1. InSSIDer- it is strange, but although I see on my note - Samsung NP 700Z5C- connected to 5 Gz channel with Usb N53, but InSSIder shows channels at 2.4Gz range only. I did not succeed to see 5 Gz there, but wireless net view shows it.
I do guess my note's broadcom wirelless card is not dual, maybe due to it. Maybe I have to play still with InSSIDer settings, too.
2. 5Gz channel is 48.
3. I have increased power - TX -until 100 mW on both bands being desperate due to 5Gz. Do you think need to decrease this until default?
4. Looks I did not see both antennas running at once. Will check signal strength being at home - in 3-4 hours...
Can you send a screenshot where you see 2 antennas?