I have used strobe tuners and know how they work.  I am sure one of you
out there can answer this young lady's question better than I and help
her get an "A" in her school work.

Thanks

Ed Gaida
egaida@txdirect.net

 -- forwarded message, please reply to sender and MMD --

From: hritz@acc-net.com (John Hritz)(fwd)
To: egaida@txdirect.net (Ed Gaida)

I recently came across your article on the history of standard pitch,
A=440 Hz, in the Mechanical Music Digest.  My daughter (7th grade)
is doing a report on whether different manufacturers of reeds make a
difference on a clarinet's intonation.  The science teacher has asked
her to explain how a strobotuner works.  How does a sound wave go into
the tuner and then make the needle go left or right determining flat or
sharp?  We have looked at our local library and the Internet.  We have
turned up nothing.  Do you know where she could go to discover informa-
tion on what makes a tuner work or how a sound wave goes into the tuner
and then determines whether the instrument is playing flat or sharp?
Thanks for any help you can offer.

John Hritz
hritz@acc-net.com

 [ Editor's comments:
 [
 [ The science teacher speaks of an indicator needle which moves to
 [ the right or left, which describes a modern electronic "frequency
 [ counter" device with an indicating meter (a stationary dial and 
 [ a moving pointer).
 [
 [ The stroboscopic frequency indicating machine, such as the Conn
 [ Strobotuner, is a spinning disc with radial lines illuminated by
 [ a stroboscope ("strobe") lamp whose light intensity varies with
 [ the audio waveform picked up by a microphone.
 [
 [ The Strobotuner presents a stroboscopic image which rotates according
 [ to the difference frequency between the audio frequency and the
 [ number of lines per second of the rotating disc, whereas the modern
 [ frequency meter is analogous to an automobile speedometer which
 [ displays the average frequency.
 [
 [ The human mind and eye can view the rotating stroboscopic image and
 [ see much more information than a simple meter indicator provides --
 [ the overtones in the waveform and their "stretch" against the
 [ harmonic series are readily apparent.  (It also works well for
 [ very short duration sounds like a xylophone.)
 [
 [ Regarding the intonation of certain reed instruments, jazz man
 [ George Probert (Firehouse Five) says about the soprano saxophone,
 [ "Shove the mouthpiece down all the way and lip it into tune!"
 [ (Intonation is not a critical performance issue with George.  ;)
 [
 [ -- Robbie