Increasing the TXpower above what is allowed in your country can be illegal. If you decide to make these changes to your system and use the wireless above the allowed legal limit, that is down to you and I will not be held responsible. This document is for educational research only and should not be used for any illegal purposes.
having said that…. let get on with it.
You will need to download and install some bits to get this to work
apt install multiarch-support pkg-config python-m2crypto libgcrypt11-dev
dpkg -i *.deb
you need to download these two files wirelessregdb and crda
tar zxf wireless-regdb-2014.06.13.tar.gz
git clone https://git.kernel.org/cgit/linux/kernel/git/mcgrof/crda.git/
Extract the files from the tar.gz file
after you’ve extracted all files to their folders, go to the Wireless-regdb folder and right click and open up a terminal
this will open the db.txt and you can edit it to your needs. you will notice the country 00, it is the world regulatory domain and that is applied before everything else so in this case you will have to comment out all of the country code 00 section
You now want to look for your county code and replace those values with the ones for GB country (or whateveryour country code is). do that and then you can change (20) to anything you want like (30) or (33). if you want to use 5.8Ghz channel, change both values. (33 dBm gives you 2W so i assume you know what that means. = !!!!!!!DANGER!!!!!!)
go back to Wireless-regdb directory and edit the makefile, on kali linux 2.0 you need to remove the /usr on the /usr/lib/crda on the 3rd line down.
Then save it and then do a “Make” in the same folder. this will create some additional files including regulatory.bin that we need.
copy the regulatory.bin file to /lib/crda directory and replace it but if you want you can backup the original file before replacement.
exit the folder and go back to Wireless-regdb folder on your desktop and find all files with extension of (.pem), copy them all and paste them into the gitcloned crda/pubkeys folder on.
now it’s the last step, go back to your crdafolder in terminal and type these commands
you now want to type
modprobe cfg80211 ieee80211_regdom=GB
Restart the machine / VM and do a :
iwconfig wlan0 txpower 30
You now have a stronger TXpower for your wireless testing.
This resolved it for me, remember to only add power that the wireless adapter can take, in my case its the ALFA AWUS036ACH