Humidity Change and Unisons

[John Lillico, RPT]

>I trust everyone has this all figured out now, but no one suggested it
>might be the casters. Curious.

You've got to be kidding! But then, Don Rose keeps on "rolling" on about it!
>
>See John L, this is what happens when I don't post in and scare them off
>once in a while.  <G>
>
>Ron N

Where were you? In your absence though, a few techs did pick up on the point I was trying to make by emphasizing plate movement. Don's original quandry was trying to figure out why the right string of a tri-chord was sharper than the left one on both uprights and grands, presumably using the middle string as a guide. (I presume that this is a recent observation of his and not one he made last winter.) We_know that when a soundboard with crown swells, the pitch will go sharp! When this happens the right string, having the shortest segment from the rear bridge pin to the plate edging receives the greater tension and goes sharp. My illustration of plate swelling or tilting was to focus attention away from the soundboard and bridge to the angular edging of the plate and I still don't know if Don caught on! But Larry Messerly did.

The exception to this is when you have those duplex gadgets which permit all three string tail segments to be the same length. I proved it today with a Yamaha A1.

This has been a very entertaining and thought provoking post and I've had a few laughs. Kind of wish Larry was our RVP. He's so easy to convince.

John Lillico, RPT
Oakville, Ontari-ario (or wherever)