Re: [Discuss-gnuradio] using sig_source_c on a USRP2

[Charles Brain]

Hello Brian,

Sorry it is not possible to get a screen shot at the moment mainly because I 
have turned everything off for the day and not having a GPIB i/f on the 
analyser I would have to find my video digitiser and take a snapshot 
from the video out. 

I can see the residual at 1 GHz it is just that the main signal is not where 
I was expecting it. The signal is > 30 db above the residual. When I 
set the frequency to 10 MHz for example the main signal is at about +2 Mhz 
above the residual (from memory). 

I thought I might be doing something wrong or using something that
was not supported. The documentation is fairly sparse and even more 
so on the USRP2. The USRP2 sinks don't have the same naming format 
as those for the USRP1 i.e sink_32fc vs  sink_c which confuses me.

- Charles




----- Original Message ----- 
From: "Brian Padalino" <address@hidden>
To: "Charles Brain" <address@hidden>
Cc: <address@hidden>
Sent: Sunday, February 21, 2010 7:55 PM
Subject: Re: [Discuss-gnuradio] using sig_source_c on a USRP2


> You should definitely be able to see something at 1.001GHz, but any
> residual DC offset will also cause a spike at 1.000GHz when using a
> vector modulator.
>
> What's your resolution bandwidth set at on your spectrum analyzer?
> Can you post a link to a screen shot or two?
>
> Brian