Paul Burridge wrote in message . ..

Hi,

I'll avoid posting a screen shot of this one since so many people seem
to have difficulty finding them on abse or can't get the group at all
from their servers.

Imagine a two-state, high/low (on/off) wave form; i.e., negligible
rise/fall times. Amplitude 5V. A bit like a square wave, in fact,
except that the on and off period appears *different* between one
cycle and the next and the next and so on. There's quite a bit of
variation (anything from one whole time division to up to seven divs
and all times between the two). There does appear to be an eventual
series repetition, but it's only noticeable after about 30 cycles. I'm
not sure how I've ended up with this, but would it be rich in odd and
even order harmonics and suitable for generating them for frequency
multiplication purposes, d'you think?

Thanks,
P.


Think about it this way: say it has at least one 3f half cycle per 30
cycles. Therefore if you feed it to a high Q filter that rings at 3f,
it will duly give you 3f.

But only if the 3f is present in the original wave. To ring at 3f off
one half cycle per 30 cycles it needs to be reasonably high q, and a
high q filter is not going to work off 2.7f, so a fixed pattern is
going to be better than a random pattern that might not contain the
right f at times.

I wouldnt be surprised if someone critiques this 'visual' analysis
though, I wait and see.


Regards, NT