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hytanium
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Power-Offset SR5 and SR9

Thu Aug 16, 2007 4:34 am

Please,...can someone give me a clear answer?

I run the SR5 @ 26dbm cardrates setting and SR9 @ 28dbm cardrates setting on version 2.9.45.

It this right? Or is this wrong. Ubiquity just published a study on thier website suggesting we choose default for these cards... For example the SR9 shows in winbox advanced status shows 26dbm rather than the 28dbm it is capable of.
The SR5 set to default shows 16dbm.

On another note, I changed my XR5 backhauls to default, and my links are 50% better and smoother.
 
0ldman
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Re: Power-Offset SR5 and SR9

Thu Aug 16, 2007 7:11 am

My SR9 showed 26dB default in 2.9.38 and 2.9.45.

I can't speak for the other cards.
 
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Equis
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Re: Power-Offset SR5 and SR9

Mon Aug 20, 2007 2:46 pm

Hello,

Can I bump this post :-)

If I set manual power to 10 with sr/xr will it output 10 or 10 + whatever it's amp is (10?)

I would like these cards becuase they hear better but must stay legal (low power output)

Thanks

:-)
 
hytanium
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Re: Power-Offset SR5 and SR9

Mon Aug 20, 2007 3:30 pm

Like I was mentioning in the previous post, If I set the SR9 to default: in the Advanced Status tab of a WDS client its shows:

6Mbps-26dbm
9Mbps-26dbm
18Mbps-26dbm
24Mbps-26dbm
36Mbps-24dbm
48Mbps-21dbm
54Mbps-19dbm

If I set the SR9 to Cardrates @ 28dbm: in the Advanced Status tab of a WDS client its shows as it should:

6Mbps-28dbm
9Mbps-28dbm
18Mbps-28dbm
24Mbps-28dbm
36Mbps-26dbm
48Mbps-23dbm
54Mbps-21dbm
All I want to know is if this is right? The whole power offset thing does not make sense according to these findings? MIKE, can you shed some light on this. I use version 2.9.45 of MT OS.
 
Gerard
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Re: Power-Offset SR5 and SR9

Mon Aug 20, 2007 5:40 pm

Read the white paper..
Using power setting override can lead to a variety of problems and it is highly recommended that the
default power settings be used for all Ubiquiti cards. The only instance the power settings should be
used is to lower the overall power
. However, when lowering the power, it is important to note that
higher data rate power must be kept at specifications in line with Ubiquiti's datasheets in order to
ensure smooth error-free throughput. Below is a table of Ubiquiti cards, power offset information,
and whether Mikrotik has implemented correction for the offset (as of 8/2007).
-Gerard
 
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Equis
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Re: Power-Offset SR5 and SR9

Tue Aug 21, 2007 2:58 am

Thanks!

Thats what I was after :-)
 
transporter_ii
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Re: Power-Offset SR5 and SR9

Tue Aug 21, 2007 4:05 am

This is an aggravating subject for me, and I have posted about it before.

If you really want to pull some hair, buy a good quality power meter that checks the power out straight from the card. We have a Berkeley Varitronics Systems Wi-Fi Power Analyzer called a Caterpillar. It is worth the money because you start to see what is REALLY coming out of the radios.

We have numerous cards on default power levels that put out far less than the cards rate, but if you ask about this, you are told never to manually set the cards rates, as you could burn the radio up (how can it burn a card up to put out the full power it is rated for?).

I'm going to flat out say that I'm NOT REFEREEING TO MIKROTIK here, but other manufactures are selling equipment that says it is putting out, say 24 dBm, when in fact it is putting out less than half of that. We busted someone just today doing that exact same thing...and they flat out admitted the literature for the card was not correct. If we had not had the analyzer, we wouldn't have known.

But it is frustrating with Mikrotik as well, because some cards just put out the right power right out of the shrink wrap (our last XR2's did), and others do not.

And if you do not have a power analyzer, you will never know.

At some point, we thought our Analyzer was off, but when it says the output is low, the APs do not get the range they should, so I think it is right. It is also my personal opinion that people have paid extra money for high-powered cards, and did not get anywhere close to what they should have out of those cards.

What I wish is if more people would spend the money for the power analyzers...because then more people might be getting vocal about this issue...

Just my two cents.

transporter_ii
 
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Equis
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Re: Power-Offset SR5 and SR9

Tue Aug 21, 2007 4:36 am

Thanks!

My problem is I need to be right on the limit of 36db at the antenna, no more

as you know a couple of db make all the difference so I want to be sure I am on the edge :-)

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