Pitch Raise Sequence 160+ FLAT!!

[Farrell]

I have been curious about such a case. One third overpull starting from 170
cents flat would be raising the pitch in the treble about 60 cents above
standard pitch. I have been told (can't recall where or by whom) that one
should not raise string pitch more than about 25 cents above standard pitch,
or there will be a risk of stretching the string so much that it looses its
elasticity (or it goofs the steel up somehoworother).

I would have recommended two pitch raises, I would set my SAT at 10 cents
sharp (or even 20 cents sharp on such a new piano) and go through the whole
piano once. It should then be about 40 - 50 cents flat. Then I would go
through the entire piano a second time using the pitch raise function, and I
would never be overpulling more than about 20 cents.

When a piano is that flat I will ALWAYS do two passes - not because of the
risk of strings breaking (you can really pull a newer piano way over pitch -
don't ask how I know) - but because I don't want to exceed that 25 cent
thing. Am I being cautious for a good reason?

I suspect overpulling too much could even induce false beats by deforming
the string (just my hunch). Does anyone have better info on how much
overpull is Okey Dokey, and what can happen (besides breaking the string) if
that magic tension is exceeded?

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

----- Original Message -----
From: "Charly Tuner" <charly_tuner@hotmail.com>
To: <pianotech@ptg.org>
Sent: Sunday, September 10, 2000 12:19 PM
Subject: Re: Pitch Raise Sequence 160+ FLAT!!


> I tuned a customer's 1975 K & C spinet yesterday...it was nearly OFF the
> scale at 164 Cents Flat!!! I told the customer that even though the
strings
> are in good condition, that there would be a very real chance of mutliple
> string breakage, during the pitch raise sequence. He said to go ahead, and
> we'll hope for the best. So i computed the 1/3 OVER-pull in the treble,
and
> a little less in the tenor, then brought up the bass. NO broken strings!!
> The treble area was flatter than i have EVER encountered, at 163-170 cents
> flat. Here's the neat part; I was able to get it close enough to fine tune
> after just ONE pass! I was astonished to see that the pitch dropped right
> into the ballpark across the board. So I finished the tuning, eased a few
> sticking keys, vacuumed out the piano, and booked another tuning in 6
> months.
>
> Terry Peterson
> Los Angeles, CA
> Associate Member, PTG
>