sagging center string

[Ed Carwithen]

Most of my clients have older (much older) pianos (mostly uprights).  I
don't have much trouble with the lower or middle section, but that treble
section often is a real pain.  I use an SAT (God Bless Mr. Sanderson), so I
am able to get immediate feedback when the pitch slips, and after tuning
the center string, I go for the treble (right) string, and when it comes in
tune, the center has slipped, sometimes a lot.  By the time the left string
is being worked on the center may be even flatter than when I started.  

I start compensating by leaving the center string higher and higher with
each set, and sometimes this helps, but chasing the pitch of the center
string down the musical scale is a real pain.

Eventually, I get the strings to go where I want, they even stay in tune
pretty well, but the time involved is frustrating.  There are times when it
takes me more time to tune from F4 to C7 than the entire rest of the piano.


Does anyone have any suggestions as to how I might improve my technique in
this area of the piano.

P.S.  I already do a quick pitch raise if the piano is 6 cents or more away
from 440; I will even to do the treble section quickly a second or third
time if it drifts flat.


Ed Carwithen
John Day, OR