---------- > From: LTpianoman@aol.com > To: pianotech@ptg.org > Subject: Ridiculous Pitch Raise! > Date: Friday, August 29, 1997 10:53 PM > > Dear List, > With the kind help of the List I recently performed my first valid pitch > raise on an old but sound Hobart M. Cable upright. I did a pitch raise on a > piano before I really knew very much about tuning and I was unaware that it > was a pitch-raise...I just thought, "gee, this piano is really flat!", and > you can imagine what a disaster that was, treating it like a fine tuning and > going crazy. Well, now I'm confronted with an 1898 Sohmer upright "grand" > that I am re-conditioning which is 139 cents flat. The plate is good, all > bolts are tight and it is a solid piano. I have heard from some techs that > older Sohmers do not take too well to pitch raises. (?) Also, 435-A is > factory-enscribed on the plate. My question is, if this is done properly and > with all precautions taken, would it be adviseable to take it up to 440 or > should I only go up to 435 as it came from the factory? Any input is > appreciated. Thank you in advance. > > P.S.-The Hobart came out very stable and right on 440 in 3 passes with only 2 > broken bass strings...and it sold for $1100 in a few days. My first major > accomplishment!! (it was a candidate for the dumpster and it transformed > into a beautiful instrument). > > Larry Trischetta > Scranton,Pa. Pocono Chapter > Randy Potter Student > LTpianoman@aol.com Dear Larry, On the Sohmer here is how I would proceed. Pass #1 If you use an SAT bring it up to -20c the first pass, this would be the A-435. Pass #2. If needed, use the pitch raising program in the SAT to -20c. Pass #3 Fine tune. If you use a fork bring it up the first time to 5 BPS flat to the fork. Next pass overshoot by about 1/3 the amount it is flat. Pre-Passes. Lube under bearing points, pressure bars, upper offset pins. Go slow and carefully and confidently. If alll this goes well I would consider bringing it up to A-440 the next time you tune it which ought to be in a bout 2 weeks. James Grebe RPT from St. Louis pianoman@inlink.com
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