In a message dated 2/7/2010 9:36:45 P.M. Central Standard Time, a440a at aol.com writes: Greetings, I wrote: >>I would think that a 40 cent raise would be pulling new wire around the bridge pins,(especially in a new piano that has sat for a year at that low pitch). Paul writes: This may or may not be true. Jim Ellis suggests through his demonstrated research that strings don't begin to render on the bridge top unless more than 50 cents is added to the pitch. 40 or 50 in this case might make no difference. Just a thought. I can see the logic of the above inre a stable piano that is near pitch, but consider that the starting pitch will determine how much tension must be added to move the slack out of the backstring into the speaking length: to wit, (since I am already half way there...), the looser the string, the less tension is required to overcome the friction of the bridge and bridge pins. Once the string is at pitch, you almost have to break the string before the pitch of the backstring changes with added tension from the tuning pin. On a new piano, the backstring just might have a fair amount of slack in it from the bend at the hitch pin resolving itself during the first year. If Diane is bringing up strings 40 cents, I would expect there to be some measurable pitch change in the back string. Easy to measure on the grands with the rear duplex. Maybe less so on the uprights, as they usually seem to have much shorter backstrings. Regards, Ed Foote RPT http://www.uk-piano.org/edfoote/index.html Ed: I totally agree with everything you say. The only difference I can see that would be germane would be the over-pitch pull as an additional tension which would probably overcome the "limit" that Ellis describes. Thanks, Paul -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20100207/c8be97b3/attachment.htm>
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