For those who use Kali for wireless penetration testing I've created some software which may help & I believe solve the tx power to 33dbm which has come up on a few forums. Please check it out at GitHub. There are three flavours which cover extensive use, just basic wardriving and pen testing and a version for raspberry pi. Links are as follows:
https://github.com/smoz1986/WHAT.git
https://github.com/smoz1986/WHAT-PRO.git
https://github.com/smoz1986/WHAT-Pi.git
