The default TX-Power of wireless adapters in Kali linux is set to 20 dBm. You can however increase that value making it operate at 30 dBm allowing you to have clearer and stronger signals. Be warned though that raising the power is actually illegal in some countries.
And as a side note this is not something that works for all wireless cards and if you set the power to high for to long their is a chance of messing up your wifi card as the manufacturer may have not provided an adequate heat-sink for your device to operate at such a high level.
Commands To Use:
ifconfig wlan0 down
iw reg set BO
ifconfig wlan0 up
iwconfig wlan0 txpower 30
Following video is the whole process as well as a little showing how it affects your reception, All commands and why they where used are in the comments of the video on youtube Video URL: http://youtu.be/-7dpNNB-c50
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