Hello,
I use Point to Point between a Mikrotik (sxt 5hpnd) as Transmitter and Ubiquiti (Nanostation5) as Receiver, From the Mikrotik AP I use 20/40mhz eC, Ce and use a frequency like 5800(which exist on Nanostation frequency list) and then change the country to USA or Australia but, from Nanostation receiver when I use 40Mhz and searching for the AP it can't find it, I must change 40Mhz to 20Mhz from Nanostation then searching I can find the AP, the question is here I want to send the Internet with 40Mhz and receive it also with 40Mhz.

Thanks Please help me it's very important to me...

A few days ago I was playing with similar setup (PtP link on 5GHz) and I had a similar problem. I was using two hAP ac lites (so Mikrotik on both sides).

One thing: according to wikipedia list of channels, frequency 5800 doesn't seem to be a valid channel, it seems like one should choose either 5785 or 5805 MHz for 20MHz channel. It also seems to me (or I understand the table wrongly) that if you want to use 40MHz channel in eC arrangement, you really should use 5805 because this frequency marks the centre of upper half of allowed 40MHz channel (with its centre at 5795MHz).

But then things got weirder: if I selected country=Brazil on both ends, link worked really nice. If I selected US or Australia (according to wikipedia table and country-info from ROS it should be fine as well) it did not work. So that link is officially in Brazil now

The problem I've had during my experimentation was that both devices were remote and the second one could only be accessed through working PtP link via the first one. So the process of finding out working setup was slow and painful.

@mkx Thank you,
but from Nanostation when I choose 40Mhz and country set to the USA only just two Channels available 5760 and 5800.

do have any solution?

please help.......?