That particular method is vulnerable to a lot of things. :-P -- john, KE5FX
> -----Original Message----- > From: [email protected] [mailto:[email protected]]on > Behalf Of Bruce Griffiths > Sent: Friday, August 21, 2009 2:20 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Using cheap sound cards for measurements > > > That particular method is vulnerable to RF pickup from within the PC. > The coax screen should be RF grounded at both ends. > > Bruce > > Christian Vogel wrote: > > Hi Lux, > >> Syncing inexpensive cards is a real chore (and the only reason to be > >> thinking about using this in the first place is to keep the cost to a > >> minimum, otherwise, you might as well build a special purpose little > >> box with counters & A/Ds, and an interface) > > I've had too many problems with cheap (onboard) soundcards in the > > past, even when using them for their intended purpose, so I would not > > advice to use them for anything quantitative. > > > > But if you *really* want to syncronize inexpensive soundcards, it's > > rather trivial, see for example > > http://quicktoots.linuxaudio.org/toots/el-cheapo/ . > > > > Just buy a few dozens for a EUR/$ each and hunt down the ones with > > identical oscillator frequencies ;-). But don't expect miracles, you > > end up with a few synchronized cards that only happen to not skip > > samples with respect to each other. Compared to decent signal input > > they are still cheap cards, and hog the CPU for their individual > > servicing. > > > > Chris > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
