F3/A4 as pitch test

[ed440@mindspring.com]

Ric and List:

The problem I have with this is that if we use F3/A4 as a test, we are listening to the pitch at A5, not at A4.
Tuning forks have a weak partial at A5, so it is possible to hear a rather weak beat there.  When we play F3/A4 on the piano, we seem to hear a beat at A4, but with careful listening, we realize the beat occurs at A5.  We are setting pitch to the second partial of the fork at A5.  If we test F3/A3, we are setting A3 to the fork at A5.

Using Cybertuner on Pianalyzer mode, I tested 7 tuning forks 6 times each, reading the pitch readouts at A4 and A5.  The forks range from 2 19th century forks to two contemporary Walker forks and a new Nippon fork.

At A4, the forks were very stable, showing a small drop in pitch over the six tests, averaging about 0.3 cents, with a maximum drop of 0.9 cents.  This was probably due to temperature change from being held in my hand at the handle.

At A5, the measured variance is so wild and erratic that I wonder if it is correct, or an artifact of the measuring system.
Dropping the most extreme reading of each fork, and dropping the 19th century forks, which were extremely wild, the remaining forks show variences of 2.1, 9.9, 5.4, 12, and 11.5 cents at A5.  There is no pattern relating to time the fork was held, or how hard it was struck.  The variances are erratic and unpredictable.

Perhaps someone else could test a fork against a spectrum analyzer and report the results.

Ed Sutton