RE: motor speed sound (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sun, 16 Sep 2007 21:03:48 -0500
From: sparks@xxxxxxxxxxxxxx
To: Tesla list <tesla@xxxxxxxxxx>
Subject: RE: motor speed sound (fwd)

> My question is, can I use my digital tuner (for music stuff)
> to "measure"
> the pitch of the sound, and then convert that to frequency,
> and convert
> that to RPM,

Yes, you can, but you may be limited if the sound of the motor does not
fall within a range of frequencies that the tuner can decode. (Been
there; done that!)

Much better is to load up a program such as audio analyzer, "Spectrum
Laboratory," written by Wolfgang Buescher, DL4YHF.  His web site is at
http://www.qsl.net/dl4yhf. That will give you a much better frequency
display, and it is completely adjustable.  And it's free!

I use it on my laptop computer to analyze the sound of gas engine driven
electric generator sets when I set them up.  Even is the system is
making lots of racket, you can easily visually zero in on a specific
frequency out of the band of stuff displayed on the screen.

If you can't easily locate a "shaft fundamental" frequency, i.e., one
pulse per shaft revolution, you can stick a length of thin cardboard to
the shaft to make some wind noise as the shaft rotates and look for that
sound.

Have fun!

73,

Ralph   W5JGV - WD2XSH/7
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