Re: [casper] Skewed data samples

[Rick Carlson]

Rick. Carlson, 42 Pinhey St, Ottawa ON, K1Y 1T2 Home 613-728-2074, cell 613-697-2669 From: Dan Werthimer Sent: Friday, April 24, 2015 8:35 PM To: Kuiper, Thomas (3266) Cc: Casper Lists Subject: Re: [casper] Skewed data samples hi tom, if you are using casper adcs: all the casper adc boards are AC coupled (they have baluns and coupling capacitors),  so  even if your input signal has a DC offset, it won't couple into the ADC.   however, there are slight DC offsets in the ADC, so there will be a small spike in the DC bin, but probably not from the signal your are injecting.  best wishes, dan   On Fri, Apr 24, 2015 at 4:38 PM, Kuiper, Thomas (3266) <kui...@jpl.nasa.gov> wrote: I think they do but am not sure.  I didn't have time to download firmware from JPL (I'm in Canberra) to get actual data samples.  We shoved the signal into a DSN data processor.  It has a display, reports rms but no mean.  (After all, RF data is always zero mean, right?)  I'm wondering about the fiber-optic links.  You have some experience with that. Tom ________________________________________ From: G Jones [glenn.calt...@gmail.com] Sent: Friday, April 24, 2015 4:34 PM To: Kuiper, Thomas (3266) Cc: Casper Lists Subject: Re: [casper] Skewed data samples Hi Tom, Wouldn't that just cause extra power in the DC bin? Or do the samples still have zero mean? Glenn On Fri, Apr 24, 2015 at 7:32 PM, Kuiper, Thomas (3266) <kui...@jpl.nasa.gov<mailto:kui...@jpl.nasa.gov>> wrote: Does any have an idea what might happen to a PFB if the data samples have a slight skewness towards negative values?  Maybe someone has the answer before I start modeling. Thank Tom