This TOTAL power is spread out in a SIN(x^2)/x^2 pattern. This seems to be strange... May be You mean SIN^2(x)/x^2 ? 73 de RA9MB/Alex http://www.qsl.net/ra9mb
OK, Thanks to all for replies on the noise generator calculations. I'm now quite convinced its a simple SQRT(2*BW / Fclock) power division from the total calculated from peak waveform voltage. The la
Yes please, do that. My feeling is that there 'has' to be a pi in there somewhere, Errors in H&H aren't unknown... I dislike SIN(X)/X calculations, they always involve PIs in strange places and never
Right, think I have an answer now, thanks to Stewart and Stewart... If the total integral = pi watts (Ok, volts squared over an arbitrary impedance, but call them watts for now :-) this is what my 2.
Yes, the power spectrum of a SIN(X) / X pattern. To Brian 'GVB, the limits will be (theoretically at least) - infinity to infinity, but in practice a few lobes will be sufficient, say about +/- 5 And
Is there anyone who can answer this... I want to make a calibrator to enable accurate (better than 0.5%) absolute audio measurements using a soundcard - ie. at audio frequencies to 20kHz. Generating
Dear Andy, Stewart et al, I have written my noise voltage calculation as a word document. There are plenty of 'pi's in it, but they all disappear by the time you get to the end, which may be good or
Dear Andy, LF Group I hate to throw a spanner in the works, but... A noise source of exactly this type is discussed in Horowitz & Hill "The Art of Electronics" 2nd ed., section 9.34. This gives the f
[...] I'm quite incapable of integrating SIN(x^2)/x^2 from first principles (or any other way for that matter :-) to calculate the level of the main lobe. Can anyone point out the best way to do this
Andy According to http://integrals.wolfram.com/index.en.cgi integral (sin[x^2)]/(x^2) is sqrt(2 pi) * FresnelC[sqrt(2/pi) * x] - sin(x^2)/x and according to http://functions.wolfram.com/GammaBetaErf/
Hi all, Jim solved the noise generator puzzle! His key observation is: The complete story has been posted to http://www.scgroup.com/ham/Noisegen.pdf It's not all easy as pi :) 73, Stewart KK7KA writt
Hi Andy and all, I was unaware of H&H, but my previous post gave the same answer. It was based on my naive analysis that white noise was spread evenly from 0 to fs/2, and that the sin(x)/x effect sho
Hi Andy, IMO, you are being too much of a perfectionist to worry about sin(x)/x. I believe that x must be pi * fsig / fsample, because the spectrum goes to zero at multiples of fsample. So at 20 kHz
