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Offline JimmySte

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Rigol DS2072 Review
« on: August 09, 2012, 08:20:17 am »
Hi all...
Due to the total lack of reviews of the DS2000 series of scopes online I thought I would give reviewing a crack... :)

/*Background
I'm currently a student studying Electrical Engineering and approaching the pointy end of my course,
I thought it was high time to "graduate" from my father's 20MHz analogue scope and get my own...
I started out looking online at the Rigol DS1052, also discovering the DS2072 but unwilling to spend the dough...
Knowing that the DS1052 was very liked in reviews, on this forum and I'd used them at university, all be the 200MHz version.
So I was tossing up between the Rigol and the Atten ADS1062CAL... I liked the Atten because of it's larger screen, having experienced that menus covered almost half of the screen.
I eventually pulled the trigger Olympic pun... :) and got the Atten, got home, turned it on... and it had a faulty power supply :( not to dissimilar to the issue playfsx on the formums has/had with their scope...



Called up the shop and took it back, they connected it up to a Rigol DG4102 and the interference continued...
So they were quite apologetic and were willing to replace it with another Atten, until I asked what they thought about the DS2072 and if they were willing to let me play with one...
First impression WOW, not just for me but the shop owner, it was the first time either of us has seen one operating, the quality of the display make the Atten's look like dirt...
And as they say the rest is history...

/*Review - I think...
The Rigol DS2072 is a 2 channel DSO 2GSa/s clocking in at 70MHz, I got mine here in Australia at www.eyou.com.au for $839 + GST
They were a delight to buy from, as can be seen by the comments above...

It came double boxed with a English user manual, 2x 300MHz passive 1-10x probes, Australian power cable, USB cable and a CD
The first thing I noticed about the device was it's weight at 4.8kg, it's solid, double the Atten's 2.4kg.
Second was the quality of the screen at 8" 800x480 its massave and very clear to read.
The scope is a pleasure to use, the GUI is straight forward and with enough button presses the basics can easily be nutted out...
And for the more advanced aspects the user manual is quite comprehensive

And now for some images :)

An example of the low noise level of the scope


Connecting the channel 1 probe up to the 1kHz test point and pressing AUTO I got


Displaying all of the waveforms summaries


Some summaries at the bottom


Raising edge of the square wave


FFT of the Square wave


Other math operations available


The scope has an internal recording ability to take snap shots of a waveform and review them one at a time


I connectedthe TX from an Arduino to the scope and used it's ability to decode RS232


Although unfortunately these functions have a limited life and require more $$$ to keep them

And the time counts down weather you are using the function or not...

So that's about all... the DS2072 is a wonderful scope and money well spent :)
« Last Edit: August 09, 2012, 11:45:47 pm by JimmySte »
 

Offline T4P

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Re: Rigol DS2072 Review
« Reply #1 on: August 09, 2012, 02:25:05 pm »
Nice, i haven't really seen snapshots of internal operations before
but 1 thing is striking me,
What's this mythical "Attan" ADS1062CAL?
 

Offline Rosendorfer

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Re: Rigol DS2072 Review
« Reply #2 on: August 09, 2012, 04:04:05 pm »
Hi JimmySte

Seems that You have very nice scope there...
From my side any DS2000 series infos are more than welcome...

As for me 
If You could investigate bit more FFT functionality :D,
Please run again Your FFT test but with dBVrms and markers ON.
Not sure if You have Signal Generator to run some more tests but If You could run similar test as mine:  https://www.eevblog.com/forum/product-reviews-photos-and-discussion/fft-high-precision-mode-with-hameg-hmo-vs-rigol-ds2000-scopes/45/ we could hopefully have some comparison against DS1052E and bet that could be very interesting to many.

Rosendorfer


 

Offline prenato

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Re: Rigol DS2072 Review
« Reply #3 on: August 09, 2012, 06:49:32 pm »
Hi Jimmy,

Thanks a lot for your review! As you know from my other post, I'm also considering buying this scope and your review is very helpful. It looks very good.
Is there any aspect that you think could be improved in the scope?

