In the specifications of the new 6ghz SXT en Dynadish the max frequency of the hardware is 6.4 GHZ but is this the exact max frequency ? licences band start here at 6425 Mhz.
So is it possible to set the freq just above the 6.4Ghz ? some kind of superchannel mode ?
I suspect that is the highest frequency of the wireless chipset in the wireless board.
A note - you may want to avoid extream near-limits of the wireless chipset. I have had some wireless cards brick on me when simply performing a scan/freq-usage with the scan list set at the maximum high/low limits.