mkx am sure you can set lower antenna Gain, lest say 1dbi.. i ve tested it in a rb951ui 2hnd and recently on a 952…
So what happens when i set it to 1 dbi and i use regulatory domain while my actual antenna gain is 2 dbi? Will my total Tx power be +1 dbi more than it should be or not? Does ROS ignore the 1 dbi since it knows its antenna is 2dbi?
Just tried on my RBD52G running ROS 6.45.1 and country properly set.
When I tried to set antenna-gain=0 on 2.4GHz wireless, it complained with “failure: minimal antenna-gain for this country is 3” … So it seems to me that ROS wants me to stay legal 
I’m not sure if minimum antena gain feature was retrofitted to older models or is it only available for recent ones …
mkx you are right… i got confused…
Tried again in a 951 and same for me, " minimal antenna gain for this country is 3 (6) "
mkx can i contact you for a post here i need some help?
Now I see this too: just needed to try more countries 
Yes… it lets you set Gain to 0 for some Countries… i dont know why…
I think that’s because for some devices and some countries you can work on max tx-power without breaking any rules.
One thing remains now, does a product that is indicated in the datasheet with lets say 28 dbm Tx power include the Antenna’s Gain which is for example 12 dbi or not ?
You are confusing different things.
TX-power indicates the total amount of power radiated, it will not change if you change the antenna.
That is wrong…
If you set regulatory domain and you have a 6 dbi antenna Gain, if you go to current Tx power tab you will see two values… one with lets say Tx power 10dbm and one indicated as total Tx power witch will be 16 dbm (10 Tx+6 Gain)…
Besides that, EiRP which is the effective radiated power is exactly that, for the values above it would be EiRP= 10 - 0 + 6 = 16 dbm , in case there are no losses…
So the total radiated power has two factors, the Tx power of our transmitter and the Antenna’s Gain…
Nope.
TX-power and Total TX-power indicate values for one chain and for all enabled chains.
The difference between them has nothing to do with antenna gain.
That is totally wrong.
TX-power is a characteristic of the radio emitter, totally independent from the used antenna.
Antenna gain shows the distribution of this power in space (compared with an isotropic antenna, which radiates equally in all directions).
EIRP is a characteristic of a point in space - it shows TX-power needed on a theoretical device with isotropic antenna to have the same signal strength, that is actually measured.
xvo, if i have a 802.11 n card with lets say both chains enabled, if my Tx power is 10 dbm and the antenna Gain is 3 dbi then the total Txpower will be 13 dbm…
Without changing anything with the chains,still using 2 chains, if i set the Gain to 6 dbi then the total Txpower will be 16 dbm…
The wiki talks about changing the number of the chains 1, then 2 then 3 and how Tx power is affected by that
Again, the EiRP shows the power radiated, and that is the power that should be inside the legal limits, and TX + Gain give us the final dbm value… i dont understand why you say that Gain has nothing to do when thetr is a formula for that thing…
Have you tried it?
If you have tx-power-mode=default, antenna-gain=3dbi and tx-power/total-tx-power=14/17dbm and then change to antenna-gain=6dbi you will end up with 11/14dbm!
Because the device lowered the Tx-power to stay inside the regulations.
Seriously, just try it.
You can use tx-power-mode=all-rates-fixed, and see that setting antenna gain has no impact on total tx power.
Yes!
Tx-power + gain will give you the maximum theoretical signal that you can achieve!
So to be inside the regulations it has to be lower than specified EIRP!
But gain don’t change tx-power, you (or your device) need to do it.
But gain don’t change tx-power, you (or your device) need to do it.
No it wont change the Txpower, however it affects it in other ways…
For, example the Txpower will get lower and lower as we increase the Gain in order to stay legal…
And also if lets say i use an Antenna with a Gain of 6 dbi instead of one with 3 dbi, its like"doubling" the power because of the better directivity, concentration and distribution of the radiated power…
All of that is true, but I never said the opposite.
And it is not what we were arguing about.
I only pointed that you have a misunderstanding of the physics of the process.
Tx-power can’t include antenna gain, because they are two different things.
And indeed it is not included.
And I also corrected you about the meaning of tx-power and total tx-power columns, and that the difference between them has nothing to do with antenna gain.
And indeed it hasn’t.
You can test all the above:
I just thought that the Total Tx power in ROS had the meaning of EiRP, thats why i wondered if the gain is included… 
leave only one chain.
2) set any european country and your minimal gain of 3.
3) you get 17dbm per chain and 17dbm total: 17+3 will be exactly the allowed 20dbm
4) enable the 2nd chain and you will get 14dbm per chain and 17dbm total - again >
Looks correct…
So I guess all the questions are of the table now
The main thing we figured out: Mikrotik in regulatory-domain mode won’t let us break the law after all…
…For that we have manual-tx-power and superchannel! 
In RouterOS 6.47.10 (May/31/2021) I had to set Frequency Mode to regulatory-domain first (and press Apply button). Then switch Installation to any [or indoor] (and press Apply button) to be able to connect to the indoor 5 GHz network.
I checked the status of the wireless interface (connection/disconnection/error state) by enabling debugging output in the Log window:
[admin@MikroTik] > /system logging
[admin@MikroTik] system logging> add topics=wireless,debug action=memory
I’m unable to set Country still to anything than no_country_set (the error message is: Minimal antenna gain for this country is 16 (6) and I don’t know what to set in Tx power mode.
ON WinBox Push the “Reset Configuration” button when open wireless interface, then select your country,
then do not touch anything to do with “power”, then configure the rest, on this way you do not rmp i cglion to the neighbors.