set TXPOWER for awus036nh

Hey,

did anyone of you find a way to set the txpower for alfa awus036nh (rt2800usb) to 30 dbm ?
When i try:

iwconfig wlan2 txpower 8dbm
Error for wireless request "Set Tx Power" (8B26) :
SET failed on device wlan2 ; Invalid argument.

i also tryed
iw reg set BO
iwconfig wlan0 txpower 30dBm

any other ideas ?
thx

how aout puting the card first down with "ifconfig wlanX down" ---> "iw reg set BO" ---> ""ifconfig wlanX up" ... and dont forget to disconect from the network first :) how are you doing with that card on Kali 1.0.3 ?