Paulo
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Offline olsenn

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Re: Rigol DS2072 Review
« Reply #4 on: August 09, 2012, 06:56:45 pm »
Seriously, I really don't understand why anyone would buy the DS2000 scopes? I'm not saying they're bad, but they're far more expenive than the DS1102E, which is almost as good, and for not much more than the DS2000-series, you can get a DS4000-series, which is FAR superior!

Am I missing something?
 

Offline Rosendorfer

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Re: Rigol DS2072 Review
« Reply #5 on: August 09, 2012, 07:27:21 pm »
Seriously, I really don't understand why anyone would buy the DS2000 scopes? I'm not saying they're bad, but they're far more expenive than the DS1102E, which is almost as good, and for not much more than the DS2000-series, you can get a DS4000-series, which is FAR superior!

Am I missing something?

Hi olsen

Well spoken......
But actually where from do You know DS2000 is almost as good or as some will tell as bad as DS1000 series, we are actually looking for any info on that. If You know something please share with us. 
Right now we do have nice looking marketing brochures full of features that makes DS1000 looks like toy in comparison and just few, early adopters reports.
And  regarding DS4000 being almost the same price... so where I can buy DS4000 for "not much more" than 900EUR or USD..?
So how much is actually "not much more".. 500-600-700-800 EUR or USD?

Rosendorfer
 

Offline prenato

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Re: Rigol DS2072 Review
« Reply #6 on: August 09, 2012, 08:22:39 pm »
Seriously, I really don't understand why anyone would buy the DS2000 scopes? I'm not saying they're bad, but they're far more expenive than the DS1102E, which is almost as good, and for not much more than the DS2000-series, you can get a DS4000-series, which is FAR superior!

Am I missing something?

Hi Olssen,

The DS2000 series has a few significant advantages  over the DS1102E:
- 14M memory versus 1M
- 2GS/s versus 1Gs/s
- 500 uV/div instead of 2mV /div minimum vertical sensitivity
- Better refresh rate
- Much more advanced math functions and serial decode
- The build quality also seems  "a step above" going by the weight Jimmy quotes above:)

Whether this justifies 2x the price is another story, but there are some real advantages.

Paulo
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www.paulorenato.com
 

Offline JimmySte

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Re: Rigol DS2072 Review
« Reply #7 on: August 10, 2012, 09:00:21 am »
Hi JimmySte

Seems that You have very nice scope there...
From my side any DS2000 series infos are more than welcome...

As for me 
If You could investigate bit more FFT functionality :D,
Please run again Your FFT test but with dBVrms and markers ON.
Not sure if You have Signal Generator to run some more tests but If You could run similar test as mine:  https://www.eevblog.com/forum/product-reviews-photos-and-discussion/fft-high-precision-mode-with-hameg-hmo-vs-rigol-ds2000-scopes/45/ we could hopefully have some comparison against DS1052E and bet that could be very interesting to many.

Rosendorfer

Hi Rosendorfer

Unfortunately I don't have a proper signal generator... could use my pc soundcard if I ground everything correctly

So I redid the FFT of the 1kHz square wave with the FFT set to dbV


And again with some coursers


And again with the FFT set to Hanning, as opposed to Rectangular


I hope this helps...
 

Offline EEVblog

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Re: Rigol DS2072 Review
« Reply #8 on: August 10, 2012, 10:18:21 am »
The DS2000 series has a few significant advantages  over the DS1102E:
- 14M memory versus 1M
- 2GS/s versus 1Gs/s
- 500 uV/div instead of 2mV /div minimum vertical sensitivity
- Better refresh rate
- Much more advanced math functions and serial decode
- The build quality also seems  "a step above" going by the weight Jimmy quotes above:)

I do believe it also has a high resolution mode like the Agilent et.al, and a corresponding lower noise floor.
And the huge 800x480 screen.

Dave.
 

Offline muvideo

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Re: Rigol DS2072 Review
« Reply #9 on: August 10, 2012, 10:54:15 am »
Hello, is it me or the probe seem undercompensated?
Fabio Eboli.
 

