Replacing plain wire

[David M. Porritt]

Del:

Thanks so much for the information.  I think I'm going to select one
that has a really weak sound in that area and see what can be done
with the "Pure Sound" wire.  It'll probably have to wait until next
summer when time is not quite as highly structured.  

I'll post the results.

dave

*********** REPLY SEPARATOR  ***********

On 11/12/01 at 10:03 PM Delwin D Fandrich wrote:

>----- Original Message -----
>From: "David M. Porritt" <dm.porritt@verizon.net>
>To: <caut@ptg.org>
>Sent: November 12, 2001 7:19 AM
>Subject: Re: Replacing plain wire
>
>
>>
>> I was meaning the lowest plain wire section - F3 - A3 or so.  That
>> area of the 243HP is improved over the 243, but still sounds like
too
>> low a tension.  Do you have tension figures off hand?
>>
>> dave
>> *********** REPLY SEPARATOR  ***********
>
>Yes. Tensions for the first octave are:
>F-33 = 158 lbs (72 kgf)
>F#-34 = 167 lbs (76 kgf)
>G-35 = 174 lbs (79 kgf)
>G#-36 = 183 lbs (83 kgf)
>A-37 = 174 lbs (79 kgf)
>A#-38 = 182 lbs (83 kgf)
>B-39 = 189 lbs (86 kgf)
>C-40 = 197 lbs (89 kgf)
>C#-41 = 186 lbs (84 kgf)
>D-42 = 193 lbs (88 kgf)
>D#-43 = 199 lbs (90 kgf)
>E-44 = 206 lbs (94 kgf)
>F-45 = 194 lbs (88 kgf)
>(Your results may vary depending on actual bridge placement. This
tended to
>vary just a bit.)
>
>That whole redesign was a compromise--as are most redesigns of
existing
>pianos. The piano really needed a new plate, changing the scale from
a 28
>bass to a 32 bass section. Lacking that it could really use a
transition
>bridge for the lowest four notes in the tenor section (C#-29 through
E-32),
>a longer F-33 and a shorter mid-tenor. This, however, would have
involved
>rather more extensive changes to the plate pattern than the company
was
>willing to consider at the time. And there was no interest at all in
a
>whole
>new plate. As it is, tensions are extremely high from about C40
through
>F#-58 (several are comfortably above 200 lbs (91 kgf) but drop off
rather
>rapidly below that. As I recall the total scale tension was around
43,500
>lbs (19,750 kgf)--rather high for a piano of this size. About all I
can say
>is that it is less erratic than its processor and I'd love to do a
new
>scale
>and a new plate for a piano of this size. Or, at the least, move the
V-bar
>around to correct for the erratic hammer strike point and make
another
>tenor
>bridge for the piano--including a separate transition bridge for the
lowest
>four notes in the tenor section--and a new bass scale. Ah, well....
>
>I'm not sure what I'd recommend to improve the tone in the area that
>bothers
>you. It's a bit high up in the scale for wrapped strings. As it is
F-33 is
>only 812 mm long but, as you can see, the tension is up around 158
lbs (72
>kgf) and it took a #21 wire to get it there. I don't think I'd want
to see
>anything any thicker.
>
>I do have a new tenor/bass string scale for this piano (leaving the
bridges
>alone) that actually lowers tensions and smoothes things out a bit
more,
>but
>the lowest tri-chords remain the same.
>
>An aside, you might check string bearing--this was often a somewhat
>flexible
>parameter on these pianos and can cause real problems down
>there--especially
>if it is too high.
>
>Regards,
>
>Del


_____________________________
David M. Porritt
dporritt@mail.smu.edu
Meadows School of the Arts
Southern Methodist University
Dallas, TX 75275
_____________________________