Author Topic: Help to chose 4 oscilloscopes for 2500usd togeather.  (Read 10208 times)

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Offline pxl

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Re: Help to chose 4 oscilloscopes for 2500usd togeather.
« Reply #50 on: May 06, 2016, 08:51:56 am »
For those who say there in no real intensity grading in GDS-2000E

Nice! Is that with persistence off?
 

Offline wraper

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Re: Help to chose 4 oscilloscopes for 2500usd togeather.
« Reply #51 on: May 06, 2016, 09:23:57 am »
For those who say there in no real intensity grading in GDS-2000E

Nice! Is that with persistence off?
You can see on the picture that it is 16ms. But this setting does not matter, intensity grading works regardless unless you switch persistence off completely. In my Rigol DS-2072, there is no persistence off setting at all, only MIN. And when you set anything higher than MIN, intensity grading stops working. As of the visual appearance, it looks nicer for the eye on Rigol but it is because there is some overall display smoothing going on which is not present in GW instek. As of the feel of scope overal, Rigol DS-2000 feels almost like a piece of crap compared to the GW instek standing nearby. Buttons so much nicer, menu so much easier to use and instant fast, controls not cramped together.
 

Offline Wuerstchenhund

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Re: Help to chose 4 oscilloscopes for 2500usd togeather.
« Reply #52 on: May 06, 2016, 09:33:58 am »
PS: You think 3000 Euro scopes or Mercedes Benz are perfect? They might make more effort, but...

Not commenting about MB but for scopes 3k€ is pretty much roughly where it changes from 'mostly a toy' to 'a reliable, dependable and well supported professional tool'.
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Offline ebastler

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Re: Help to chose 4 oscilloscopes for 2500usd togeather.
« Reply #53 on: May 06, 2016, 06:59:51 pm »
For those who say there in no real intensity grading in GDS-2000E


This is an amplitude-modulated sine wave, right? So why is the curve with the lowest amplitude so much brighter than the others, and specifically brighter than the one with the highest amplitude?

It seems that, on the GDS-2000E, the brightness of a dot is a measure of how long ago the dot was written to the display (consistent with the term "visual persistence oscilloscope" which GW Instek chose). In contrast, what I look for in an intensity graded display is that the brightness indicates how often a dot is re-written. In the latter case, the minimum and maximum modulation curve should be of equal brightness in your example, I think.

I believe this difference is what others have also pointed out earlier in this thread, when they questioned whether GW-Instek has "real" intensity grading. I would also argue that GW-Instek simulates persistence, but not intensity grading (which enables discrimination of rare events from regular signals).
 

Offline wraper

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Re: Help to chose 4 oscilloscopes for 2500usd togeather.
« Reply #54 on: May 06, 2016, 07:10:11 pm »
This is an amplitude-modulated sine wave, right? So why is the curve with the lowest amplitude so much brighter than the others, and specifically brighter than the one with the highest amplitude?

It seems that, on the GDS-2000E, the brightness of a dot is a measure of how long ago the dot was written to the display (consistent with the term "visual persistence oscilloscope" which GW Instek chose). In contrast, what I look for in an intensity graded display is that the brightness indicates how often a dot is re-written. In the latter case, the minimum and maximum modulation curve should be of equal brightness in your example, I think.

I believe this difference is what others have also pointed out earlier in this thread, when they questioned whether GW-Instek has "real" intensity grading. I would also argue that GW-Instek simulates persistence, but not intensity grading (which enables discrimination of rare events from regular signals).
That setting is 16ms persistance, read during 1 frame at 60 fps. As how waveform looks like, it is about the same on Rigol DS-2000. What people don't get is that there is no intensity grading without persistence on Rigol too  :palm:, actually you cannot turn off persistence on Rigol.
Quote
how long ago the dot was written to the display
In that case this waveform would be in one monotone color with no color grading at all.
Quote
In the latter case, the minimum and maximum modulation curve should be of equal brightness in your example, I think.
No, because during the same time period minimum modulation trace takes less screen area than max modulation trace = max modulation trace hits the same dot on the screen for less time that min modulation trace.
« Last Edit: May 06, 2016, 07:45:44 pm by wraper »
 

Offline wraper

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Re: Help to chose 4 oscilloscopes for 2500usd togeather.
« Reply #55 on: May 06, 2016, 07:23:13 pm »
 :palm:
 

Offline ez24

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Re: Help to chose 4 oscilloscopes for 2500usd togeather.
« Reply #56 on: May 06, 2016, 07:29:39 pm »
I think with so much passion on persistance, someone should start a new topic on it.  Really no answer to OP who has been scared away.
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Offline Fungus

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Re: Help to chose 4 oscilloscopes for 2500usd togeather.
« Reply #57 on: May 06, 2016, 07:42:38 pm »
Seen side by side, I don't think there can be much argument over who's doing it properly:



Can anybody do the DS1054Z? I believe there's not much difference between that and the DS2000 but it would be nice to see a pic.
« Last Edit: May 06, 2016, 07:45:25 pm by Fungus »
 

Online David Hess

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Re: Help to chose 4 oscilloscopes for 2500usd togeather.
« Reply #58 on: May 21, 2016, 08:30:58 am »
In my place people always choose the 200MHz crappy Tek DPO2k and 350MHz Tek MDO3k, while there is a 2GHz Tek DPO5k, and a 1GHz Keysight MSOX3k, and nobody but me uses them.

I would not use the Tektronix DPO5k either unless I had to.  When I evaluated one a couple years ago, the human factors engineering was poor, the graphical interface had lots of bugs, and it crashed a lot.
 

Online David Hess

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Re: Help to chose 4 oscilloscopes for 2500usd togeather.
« Reply #59 on: May 21, 2016, 08:36:09 am »
1 "refurbished" analog Tektronix
3 Rigol

Seriously? How about

0 analog boat anchors that have been obsolete for almost two decades now and are pretty much unsupportable, plus lack even the most basic features found in any DSO like storage or measurements?
4 Rigols

Rigol scopes aren't exactly stellar but even the cheap-ass DS1054z is a much more capable scope than any old analog banger.

Are there any features in even hacked DS1054Zs which can make up for low bandwidth?  For some measurements, that is all that counts.  I could understand buying a pair of DS1054Zs along with a couple of used high bandwidth analog oscilloscopes.
 


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