Offline Rosendorfer

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Re: Rigol DS2072 Review
« Reply #10 on: August 10, 2012, 12:35:28 pm »
Hi JimmySte

Thanks for the tests...
Having Sig Generator would be handy... Have a look at Siglent seems to be pretty decent for the money...
But If You could have a look at Your PC sound card output would be also very interesting, but as for me please do not play music, but just simple sin-wave... 8) and run FFT's...

And PLEASE !!! check program from dexter2048 : https://www.eevblog.com/forum/general-chat/using-rigol-ds1052e-for-spectrum-analysis/ . Big question if if it is working OK with DS2000 series files.
Well if You could check if it accepts wfs from famous but never used 12bit HR mode that would be also very interesting.

Rosendorfer
 

Offline JimmySte

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Re: Rigol DS2072 Review
« Reply #11 on: August 10, 2012, 03:02:36 pm »
Hi JimmySte

Thanks for the tests...
Having Sig Generator would be handy... Have a look at Siglent seems to be pretty decent for the money...
But If You could have a look at Your PC sound card output would be also very interesting, but as for me please do not play music, but just simple sin-wave... 8) and run FFT's...

And PLEASE !!! check program from dexter2048 : https://www.eevblog.com/forum/general-chat/using-rigol-ds1052e-for-spectrum-analysis/ . Big question if if it is working OK with DS2000 series files.
Well if You could check if it accepts wfs from famous but never used 12bit HR mode that would be also very interesting.

Rosendorfer

Hi Rosendorfer
I downloaded WFM Viewer and tried to open a saved waveform off my scope, unfortunately I got the following error message

The trigger is set to Auto and Edge so I don't know what the matter is...

And I don't understand what you mean by "12bit HR mode"??
 

Offline Rosendorfer

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Re: Rigol DS2072 Review
« Reply #12 on: August 11, 2012, 11:29:23 pm »
Hi JimmySte

Thanks for trying... as regarding wfm Viewer error seems that wfm format from DS2000 is different than DS1000. Maybe You could contact  dexter2048 regarding that and supply him few DS2000 wfm files.

Look at http://www.batronix.com/pdf/Rigol/Datasheet/DS2000_DataSheet_EN.pdf
At page 6 from DS2000 datsheet You will find remark of 12 bit HR mode.
I'm trying to get any info on that HR mode for some time as there is no much info on it in regular scopes reviews. My small theory is that most of 12 bit mode should be seen at FFT screen. If You could run few tests about it would be great.

Rosendorfer
 

Offline JimmySte

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Re: Rigol DS2072 Review
« Reply #13 on: August 12, 2012, 05:54:36 am »
Hi Rosendorfer

I got myself a signal generator and ran the 10kHz triangular FFT test


As for the High Res mode I found it...
Normal

HR
 

Offline Rosendorfer

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Re: Rigol DS2072 Review
« Reply #14 on: August 12, 2012, 09:44:03 pm »
Hi JimmySte

Interesting pictures....
And if You still have that generator PLEASE show FFT !!! from 12 HR mode.
There is rather little chances to see big differences between normal 8 bit and 12bit HR mode on 300pixels screen.
12 bit would require about 4000pixels screen resolution, maybe one day but not now.
So as I told there is my little theory that 12bit HR mode should bring improvement at noise floor level and dynamic (SFDR) of FFT measurements.
So if You could run simple sinewawe, that should give us more clear picture, at normal and HR mode FFT !!.
Interested to see if there are any improvements there.
Just as remark, as far as I know and tested myself there is no special magic in triangle being shown on the scope, seems that just nctnico for some reason have problems to do that on his Tek 7 series.
Anyway .......
FFT !!!!!!!! of simple sinewawe at normal and 12 bit HR mode, please!!  ;D

Rosendorfer
 

Offline JimmySte

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Re: Rigol DS2072 Review
« Reply #15 on: August 15, 2012, 11:30:32 am »
Hi Rosendorfer

The HR mode appears to have no effect on the FFT...
Normal


HR

 

Offline Rosendorfer

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Re: Rigol DS2072 Review
« Reply #16 on: August 15, 2012, 11:08:09 pm »
Hi JimmySte

Well.... seems that HR mode is just marketing bs....

