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New Rigol DS7000

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iMo:

--- Quote from: nctnico on July 30, 2018, 09:31:34 am ---
--- Quote from: bson on July 30, 2018, 08:57:59 am ---
--- Quote from: imo on June 24, 2018, 11:03:10 am ---With 8bit input you get 8bit output. Any advanced math co-processor or any fastest ASIC cannot change that..

--- End quote ---
Any band filtering, even decimation using an elementary boxcar filter, will enhance precision.

--- End quote ---
Not at all. You may get more resolution but only if there is enough noise AND the ADCs are linear (which they aren't) otherwise you'll see a fantasy signal.

--- End quote ---
There are some basic laws of physics which, as of today and in this Universe, still apply. You get samples with 8bits of amplitude "V", and, you get them the time "T" apart. Creating any other better values out of these 2 is just the "fantasy", correct.

2N3055:

--- Quote from: imo on August 05, 2018, 12:23:27 pm ---
--- Quote from: nctnico on July 30, 2018, 09:31:34 am ---
--- Quote from: bson on July 30, 2018, 08:57:59 am ---
--- Quote from: imo on June 24, 2018, 11:03:10 am ---With 8bit input you get 8bit output. Any advanced math co-processor or any fastest ASIC cannot change that..

--- End quote ---
Any band filtering, even decimation using an elementary boxcar filter, will enhance precision.

--- End quote ---
Not at all. You may get more resolution but only if there is enough noise AND the ADCs are linear (which they aren't) otherwise you'll see a fantasy signal.

--- End quote ---
There are some basic laws of physics which, as of today and in this Universe, still apply. You get samples with 8bits of amplitude "V", and, you get them the time "T" apart. Creating any other better values out of these 2 is just the "fantasy", correct.

--- End quote ---

E... No.

(don't attack me for lack of mathematical rigor here... it is deliberate)

If you do have A/D converter that is 8 bits for example, and very linear and monotonic (it has accurate step).  And you have signal that is right between two steps, what you get on the output?
Signal will have a certain amount of noise in it, and if it is random noise, you will get random rounding to lower and upper value on output of A/D converter. In a 100 samples, average of those 100 samples would be pretty much exactly in between bits. If signal was a little lower, you would get more flicking to low value and less on high value.
In a way it would look like a PWM modulation between two bits, and average of several measurements would converge to a true value, to an accuracy higher that A/D has.

Sometimes noise is deliberately introduced, that's called dithering.

It is valid technique, but has limitations. 

EDIT: Sorry I pressed something and it got posted before I was finished.

nctnico:

--- Quote from: 2N3055 on August 05, 2018, 03:02:56 pm ---
--- Quote from: imo on August 05, 2018, 12:23:27 pm ---
--- Quote from: nctnico on July 30, 2018, 09:31:34 am ---
--- Quote from: bson on July 30, 2018, 08:57:59 am ---
--- Quote from: imo on June 24, 2018, 11:03:10 am ---With 8bit input you get 8bit output. Any advanced math co-processor or any fastest ASIC cannot change that..

--- End quote ---
Any band filtering, even decimation using an elementary boxcar filter, will enhance precision.

--- End quote ---
Not at all. You may get more resolution but only if there is enough noise AND the ADCs are linear (which they aren't) otherwise you'll see a fantasy signal.

--- End quote ---
There are some basic laws of physics which, as of today and in this Universe, still apply. You get samples with 8bits of amplitude "V", and, you get them the time "T" apart. Creating any other better values out of these 2 is just the "fantasy", correct.

--- End quote ---

E... NO.

(don't attack me for lack of mathematical rigor here... it is deliberate)

If you do have A/D converter that is 8 bits for example, and very linear and monotonic (it has accurate step).  And you have signal that is right between two steps, what you get on the output?
Signal will have a certain amount of noise in it, and if it is random noise, you will get random rounding to lower and upper value on output of A/D converter. In a 100 samples, average of those 100 samples would be pretty much exactly in between bits. If signal was a little lower, you would get more flicking to low value and less on high value.
In a way it would look like a PWM modulation between two bits, and average of several measurements would converge to a true value, to an accuracy higher that A/D

--- End quote ---
First of all the noise will need to have a higher amplitude than 1 LSB, secondly that noise would need to have a perfect Gaussian distribution. In reality 8 bit ADCs are made to have 8 bits. Any extra linearity is just a waste of money & effort because that is not the goal (IF it is even possible to get the extra linearity).

pascal_sweden:
It could have been a nice order configuration option from Rigol that the user can select a Matte display or Glossy display upon ordering the oscilloscope.

Some people prefer Glossy, while other people hate it. In fact I personally prefer Matte display so much better, as the reflections on a Glossy display can make the oscilloscope display useless in some lab environments.

Or if it is too hard to implement a configuration option, why not just stick with a Matte display which works for most people?

What do other people on this forum think about this? Why would one like to have a Glossy display in the first place? Is there any advantage at all, or is it really only a disadvantage as such?

2N3055:
Glossy screens are crap. There is no option where they are better that matte... Glossy is cheap multimedia crap that is so ubiquitous because tablets use them.  Which would be so much better with matte screens too.  And matte screens show less smudges from fingerprints ...
I guess  it needs additional cost to make matte screen and apply anti reflective coating.

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