Why is channel 140 not present for Europe (or maybe just a specific country)?
I have a document that describes the available frequencies in Europe and from it all I can see is that ch140 is allowed, however it's not present in the menus for our country (Slovenia). Are there some restrictions I have missed there?
Channel 140 is available for Slovenia country setting - set the 5 GHz channelization to 20 MHz and you should see Ch 140 option appear. This is because Ch 140 is right at the band edge where there is room for a 20 MHz channel but not a 40 MHz channel.