[USRP-users] problem with USRP example on X310 with CBX-120

Jim Hunziker jhunziker at bcisensors.com
Mon Oct 27 10:48:24 EDT 2014


Thanks. It looks like this patch isn't against 3.7.3. We're not running
against the master branch right now. Is this patch intended for 3.8-rc?


-- 
Jim Hunziker
BCI Systems and Software Engineering
(973) 348-9299
jhunziker at bcisensors.com

On Fri, Oct 24, 2014 at 5:55 PM, Michael West <michael.west at ettus.com>
wrote:

> Hi Jim,
>
> An experimental UHD patch was sent to your colleague to address the
> calibration issue.  Please let me know if you need the patch sent to you
> directly and I will get it to you.
>
> Best regards,
> Michael
>
> On Thu, Oct 23, 2014 at 10:40 AM, Jim Hunziker via USRP-users <
> usrp-users at lists.ettus.com> wrote:
>
>> Marcus Leech responded to me off-list that I was using gain settings that
>> were too low. Setting them to 10 greatly improved my signal, though there's
>> still a carrier component that's bigger than my signal and not getting
>> removed. A colleague tells me he's working with Ettus regarding this
>> problem.
>>
>>
>> --
>> Jim Hunziker
>> BCI Systems and Software Engineering
>> (973) 348-9299
>> jhunziker at bcisensors.com
>>
>> On Wed, Oct 22, 2014 at 4:42 PM, Jim Hunziker <jhunziker at bcisensors.com>
>> wrote:
>>
>>> It looks like some of my problem was plotting abs(sig_c) rather than
>>> real(sig_c), but the signal still doesn't look great.
>>>
>>>
>>> --
>>> Jim Hunziker
>>> BCI Systems and Software Engineering
>>> (973) 348-9299
>>> jhunziker at bcisensors.com
>>>
>>> On Wed, Oct 22, 2014 at 12:15 PM, Jim Hunziker <jhunziker at bcisensors.com
>>> > wrote:
>>>
>>>> Hi. I have an X310 with a CBX-120 and a GPSDO, and I'm running the
>>>> txrx_loopback_to_file example with UHD version 3.7.3 like this:
>>>>
>>>> ./txrx_loopback_to_file --tx-args addr=10.10.10.90 --nsamps=250000
>>>> --tx-rate 2500000 --rx-rate 2500000 --tx-freq 56000000
>>>> 00 --rx-freq 5600000000 --rx-ant CAL --wave-type SINE --ref internal
>>>> --wave-freq 1000
>>>>
>>>> (It makes no difference if I use the RX2 antenna and a loopback cable.)
>>>>
>>>> With a sampling rate of 2.5 MHz and a sine wave of 1 KHz, I expect to
>>>> see a sinusoidal cycle every 2500 samples. I'm plotting them with GNU
>>>> Octave and the following commands:
>>>>
>>>> fid = fopen("~/uhd/host/build/examples/usrp_samples.dat", "rb");
>>>> [sig, count] = fread(fid, Inf, "int16");
>>>> sig_c = sig(1:2:end) + j * sig(2:2:end);
>>>> plot(abs(sig_c));
>>>>
>>>> The signal seems very noisy, and it's pretty much gone towards the end
>>>> of the capture. Am I doing something wrong?
>>>>
>>>> --
>>>> Jim Hunziker
>>>> BCI Systems and Software Engineering
>>>> jhunziker at bcisensors.com
>>>>
>>>
>>>
>>
>> _______________________________________________
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>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>
>>
>
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