Bit unexpected...but not going argue with reality...
Thanks for doing the tests ... and have fun with new scope...still  "dream machine"...

Rosendorfer
 

Offline Gunb

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Re: Rigol DS2072 Review
« Reply #17 on: August 17, 2012, 12:16:04 pm »
Hi there,

Hi JimmySte

Well.... seems that HR mode is just marketing bs....

Bit unexpected...but not going argue with reality...
Thanks for doing the tests ... and have fun with new scope...still  "dream machine"...

Rosendorfer

No, that's wrong.

It's essential to understand what the HiRes-mode of DSOs means in detail and how it works.

Switching on the HiRes-mode means that the scope works with full sample rate, even if the displayed sample rate is lower.

A signal sampled with a lower sample rate than the scope offers means, that between two samples information gets lost. Switching on the HiRes-mode causes the scope to sample
with maximum sample rate always, even if the display shows a much lower sample rate --> higher horizontal accuracy!

Let's assume you sample with 5MSa/s but your scope has got a maximum sample rate of 2GSa/s. With HiRes activated the scope is sampling with 2GSa/s although it shows 5 MSa/s only. In this case 4 samples will be taken by the ADC per displayed sample. In detail the 4 samples will be summed up and divided by 4 and the result appears as a sample on screen.

Why that?

You get more information with lower sample rates because every displayed sample consists of the average of 4 real samples!

Where's the rub?

#1: It always depends on the ratio of the maximum sample rate of the scope and the chosen one. In case they are equal, i.e., the scope's display shows 2GSa/s and the maximum sample rate is also 2GSa/s you will not see any difference between normal mode and HiRes-mode.

#2: You get an averaged signal (if maximum sample != selected sample rate)! Let's say you search for an outlier, than it might get lost because the neighboured samples are much smaller and the average calculates the outlier away! In this case you would never use the HiRes-mode.

When I interprete the results above then it's exactly what I've expected. In both cases the signal is sampled with the maximum sample rate of the scope - what additional information should be there in this case? None!

Concluding: the limitations of an ADC can't be improved by software. Scopes with HiRes-mode offer the capability to take more samples into account of the displayed signal at lower sample rates. If the selected sample rate is equal to the maximum, there will be no difference.

For real accuracy an ADC with more resolution is mandatory. The HiRes-mode of scopes is only a mathematical approach using filter algorithms to use the maximum sample and take the maximum no. of samples into account than throwing them away at lower sample rates


Note: horizontal accuracy caused by the no. of ADC-bits != horizontal accuracy caused by filter algorithms

And: ERES != HiRes-mode. That's another way of calculating more accuracy.

Kind regards
Gunb


« Last Edit: August 17, 2012, 12:29:12 pm by Gunb »
 

Offline Rosendorfer

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Re: Rigol DS2072 Review
« Reply #18 on: August 17, 2012, 06:22:34 pm »
Hi Gunb

Thank You for sharing this informations.
There is no any real info on that, and lots of things I could find let me thing that HR mode is kind of multisampling  where ADC is exchanging time, as multiply measurements just takes longer for more data/"resolution" and lower noise floor. And that all leads to more SFDR that could be used at FFT scope measurements.

At Rigol DS2000 datasheets HR is described:

>>>>>>>>>>>>>>>>>>>>>>>>>

High Resolution

12 bit of resolution When ?5 ?s/div @ 1 GSa/s
(or ?10 ?s/div @ 500 MSa/s).

>>>>>>>>>>>>>>>>>>>>>>>>>

That what Rigol and Hameg puts in their dataset do not sounds like just switching to 2GSa/s constant.


Switching on the HiRes-mode means that the scope works with full sample rate, even if the displayed sample rate is lower.

