Hi Julia, The PTG Piano Action Handbook (1991) lists the following specs for the U3: Key Height (measured from the key bed to the top of the key covering at the end of the key) - 64mm. Footnote adds a measurement of 21mm from the top of the keyslip to the top of white keys on all vertical models. Sharp Height (top of white key covering to top of sharp at front of the key) - 12mm Hammer Blow - 47mm Hammer Let-off 3mm bass graduated to 2mm treble. Key Dip (white keys) 10mm. Sharps regulated to touch. Back Check Distance - 13mm I realize Tom Driscoll has already given you a more nuanced response, but since I have the published specs, I decided to pass them on. Floyd Gadd Manitoba Chapter -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100215/47f7e212/attachment.htm>
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