Alan and David on F3/A4

[ed440@mindspring.com]

Kent-

Two or three comments.

In my tests last night the Walker forks showed the least variance in the second partials, and frequently showed zero or slight inharmonicity.

But looking at my list of readings, I see that I did extra readings on the nickel plated Walker, and there is perhaps a heat-induced rise on the last readings, where I used very long ring times.  I discounted these readings last night because I used just the first six readings on all forks.

Second: When I set Pianalyzer at A5, it is almost impossible to get an air reading at 880hz (sometimes the Walkers give a reading in air), attempts to get a reading by holding the side of the handle against the case vary, and readings taken with the tip of the handle standing on the Cybertuner case almost always read, but the results are not consistant from one reading to the next.  Sometimes 5 or 6 higher partials are reported, sometimes none, with the same fork.

This supports a hypothesis that the 880hz signal is caused by up and down movement of the handle as the prongs move side to side at 440hz.  It has been suggested that because of this, we should not hold the fork against the case for resonance, as it will amplify the 880hz signal.

Third: But is this what we hear when we play F3 against the fork? Or is it an interaction of 440hz from the fork with 880hz from F3? Can anyone answer this?

I concur with your conclusion:Use F2 as a test note; then you don't need to answer these questions!

Ed Sutton

-----Original Message-----
>From: Kent Swafford <kswafford@earthlink.net>
>Sent: Jan 9, 2006 12:40 PM
>To: Pianotech <pianotech@ptg.org>
>Subject: Re: Alan and David on F3/A4
>
>On Jan 9, 2006, at 10:57 AM, BobDavis88@aol.com wrote:
>> Not meaning to embarrass anyone, but just to avoid confusion to  
>> those learning the trade, this is not correct. A perfectly tuned  
>> 440 A4 on the piano produces a second partial which is slightly  
>> sharp of 880. IF the fork produces 880 at A5 (which has recently  
>> been called into question), we would have to bring A4 DOWN (under  
>> 440) to match its 2nd partial to the fork's 2nd partial.
>>
>> Bob Davis
>
>
>Who just said this subject was easy?   8^)
>
>Let's see if I can get it right. Here are a few readings taken this  
>morning of a John Walker A fork and a Yamaha grand. They show that  
>Bob is correct. No obfuscations. No smoke and mirrors.
>
>The first attached graphic shows an RCT Pianalyzer readout of an A4  
>tuning fork. Note that the Inharmonicity column shows uniformly zero  
>inharmonicity.
>
>?
>
>The second attached graphic shows an RCT Pianalyzer readout of a  
>piano's A4. If the 2nd partials from the two graphs were tuned  
>together (as would be the case using F3 as a test note to tune the  
>two together), then there would be a 1.2 cent offset at the  
>fundamental. That is, if the piano A's 2nd partial were tuned down to  
>match the 0.0 of the fork's second partial, then the piano's A would  
>be flat by 1.2 cents.
>
>If this were on the PTG tuning exam, the examinee would have used up  
>a substantial portion of the tolerance in doing so. Please use F2 to  
>match the fundamentals of the pitch source and the piano's A when  
>setting pitch.
>
>
>?
>
>
>Kent
>