[Skimmertalk] Red Pitaya - Update #2

[kazeringue at aol.com]

OK.  So turns out the 1400-1600hz images were NOT eliminated by the 
cleaner power supply.

I had configured the Red Pitaya using the most current version of the 
OS(v 0.96.??)

The author of the SDR programs recently posted a note in the RP forum 
indicating a compatibility issue with v0.96 and the SDR applications, 
including the one needed for CW skimmer.
see:
http://forum.redpitaya.com/viewtopic.php?f=11&t=265&p=6463#p6388

So I set up another SD with the suggested OS version.  Poof.  Problems 
solved.

With the current OS I was seeing what look like intermod or ghost images 
on the actual signals.  About 25db above noise level generated images.

With the suggested 0.95 version of the OS I gathered K2AV spots between 
47 and 54 db with no images at all.  Under HPSDR the signals looked very 
good, the signal level at about -52 to -55 dbm and no indication of 
images spikes appearing.

The reason I had chosen to use the current version of the OS was to be 
able to make a persistent change to the password more easily.  That was 
not possible with the original ecosystem on Pavel's SDR web site.  It
is possible to make the change in the 0.95 OS linked in Pavel's post.

So.  I now have cleaned up the front end of the skimmer antenna system 
quite a bit, and now have a nice BCB filter that really kills 680 WPTF 
and 850 WPTK.

Feeding spots to RBN again, until any other/new problems surface.

Executive summary:
Red Pitaya OS v0.96 bad for skimmer and HPSDR.
Red Pitaya OS v0.95 good for skimmer and HPSDR.


73 de w4kaz