humidity effect

[Roger Jolly]

>Well I just measured another piano and guess what--I see the exact same
>effect (only less obvious).

Hi Don,
              A reasonable test would be to tune the treble string first,
then pull the unisons to that string, and see if there is a difference in
reaction.
Ideally it would be good if you find the same model of piano to make a
comparison.
This would give some indication that the second and third string is trying
to hit a moving target.
Less obvious may be due to old tired wire.
Regards Roger
Roger Jolly
Saskatoon, Canada.
306-665-0213
Fax 652-0505