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Why is IQ cal disabled when using external LO

EG
Eugene Grayver
Tue, Dec 10, 2024 6:42 PM

Hi,

I just noticed that the calibration tables are disabled/ignored when external LO is used.  Why is that?  I understand that the automatic calibration utilities will not work (over frequency).  However, we are generating those tables ourselves, and expect UHD to use them.  Now I have to hack my own code to duplicate the calibration functionality and 'manually' call set_dc_..., etc functions.

Thanks.

Hi, I just noticed that the calibration tables are disabled/ignored when external LO is used. Why is that? I understand that the automatic calibration utilities will not work (over frequency). However, we are generating those tables ourselves, and expect UHD to use them. Now I have to hack my own code to duplicate the calibration functionality and 'manually' call set_dc_..., etc functions. Thanks.
MD
Marcus D. Leech
Tue, Dec 10, 2024 9:05 PM

On 10/12/2024 13:42, Eugene Grayver wrote:

Hi,

I just noticed that the calibration tables are disabled/ignored when
external LO is used.  Why is that?  I understand that the automatic
calibration utilities will not work (over frequency). However, we are
generating those tables ourselves, and expect UHD to use them.  Now I
have to hack my own code to duplicate the calibration functionality
and 'manually' call set_dc_..., etc functions.

Thanks.

I guess because the CAL* utilities run the chip in local-LO mode, and
the IQ and DC cals are only valid for it.

Now, your point about producing those tables yourself is actually a good
point, and I think this constitutes a
  feature request...

On 10/12/2024 13:42, Eugene Grayver wrote: > Hi, > > I just noticed that the calibration tables are disabled/ignored when > external LO is used.  Why is that?  I understand that the automatic > calibration utilities will not work (over frequency). However, we are > generating those tables ourselves, and expect UHD to use them.  Now I > have to hack my own code to duplicate the calibration functionality > and 'manually' call set_dc_..., etc functions. > > Thanks. > I guess because the CAL* utilities run the chip in local-LO mode, and the IQ and DC cals are only valid for it. Now, your point about producing those tables yourself is actually a good point, and I think this constitutes a   feature request...