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| JPortici:
--- Quote from: Sherlock Holmes on December 12, 2022, 09:59:30 pm ---Well, there's zero quantization noise, so I was wandering if some applications find that important? --- End quote --- Such as? Because I can't think of any --- Quote from: Sherlock Holmes on December 13, 2022, 12:13:56 pm ---Yes, really. Didn't you know? if you convert an analog voltage to a digital representation of that voltage, you'll introduce quantization noise. --- End quote --- but for most (all?) practical purpose it doesn't matter (that's what he meant with "can you differentiate"), storage is much more valuable than the quantization noise that's introduced with sampling/converting. I read once a paper from tek that given the size of the CRT and the linearity of the circuit, sampling at 8bit was sufficient to mimick an analog scope. Signal is too low in amplitude? That's what amplifiers are for |
| tggzzz:
--- Quote from: JPortici on December 13, 2022, 12:29:42 pm --- --- Quote from: Sherlock Holmes on December 12, 2022, 09:59:30 pm ---Well, there's zero quantization noise, so I was wandering if some applications find that important? --- End quote --- Such as? Because I can't think of any --- End quote --- Measuring wideband white noise, and hence signal-to-noise. Easy and fast on an analogue scope, tricky on a digitising scope (display technology, quantisation). --- Quote --- --- Quote from: Sherlock Holmes on December 13, 2022, 12:13:56 pm ---Yes, really. Didn't you know? if you convert an analog voltage to a digital representation of that voltage, you'll introduce quantization noise. --- End quote --- but for most (all?) practical purpose it doesn't matter (that's what he meant with "can you differentiate"), storage is much more valuable than the quantization noise that's introduced with sampling/converting. I read once a paper from tek that given the size of the CRT and the linearity of the circuit, sampling at 8bit was sufficient to mimick an analog scope. Signal is too low in amplitude? That's what amplifiers are for --- End quote --- Spectrum analysis and allied measurements are a good counter-example. Amplifiers have their own "infelicities", e.g. frequency response, noise and headroom. |
| JPortici:
--- Quote from: tggzzz on December 13, 2022, 12:43:05 pm ---Measuring wideband white noise, and hence signal-to-noise. Easy and fast on an analogue scope, tricky on a digitising scope (display technology, quantisation). --- End quote --- True, i had actually that in mind as an option --- Quote ---Spectrum analysis and allied measurements are a good counter-example. --- End quote --- but we're talking about scopes here :) correct me if i'm wrong, but in the frequency domain we use intruments that downconvert a portion of the spectrum so it can be acquired with low samplerate / high resolution converters (unless the bandwidth of interest is low enough that direct sampling can be used such as in audio analyzers) so in theory the quantization noise can be lowered enough to be lower than the noise --- Quote ---Amplifiers have their own "infelicities", e.g. frequency response, noise and headroom. --- End quote --- agreed |
| Sherlock Holmes:
--- Quote from: JPortici on December 13, 2022, 12:29:42 pm --- --- Quote from: Sherlock Holmes on December 12, 2022, 09:59:30 pm ---Well, there's zero quantization noise, so I was wandering if some applications find that important? --- End quote --- Such as? Because I can't think of any --- End quote --- Well that's the same question I'm asking, I don't know, that's why I asked! --- Quote from: JPortici on December 13, 2022, 12:29:42 pm --- --- Quote from: Sherlock Holmes on December 13, 2022, 12:13:56 pm ---Yes, really. Didn't you know? if you convert an analog voltage to a digital representation of that voltage, you'll introduce quantization noise. --- End quote --- but for most (all?) practical purpose it doesn't matter (that's what he meant with "can you differentiate"), storage is much more valuable than the quantization noise that's introduced with sampling/converting. I read once a paper from tek that given the size of the CRT and the linearity of the circuit, sampling at 8bit was sufficient to mimick an analog scope. Signal is too low in amplitude? That's what amplifiers are for --- End quote --- Well in audio we routinely see 16 bits because of quantization noise, why do you think we see 12bit DSOs as well as 8bit? its to increase dynamic range, increase the vertical resolution. |
| JPortici:
Read between the lines! That comparison was between digital scopes and analog scopes, those things with thick traces and 10x8cm CRTs. Compared to those 8bit resolution is adequate. Todays digital scopes use 8-12" screen with full HD resolution, even more if they connect directly to your PC, there is already a benefit in higher resolution converters when you display the waveform, let alone when you zoom in into a previous acquisition, and when you perform analysis on the data.. all thing you can't do with an analog scope anyway. The point being that quantization noise while it's present, it's irrelevant if it's something you can't do with an analog scope anyway |
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