SAT Pitch Raise to Lower Pitch

[Jim Coleman, Sr.]

HI Terry:

To do what you want to do is quite simple. Measure your FAC numbers at
pitch first, then reset you machine to -50cents. Then do the roll-over
from STRETCh to MEM. All of your numbers in the calculated tuning program
will be negative numbers centered around -50 cents. When you do the pitch 
raise function (either one), it will calculate a positive number for 
your overshoot just as in a regular pitch raise.

Jim Coleman, Sr.

On Wed, 9 Feb 2000, Farrell wrote:

> Dear SAT Wizzes:
> 
> I am having trouble with use of the SAT pitch raise and pitch offset feature
> (I am using a SAT III). I know how to, and use, both independantly without
> problem. However, take the case where a poor neglected piano :-( is 100
> cents flat in bass, 125 cents flat in tenor, and 150 cents flat in upper
> treble. If the goal is to get the thing up to standard pitch - no problem.
> But lets say that we choose (or are directed to by piano owner) to only
> bring the piano up to a pitch 50 cents below A440 (i.e., do the final tuning
> 50 cents flat).
> 
> In this situation, I set a pitch offset for 50 cents flat. My plan would be
> to to a pitch raise (using the pitch raise overpull feature of the SAT)
> starting in the bass section (I want to pitch raise, with appropriate
> overpull, to a final pitch of 50 cents below A440). So starting on A0, I
> strike the key and press the measure button and see that the SAT indicates
> that A0 is 50 cents flat (it is 100 cents flat of A440, but because I have
> the pitch offset set at 50 cents flat, it only indicates that A0 is 50 cents
> flat of the target pitch offset). Then the next step is to have the SAT
> calculate an appropriate pitch compensation to overshoot the 50 cent flat
> target pitch and would presumably result in an overshoot of about 10 cents
> above the 50 cent flat target for a resultant value of about 40 cents flat
> (then of course, by the time I am done pitch raising, A0 has fallen back to
> the targeted 50 cent flat pitch offset).
> 
> Unfortunately, it doesn't work that way. When I use the pitch raise feature,
> it completely ZAPS any reference to the original targeted 50 cent flat
> offset and simply calculates an appropriate pitch raise overpull for pitch
> of A440, i.e., if I were to then tune A0 after using the pitch raise
> feature, it would indicate that I need to raise A0 about 125 cents (the
> original 100 cents it was below A440, plus the 25% overpull for the pitch
> raise that the SAT throws in).
> 
> Is this a limitation of the SAT :-(?  I find it hard to imagine that I am
> the only one that needs to do such an undesirable procedure. Please tell me
> I am overlooking something :-) (and then be specific as to what)! If it is a
> limitation (I can't believe Dr. Sanderson missed this situation), does
> anyone know of a slick way around it?
> 
> Terry Farrell
> Piano Tuning & Service
> Tampa, Florida
> mfarrel2@tampabay.rr.com
> 
>