On Mon, Jan 24, 2011 at 7:45 AM, Andrew Anderson <anrebe at gmail.com> wrote: > It really depends on how far the hall climate is from the climate > maintained in the piano. I was tuning a S&S D that got unplugged while I > was working on it. Everything was moving within a couple minutes, and not > just a little! When I showed the manager how much, he made a hard rule: the > piano is never unplugged. They have a stage hand specifically to manage the > cord when it is moved between numbers in a concert. > When the tuning moves that much, the unisons do not come back perfectly > when it is plugged in again. > Andrew Anderson > Not saying that you didn't observe pitch movement. But it doesn't come from humidity rushing into the piano once the DC is turned off. Changes that happen that quickly are from temperature changes--not humidity. And, remember ... there is quite a bit of heat coming from the dehumifidier bars. Opening the lid and beginning to tune right away will be an exercise in futility. When the warm inside is suddenly assaulted by room temp air, you gotta take a few minutes to let things acclimate. (Thanks again to Ron Nossaman for pointing this out some years ago. I had been wondering how I mysteriously and suddenly turned into a dunce tuner only on the DC pianos. <G>) FWIW, since that "discovery," I've measured a 1 Hz change at A4 for vertical pianos once the lid is opened to begin tuning. That was within 5-10 minutes. -- JF -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20110124/42f9c2af/attachment.htm>
This PTG archive page provided courtesy of Moy Piano Service, LLC