[pianotech] Yamaha Upright String Breaker

[David Love]

Yes, well the next question is what to do.  I replaced one string on this
bichord about a year ago and while tuning the piano that string broke which
caused me to do some analysis.  I suppose I could just drop the tension on
this bichord but then will it blend?  Or I could analyze the entire top end
of the scale and blend it back several notes (they'll love that idea).  Or I
could refer them to my least favorite tech in the area.  So may
possibilities.  

David Love
www.davidlovepianos.com

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Saturday, January 08, 2011 11:24 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] Yamaha Upright String Breaker

On 1/8/2011 1:04 PM, David Love wrote:
> I've got a Yamaha studio upright that continues to break strings at D3
> (wrapped bichord).  The speaking length is 890mm, the core wire 14 gauge
and
> the outside wrapped dimension is .058".  My spread sheet shows that at 69%
> BP but my own formula might be low.  Any string makers care to input here?
> It seems to me it's got to be too high.

I get 69% too, and while I'm not a string maker, I call it too high too. 
I know at least three makers who would complain immediately and loudly 
if I specified something like this in a custom set.
Ron N