Hi again friends, Been absent from the list for a long time. This is an issue I've been reading with interest, as I, too, am considering the RPT exams. Tuning fork accuracy and the test has been something I've been very curious about and has been one of my deterrents to this point from taking the test. These discussions are shedding some light, but I have some questions about some of the suggestions. I also use the John Walker (Sheffield) forks. I used the lightweight blued forks for years until someone encouraged me to spend the money for the heavy weight chrome one a couple of years ago. It rings much louder and longer, though it produces a whole smorgasboard of partials which don't match anything. I still like it better, though because it produces a clearer fundamental tone. I have a hard time comparing the pitch of the electronic pitch devices I've seen with piano tones. Regarding temperature. The little paper which came with my fork says it is tuned to A-440 at 20 degrees Celsius, and the supply catalogs read that they're "guaranteed accurate" (whatever that means). Best I can determine, that translates into 68 degrees Fahrenheit. My questions are these: If it is more accurate to completely rebuild the fork so that it works at body temperature, then why don't fork manufacturers just do that in the first place? Isn't pitch relative to temperature, anyway? (See: The Tuning Examination: A Source Book, Chapter 1 "Learning to Pass the PTG Tuning Examination", pp. 13-16, Michael Travis.) Are we guaranteed that we will be tested on a 70 degree piano? If you use the fork at body temp, I can foresee that extending the time required for taking the exam if you follow the recommendations in the Tuning Exam Source Book. Once you have set your initial pitch, you've got to put the fork down somewhere, because you surely can't keep it under your arm while tuning. It is recommended that you tune through the piano 3 times if possible. Now, you've got to come back the second and third times to recheck your A49, right? If you stick it in your shirt pocket, I'd bet you wouldn't get the same temp as under your arm, as in your pants, etc. Terry, if you get a reading on the SAT at -3.6, that tells me that for a 30.6 degree increase in temp, assuming your body temp is normal, the fork goes flat by (only) 3.6 cents, assuming that the fork is "guaranteed accurate at 20C/68F" in the first place. Now if you're tuning in a room at 72 degrees, your fork ought to be very accurate if you acclimate the fork to room temp, right? Realizing that the thermal expansion properties of tuning fork steel probably won't follow exactly, but would probably be close, a straight statistical conversion of a 4 degree deviation compared with the -3.6 cents at 30.6 degree deviation results in a mere -0.471 cents deviation. Now who can hear that? I keep a Radio Shack Thermometer/Hydrometer in my case at all times, and can within 5 minutes or so have a pretty good idea of what temp the room is, but certainly immediately know what temp the fork has been stored at. The next question I have is with the SAT. While I am somewhat SAT illiterate, I thought Mr. Coleman's statement summed up my big concern beautifully: >Assuming your SAT 3 is in calibration (it should be unless someone has >messed with it. It's easy to correct) I do, however, own a Sight-O-Tuner which I purchased in 1984 while I was learning to tune, and used for a couple of years before I realized I could do much better aurally. I walked off from it partially because my A440 was being challenged by someone tuning with a fork, and they were right, because the S-O-T was centered on C40. I later learned that electronics have to be periodically calibrated. A relative of mine, who is an electronics/computer tech, and formerly an Allen Organ tech, explained that this is necessary because of thermal wear on electronic components. If the SAT is "easy to correct", to what does one correct it? (I used my tuning fork to recalibrate my S-O-T to A440.) Whatever did we do before the SAT? Please enlighten me, as well. (Sorry for the length) Jeff Tanner, Piano Technician School of Music University of South Carolina Columbia, SC 29208 (803)-777-4392 (phone) (803)-777-6508 (fax)
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