Dear crispyoz! Thank you for answer. I saw the document, but as you wrote " Since the warp core driver is not documented or open source it may not implement all functions", it's a current status. Interesting, that in 2016, was a similar issue: https://community.onion.io/topic/1138/connecting-the-omega2-to-wifi-channels-12-to-14-for-non-us-users

I think, RnD team must to know, when we change option country, or option htmode, or option channel parameters in file /etc/confog/wireles, system behavior becomes unstable.
Every 5 seconds the system freezes and does not respond on ping for 1-2 seconds.
My problem, that sometime system wakes up on Channels 10/11/12, but we can not use these channels, according to regulation acts.
In case, that issue hasn't solution, we can not use Onion Omega in our product.

I tried to define static AP channel. As I understand it defined in
/etc/config/wireless:
option channel 'auto'
I changed it to '1'.
uci show wireless print me:
config wifi-device 'radio0'
option type 'ralink'
option variant 'mt7628'
option country 'US'
option hwmode '11g'
option htmode 'HT20'
option channel '1'
option disabled '0'
option device_mode 'apsta'
option op_mode 'preference'

But see AP on channel 12, configuration still not works.
Some idea?
Thank you, Shimon