Emory,

We're on the same page.....the bandwidth is defined as the delta(f) at the half power point ....3dB drop to you EE guys ;).....me trying to simplify things again. lol A system that exhibits an exceedingly narrow resonance peak will produce an exceeding high Q factor. In the simplest terms, the Q is a measure of the sharpness of the resonance peak.

The Q is also inversely proportional to the damping factor, and the Dynamic Mechanical Analyzer (DMA) can be used to measure the damping of a material to a very high degree of precision (e-4) One problem though, is that the DMA can experience control problems around the resonant frequencies (sample and instrument) so you sometimes are unable to sweep the complete frequency spectra and characterize all the slopes. Interestingly, you can see significant effects on damping of something as subtle as the coatings on the blanks.

I have seen some of Dr. Spoleks work, the Prof from Portland Sate right? I'll have to look that particular paper up. A mechanical driver with low inertia should work if you can control frequency to a fine degree.

Mike, Thanks for the offer to check out your software. I'll get a little more unloaded at work and past kids fall sports and take you up on that.

Mark

Mike,
Sure, you are right. I would like to see a copy of your software when you have up-dated it. I had a lot of fun with the previous version. I am sure that there are other that would like to experiment with it as well especially if they knew how easy it was to use.

Mark,
OK now we agree on Q and Damping.
That is 3db voltage, 6db power, 10x log V1/V2 and 20x log P1/P2 to we EE guys.
Yes, Dr. Spolek is actually the head of the mechanical engineering department at Portland State. He is also a fly fisherman and has written a number of papers on the subject. He actually uses a driven system, with fine frequency control, to find the resonant frequency of rods. (This time I used resonant frequency the way you use it). The resonant frequency being the frequency at which he gets the maximum deflection.
If you would like I can send you a copy of a couple of his papers.