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Sight-O-Tuner Slide Rule

  • 1.  Sight-O-Tuner Slide Rule

    Registered Piano Technician
    Posted 06-26-2023 11:56

    I'm researching early electronic tuning approaches, and I've heard about the slide rules that were used with the original Inventronics Sight-O-Tuner. On the Inventronics website I found a manual for the Sight-O-Tuner II. Unlike the first Sight-O-Tuner the model II had the different generic stretch models built into it. https://www.accu-tuner.com/pdfs/2012_SOT_II_Manual_H.pdf 

    Does anyone on this list have one of those original slide rules that I could borrow or buy? 



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    Ryan Sowers RPT
    Olympia WA
    (360) 480-5648
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  • 2.  RE: Sight-O-Tuner Slide Rule

    Registered Piano Technician
    Posted 06-26-2023 12:50
    Oh, the geek I was in the day!  Sorry, my slide rule is no longer hanging from my belt!  Log gone ��

     

     

    http://bit.ly/Schedule_My_Piano

     

    "Good, better, best; never let it rest, 'til the good is better and better best!"


    "Providing quality service for the world's pianos"

     

    George W.R. "Bill" Davis, RPT

    The Piano Place GA

    2315 Rocky Mountain Rd NE

    Marietta GA 30066

    www.pianoplace.net

    bill@pianoplace.net


    Sent from my iPhone



    Original Message


  • 3.  RE: Sight-O-Tuner Slide Rule

    Registered Piano Technician
    Posted 06-27-2023 02:51
    Somewhere I still have my slide rule (blue cover, black lettering-but I am preparing for a vacation, and won't be able to look for it until after the vacation-hopefully it is not buried in one of my multiple storage boxes of "neat stuff I can't throw away" but somewhere in one of my tool boxes! or maybe even in a sight-O-Tuner case.
    David D.



    Original Message


  • 4.  RE: Sight-O-Tuner Slide Rule

    Registered Piano Technician
    Posted 06-28-2023 08:27

    R,

    Perhaps there's one in the PTGF Museum? If not, one definitely needs to be preserved there.

    Best regards,

    Allan



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    Allan Gilreath, RPT
    Registered Piano Technician & President
    Allan Gilreath & Associates, Inc
    Calhoun, GA
    706-602-7667
    allan@allangilreath.com - www.allangilreath.com
    ------------------------------

    Original Message


  • 5.  RE: Sight-O-Tuner Slide Rule

    Registered Piano Technician
    Posted 06-28-2023 10:39
    My SOT is in the museum, but I can’t remember if I included the calculator.

    Wim

    Sent from my iPhone


    Original Message


  • 6.  RE: Sight-O-Tuner Slide Rule

    Registered Piano Technician
    Posted 06-28-2023 12:51

    Thanks for the suggestions, gang! The museum is a great suggestion - and if they don't have one, we should put a call out in the Journal for someone to donate one. I'm not clear on how it worked exactly. 

    Wasn't it designed to allow you to take direct inharmonicity measurements in order to calculate an inharmonicity curve for the specific piano?

    Ryan



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    Ryan Sowers RPT
    Olympia WA
    (360) 480-5648
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    Original Message


  • 7.  RE: Sight-O-Tuner Slide Rule

    Registered Piano Technician
    Posted 06-28-2023 13:28

    Ryan,

      Yes, you measured (if memory serves me right) f3 and f4 at with the SOt set at 4 & 5 I think (with them in tune with each other) and the difference you pull the calculator card to match that and it gives you the settings for all the rest of the notes (or the intervals between them--too long ago!)

    David D.




    Original Message


  • 8.  RE: Sight-O-Tuner Slide Rule

    Registered Piano Technician
    Posted 06-28-2023 13:13

    I'd check with the family. They may have some leftovers in a box in the attic.



    ------------------------------
    William Ballard RPT
    WBPS
    Saxtons River VT
    802-869-9107

    "Our lives contain a thousand springs
    and dies if one be gone
    Strange that a harp of a thousand strings
    should keep in tune so long."
    ...........Dr. Watts, "The Continental Harmony,1774
    +++++++++++++++++++++
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    Original Message


  • 9.  RE: Sight-O-Tuner Slide Rule

    Registered Piano Technician
    Posted 06-30-2023 11:34

    Update:

    Paul Sanderson sent me a link to a Site-O-Tuner on Ebay with all its original paperwork so I just bought it. I'll follow up once I have a chance to play around with the stretch calculator. Here's some pics:



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    Ryan Sowers RPT
    Olympia WA
    (360) 480-5648
    ------------------------------

    Original Message


  • 10.  RE: Sight-O-Tuner Slide Rule

    Registered Piano Technician
    Posted 07-01-2023 02:14
    What was common to all of the stretch calculators was 1/2 bps at the 4:2 between A3 and A4. We would now consider this a little to wide.

    Sent from my iPad
    CarlPianoTech.com


    Original Message


  • 11.  RE: Sight-O-Tuner Slide Rule

    Registered Piano Technician
    Posted 07-02-2023 15:48

    Thanks for that Carl - that is interesting. After reading your response I went and checked the width of the A3-A4 octave on the Steinway O in my living room. The way I do it with TuneLab is to set the machine on manual note switching and have it listen to A5 while playing A3 and A4 after stopping the display on each note and noting the Hz reading. 

    I could hear just a slight but noticeable difference using the 3rd/10th test that proved my 4:2 octave was wide. My measurements showed that the actual Hz difference was closer to .3 which corroborates your comment that .5 Hz is probably a little too stretchy. I think 1/3  beat wide is probably about the sweet spot in that area of the piano in many cases. 



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    Ryan Sowers RPT
    Olympia WA
    (360) 480-5648
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    Original Message