Pitch Raise Sequence

[Ron Nossaman]

> 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