Thanks, Patrick! If I understand this, then, here is what I should expect:
My sound card calibrates to 48009.37, which is .9998% fast I transmit with an audio frequency of 2415 Hz I am therefore actually transmitting on 2439 Hz, or .9998% higher than indicated Does that sound right? Tnx es 73 Dave KB3MOW Patrick Lindecker wrote: > > Hello Dave, > > It is simple. If the offset in sampling frequency is x% and the true AF > frequency is f0, the displayed frequency f will be equal to > f=f0*(1-x/100) > Example: if the sampling offset is +1% and f0 is 1000 Hz, the frequency > displayed will be equal to 1000*(1-0.01)=990 Hz > > 73 > Patrick > > ----- Original Message ----- > From: "Dave" <[EMAIL PROTECTED] <mailto:dcorio%40zitomedia.net>> > To: <digitalradio@yahoogroups.com <mailto:digitalradio%40yahoogroups.com>> > Sent: Tuesday, October 07, 2008 3:57 PM > Subject: [digitalradio] Re: Sound card question > > > Thanks, Simon! It makes sense that if the "native" speed is 48K, any > > other speed would require some type of "conversion". > > > > One more question, if I can impose on your good nature! > > > > What impact, if any, does the error in sampling rate have on any > > TX/RX offset? During the Tara Rumble I noticed that almost every > > station that responded to my CQ, came back a bit lower in frequency > > than mine. One station I responded to even told me I was off- > > frequency. I don't believe my IC-746 has any offset, and my RIT/XIT > > was off. Does that large error rate of 6984 ppm create an offset, and > > can I determine how great it is? > > > > Tnx es 73 > > Dave KB3MOW > > > > > > --- In digitalradio@yahoogroups.com > <mailto:digitalradio%40yahoogroups.com>, "Simon Brown \(KNS\)" > > <[EMAIL PROTECTED]> wrote: > >> > >> It means that the drivers are better - the internal clock runs at > > 48kHz, > >> other rates are created by either the driver or (very often) > > Windows. > >> Windows XP does not do a good job of this, VISTA however is > > excellent at > >> converting the sample rates. > >> > >> Simon Brown, HB9DRV > >> www.ham-radio-deluxe.com > >> > >> ----- Original Message ----- > >> From: "Dave 'Doc' Corio" <[EMAIL PROTECTED]> > >> > I've calibrated my sound card (Diamond PCI) two ways, using > > MMSSTV > >> > at 48000 Hz, and MMTTY at 11025 Hz. Here are the results of the > >> > calibration: > >> > > >> > MMSSTV 195 PPM 48009.37 > >> > > >> > MMTTY 6984 PPM 11102 > >> > > >> > > > > > > > > ------------------------------------ > > > > Announce your digital presence via our Interactive Sked Page at > > http://www.obriensweb.com/sked <http://www.obriensweb.com/sked> > > > > 30M digital activity at http://www.projectsandparts.com/30m > <http://www.projectsandparts.com/30m> > > > > Recommended software : DM780, Multipsk, FLDIGI, Winwarbler ,MMVARI. > > Yahoo! Groups Links > > > > > > > > > > > >