyhoo. :)

    As to connectivity in the 60's and 70's range, you are not alone my friend. I just finished a huge article about all ALFA adapters today so it's time for me to take a break for a while, but.....

    Try out my custom drivers also on here, where you can forcibly lower the connection rates at these signal strengths you are having issues with and see how you get on. You may be experiencing some kind of destructive interference which is invisible. :surprisedrage:
     
    #2 kevsamiga, 17 Jan 2014
    Last edited: 17 Jan 2014
  3. Remington

    Remington Well-Known Member
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    I can confirm everything Kevsamiga said above. :woot:
     
  4. Xcell

    Xcell Wireless 'r' us!
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    Yeah my ALFA has that smudge. Didn't know that. Thanks Kevsamiga!
     
  5. vinnie

    vinnie Member

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    kevsamiga thanks for your answer! My ALFA has the plastic smudge :D

    You're message is very valuable to me becouse initially I thought that my Alfa wasn't working well and I was thinking to buy another, but now I know that is not only my 036H.
    If every 036H has problem working at -60dbm, -70dbm then ALFA company has wrote wrong specifications.

    With this 036H there are many singularity, first of all why a network with -65dbm that is detected by Windows/Linux with 3/4 bars doesn't work?


    Great work, I tried your drivers, they're better than default drivers, the connection is a bit more stable, but I would like to have them on linux distros :(

    I read your great article, seems to me that 036H despite of all this problems, is still the better adapter to get (and connect to) far signals...am I right?

    However your review about 036NHA makes me curious, all people spoke about it's low range, but if it can connect with one bar it should perform better than 036H with far signals too!!!
     
    #5 vinnie, 17 Jan 2014
    Last edited: 17 Jan 2014
  6. Kostja_V

    Kostja_V Well-Known Member
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    My experience says that AWUS036H is sensitive, so sensitive that is very affected by interference. Link speed and quality with 7dbi directional antenna from about 15 meters is much more better than 9dbi omni antenna from 4-5 meters. And any other router working near AWUS036H (on the same channel or near) makes Alfa to drop speed to 1-2mbps even with great RSSI.
     
  7. kevsamiga

    kevsamiga Well-Known Member
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    I would agree on this diagnosis. In all of my testing across the 4 adapters, the 036H and to some extent the 036NH is affected strongly by interference, the others less so.

    This doesn't have to be interference from microwave ovens or electrical impulse noise etc, but can simply be anything from too many other access points around you transmitting (bearing in mind on G there is only 3 non overlapping channels which everybody is fighting over) to whether the ground is wet outside absorbing the signal.

    I would also agree with the 7dbi panel being superior to the 9dbi Omni as for a panel listed at the same dbi as an Omni is superior as you get backside rejection concentrating on only those signals that interest you. I have them fitted on most my ALFA's and mostly ditched the Omni's.

    It's not about sticking the largest twig on there since they are just passive devices that focus the beam. It's about finding a twig with just the right amount of dbi gain and angle of radiation pattern to just reach (but no more) and lobe over over the access point to get a good connection. Any higher dbi twigs and the performance just get's worse, so it's best to have a few to pick and choose from if you see what I mean.

    Larger Omni's like the 9dbi can increase the amount of signal and amount of AP's around you, but also increase the noise level (interference), and as a result the SNR goes south on the existing signals. As the radiation pattern in degrees get's tighter and flattened out.

    Like so:

    http://www.liveport.ca/images/stories//documentation/9dbi_Wave_02.jpg

    As a result, it's possible at these tighter beam widths of higher Omni's to skip right over the AP's head depending what floor your on with the adapter in comparison to AP. Radio propagation can be so unpredictable, that it's almost impossible to calculate the exact results.

    I usually need to be in the 50's range for good connections with the 036H V5, and sometimes even then, I can be connected at say -51 yet nothing is coming down the pipe. This is interference. The Kasen's G9000 RTL8187 reports I have has a 5-10% edge over the 036H at reception sensitivity (using wirelessnetview by nirsoft), and it doesn't seem to dropout as much as the 036H, but it's power amp isn't in the same league as the 036H's.
     
    #7 kevsamiga, 17 Jan 2014
    Last edited: 17 Jan 2014
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