post pitch-raise creep?

[Joe And Penny Goss]

Boy Paul are we on the same page!
I think speed of the tuning lever in getting the pin to move is also an issue here.
Slow  pull, I think has a tendency to put more twist in the pin, that is later released, allowing the pitch to drop. Those tuners who are able to get the pin to snap forward, can tune softer.
Related, soft pins from our Chinese frends are harder to feel move at the 3 o'clock position and moving to 11 to 12 o'clock helps a lot.
Joe Goss RPT
Mother Goose Tools
imatunr at srvinet.com
www.mothergoosetools.com
  ----- Original Message ----- 
  From: pmc033 at earthlink.net 
  To: dnereson at 4dv.net, Pianotech List 
  Sent: Sunday, July 09, 2006 7:13 AM
  Subject: RE: post pitch-raise creep?


  David:
      Since different techs use different pin setting techniques, it's hard to say exactly how much over pull will work for every situation.  During the last few weeks, there was a discussion of overpull percentages with RCT users.  Some had to adjust the overpull because their pianos were coming out too sharp using the default percentages.  
      For years, I had been using my SAT for pitch raises using the single string method described in the SAT manual.  That is, doing the unisons at the end.  I would pull the bass 25%, and mentally calculate the rest of the string overpull at 30%.  I would carefully set the pins as close as I could.  After pulling the unisons in, I would end up sharp in the low tenor, less sharp in the rest of the tenor section, and the treble came out ok.  I used to reduce the overpull in the tenor accordingly (lots of mental gymnastics here).  It seemed to work for me.  
      Then, I got the Pocket RCT, and began doing unisons as I went along.  I found that doing this produced a more accurate result.  After a few months of PRCT, I went back to my SAT and began using the string by string method.  The result was that my SAT pitch raises began to come out much closer to pitch than before.  Since the SAT has a default 25% automatic overpull, I use that in the bass.  In the low tenor, I use 25% also, maybe adding a few cents more (maybe closer to 28% overall).  Starting in the treble, I go back to 30% for the rest of the strings.  
      I spend much more time in the pitch raise than the final pass because I find that the result is much closer if I do that.  If I spend less time on the pitch raise, not being as careful, I have to spend more time on the final pass.  I do set the pins  while pitch raising.
      Doing the unisons string by string may seem tedious (which is why I resisted doing so for years), but the result is more accurate in my experience.  YMMV.
      Just my $.02.
      
      Paul McCloud
      San Diego


    ----- Original Message ----- 
    From: David Nereson 
    To: Pianotech List
    Sent: 07/09/2006 4:58:54 AM 
    Subject: RE: post pitch-raise creep?



      -----Original Message-----
      From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org]On Behalf Of Farrell
      Sent: Friday, July 07, 2006 6:04 AM
      To: Pianotech List
      Subject: Re: post pitch-raise creep?


      Doesn't sound right. When doing the PR, are you using an ETD?  

      Only to measure the amount it's flat and to tune the initial A4 sharp by 40% of the amount it was flat.  

       Unisons as you go?  

      No.  All the middle strings, then all the unisons, then the bass, which sometimes needs very little raising.  I can do it fastest that way.    

       41% is very large percentage for overpull. Most ETDs recommend between 20% and 35%, depending on the area of the scale. 

      And I say that's usually not enough.  If it's 20 cents flat, half of that (50%) is 10 cents, and a third of that (33%) is about 7 cents.  So I pull A4 halfway in between those numbers, or about 8 1/2 cents sharp, which is roughly 40% of the amount it was flat.  (I notice in other posts, some tuners use up to 37% in some areas of the piano.)  Then I do the pitch raise, all the octaves, then all the unisons.  Almost every time, A4 ends up right on 440, and the rest of the rough tuning is very close.   So I go ahead and do the tuning (fine tuning).  It's after I'm done with the fine tuning, when I go back to check for anything that has slipped, that I find the middle of the piano and the low tenor has crept sharp by a beat or even two.  

      Immediately after the PR, do you check the middle section for pitch?  

      Yes, and it's almost always right on 440, so I proceed with the fine tuning.  It's after the fine tuning that I find it has crept sharp in the middle.  The low tenor is also quite sharp, so now I leave that area a bit flat during the pitch raise.  And during the tuning (fine tuning), the SAT always seems to "tune" the bass too flat, even if the bass didn't need a pitch raise.  

       If it is at or near target, there is no reason for it to creek up.  

      One wouldn't think so.  

       How large a pitch gain are you talking about?  

      Anywhere from just a few beats flat to a half-step flat.

       I've never noticed such a phenomena.

      That's "phenomenon."  Phenomena is plural.  (Just for your own info.)
      --David Nereson, RPT

      Terry Farrell
            
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