A signal sampled with a lower sample rate than the scope offers means, that between two samples information gets lost. Switching on the HiRes-mode causes the scope to sample
with maximum sample rate always, even if the display shows a much lower sample rate --> higher horizontal accuracy!


Not that I would like to argue, far from that, but just to understand and learn.

Assume that we are using 10us/div timebase at HR mode so as You are saying @2GSa/s constant:
Lets do small calculation:
@2GSa/s ADAC is feeding the scope with 2 measurements per 1 ns or if my calculations are right  20 000(!!!) measurements per 10us or we get 160 000-200 000 (!!!) "horizontal data" to be squeezed at typical scope screen.
Actually DS2000 or DS4000 screens are like 800x480 so about 200 000 points of "horizontal data" is being squeezed at about 800pixels ....
Well... that just can be, we may have: "higher horizontal accuracy!" very true...
But there is question what for ..?  Do we need more "horizontal resolution"?
Actually proper question would be more than what..? And as far as I know even with normal mode ADAC is easily feeding scope with much more than needed "horizontal data" many times more than scope screen horizontal pixel count, specially at longer timebase, that is where HR can be used... bit counter-intuitive, one may say....

But as opposite we  possibly may wish more than typical  8 bit "vertical resolution"...
 With 8 bit ADAC usually 1 bit is lost in ADAC noise floor and we are left with 7 usable bits and it is just about 128 levels... Can we use/see more ..???
At 800x480 Rigol screen, that actually could be very handy. Instead interpolating about 127-180 pixels to 480 vertical screen pixels we cold use straight away without any tricks almost full 9 bits of real resolution, so we could use 10 bit ADAC.

Well actually not sure what to thing about ...
Not quite sold to HR being "more horizontal resolution" or 2GSa/s "constant on" thing or I just did not get it right...

Kind regards
Rosendorfer








 

Offline Gunb

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Re: Rigol DS2072 Review
« Reply #19 on: August 17, 2012, 10:51:21 pm »
Hi Gunb

Thank You for sharing this informations.
There is no any real info on that, and lots of things I could find let me thing that HR mode is kind of multisampling  where ADC is exchanging time, as multiply measurements just takes longer for more data/"resolution" and lower noise floor. And that all leads to more SFDR that could be used at FFT scope measurements.


Yes, that seems to be right. But additionally to say the vertical resolution becomes mathematically higher - if possible at a certain timebase - because more real samples are used for the average =  the displayed sample.



At Rigol DS2000 datasheets HR is described:

>>>>>>>>>>>>>>>>>>>>>>>>>

High Resolution

12 bit of resolution When ?5 ?s/div @ 1 GSa/s
(or ?10 ?s/div @ 500 MSa/s).

>>>>>>>>>>>>>>>>>>>>>>>>>

That what Rigol and Hameg puts in their dataset do not sounds like just switching to 2GSa/s constant.


But that's the way how "Boxcar Averaging" works and that's what Hameg has mentioned in their manual. By the way it's easy to implement. Another proof is that they speak about "up to" 10Bits resolution. At a certain timebase you can see that the displayed sample rate goes down to a quarter of the highest sample rate when HiRes is pressed and the signal becomes "slower". At highest sample rate you don't need HiRes since you don't see a difference.



Assume that we are using 10us/div timebase at HR mode so as You are saying @2GSa/s constant:
Lets do small calculation:
@2GSa/s ADAC is feeding the scope with 2 measurements per 1 ns or if my calculations are right  20 000(!!!) measurements per 10us or we get 160 000-200 000 (!!!) "horizontal data" to be


OK.


squeezed at typical scope screen.
Actually DS2000 or DS4000 screens are like 800x480 so about 200 000 points of "horizontal data" is being squeezed at about 800pixels ....


