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Re: The almighty spur reduction...

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  • k6acj
    Have you tried turning off all the unnecessary tasks in Task Manager to lighten the load on the processor? Since this PC is dedicated, I d stop the internet
    Message 1 of 2 , Feb 10, 2010
      Have you tried turning off all the unnecessary tasks in Task Manager to lighten the load on the processor? Since this PC is dedicated, I'd stop the internet connection,anti virus program and anything that reads as a scheduling task. Task Manager will also show the CPU load per task which could be useful.

      I tried to dedicate an Win XP IBM E600 300Mhz Thinkpad to a USB Signalink for PSK31 and found performance to be marginal with popping and other disturbing noises so this laptop is too slow and will be dedicated to Serial TNCs or simple Digipan only.

      The SoundMax audio in my Lenovo X61 2.3ghz laptop works fine making me think > 1gHz CPU speed is more desirable.

      Bill k6acj

      --- In powersdr-iq@yahoogroups.com, "flowin3802000" <naf3770@...> wrote:
      > I'm posting my experience after seeing jamespond video, hoping it will be useful for other users.
      > I have a pmsdr connected to an old lapotp (ibm t30), running xp sp2; I know this is non an ideal setup, but i decided to devote a pc ONLY for sdr use, thus avoiding the virus-crapware-connection hassles that periodically plague my main pc. The first source of trouble is the audio card (soundmax): every now and then it seems there is a phase shift between l and r channels (maybe there is a sample delay), and I see signals mirroring from one side of the tuning line to the other, sometimes they alternate, other times simply disappear from one side and reappear on the other; this happens more frequently when i drag the bar and fine-tune. If you have spur reduction enabled in a situation like mine, you're heading for big trouble: every time you tune, the signal bounce (for the audio card issue), and the spur reduction make it bounce even more on it's own accord... it took me some time to figure this out.
      > The simple solution is to connect an external usb audio card (I have a venerable griffin iMic, which works perfectly, and I've recently ordered a second hand audigy2zs pcmcia, should arrive in the next days).
      > It's clear that if the audio card is not working properly, the frequency image correction routine will not work also.
      > The strange thing about jamespond predicament is that, while my problem was intermittent and usually after 2-3 seconds disappeared, he seems to have the phenomenon remain constantly.
      > So my suggestion to anyone having strange mirror/ghost signal alternating or popping now and then around the tuning line would be to try another audio card.
      > Hope this helps...
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