By the way... this glitch is nearly instantaneous... it look like it happens for several seconds just because the FFT is responding to the large jump... it is likely more than 50mhz.. that is just how the FFT smooths it. I would presume there is something odd going on with image rejection or something.
On Sat, Dec 17, 2011 at 9:57 AM, Jerry Flanders <[email protected]>wrote: > Might this result from the satellites coming in/out of view and the GPSDO > switching among them? Maybe try it without the GPSDO. > > I am surprised you are within 100 microHz on your measurement - my 5000a > synthesizer seems to _always_ be 20 -60mHz off. > > Jerry W4UK > > > At 10:40 AM 12/17/2011, Bill Dailey wrote: > >> I don't know who to contact on this so I will put it here and leave it up >> for grabs. I have been dealing with this and trying to trouble shoot it >> for a couple of months. Fairly complex setup: >> >> Flex-5000a PowerSDR version 2.2.3 (I havent checked other versions), >> windows 7, i7 speed demon computer >> IF offset 0 hz, dds offset 0 >> Stanford Research DS345 Signal generator >> Both disciplined to a Jackson Labs Fury GPSDO 10Mhz reference >> Sending audio via VAC - all sample rates verified to 48khz >> I am sending audio to fldigi (have verified with spectrum lab also, >> identical results) >> >> Excellent frequency resolution.. right on where I would expect (within >> about 0.1mhz) ...BUT..... >> >> Every 9 minutes there is some odd abberancy that occurs with either >> powerSDR (probably), the radio or VAC that shifts the measurement by +50 >> mhz. image of graph: http://img703.imageshack.us/** >> img703/9382/spikesbf.jpg<http://img703.imageshack.us/img703/9382/spikesbf.jpg> >> I have tried various buffers and cant seem to affect the timing or the >> magnitude of the shift. I used to get noise that would surge like this >> with past powersdr versions so I am virtually certain this is a software >> issue. >> >> Anyone have any suggestions of what may be causing this behavior? >> >> Doc >> KX0O >> > > -- Doc Bill Dailey KXØO _______________________________________________ Flexedge mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software development and experimentalist who are using beta versions of the software.
