Pertaining to bridges

[Joe & Penny Goss]

Richard,
It seems to me that you have said that all things are conected for the final
result and any one of the items will change the final out come.
HUM sort of like regulating an action isn't it
Joe Goss
imatunr@primenet.com
http://www.primenet.com/~imatunr/

----- Original Message -----
From: "Richard Brekne" <Richard.Brekne@grieg.uib.no>
To: "PTG" <pianotech@ptg.org>
Sent: Friday, February 16, 2001 1:34 PM
Subject: Pertaining to bridges


> This thread on Virgils beats, ETD question and related stuff
> prompts me to aks a question of our rebuilders who are familiar
> with this stuff about bridges.
>
> Also... Weinreich talks about the impedance from the bridge
> having three main possible characters. Massy, Springy, and
> Resistive. Are these to anydegree something one can design into a
> bridge / soundboard  assembly ?
>
> To mind pops up Ron Overs recent postings on the orientation of
> bridge wood grain relating to supporting bridge pins... how does
> grain orientation fit in (if at all) with impedance charachter ?
> For that matter... loose bridge pins themselves.  Would seem to
> me that a bridge pin that can give a bit sideways would tend to
> effect the whole assembly (for affected notes) in the direction
> of being springy...which in turn tend to lend itself towards
> pitch drop.
>
> Another thing that I am a bit foggy on here is how exactly does
> coupling in more strings exasperate these three conditions ? Take
> for example a springy termination. Muting the string would tend
> to hold the bridge a bit stiffer right ? .... aslo increasing
> impedance seen by the string allowed to vibrate.. and releasing
> the muted string then releases that stiffening effect on the
> bridge... with a resultant decrease in impedance seen by the
> first string.  But this affects only the amount of apparant
> bridge impedance... not its character ??? or does it also
> compound or otherwise effect the character of impedance ??
>
> Anybody want to clear this up for me ??
>
> Or is my mind
>
> --
> Richard Brekne
> RPT, N.P.T.F.
> Bergen, Norway
> mailto:Richard.Brekne@grieg.uib.no
>
>
>