pitch raises & tuning pins

[Don]

Hi Carl,

I would rather spend *time* on a very accurate compensated tuning using RCT
than the *quick* and dirty method. I have had exceptional results for
example tuning a piano for the second time in its brief life raising pitch
between 38 and 72 cents and finding A4 *exactly* at A440, and no other note
more than 4 cents away from the ideal. With dealers unwilling to pay for
the necessary work for stablilized tunings RCT is a god send! For a concert
double tunings are still a necessity but in homes I question whether it is
any more effective than waiting for a month and coming back to fine tune
the instrument.

My general rule of thumb is at A4:

pitch change 10 cents see you in 3 months
pitch change 20 cents see you in a month or 2
pitch change 30 cents or greater see you in a week or 2.

I carefully document the humidity and pitch swing(both at A4 and worst
note). On the second visit I simply divide the pitch change at A4 by the
*time* (days usually) and that will give the client a good idea of how much
pitch is dropping. Then take that figure and divide 4 cents by it. The
result will be the the *best* case for a project for the next service. I
hope to add a compensation for humidity changes as well but don't have the
necessary data yet. 

For now the formula for prediction reads:

pitch change at A4/time = drop per unit of time A4(dpuota)

4 cents/dpuota = prediction of next recommend service (conservative)

and

pitch change worst note/time = drop per unit of time worst (dpuotw)

4 cents/dpuotw = prediction worst case of next recommend service.

At the moment I do average the 2 times to come up with next recommended
service and I do try to account for winter humidity vs summer time. 

At 01:32 PM 2/27/99 -0400, you wrote:
>For major pitch raises, I use no mutes.  I used to use my Accufork and
>now use RCT - you need some sort of visual or aural target, as opposed
>to just yanking everything up a half step, as someone once suggested. 
>I've only done two or three major pitch raises with RCT, so there's lots
>more for me to learn about applying my old method.  
>
>You can go through a piano very quickly without mutes.  I doubt that the
>next pass with mutes will give you a fine tuning, though, since the
>center strings, or which ever you chose, will not necessarily reflect
>the the overall tension level of the chipped piano.  Precise overshoots
>that the RCT is capable of may not be much use here, so a quicker tuning
>in fine mode without waiting for the machine to calculate the overshoot
>each time, may be just as accurate.   
>
>Carl Root, RPT
>Rockville, MD

Regards,
Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.

Tuner for the Saskatchewan Centre of the Arts

drose@dlcwest.com
http://www.dlcwest.com/~drose/
3004 Grant Rd.
REGINA, SK
S4S 5G7
306-352-3620 or 1-888-29t-uner