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Nutcracker
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Tx Power not changing anything

Tue Aug 13, 2013 4:20 pm

Hi all

I have been digging around a bit but couldn't find anything, so decided to try my luck with a new post.

We recently got 2 x RB912UAG-5HPnD to test with and see how they perform versus Ubiquiti Rocket M5's. Thusfar, we have not gotten the greatest results, but as I keep telling the higher ups, it is a work in progress.

Here are the current link details:
5GHz AirMax Dish 30dBi on each side with the RB912UAG-5HPnD connected to it running ROS 6.2(firmware 3.07)
Signal is sitting around -47dBm
Link length is 7.6Km
Noise Floor is -104dBm on the one end and -109dBm on the other end

Now as I understand it, it is better to drop the radio cards output power to reduce the error correction rate or some such. While I can reduce the power of the radio by sing the "all rates fixed" setting, I can not reduce the power with the "card rates" setting.
I have gone as low as -30 with when using "card rates" and the signal still sits at -47, where as if I use the same on "all rates fixed" the link doesn't establish(naturally).

What it all comes down to is that I would like to get as much as possible out of the link as I can, and any help would be appreciated.

If any more info is needed it can be provided.
 
FabFab10
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Re: Tx Power not changing anything

Tue Aug 13, 2013 5:09 pm

-47 is a bit too much for this type of devices, actually you are using 30 dbi antenna for a medium distance link.
What about your CCQ??
It's pretty strange that you can't lower the power , have you tried both "card rates" and "all rate fixed"?

Another way is to put something like 15 in "antenna gain" inside "wireless" tab.
Since the EIRP should be 30 dbm, by inserting 15 db in antenna gain it should lower TX power to 15 db.

let us know how it's going.
 
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kwagga
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Re: Tx Power not changing anything

Wed Aug 14, 2013 11:32 am

I also want to know why card-rates with a manually specified value, doesn't lower the tx output?...


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uldis
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Re: Tx Power not changing anything

Wed Aug 14, 2013 12:17 pm

for the new atheros chipset board you need to use all-rate-fixed option or use antenna-gain when you have frequency-mode=regulatory-domain
 
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kwagga
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Re: Tx Power not changing anything

Wed Aug 14, 2013 3:39 pm

for the new atheros chipset board you need to use all-rate-fixed option or use antenna-gain when you have frequency-mode=regulatory-domain
Thanks for the heads-up Uldis, may I suggest we add it to the wiki: http://wiki.mikrotik.com/wiki/Manual:Interface/Wireless
 
Nutcracker
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Re: Tx Power not changing anything

Fri Aug 16, 2013 12:16 pm

Thanks for the update indeed. I have tried dropping the TX power by shuffling the antenna gain and power rates till I got the signal around -60, but I am getting much worse reults than just keeping it all default.

While I am fine blasting away and getting my speed for now, I would like to start moving towards using what I need to reduce the over all interference we put out.

My CCQ's aren't looking to hot. Sitting around the 60's, doesn't matter what frequency I am using.

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