[USRP-users] uhd_cal_tx_iq_balance skips wide frequency range

Michael West michael.west at ettus.com
Thu Oct 9 15:03:08 EDT 2014


Hi Urban,

If I am understanding you correctly, you are saying that there is no
calibration data for those frequencies in the resulting file.  That does
not mean the frequencies are being skipped by the utility.  That only means
that a suppression of over 30 dB could not be achieved for those
frequencies, so no correction data was saved.  You can set a lower
threshold for the minimum suppression by changing the value in the
following line in each IQ calibration utility:

        if (best_suppression > 30){ //most likely valid, keep result

Best regards,
Michael

On Thu, Oct 9, 2014 at 8:57 AM, Urban Hakansson via USRP-users <
usrp-users at lists.ettus.com> wrote:

> Hi everybody,
>
> I am trying to calibrate my N210 SBX daughterboard using the three
> calibration scripts uhd_cal_rx_iq_balance, uhd_cal_tx_iq_balance,and
> uhd_cal_tx_dc_offset using different values for freq_start, freq_stop, and
> freq_step.
>
> uhd_cal_tx_iq_balance utility that is not behaving as I expected.
> (uhd_cal_rx_iq_balance and uhd_cal_tx_dc_offset give me no problems).
>
> If I run uhd_cal_tx_iq_balance with any other values besides the default
> values it will skip approximately 300MHz of frequencies from 790 MHz to ~
> 1100MHz.
>
> Here are a few of my attempts.
>
> uhd_cal_tx_iq_balance --freq_start 500000000
> uhd_cal_tx_iq_balance --freq_start 600000000
> uhd_cal_tx_iq_balance --freq_start 700000000
> uhd_cal_tx_iq_balance --freq_start 785000000
> uhd_cal_tx_iq_balance --verbose --freq_step 100000
> uhd_cal_tx_iq_balance --verbose --freq_step 110000
> uhd_cal_tx_iq_balance --verbose --freq_step 225000
> uhd_cal_tx_iq_balance --verbose --freq_step 900000
> uhd_cal_tx_iq_balance --verbose --freq_step 1000000
> uhd_cal_tx_iq_balance --verbose --freq_step 1100000
> uhd_cal_tx_iq_balance --verbose --freq_step 2000000
> ...
> uhd_cal_tx_iq_balance --verbose --freq_step 7300000
>
> uhd_cal_tx_iq_balance always stops just before 790MHz and just sits there,
> but does not abort, and after a really long time continues at ~ 1100MHz and
> continues all the way to 4370MHz without any further gaps.
>
> I attach the calibration scripts I am using and the three csv files for
> one example, uhd_cal_tx_iq_balance --verbose --freq_step 225000.
>
> General background information about my environment:
> Fedora 17 Linux; GNU C++ version 4.7.0 20120507 (Red Hat 4.7.0-5);
> Boost_104800; UHD_003.007.001-0-unknown
>
> N210 informationfrom uhd_usrp_probe:
> | Device: USRP2 / N-Series Device
> | _____________________________________________________
> | /
> | | Mboard: N210r4
> | | hardware: 2577
> | | mac-addr: 00:80:2f:0a:e6:15
> | | ip-addr: 192.168.2.199
> | | subnet: 255.255.255.255
> | | gateway: 255.255.255.255
> | | gpsdo: none
> | | serial: F4A09C
> | | FW Version: 12.4
> | | FPGA Version: 10.1
>
> What could the cause of this behaviour be?  Are there only certain
> combination of values that work? What do I need to do to make
> uhd_tx_iq_balance not hang right before 790MHz?
>
> Thanks for you consideration.
>
> Regards,
>
> Urban Hakansson
> Senior Software Engineer
> Tecore Networks
> Phone: +1 410 872 6315
> Fax: +1 410 872 6010
> Email: uhakansson at tecore.com
>
>
> Urban Hakansson Senior Software Engineer Tecore Networks Phone: +1 410
> 872 6315 Fax: +1 410 872 6010 Email: uhakansson at tecore.com
>
> Urban Hakansson
> Senior Software Engineer
> Tecore Networks
> Phone: +1 410 872 6315
> Fax: +1 410 872 6010
> Email: uhakansson at tecore.com
>
>
>
>
>      This e-mail may contain privileged, confidential, copyrighted or other
> legally protected information, and is intended exclusively for the intended
> recipient.  If you are not the intended recipient (even if the e-mail
> address above is yours), you may not review, store, use, copy, disclose or
> retransmit it in any form.  If you are not the intended recipient or
> otherwise have received this by mistake, please immediately notify the
> sender by return e-mail (or sysadmin at tecore.com), then delete the message
> in its entirety. Thank you.
> _______________________________________________
> USRP-users mailing list
> USRP-users at lists.ettus.com
> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20141009/1d73cb62/attachment-0002.html>


More information about the USRP-users mailing list