Re: [Discuss-gnuradio] BasicTX PLL and some TX doubts

[Ronaldo Nunez]

Thank you for your answer Mr. Blossom,

> Please read the USRP FAQ then ask again if you're still not clear.
>
   http://gnuradio.org/trac/wiki/UsrpFAQ
 > http://gnuradio.org/trac/attachment/wiki/UsrpFAQ/USRP_Documentation.pdf

Sorry, but, I read all FAQ, and i just found the answer of my third question ("And for the other dboards, how tune() works for them?")

> Have you looked at the code that implements tune?
>
> Eric

usrp_stardard.{cc,h}? Yes...

I (think) understood the tune process when I read it.

First, the "tune()" tells to d'board to tune as close as it can. After, with the result of that operation (maybe, f_db - f_target = f_duc) "tune()" configure the DUC. Is that right? (Be free to correct me...)

But, the BasicTX doesn't have a PLL, or a VCO or another component to tune at a frequency...Should FPGA do tune job for the basicTX?

Please, be free to correct my affirmations...

Sorry my poor English (and my ignorance) , thanks all!

Ronaldo

2009/1/13 Eric Blossom <address@hidden>

On Tue, Jan 13, 2009 at 05:19:32PM -0200, Ronaldo Nunez wrote:
> Hello community,
>
> I'm trying to understand how signals are transmitted by the USRP with a
> basicTX.
> I studied a lot about Quadrature Modulation, Single Sideband transmission...
> and I've read all the available documentation about USRP and GNUradio.
>
> Eric and other guys have helped me, but some doubts persists! :(
>
> There is a PLL in the BasicTX daughter board?
> How tune() function access that PLL?
> And for the other dboards, how tune() works for them?
>
> If somebody could help me, i will be thankful for life!

Please read the USRP FAQ then ask again if you're still not clear.

 http://gnuradio.org/trac/wiki/UsrpFAQ
 http://gnuradio.org/trac/attachment/wiki/UsrpFAQ/USRP_Documentation.pdf

Have you looked at the code that implements tune?

Eric

-- 
__________________________________
Ronaldo A. Viera Nunez
Acadêmico/Engenharia Elétrica
Universidade Federal de Santa Maria 

Santa Maria - RS - Brasil