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Ticket #2115 (new defect)

Opened 11 years ago

Last modified 10 years ago

new 20080815 hal doesn't correctly set tx power on Ubiquiti XR2

Reported by: Assigned to:
Priority: major Milestone:
Component: madwifi: HAL Version: trunk
Keywords: XR2 power setting broken Cc:
Patch is attached: 0 Pending: 0


I've got a power meter and I measured the peak output power of a Ubiquiti XR2 card using the HAL provided by Ubiquiti (ubnt-hal-0.7.379), and the peak output power was measured to be 1.1W. I've talked to Mike Ford at Ubiquiti and verified that this output was correct / expected.

Using the new 20080815 HAL peak output power on the same XR2 appears to be only around 340mW .. this is substantially lower than even a Ubiquiti SR2 card, where I've measured peak output power at 480mW using this new 20080815 HAL ..

In the past I've noticed that with hal, power setting is similarly broken on XR2, XR5, and XR9.


Change History

09/04/08 12:39:02 changed by BrainSlayer

the power setting is not broken. the ubiquiti card uses a internal not visible extra amplifier. but this doesnt count for the madwifi hal. you set your txpower as required. thats all. (16 dbm max internal settings for ubiquiti XR cards) the ubiquiti hal is different and does internally show out the real power by adding the amplifier value which is about 10 dbm for XR cards.

so i assume. you cannot compare power settings with madwifi and the standard hal with the ubiquiti hal. within my own products i use the new madwifi hal since a long time and i didnt had any problems with output power. we always measured the correct value

11/15/08 01:08:52 changed by anonymous

brainslayer, please read the bug report again. How does one set the txpower "as required" for maximum output power? I read "maximum" as not a number, but rather a procedure for adjusting the number until the attached power meter reads the highest power envelope. For testing "maximum," it should make no difference what the proprietary HAL is adding or subtracting, so the power with standard and ubiquiti HAL's _can_ be compared.

Your stated result with the XR agrees with the poster's result---the XR works and the XR2 does not.

You say you always measured the correct value. Again this applies only to the XR, not the XR2 about which the bug asks, but: how did you measure the the value, and how did you decide it was correct? The OP answered both for his measurement.

I think we need a new Usenet faq to go with "how to ask smart questions." maybe we call it "how to give answers that are not obstructionist."

11/15/08 03:14:49 changed by

Brainslayer appeared to not have read "I used an external power meter" to read the output power .. this is a physical hand-held device - and not cheap - it cost around $1000 US .. Reading his answer I can only assume that he thought I was looking at values returned by the HAL itself.

I'm not sure that I understand why ubi hasn't fed the magic incantation, if one is required, to fully power the amplifiers on their XR series cards back to madwifi ...