Re: [Discuss-gnuradio] about uhd_fft.py

[Andrew Davis]

They might be internal noise from the USRP, turn up the gain input to
drown them out. That's what I do.

~Andrew

On Sat, Mar 10, 2012 at 6:28 AM, Orkhan Badirkhanli <address@hidden> wrote:
> Andrew
>
> Sorry for the late reply. I am using SBX daughterboard.
>
> The attachments I included earlier are inaccurate and seems like I was see
> that output because I was terminating uhd_fft file using ctrl+c
>
> Right now I have my noise level at -110dB and I can see different carriers.
> The only ambiguity I am facing is that as I change by center frequency by
> 0.0001GHz I see some carriers gone and different ones emerged at various
> frequencies.
>
> This is happening in every band.
>
>
> On Thu, Mar 8, 2012 at 7:24 PM, Andrew Davis <address@hidden>
> wrote:
>>
>> The thing in the center is caused by a lot of things, like IQ
>> imbalances and the distribution of noise towards zero etc. We all get
>> it when the gain is high. Do you have something you are trying to
>> detect? Do you have an antenna connected to the right port? What
>> front-end board are you using? Try 100MHz and look at some local radio
>> stations.
>>
>> On Thu, Mar 8, 2012 at 8:47 AM, Orkhan Badirkhanli <address@hidden>
>> wrote:
>> > Hello
>> >
>> > I've just successully installed gnuradio and connected my new USRP n210.
>> > I
>> > run uhd_fft.py to test my hardware and it all works well, I activity in
>> > the
>> > spectrum.
>> >
>> > The thing is, whatever I set the center frequency, all I see is a
>> > carrier at
>> > that center frequence at -50dB and "noise" at other frequencies at
>> > -70dB. I
>> > have included 2 screenshots with center frequencies of 2.4G and 2.4001G,
>> > the
>> > situation is the same in both of them.
>> >
>> > I thing there is something really wrong with this. Besides, I remember a
>> > few
>> > time when I ran uhd_fft.py file, I saw noise at -110dB and several
>> > carriers
>> > at different frequencies. But that carrier at center frequency was there
>> > too.
>> >
>> > I appreciate any help
>> >
>> > Thanks
>> >
>> > --
>> > Orkhan
>> >
>> > _______________________________________________
>> > Discuss-gnuradio mailing list
>> > address@hidden
>> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>> >
>
>
>
>
> --
> Orkhan