# UHD Calibration

**URL:** <https://www.ruby-forum.com/t/uhd-calibration/214846>\
**Category:** GNU Radio\
**Created:** [December 13, 2011, 6:18pm UTC](https://www.ruby-forum.com/t/uhd-calibration/214846 "2011-12-13T18:18:47Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\
**Post date:** [December 13, 2011, 6:18pm UTC](https://www.ruby-forum.com/t/uhd-calibration/214846/1 "2011-12-13T18:18:47Z")

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I would like to say that I just received a new N210 and am very happy  
with  
the quality and performance of the device. I have started to  
familiarize  
myself with the included utilities and have run the uhd\_cal\_\* routines.

My question is does repeated runs of the calibration increase the  
performance? For example, does running the sequence  
uhd\_cal\_tx\_iq\_ballance,  
uhd\_cal\_tx\_dc\_offset, uhd\_cal\_tx\_iq\_ballance, uhd\_cal\_tx\_dc\_offset  
produce  
better calibration than just the sequence uhd\_cal\_tx\_iq\_ballance,  
uhd\_cal\_tx\_dc\_offset?

Evan M.

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**Author:** ![Evan\_M](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/cab0a1/32.png) [@Evan\_M](https://www.ruby-forum.com/u/Evan_M)\
**Post date:** [December 13, 2011, 6:55pm UTC](https://www.ruby-forum.com/t/uhd-calibration/214846/2 "2011-12-13T18:55:56Z")

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On 12/13/2011 09:17 AM, Evan M. wrote:

> I would like to say that I just received a new N210 and am very happy with  
> the quality and performance of the device. I have started to familiarize  
> myself with the included utilities and have run the uhd\_cal\_\* routines.

Thanks!

> My question is does repeated runs of the calibration increase the  
> performance? For example, does running the sequence uhd\_cal\_tx\_iq\_ballance,  
> uhd\_cal\_tx\_dc\_offset, uhd\_cal\_tx\_iq\_ballance, uhd\_cal\_tx\_dc\_offset produce  
> better calibration than just the sequence uhd\_cal\_tx\_iq\_ballance,  
> uhd\_cal\_tx\_dc\_offset?

I guess the idea is that the transmit calibration is somehow more  
accurate after receive has been calibrated. Thats possible, but I  
haven’t observed it in practice. If I had to make a recommendation, I  
would say to run the RX IQ cal first.

-Josh

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**Author:** ![Evan\_M](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/cab0a1/32.png) [@Evan\_M](https://www.ruby-forum.com/u/Evan_M)\
**Post date:** [December 13, 2011, 11:13pm UTC](https://www.ruby-forum.com/t/uhd-calibration/214846/3 "2011-12-13T23:13:13Z")

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Evan M. wrote in post #1036544:

> I would like to say that I just received a new N210 and am very happy  
> with  
> the quality and performance of the device. I have started to  
> familiarize  
> myself with the included utilities and have run the uhd\_cal\_\* routines.
> 
> My question is does repeated runs of the calibration increase the  
> performance? For example, does running the sequence  
> uhd\_cal\_tx\_iq\_ballance,  
> uhd\_cal\_tx\_dc\_offset, uhd\_cal\_tx\_iq\_ballance, uhd\_cal\_tx\_dc\_offset  
> produce  
> better calibration than just the sequence uhd\_cal\_tx\_iq\_ballance,  
> uhd\_cal\_tx\_dc\_offset?
> 
> Evan M.

Another questions… should I terminate the inputs/outputs (i.e. 50ohm)?

-Mark