Unable to change TX Power

[OrzechowyJoe]

Hello, I have problem with setting TX power for my WiFi interface.

I have two WiFi interfaces (wlan0 and wlan1) so I disable both of them (because there is problem to set proper reg if wlan0 is up):

root@kali:~# ifconfig wlan0 down
root@kali:~# ifconfig wlan1 down

In next step I set proper reg

root@kali:~# iw reg set GY
root@kali:~# ifconfig wlan1 up
root@kali:~# iw reg get
country GY: DFS-UNSET
(2402 - 2482 @ 40), (N/A, 30), (N/A)
(5735 - 5835 @ 80), (N/A, 30), (N/A)

So now I should be able to edit TX Power to max 30 dBm

Lets check what value it is for now:

root@kali:~# iwconfig wlan1 | grep Tx
Tx-Power=20 dBm

and try change it to 30

root@kali:~# iwconfig wlan1 txpower 30
root@kali:~# iwconfig wlan1 | grep Tx
Tx-Power=20 dBm

Well... Nope. So am I able to set it to... eg. 15?

root@kali:~# iwconfig wlan1 | grep Tx
Tx-Power=20 dBm

Also it didn't work. So its look like there is no problem with "iw set reg" but "iwconfig wlan1 txpower" have no effect

root@kali:~# uname -a
Linux kali 4.0.0-kali1-686-pae #1 SMP Debian 4.0.4-1+kali2 (2015-06-03) i686 GNU/Linux

root@kali:~# iwconfig wlan1
wlan1 IEEE 802.11bgn ESSIDff/any
Mode:Managed Frequency:2.472 GHz Access Point: Not-Associated
Tx-Power=20 dBm
Retry short limit:7 RTS thrff Fragment thrff
Encryption keyff
Power Managementff

WiFi cart: ALFA AWUS036NHA

[Laserman75]

"iw reg set" will not work with ALFA AWUS036NHA !

You must edit the driver, follow this guide https://forums.kali.org/showthread.p...ght=AWUS036NHA

[buggie]

Guys it just doesn't work - believe me :-) I saw some tests and the singal strong/quality was the same. For eg. now on kali 2.0 i can change on my AWUS036H txpower to 33dBm (~2000mW) and the signal is same as on 20dBm (100mW).

wlan0mon IEEE 802.11bg Mode:Monitor Frequency:2.462 GHz Tx-Power=33 dBm
Retry short limit:7 RTS thrff Fragment thrff
Power Managementn

It is just a marketing babble. In those chipsets for eg. in AWUS cards you can't change TX Power!

For eg. in AWUS036H there were to versions. Manufacturer was claiming that ver1.0 has 500mW and ver2.0 has 1000mW, but the true is that, those chipsets had the same power, the difference was in antenna :-) ver 1.0 had 3dBi and ver 2.0 had 6dBi. After doing some calculations those +3dBi gives You theoretical 1000mW TX Power.

ver1.0 500mW = 27dBm
ver2.0 1000mW = 30 dBm

30dBm - 27dBm = 3dBm, so this is +3dBi antenna :-P

The power which manufacturer claims is the card + antenna So the best option is to buy GOOD ANTENNA :P for. eg. 12dBi omni directional. But remember BUY a GOOD ONE, not that for a few bucks.

[mokba]

of course it doesn't work. if you wish to make it happen please contribute in this thread: https://forums.kali.org/showthread.p...-via-UART-JTAG