noise lecture

by "small" I mean gigantic compared to the 19" Zenith my parents had in the 1980s but modest compared to the ones that take up a whole wall

Noise bandwidth != 3 dB BW--pi/2 times wider for one pole, 1.22 times wider for two pole RC

The goodness of steep edges and fast-responding parts as a result.

Depends. The source of those mysterious factors of 2 in the fundamental noise sources is good--shot noise is counting statistics (sqrt N) but when you convert to analytic signal the negative frequencies double the noise power.

Cheers

Phil Hobbs

Gaussian amplitude statistics

John Larkin wrote in news: snipped-for-privacy@4ax.com:

As a function of 'plot area', sure. As to it being accurate... not so much.

Another reason is that RMS is about power and random noise typically does not push much.

You could also measure low-entropy noise in NPRs or NYTs.

RMS just means "root of the mean of the the average of the squares of each observation".

It doesn't have any implication that the waveform being looked at is sinuso idal - though Fourier's point was that any series of arbitrary numbers coul d be perfectly represented by it's Fourier transform - a harmonic series of sinewaves can exactly represent any series of numbers.

The significance of peak-to-peak measurements is based on the idea that suc cessive observations can - as they often do - conform to a Gaussian distrbu tion. so you can assign a probability to the chance of a particular deviati on from the mean as a function of size of the means deviation from that mea n.

No sinusoids there either.

Obviously - you can't have a root mean square without enough observations t o define a "mean" which has to be two or more.

John Larkin wrote in news: snipped-for-privacy@4ax.com:

You know what I was referring to you rotten bat's turd.

Try pk-pk.

You gonna say that is wrong too?

John Larkin wrote in news: snipped-for-privacy@4ax.com:

That hardly qualifies as a lecture.

John Larkin wrote in news: snipped-for-privacy@4ax.com:

So you are 100% unaware that there is a wealth of educational programming out there.

You are a real piece of work, Larkin. You make some of the most stupid remarks in the group.

I'd bet that even your duaghter would say so, as long as it was not revealed that it was you she was performing an analysis on.

"John Miles, KE5FX" wrote in news: snipped-for-privacy@googlegroups.com:

Your posts would also make a good noise source.

This is a 100% reproducible observation.

You are 100% reproducible. You try to offend everyone.

It went well, and took just about an hour to hit the good stuff. A couple of people stayed a while longer with specific things to discuss. Of course I had a good audience.

I think it is a natural, evolved thing for older people to want to teach. That's one way that tribes survived. The old guys passed the tricks on to the younger ones.

They want more. Maybe I'll do transmission lines and fast logic next.

Then maybe a review of the basics of Signals and Systems.

And maybe some basic control theory, Bode plots and things.

Basically I'm kickstarting them by making them aware of topics. The ones who are interested will follow up on their own. We will definitely add "noise" as a topic to address in design reviews.

I do remember, in the earlier days of TV, that there was educational stuff. I'm not aware that there is any now. Got examples?

She is not shy about sharing opinions.

I've done the two trick... but diodes only match to ~25%.. so on average only helps some. And still not Gaussian.* I use 20 V zeners (~10-100 uA) but they've gotten less noisy lately... I've got a bag of 100 vishay tacked to my wall.. waiting for some spare testing time. A little less noisy and a faster slewing opamp seems to keep the output noise about the same.

This is 'audio' freq. noise. banging opamps hard, triangle spikes, ugly. (I love opamps!)

George H.

We don't do RF, so that sort of stuff isn't priority.

Are these NEDs (Noise Emitting Diodes) ?

John Larkin wrote in news: snipped-for-privacy@4ax.com:

You're a goddamned idiot.

Nope. Just idiotic assholes like you going around making retarded cracks about the Space Program.

John Larkin wrote in news: snipped-for-privacy@4ax.com:

Did you hire zero experience personnel?

I have trouble believing that engineers lack noise abatement technique and method knowledge or experience.

John Larkin wrote in news: snipped-for-privacy@4ax.com:

That is why we have the Space Program, Johnny.

But you have horse blinders on, self applied.