[Discuss-gnuradio] Passband anomaly with dual-channel LimeSDR

[Marcus D. Leech]

First, a pic of two FFTs from the two channels of LimeSDR, tuned exactly 
the same.

http://www.ccera.ca/files/dual_channel_limesdr.png

Then the flow-graph that produced it:

http://www.ccera.ca/files/untitled.grc


The differences are somewhat subtle--one channel has a 5dB roll-off, 
while the other doesn't.   This may just be subtle analog differences in 
the noise
  spectrum.  But it might be useful to check that filters are being set 
properly in the two-channel scenario.

Also, the DC offset is quite large, but this may not be a "fair" test, 
since the inputs are just "dangling" with no external signal at all.