Tuning machines & RPT exam

[Dean L. Reyburn, RPT]

I wrote:
>>  With the Macintosh version of TM, I use Chameleon 2 to
>> record the piano using digital audio, and the calculate a great custom
>> tuning for transfer to the SAT.  Chameleon is called that since the user
>> can decide the tuning "color" or octave stretch.  (Chameleon 2 passed the
>> RPT exam at 100% several times!)
>
Allen writes;

>Anybody know if the Yamaha PT100 has ever been given the RPT exam?
>I set my PT100 to the scale nearest the piano I'm going to tune, and then
>per Reblitz, I adjust the width of the temperament octave such that
>the width is defined as the spacing from the first partial of F3 to the
>second partial of F3.  I'm curious how well this scheme would do on
>the exam.
>
Sorry I didn't explain that very well Allen.  I gave the short version.
I have used the tuning that my Chameleon program produces several times
to demonstrate passing the RPT exam.  It produces a tuning without user
intervention, and I used the special "RPT Exam" tuning style built into
the program that I set specifically to beat the exam.  I have been in on
a number of master tuning sessions, and have given the RPT test many
times, so I have the unfair advantage of knowing how the average
committee of 3 CTE/RPT's tunes.  I have captured this in software!

The unisons and stability portions of the exam are not applicable here
since that tests the human, not the tuning method.  The machine could
tune unisons, but that is beside the point here.  Tuning stability is a
human only thing.

The Chameleon tuning is transferred to the Sanderson Accu-Tuner, and then
of course, to the piano.  It is not the machine being tested so much as
the tuning method.  The SAT's FAC will normally pass the RPT exam in the
80% or even 90% range if the tuning is carefully measured and layed on
the piano.  (Remember though, aurally tuning two octaves (C3-B4) is
required to pass if you use a "VTD" or visual tuning device.)

If I understand the tuning you describe correctly, you are tuning a 2/1
octave between F3 and F4.  That is matching the second partial of F3 to
the first partial of F4.  I have studied how much tuners stretch the
octaves in different parts of the piano, and this much stretch would be
very VERY conservative.  Most aural tuners will set a 4/2 octave slightly
wide at F3-F4, say 1/4 to 1/2 bps wide.  That is, the major-third/major
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