No, there's nothing squeezed into 800pixels. You're mistake is that you do no not distinguish between the samples in the sample memory and the displayed samples that reside in display memory!
You're calculation is right but additionally you have to calculate 200.000 / 800 = 250. Not every sample in memory can be displayed because of the 800 pixels, only each 250th point is shown on screen at the timebase you've chosen for your example. What you will see is an interpolated sequence of every 250th sample, if you want to see more details you have to zoom in, as long as you see the real samples without interpolation. Disadvantage is that you can only see a small window of the complete signal, but without interpolation you'll see the real samples at small timebases.

That's a general restriction of digital scopes opposed to CRTs with their "infinite" tube resolution - there are simply no limiting pixels. But that has nothing to do with Hires-mode, that's the "problem" of all DSOs. As you've calculated you can see that you need more and more memory to keep the real samples for further investigation, for instance if you press RUN/STOP.



Well... that just can be, we may have: "higher horizontal accuracy!" very true...
But there is question what for ..?  Do we need more "horizontal resolution"?
Actually proper question would be more than what..? And as far as I know even with normal mode ADAC is easily feeding scope with much more than needed "horizontal data" many times more than scope screen horizontal pixel count, specially at longer timebase, that is where HR can be used... bit counter-intuitive, one may say....

But as opposite we  possibly may wish more than typical  8 bit "vertical resolution"...
 With 8 bit ADAC usually 1 bit is lost in ADAC noise floor and we are left with 7 usable bits and it is just about 128 levels... Can we use/see more ..???
At 800x480 Rigol screen, that actually could be very handy. Instead interpolating about 127-180 pixels to 480 vertical screen pixels we cold use straight away without any tricks almost full 9 bits of real resolution, so we could use 10 bit ADAC.

Well actually not sure what to thing about ...
Not quite sold to HR being "more horizontal resolution" or 2GSa/s "constant on" thing or I just did not get it right...

Kind regards
Rosendorfer


No, keep these things separated. The horizontal resolution has nothing to do with HiRes-mode.  You should differ between the sample memory and the display memory. The HiRes-mode relates at the sample memory first. In case your scope samples with 625MSa/s at a certain timebase and your ADC is able to sample with 2.5GSa/s  physically you get two options:

 #1: Sample with real 625MSa/s and store a sample every 1.6ns -> scale your y-axis with 8 Bit -> 256 steps
or
 #2: Sample with real 2.5Gs, add 4 samples and divide by 4, and store the result again every 1.6ns -> higher vertical resolution, not horizontal, but "slower" signal because of averaging. The effective sample rate is 2.5GSa/s / 4 = 625MSa/s again -> scale your y-axis with 10 Bit -> 1024 steps.

Now the timebase and screen resolution decides again which of these samples you will see on screen and be connected by interpolation. If you're timebase is small enough that 1.6ns can be resolved you will see every sample without interpolation.

By the way: the higher vertical resolution is caused by calculcated values that cannot be sampled so accurate because of the ADCs smallest resolution.

Kind regards
Gunb
« Last Edit: August 17, 2012, 11:32:12 pm by Gunb »
 

Offline Rosendorfer

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Re: Rigol DS2072 Review
« Reply #20 on: August 18, 2012, 10:44:14 am »
Dear Gunb

Thanks for all the info.... very appreciate You find time for explaining that.

Seems that we are now missing just one thing....
What actually all that technology can do for us ?

Any chance You could post any screens showing normal vs HR mode, so we could actually see something ?

Kind  regards
Rosendorfer
 

Offline PA4TIM

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Re: Rigol DS2072 Review
« Reply #21 on: August 18, 2012, 01:14:41 pm »
It would be nice if this reviews could be accompanied by real tests instead of just display pictures of unknown sources.
For instance something as simple like a fast puls with known risetime and amplitude
Runt detections
Trigger tests on more complex signals
Bandwidth test on sinewave and pulse
Consistency of measurements
Channel separation
Input impedance vs frequency
Accuracy of timebase and amplitude
FTT from a signal of known amplitude and harmonics. So we see if intermodulation is caused by the scope, if harmonic amplitude is correct ect.

