<HTML style="FONT-SIZE: x-small; FONT-FAMILY: MS Sans Serif"><HEAD> <META http-equiv=Content-Type content="text/html; charset=iso-8859-1"> <META content="MSHTML 6.00.2900.2912" name=GENERATOR></HEAD> <BODY> <DIV> <DIV>What ETD are you using? Don't they all have a built in PR program nowadays?</DIV> <DIV> </DIV> <DIV>I'm using Tunelab and find that the machine-calculated overpulls put pitch right on the money, amazingly so.</DIV> <DIV> </DIV> <DIV>In the olden days, I was using a Yamaha PT-100 II which didn't have the calculated overpulls. They recommended pulling it up (or down as the case may be, and I THINK I remember these fractions right, others may need to correct me) of 1/3 the difference in the bass, 1/5 the difference in the low tenor (about 6 unisons), and 1/4 the difference in the upper tenor and treble. So if the bass is averaging 18 cents flat, for example, you'd tune it 6 cents sharp.</DIV> <DIV> </DIV> <DIV>Anyway, my point is that that method used to be very accurate, also.</DIV> <DIV> </DIV> <DIV> <DIV>Alan Barnard</DIV> <DIV>Salem, Missouri</DIV> <DIV> </DIV></DIV></DIV> <DIV> </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid"> <DIV style="FONT: 10pt Arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B> <A title=dnereson@4dv.net href="mailto:dnereson@4dv.net">David Nereson</A> </DIV> <DIV style="FONT: 10pt arial"><B>To: </B><A title=pianotech@ptg.org href="mailto:pianotech@ptg.org">List Pianotech</A></DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> 07/07/2006 2:28:36 AM </DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> post pitch-raise creep?</DIV> <DIV><BR></DIV><FONT size=2> <DIV><SPAN class=114315606-07072006><FONT face=Arial size=4>    I do many many many pitch raises -- almost every piano I tune, for the last 27 years.  (Almost everybody lets them go too long.)</FONT></SPAN></DIV> <DIV><SPAN class=114315606-07072006><FONT face=Arial size=4>    I've found that the ideal average overpull is halfway between 1/3 to 1/2 the amount sharp as it was flat.  In other words, a 41% overpull of the amount it was</FONT></SPAN><FONT face=Arial><FONT size=4><SPAN class=114315606-07072006><FONT size=+0> flat.  For an easy-figuring example, say the piano is 18 cents flat.  Half of that is 9 cents and a third of that is 6 cents.  Half-way between 6 and 9 is 7.5, so I pull it 7.5 cents sharp, and almost invariably A4 ends up right on 440 Hz, or very close.  </FONT></SPAN></FONT></FONT></DIV> <DIV><SPAN class=114315606-07072006>    <FONT face=Arial size=4>However, if the piano is a half-step flat, I don't pull it 41 cents sharp.  That would be too much.  There's some degree of flatness where the usually-id</FONT></SPAN><SPAN class=114315606-07072006><FONT face=Arial size=4>eal 41% overpull has to taper off.  For a half-step pitch raise, I usually overpull so that A4 is beating about 5 beats sharp.  That's approximately 20 cents, I believe.  Sometimes more is required, sometimes less.  It varies.  That's here in Denver -- probably different elsewhere.  </FONT></SPAN></DIV> <DIV><SPAN class=114315606-07072006><FONT face=Arial size=4>    But what I often experience is:  even though after the pitch raise, A</FONT></SPAN><SPAN class=114315606-07072006><FONT face=Arial size=4>4 is at 440; after I've gone through the fine tuning and     </FONT></SPAN><SPAN class=114315606-07072006><FONT face=Arial size=4> pulled in unisons, when I go back to do the final check and touch up anything that has slipped, I find that the whole middle section is sharp!  Why?</FONT></SPAN></DIV> <DIV><SPAN class=114315606-07072006><FONT face=Arial size=4>    --David Nereson, RPT</FONT></SPAN></DIV> <DIV><SPAN class=114315606-07072006></SPAN> </DIV> <BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px"> <DIV><SPAN class=114315606-07072006><FONT face=Arial size=4></FONT></SPAN> </DIV></BLOCKQUOTE></FONT></BLOCKQUOTE></BODY></HTML>