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masterl1nk

Member

From: Buenos Aires, Argentina

Registered: 2011-03-21

Posts: 7

Website

rt2800: tx-power stuck at 0dBm

Hi! I recently bought an Alfa awus036nh equiped with a Ralink RT3070/2870.

It works out of the box without problems. BUT! I can't set the tx-power, is ever stuck at 0dBm

iwconfig's output:

wlan1     IEEE 802.11bgn  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=0 dBm   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:on

When I do

[nico@latitude ~]$ sudo iwconfig wlan1 txpower 20dBm
Error for wireless request "Set Tx Power" (8B26) :
    SET failed on device wlan1 ; Invalid argument.

even if I set it to 10 or 1dBm. It works only with 0dBm.

I booted Backtrack 5 with 2.6.39.4 kernel and I can set the tx power up to 30dBm!

I tested everything I found.
I've readed this mailing list: http://thread.gmane.org/gmane.comp.embe … ocus=91183
and tried to compile compat-wireless-daily with no luck.

Also I tried to set the zone with "sudo iw reg set BO" (using BO,US, etc)

some info about my system:
uname -a:

Linux latitude 3.4.3-1-pae #1 SMP PREEMPT Tue Jun 19 20:58:39 EDT 2012 i686 GNU/Linux

blacklist.conf:

blacklist rt2x00lib
blacklist rt61pci
blacklist rt2800pci
blacklist rt2x00usb
blacklist rt2x00pci
blacklist rt3390sta
#blacklist rt2800usb
blacklist iTCO_wdt

Sorry for my english

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Home server: Athlon 5000x2 + ECS A780GM-A + 320gb WD + 500gb Seagate + Tt Swing + LG W2252S-PF @ Archlinux
Dell Latitude E6400: Intel Core 2 Duo P8600 vPro + 2x2GB ddr2 800mhz + WD Black 160GB 7200rpm + Bluetooth + backlit keyboard @ Archlinux
Thinkpad E430: Intel i5 2450 + 8GB DDR3 1600mhz + WD500GB 7200rpm + Bluetooth + Dell UltraSharp 2007WFP @ Archlinux

Strike0

Member

From: Germany

Registered: 2011-09-05

Posts: 1,491

Re: rt2800: tx-power stuck at 0dBm

What's the legal TX limit for wireless devices in your zone/country?

masterl1nk

Member

From: Buenos Aires, Argentina

Registered: 2011-03-21

Posts: 7

Website

Re: rt2800: tx-power stuck at 0dBm

It does not matter from the moment I change the zone to which I wish, however, if I remember correctly the limit is 20dBm

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Home server: Athlon 5000x2 + ECS A780GM-A + 320gb WD + 500gb Seagate + Tt Swing + LG W2252S-PF @ Archlinux
Dell Latitude E6400: Intel Core 2 Duo P8600 vPro + 2x2GB ddr2 800mhz + WD Black 160GB 7200rpm + Bluetooth + backlit keyboard @ Archlinux
Thinkpad E430: Intel i5 2450 + 8GB DDR3 1600mhz + WD500GB 7200rpm + Bluetooth + Dell UltraSharp 2007WFP @ Archlinux

Strike0

Member

From: Germany

Registered: 2011-09-05

Posts: 1,491

Re: rt2800: tx-power stuck at 0dBm

It does not matter from the moment I change the zone to which I wish, however, if I remember correctly the limit is 20dBm

It does matter for the quality of the wifi connection though (apart from the legalese obviously).
It's a common false assumption increasing TX power for a card single-sided of a link gives you a better signal or range. It does not.