For instance on the first series of screenshots I see things I do not like. OK, nice pictures, nice resolution but it is an instrument for meaurements.
- the Tr of squarewave is 4 nS on the first squarewave picture. Then you zoom in and risetime changed. This seems to imply it has the same problem as the 1102. If I put a pulse on screen and measure Tr, then shift the trace up or down or left/ right the Tr changes. So accurate Tr meaurement is useless this way.  The same thing happend with amplitude.

- I believe it uses display memory for measurements. For instance on the 1102, press stop and change timebase and amplitude. Measurement information changes. If I do this on a Agilent, Hameg or the old B&W screened Tek TDS 210 ( or something like that, forgot the number) the measurement info is still correct

- i still think the noise is rather high ( fat traces) 500 uV/div is nice but not if the noise is allmost a dividion. I have a Tektronix plugin for my 547 and a TM5000 series diff- preamp plugin that both go sub-mV but the noise level is much lower.


10 mV/div, compare the trace noise to that with your pictures ( ok this scope is more expensive but without a compare, norm or standard a test is useless, what i think is good can be bad for someone else. Like a voltmeter showing 1.000,000 V. Nice but if the source in real is 1.000,200 V it is not so nice anymore  ;)

Most DSO's do not really measure under 10 mV/div this is just a sort of software zoom were they reconstruct a signal out of the noise by software.  I think the problem is in the analog part before the DACs. There the men get seperated from the boys. You only have 8 bit resolution.
See it like a multimeter made from an Arduino. Use the internal DAC or put a LTC1052 before it, ad a LTZ1000 and a 26 bit DAC as frontend. It can still be named an Arduino voltmeter but the measurement results are more then a bit different.

An other test. Take a squarewave, 6MHz or so, select around 10 mS/div. Then press stop and change the timebase so the squarewave is visible in detail. About 3 to 6 periods on the screen. On the Hameg (350 MHz) and Agilent ( 10 year old 200 MHz) the squarewave was still a nice correct signal. On the DS1102 ( 100 MHz) it was a mix of triangle and squares. The Tek too but not as extreme ( and in its defece, it is over 10 years old, 60 MHz and only 2.5Kp memory.
also look at amplitude and time measurement info. Correct on all scopes exceot the Rigol. That are things that , I think, are more important as nice boxes, manuals or screen colors.

But it is nice to see a overview of some features of an instrument. Also to see the inside, how well its build, but I only would like to see real tests too.
( about weight, i onces teared down a cheap redio. It looked good, felt massive, looked like real wood and aluminium. But it was useless as a radio. The cabinet was mdf with plastic woodlike folie, the thick massive looking aluminium was hollow thin plastic. So why the massive feel.  the weight was caused by a mystery box mounted inside on the back of radio. This box was filled with concrete......
 

« Last Edit: August 18, 2012, 01:24:27 pm by PA4TIM »
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Offline grenert

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Re: Rigol DS2072 Review
« Reply #22 on: August 18, 2012, 01:28:49 pm »
Seems that we are now missing just one thing....
What actually all that technology can do for us ?

Any chance You could post any screens showing normal vs HR mode, so we could actually see something ?

Sorry, I don't have this scope to provide you a picture, but hires mode will definitely lower your noise floor.  The image below shows the benefit of noise reduction in the Agilent 9000.

- i still think the noise is rather high ( fat traces) 500 uV/div is nice but not if the noise is allmost a dividion. I have a Tektronix plugin for my 547 and a TM5000 series diff- preamp plugin that both go sub-mV but the noise level is much lower.

I don't think you'll ever see a DSO have a noise level like that of an old analog scope, even a cheap one.  Really, 0.5 mV of noise is pretty good compared to other DSOs.
 

Offline Rosendorfer

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Re: Rigol DS2072 Review
« Reply #23 on: August 18, 2012, 06:57:07 pm »
Hi Grenert

Interesting picture....
If I see it right HR mode on Agilent 9000 reduces noise at 10V/div and at 10mV/div and 5mV/div where we actually care about the noise it does nothing..??

