[Skimmertalk] Red Pitaya Hears but Skimserv doesn't spot

[N4ZR]

OK, here's a mystery - I have a 14-bit Red Pitaya and a QS1R.  I 
normally feed them both off a Clifton Labs Norton preamp through a 
Mini-Circuits splitter (about 3.5 dB insertion loss).  In tests way back 
when, using number of spots as the metric, I had found the Red Pitaya to 
be substantially equal to the QS1R in performance.

A month or so ago, I noticed that the RP seemed not to be spotting, but 
I was preoccupied with other things. Today I decided to get serious 
about diagnosing the problem.  First, I verified all of the 
interconnecting cables.  Then I tested the QS1R and the Red Pitaya with 
their respective SDR software, SDRMAX V and PowerSDR.  I used an 
Elecraft XG-3 to verify the sensitivity of both SDRs, which did not 
reveal any obvious problems.

Then I started Skimserv and Aggregator on both PCs.  It's CWT Wednesday, 
so I immediately noticed a lot of activity, as measured by the number of 
decoders that Skimserv spawned.  I did notice that the number on the Red 
Pitaya lagged substantially behind that on the QS1R. The real shocker, 
though - in that hour, the QS1R system spotted over 200 stations (many 
re-spots, of course) while the Red Pitaya system logged *none.*

I'm baffled - clearly something is wrong with the Red Pitaya system, but 
what?  Any suggestions welcome!

-- 

73, Pete N4ZR
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