N66U - Transmission Power Max on 374.43 and 374.36b

[Brawn]

Hi everyone!

I have the US model of the N66U. I read that the max transmission power that you can set is 500mw, but on my current firmware (374.36b), it is limited to 200mw. Why is this?

(I believe that it was also limited to 200mw on John's 374.43 fork)
I checked the country/regulation settings in telnet and 2.4ghz's country/regulation is US, whereas 5ghz is set to Q2

Please advise!

 

[jim769]

Hi everyone!

I have the US model of the N66U. I read that the max transmission power that you can set is 500mw, but on my current firmware (374.36b), it is limited to 200mw. Why is this?

(I believe that it was also limited to 200mw on John's 374.43 fork)
I checked the country/regulation settings in telnet and 2.4ghz's country/regulation is US, whereas 5ghz is set to Q2

Please advise!

You should think about upgrading your firmware to at least John's fork. Your current firmware is full of bugs and security issues. Running 500 mw with antennas that have 3-5 db gain such as on the N66U would be illegal in the US.

 

[Brawn]

according to the FCC regulations found here: http://www.air802.com/fcc-rules-and-regulations.html
and the antennas being 3.5dbi each, i calculated that the max transmission power should be 1786mw for a total EIRP of 4w

regardless, from what i've read and understand, people with US N66U units could increase their transmission power to 500mw straight out of the box (without any nvram editing)

here's an example source: http://www.dd-wrt.com/phpBB2/viewtopic.php?p=700989

Adjustable power has always been a known and documented feature of this router. The default value is 80mw. If you are in an unrestricted zone (like North America), you can boost 2.4 GHz up to 500 mw, and 5 GHz up to 250 mw. Those limits are lower in Europe.

Edit: WOAHHH didn't notice i was quoting the almighty RMerlin on the DD-WRT forums

 

[jim769]

according to the FCC regulations found here: http://www.air802.com/fcc-rules-and-regulations.html
and the antennas being 3.5dbi each, i calculated that the max transmission power should be 1786mw for a total EIRP of 4w

regardless, from what i've read and understand, people with US N66U units could increase their transmission power to 500mw straight out of the box (without any nvram editing)

here's an example source: http://www.dd-wrt.com/phpBB2/viewtopic.php?p=700989



Edit: WOAHHH didn't notice i was quoting the almighty RMerlin on the DD-WRT forums

I am no expert when it comes to legal power output on home routers but you might be interested in this thread. Although the download link is down till hggomes post his source code. Read thread to understand why.

http://forums.smallnetbuilder.com/showthread.php?t=21489

 

[Brawn]

wow, so much drama in that thread.. thanks for the read

 

[john9527]

according to the FCC regulations found here: http://www.air802.com/fcc-rules-and-regulations.html
and the antennas being 3.5dbi each, i calculated that the max transmission power should be 1786mw for a total EIRP of 4w

That's for point-to-point, i.e. using directionally tuned antennas. The regulation for indoor home use is EIRP = 1W.

regardless, from what i've read and understand, people with US N66U units could increase their transmission power to 500mw straight out of the box (without any nvram editing)

here's an example source: http://www.dd-wrt.com/phpBB2/viewtopic.php?p=700989



Edit: WOAHHH didn't notice i was quoting the almighty RMerlin on the DD-WRT forums

Everybody gets a bit confused on setting the power going to the antennas (what is what is set in the gui) vs the EIRP which takes into account the antennas' added gain and what really matters.

If you run through the math (exercise for the reader - use 4dBi average gain for the antenna since it actually varies with freq and you want some margin)

80mW set in the gui = 200mW EIRP
200mW set in gui = 500mW EIRP

 

[Brawn]

are you sure it's for point to point? the site seems to suggest that 4w eirp is for point to multipoint though

 

[john9527]

are you sure it's for point to point? the site seems to suggest that 4w eirp is for point to multipoint though

When this whole discussion started, I took the time to try and wade through the actual FCC reg (I think it's part 15 if I remember correctly) and that's what my interpretation was. But, I've honestly seen other document quotes and interpretations that seem to say otherwise. Finally, I just gave up...