plucking F3 for SAT measurements

[Jeannie Grassi]

Dr. Jim,
Now I'm confused.  I thought I heard you say once that plucking produces a
slightly higher pitch because of string deflection.   Am I hallucinating?
By the way.....welcome back.  How are you?

jeannie

Jeannie Grassi, RPT
Associate Editor, Piano Technicians Journal
mailto:jgrassi@silverlink.net


-----Original Message-----
From: owner-pianotech@ptg.org [mailto:owner-pianotech@ptg.org]On Behalf
Of Jim Coleman, Sr.
Sent: Wednesday, January 31, 2001 10:37 AM
To: David Ilvedson
Cc: pianotech@ptg.org
Subject: plucking F3 for SAT measurements


Hi David:

When you are measuring the F3 Stretch number, sometimes it is necessary
to pluck or gently strum the string between the strikepoint and the
Agraffe or V-Bar because the hammer striking the string at its 8th node
wipes out most of the 8th partial. Plucking gives a very clean display,
but the amplitude being less produces a slightly lower pitch. This is
still accurate enough to use. Plucking does not produce a different
harmonic. Since your SAT is set at F6, it is indeed reading the 8th
partial. You could add .5 cents to your setting, but it would not
measurably change the way the Bass is calculated nor tuned. When you are
tuning the A0 with the FAC program, the SAT is listening to the pitch E3
where there is more than 10 cents per HZ change. You can see how little
a .5 cents measurement would make in this case. I don't think any of us
can hear a 1/20th of a beat.

Jim Coleman, Sr.

PS Will I see you at the Calif. State Conference in Feb.?