On 'HT' tab find 'HT Extension Channel' and set it to 'above control' or 'below control'. 40MHz.JPG Your channel will be 40MHz wide. Regards, Grzegorz. I have changed on 'HT' tab 'HT Extension Channel' and set it to 'above control' or 'below control'. But I don't see a 40MHz in the 'Channel width' ...