Pitch Raise Sequence

[Farrell]

Ron wrote:
> Working from the bass up, by the time you get
> to the treble, you may be pulling them up from farther down, but the
> required over pull is much less since the plate is already considerably
> compressed by the time you get there.

Hmmmm. This is not my observation. The SAT recommended overpulls of 25% in
tenor and 33% in treble generally work well for me. That would suggest more
overpull in treble (larger pitch correction plus larger overpull).  :-)

Maybe the best sequence would be treble first, bass next, and tenor last.

Terry Farrell
Piano Tuning & Service
Tampa, Florida
mfarrel2@tampabay.rr.com

----- Original Message -----
From: "Ron Nossaman" <RNossaman@KSCABLE.com>
To: <pianotech@ptg.org>
Sent: Saturday, September 09, 2000 10:12 AM
Subject: Re: Pitch Raise Sequence


> > The top couple octaves
> >is where the risk of string breakage is greatest. Also, when one is
raising
> >pitch, the tension of the remaining strings drop an additional amount
before
> >you even get to them (my experience is that if the hi treble is 50 cents
> >flat before starting a pitch raise, by the time you get to it after
raising
> >the bass and tenor, the hi treble will be perhaps 80 cents flat) thereby
> >increasing the risk of string breakage.
>
> With the piano at pitch, the string tensions are going to be in the
> vicinity of maybe 35% of breaking tension in the low tenor, and around 60%
> in the treble. In anticipation of the pitch drop, you have a greater safe
> over pull range in the tenor. Working from the bass up, by the time you
get
> to the treble, you may be pulling them up from farther down, but the
> required over pull is much less since the plate is already considerably
> compressed by the time you get there, so string breakage incidence should
> be lower working from the bass up.
>
> I'm a fork basher and haven't tried this either, but it seems logical to
me.
>
>
> >One of the advantages this may offer is when pitch raising on an old
risky
> >piano. I hate the thought of raising pitch on bass and tenor, just to get
to
> >the treble and find that strings are breaking right and left. If strings
are
> >going to not be able to take A440, you will find out right away if you
start
> >at C88 (of course then you are faced with the occassional problem of
tener
> >bass strings! - although in my experience that is less common).
> >
> >Terry Farrell
>
> Good point, but if my reasoning is valid, you'll have a much higher
> percentage of pianos that "won't come up" to 440. Let us know how it comes
out.
>
> Ron N