On Wed, 14 Aug 2013 19:55:03 -0700 (PDT) m240zz@gmail.com wrote:
yes, I am afraid you are assuming all of us are as smart as you on the topic so if you have time please have another go at it. You are in a unique position to do this since you have all the equpiment at hand.
OK. I will try to make things more clear.
The thing that confuses me is why is it during the sweeps due the fft look so different in each of the windows and it seems like the timing of the sweeps are different. The sweeps happen at the same time for each dongle, right? The dongles are all listening in parallel at the same time? If so, seems like they would look more alike at the same time. My apologies for the density on this end.
The dongles suffer from various problems. Overload and inadequate anti-alias filtering. A lot of false signals are generated but that is different between the different dongles.
The input is identical to all the dongles and you can see that in the beginning of the video where signal levels are low. At high signal levels they behave quite differently because false signals dominate (But not in Linrad.)
73
Leif / SM5BSZ