[USRP-users] X310 + 2 CBX daughtercards strange behaviour

boeglen herve herve.boeglen at univ-poitiers.fr
Fri Sep 19 16:02:46 EDT 2014


  

Hi Markus and Mike, 

Thank you for your answers. 

It does not
change anything whether you specify the subdev or not. 

Markus: yes
everything is wired properly. Concerning the last email, I used a
BladeRF as a generator (0dBm + 30dB attenuator). 

Here is another test
with Wifi and as you can see from the two spectrum scopes (upper is RF
1, lower RF 0), RF 1 reception bandwith seems to be larger than for RF 0
(however it's set to 20MHz for both channels). 

I have a second X310
with the same daugthercards and I get the same behaviour... 

Is there a
way to use just RF 1? 

I hope that going to sleep is going to help me
to find an idea to solve the problem :-) 

Best regards 

Hervé 

On
Fri, 19 Sep 2014 18:17:46 +0100, Mike Jameson wrote: 

> The subdev spec
should actually be:
> 
> A:0 B:0
> 
> (Thanks Marcus.L!)
> 
> Mike
> 
>
--
> Mike Jameson M0MIK BSc MIET
> Ettus Research Technical Support
>
Email: support at ettus.com [9]
> Web: http://ettus.com [10] 
> 
> On Fri,
Sep 19, 2014 at 4:56 PM, Mike Jameson wrote:
> 
>> I'm not fortunate
enough to have an X310 to test this myself, however it looks as though
you are missing a subdev spec which should be something like:
>> 
>>
"A:A B:A"
>> 
>> More information here:
>> 
>>
http://files.ettus.com/manual/page_usrp_x3x0.html#x3x0_misc_multirx
[5]
>> 
>> Mike
>> 
>> --
>> Mike Jameson M0MIK BSc MIET
>> Ettus
Research Technical Support
>> Email: support at ettus.com [6]
>> Web:
http://ettus.com [7] 
>> 
>> On Fri, Sep 19, 2014 at 4:14 PM, Marcus D.
Leech via USRP-users wrote:
>> 
>>> Are you certain that you've wired
the TX/RX ports of the two CBX to the front-panel correctly? 
>>> 
>>>
What signal levels are you injecting? 
>>> 
>>> On 2014-09-17 11:19,
boeglen herve via USRP-users wrote: 
>>> 
>>>> Hi all, 
>>>> 
>>>> I am
playing with an USRP X310 + 2 CBX dautercards (RF 0 and RF 1). My aim is
to perform a 2 antennas reception. However, when testing the two RF
inputs, RF 1 doesn't seem to work properly. With a generator, I just
enter a sum of 2 sines (100 kHz and 200 kHz) around a 3 GHz carrier,
firstly on RF 0 then on RF 1. 
>>>> 
>>>> Here are the results ( RF 0
and RF 1). The last image is a screenshot of my GRC UHD source. It seems
like RF 1 has a much wider noise bandwidth than RF 0 and as you can
notice the signal amplitude is 10 dB lower than the one observed on RF
0. 
>>>> 
>>>> Am I doing something wrong? As I understood from the X310
datasheet, it should be possible to receive or transmit simultaneously
wiith an X310 equipped with 2 daughterboards. 
>>>> 
>>>> Best regards

>>>> 
>>>> Hervé 
>>>> 
>>>>
_______________________________________________
>>>> USRP-users mailing
list
>>>> USRP-users at lists.ettus.com [1]
>>>>
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
[2]
>>> 
>>> _______________________________________________
>>>
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>>>
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[5]
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[6]
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