Can't obtain 300mbps/300mbps

Hello,
I have two routerboards
RB951g-2hnd and
RB951-2n
I can’t obtain 300mbps wds link, it is also max 150/150 also using chain0 and chain1 in TX and RX. 40mhz eC
I tried to enable mcs-15 in ht basics but if it 's enabled nobody can Connect, also the other routerboard with MCs 15 enabled.
What can i do?

See the spectral scan and select the clear frequency.

Max speed for RB951-2n is 150Mbit.
For 300Mbit you need dual chain “D” routerboard. For example 2x rb951G-2HnD

Oh. I have overlooked that one of his devices does not have dual chain radio…

and rb951-2n has the worst radio i have tested on mikrotik

works well but

very low tx power and very poor sensitivity