I am running Backtrack 4 R2 on a inspiron 6400 and i have added a TL-WN7200ND.
My problem is that when run iwconfig
wlan0 IEEE 802.11bg ESSID:"TOSTCAF"
Mode:Managed Frequency:2.467 GHz Access Point: 00:26:5A:D1:E1:1A
Bit Rate=36 Mb/s Tx-Power=20 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:off
Link Quality=48/70 Signal level=-62 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

wlan1 IEEE 802.11bgn ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=17 dBm[/COLOR]
Retry long limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:on
The maximum txpower of my TL-WN7200ND is @ 17 dBm witch is way to low considering that the internal wlan adapter is running at 20. Anyway 500mW witch is the supposed output power should be around 26 - 27.

As far as the adapter goes airmon , airodump works fine , injection test are ok but i haven't tested injection on a network without clients yet.

ls usb:
Bus 001 Device 003: ID 148f:3070 Ralink Technology, Corp. RT2870/RT3070 Wireless Adapter


Interface Chipset Driver

wlan0 Broadcom b43 - [phy0]
wlan1 Ralink RT2870/3070 rt2800usb - [phy1]
to get around this problem both ndiswrapper - no change in txpower and compat-wireless drivers including aircrack patches - still no luck

any further guidance to get the txpower up would be very much appreciated.

p.s for iwconfig wlan1 txpower ( any value lower than 17 ) the comandline works. any value above :
iwconfig wlan1 txpower 20
Error for wireless request "Set Tx Power" (8B26) :
SET failed on device wlan1 ; Invalid argument.