It's conceivable that it's the UPS itself that performs some chore at the same time everyday. You could try plugging into the mains (without UPS) during that period of time and see if the problem goes away. Otherwise, I agree that it could be some sort of once-a-day RFI that may be difficult to track down. On 05/21/2011 01:06 AM, Peter Hoffmann wrote: > Hi, > > The computer is on a UPS. > > The image is just cutout from a whole hour. > > I'm recording 24 x 1 hour per day. 23 hours are fine without spikes, > but at always the same time at 2:30 such spikes occur. > > Kind Regards, > Peter > > On Fri, May 20, 2011 at 5:22 PM, James Shatto<wwwshadow7@xxxxxxxxx> wrote: >> That seems pretty regular at 8 to 10 minute intervals. Do you live >> near a subway line? Or other electric mass transit option? Is the >> computer on a UPS or power conditioner type supply line? I get a >> spike like that when I use a battery box to power an electret mic. If >> I turn it on after pressing record. Beyond that, your guess is as >> good as mine. >> >> - James >> >> >> On 5/20/11, Peter Hoffmann<ph@xxxxxxxxxxxxxxxxxx> wrote: >>> Hello, >>> >>> I'm recording audio 24/7 with a delta 1010 sound card and have a >>> strange problem: >>> >>> Every night at 2:30 I get spikes and some inaccurancy within some >>> seconds in a one hour length recording. I've upload a screenshot to >>> illustrate the problem: >>> >>> http://img88.imageshack.us/img88/4562/spikesh.png >>> >>> My .asoundrc >>> >>> pcm.capt { >>> type dsnoop >>> ipc_key 223456 >>> slave { >>> pcm "hw:0,0" >>> rate 8000 >>> period_time 0 >>> period_size 320 >>> channels 12 >>> format S32_LE >>> } >>> } >>> >>> pcm.c1 { >>> type plug >>> ttable.0.0 1 >>> slave.pcm capt >>> } >>> >>> pcm.c2 { >>> type plug >>> ttable.0.1 1 >>> slave.pcm capt >>> } >>> >>> pcm.c3 { >>> type plug >>> ttable.0.2 1 >>> slave.pcm capt >>> } >>> >>> pcm.c4 { >>> type plug >>> ttable.0.3 1 >>> slave.pcm capt >>> } >>> >>> pcm.c5 { >>> type plug >>> ttable.0.4 1 >>> slave.pcm capt >>> } >>> >>> pcm.c6 { >>> type plug >>> ttable.0.5 1 >>> slave.pcm capt >>> } >>> >>> pcm.c7 { >>> type plug >>> ttable.0.6 1 >>> slave.pcm capt >>> } >>> >>> pcm.c8 { >>> type plug >>> ttable.0.7 1 >>> slave.pcm capt >>> } >>> >>> I'm recording with arecord -q -f cd -t wav -d 3600 -c 1 -D c1 out.wav. >>> >>> Any hints where the problem might be? >>> >>> Kind Regards, >>> Peter Hoffmann >>> >>> ------------------------------------------------------------------------------ >>> What Every C/C++ and Fortran developer Should Know! >>> Read this article and learn how Intel has extended the reach of its >>> next-generation tools to help Windows* and Linux* C/C++ and Fortran >>> developers boost performance applications - including clusters. >>> http://p.sf.net/sfu/intel-dev2devmay >>> _______________________________________________ >>> Alsa-user mailing list >>> Alsa-user@xxxxxxxxxxxxxxxxxxxxx >>> https://lists.sourceforge.net/lists/listinfo/alsa-user >>> >> ------------------------------------------------------------------------------ >> What Every C/C++ and Fortran developer Should Know! >> Read this article and learn how Intel has extended the reach of its >> next-generation tools to help Windows* and Linux* C/C++ and Fortran >> developers boost performance applications - including clusters. >> http://p.sf.net/sfu/intel-dev2devmay >> _______________________________________________ >> Alsa-user mailing list >> Alsa-user@xxxxxxxxxxxxxxxxxxxxx >> https://lists.sourceforge.net/lists/listinfo/alsa-user >> >> > ------------------------------------------------------------------------------ > What Every C/C++ and Fortran developer Should Know! > Read this article and learn how Intel has extended the reach of its > next-generation tools to help Windows* and Linux* C/C++ and Fortran > developers boost performance applications - including clusters. > http://p.sf.net/sfu/intel-dev2devmay > _______________________________________________ > Alsa-user mailing list > Alsa-user@xxxxxxxxxxxxxxxxxxxxx > https://lists.sourceforge.net/lists/listinfo/alsa-user > > ------------------------------------------------------------------------------ What Every C/C++ and Fortran developer Should Know! Read this article and learn how Intel has extended the reach of its next-generation tools to help Windows* and Linux* C/C++ and Fortran developers boost performance applications - including clusters. http://p.sf.net/sfu/intel-dev2devmay _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
