Weekend riddle answer;

[A440A@aol.com]

Greetings all;

> > >      When I finally found the problem, it was nothing to do with the
> > >strings, plate,case, or wheels,  it was not to be found in any of the
keys,
> > >whippens, hammer shanks, damper underlevers action rails, sostenuto or
> > >keyframe. It was not some exterior object rattling along with the piano.
 I
> > >had had my hand on the offending item twice during the investigation,
and
> > >then only by chance did it occur to me what it was.
> > >    the repair took  twenty seconds to effect, and 20 minutes to dry.


   The sound was coming from the damper tray spring, even though I had
threaded a strip of felt through it.   When the tray was down, and the spring
at full length, ithe felt was tight and the spring vibration was damped.
     when the tray was lifted,  the spring was squeezing the felt and was
damped.
but when the dampers were half-pedaled, the spring was able to vibrate, and
the resonant frequency was found in the Bb chord.
   I only noticed it when I strummed the spring while moving the pedal up and
down.  there was only one small place where the spring was free, and it was
humming along.
   A quick wipe of PVC-E glue over the spring caused the problem to
disappear!

So simple, and it still took almost an hour to find.   gee......
Regards,
Ed Foote
Precision Piano Works
Nashville, Tn.