Hi Paulina I would check the fft_shift as a first culprit. Try setting it to -1 (shift every stage) and see if that helps.
- Danny On Thu, Nov 10, 2016 at 9:55 AM, David MacMahon <dav...@astro.berkeley.edu> wrote: > Hi, Paulina, > > That spectrum has way too much structure in it. Something is not working > right. I'm not that familiar with tut3, but if there is a way to get a > snapshot of samples from the ADC it would be good to verify whether the > data from the ADC looks reasonable. Like most systems, the PFB is GIGO > (garbage in, garbage out) so it's good to verify that what's going on is > not garbage. > > HTH, > Dave > > On Nov 10, 2016, at 09:36, Paulina Unanue <unanu...@gmail.com> wrote: > > > Hi all > > > i'm working with the Tutorial 3: Wideband Spectrometer, with ROACH 1, i'm > using a signal generation to feed the ADC(2x1000-8 sintonize at 1 GHz) with > a tone (-40 dbm 200 MHz) but i'm obtaining a high noise floor,i had > reduced the gain > > as recommended in the instructions ( "decrease the value (for a -10dBm > input 0x100) to not saturate the spectrum" ) trying different values, > but the same problem persists. Any idea that may be causing this?. > > > To see the graphic, please check the attached. > > best wishes > > <graf.jpg> > > -- Danny Price | dan...@berkeley.edu | +1 617-386-3700
