SAT/Inharmonicity Observation

[Farrell]

>     On an other note; when a piano is that flat (-140c), the first time
> through I will just pull it up to pitch, or maybe a little sharp, and see
> what happens when I tune the unisons. I count on two pitch raises.
Otherwise
> you're pulling individual strings fourty cents sharp for a differential of
> 180 cents between the tuned and un-tuned notes. Scares me!
>    I'm sure that you do things pretty much the same way, let me know. I
just
> said that more for the newbies who may be lurking.

Oh, yeah! I got it up to pitch in 2-1/2 passes. On bigger pitch raises, I'll
go through the hi-treble an extra time so that each raise is smaller - just
less chance of breaking strings. Pulled bass, tenor, and treble 10 cents
sharp, and hi-treble just up to pitch on first pass. Went through hi-treble
again, pulling it 10 cents sharp. Then I went through the whole scale again
doing a regular pitch raise with the SAT pitch-raising feature. Before
starting the last pass, I found the bass was about 30 cents flat, tenor
about 50 cents flat, treble about 60 cents flat, and hi-treble about 30
cents flat.

Terry Farrell

----- Original Message -----
From: "Kevin E. Ramsey" <ramsey@extremezone.com>
To: <pianotech@ptg.org>
Sent: Saturday, June 02, 2001 10:50 PM
Subject: Re: SAT/Inharmonicity Observation


>     Terry, you remember the discussion we had a week or so ago about the
low
> tension in the lower tenor on the Yamaha GH1? One of the members came back
> with figures that supported my theory of the tenor section tension being
> dropped too low, and the inharmonicity factor was about double what it was
> in the top note of the bass section.
> Therefore, you could safely assume that the inharmonicity would obviously
> change  with that great a change in the overall tension of the string.
>     On an other note; when a piano is that flat (-140c), the first time
> through I will just pull it up to pitch, or maybe a little sharp, and see
> what happens when I tune the unisons. I count on two pitch raises.
Otherwise
> you're pulling individual strings fourty cents sharp for a differential of
> 180 cents between the tuned and un-tuned notes. Scares me!
>    I'm sure that you do things pretty much the same way, let me know. I
just
> said that more for the newbies who may be lurking.
>
>
>
> Kevin E. Ramsey
> ramsey@extremezone.com
> ----- Original Message -----
> From: "Farrell" <mfarrel2@tampabay.rr.com>
> To: <pianotech@ptg.org>
> Sent: Saturday, June 02, 2001 7:32 PM
> Subject: SAT/Inharmonicity Observation
>
>
> > I serviced a 1940 Chickering Studio today. Hadn't been tuned in
decades -
> > very good condition. It was 140 cents flat. I did an FAC calculation
with
> > the strings 140 cents flat. FAC values were 10.5, 11.2, and 8.5. Raised
> the
> > pitch up to A440. Figured maybe I should double check - maybe
> inharmonicity
> > would change. FAC values @ A440 were 8.7, 9.7, and 7.0. All decreased by
> > about 1.5. I would imagine this simply follows some sort of theory,
which
> > obviously I have no knowledge of. Just thought some might be interested.
> > :-)
> >
> > Terry Farrell
> >
> >
>
>