|
From: | Ben Hilburn |
Subject: | Re: [Discuss-gnuradio] about uhd_fft.py |
Date: | Wed, 14 Mar 2012 17:30:37 -0700 |
I am sending two screenshots of ffy, one with center freq 2.40002G and the other 2.40005
Please note the difference between them
I ran the calibrations too
Does anybody have an idea about how I can correct this? - Or what is the source of it?
Here is my uhd_usrp_probe output:
_____________________________________________________
/
| Device: USRP2 / N-Series Device
| _____________________________________________________
| /
| | Mboard: USRP-N210-REV4
| | hardware: 2577
| | mac-addr: a0:36:fa:25:37:df
| | ip-addr: 192.168.10.2
| | gpsdo: none
| | serial: EDR17SFUP
| |
| | Time sources: none, external, _external_, mimo
| | Clock sources: internal, external, mimo
| | Sensors: mimo_locked, ref_locked
| | _____________________________________________________
| | /
| | | RX DSP: 0
| | | Freq range: -50.000 to 50.000 Mhz
| | _____________________________________________________
| | /
| | | RX DSP: 1
| | | Freq range: -50.000 to 50.000 Mhz
| | _____________________________________________________
| | /
| | | RX Dboard: A
| | | ID: SBX (0x0054)
| | | Serial: E3R13X6XS
| | | _____________________________________________________
| | | /
| | | | RX Subdev: 0
| | | | Name: SBX RX
| | | | Antennas: TX/RX, RX2, CAL
| | | | Sensors: lo_locked
| | | | Freq range: 400.000 to 4400.000 Mhz
| | | | Gain range PGA0: 0.0 to 31.5 step 0.5 dB
| | | | Connection Type: IQ
| | | | Uses LO offset: No
| | | _____________________________________________________
| | | /
| | | | RX Codec: A
| | | | Name: ads62p44
| | | | Gain range digital: 0.0 to 6.0 step 0.5 dB
| | | | Gain range fine: 0.0 to 0.5 step 0.1 dB
| | _____________________________________________________
| | /
| | | TX DSP: 0
| | | Freq range: -250.000 to 250.000 Mhz
| | _____________________________________________________
| | /
| | | TX Dboard: A
| | | ID: SBX (0x0055)
| | | Serial: E3R13X6XS
| | | _____________________________________________________
| | | /
| | | | TX Subdev: 0
| | | | Name: SBX TX
| | | | Antennas: TX/RX, CAL
| | | | Sensors: lo_locked
| | | | Freq range: 400.000 to 4400.000 Mhz
| | | | Gain range PGA0: 0.0 to 31.5 step 0.5 dB
| | | | Connection Type: QI
| | | | Uses LO offset: No
| | | _____________________________________________________
| | | /
| | | | TX Codec: A
| | | | Name: ad9777
| | | | Gain Elements: None--On Sat, Mar 10, 2012 at 4:26 PM, Andrew Davis <address@hidden> wrote:
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
Orkhan
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