I generally tune with a SAT-3. In order to calibrate it to the piano (as I occasionally refer to it for a curious customer) one must first tune F3, A4, and C6 to zero deviation from (theoretical) partials at F5, A5, and C6 respectively. One then measures the inharmonicity differences between that partial and an octave above... i.e. F6, A7, C7. (SAT users refer to this as FAC.) After doing a pitch correction, I always re-measure FAC for my fine tuning, and it is *always* different. Sometimes it's quite significantly different, and I have always wondered why, since the center strings of F3, A4, and C6 are at the same tensions for both the pre-pitch-correction reading and the pre-fine-tuning reading. And how does keeping a piano at a particular pitch result in lowering inharmonicity? Paul Bruesch Stillwater, MN On Thu, Feb 12, 2009 at 12:49 PM, Don <pianotuna at accesscomm.ca> wrote: <snip> > Over time, if a piano is kept at a > particular pitch, inharmonicity may often become lower too--so it is best > to remeasure at every service call. YMMV </snip> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech_ptg.org/attachments/20090212/a7f1c905/attachment.html>
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