Rosendorfer


 

Offline Gunb

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Re: Rigol DS2072 Review
« Reply #24 on: August 19, 2012, 11:20:43 am »
Dear Gunb

Thanks for all the info.... very appreciate You find time for explaining that.

Seems that we are now missing just one thing....
What actually all that technology can do for us ?

Any chance You could post any screens showing normal vs HR mode, so we could actually see something ?

Kind  regards
Rosendorfer

Hi Rosendorfer,

an answer to your question (I've taken it from the net):

Boxcar Averaging: Boxcar averaging is a digital procedure for smoothing irregularities and enhancing the signal-to-noise ratio. It is assumed that the analog analytical signal varies only slowly with time and the average of a small number of adjacent points is a better measure of the signal than any of the individual points. In practice 2 to 50 points are averaged to generate a final point. This averaging is performed by a computer in real time, i.e., as the data is being collected. Its utility is limited for complex signals that change rapidly as a function of time.

I couldn't explain it better and it shows that the usage is limited to a special kind of signals: low signals with high-frequency interference and/or fast accidental irregularities.

And because of the calculated average the result might lead to a higher resolution than the ADC offers - quantization noise becomes lower.

But: it can never replace a real 10 bit ADC that always has got real 10 bit for any kind of signal.

Screenshots: I would say they won't show anything new compared to the ones that are already posted.

I believe to remember that you wanted to do some audio measurements. For that purpose I've bought a soundcard with a good SNR and PC applications - it has real 16 Bit and is much better suited for that purpose than the Hameg or the Rigol scope.


Kind regards
Gunb
 

Offline EEVblog

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Re: Rigol DS2072 Review
« Reply #25 on: August 19, 2012, 12:23:17 pm »
Here is a video from Agilent on this, comparing the 8bit 9000 series Agilent with HiRes to a 12bit ADC Lecroy HRO:


Dave.
 

Offline Gunb

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Re: Rigol DS2072 Review
« Reply #26 on: August 19, 2012, 02:23:42 pm »
Hi Dave,

excellent video, that says it all!

It also shows that the effect of HiRes-mode can be shown more with a running scope than with a single screenshot.

And: it also shows what I was thinking of when Rosendorfer has asked for a screenshot. A few month ago I had to generate a signal interfered with a small disturbing pulse of a
few millivolts to test the robustness of my signalprocessing algorithm. I've generated the signal with MATLAB and feeded my arbitrary HMF generator with it. Since the HMO scope has got really high quality ADC with low noise level the pulse could be measured - an example, where HR could be used for to remove noise and increase resolution.

Concluding it makes less sense to use standard signals as sine to demonstrate the advantage of HR mode, there have to be more details in the signal to investigate as the video shows exactly.

LeCroy introduced ERES where bandwith is decreased, Tektronix introduced HiRes (Boxcar Averaging). Looking into the manual Rigol and Hameg seem to follow the same concept as Agilent.
Hope all the manufactures try to name the same thing when they use the term "HiRes"  ;)

Thanks for the video!

Kind regards
Gunb
 

Offline Rosendorfer

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Re: Rigol DS2072 Review
« Reply #27 on: August 20, 2012, 05:00:33 pm »
Dear Gunb

I will agree... thanks to Dave for posting Agilent video, it is very interesting...

But again I will come back and ask You nicely again...:

Any chance You could post any screens showing normal vs HR mode..??,

Specially now after Agilent video, where they are claiming/showing that HR mode can bring pretty important and visible improvements to the scope user.
Agilent went far and try to even prove, that 12bit HR mode is as good as real 12 bit ADAC's.!!
They even claim that 12bit HR mode brings SFDR to 74dB..!!!!

Really like it !!!..... It is exactly the way I hope it to be !!!..
All is nice and shiny..

But...

Our only real life(!!) proof is what JimmySte have posted.
And at his screens there is nothing from Agilent's improvements ..??? 
And You have told that it is just right...??  Bit confused...

Wrong test? maybe, Wrong wave form? maybe, Do not know, Not even trying to discus ...
But still the only real thing we have got.
So Is it as at Agilent marketing video or at JimmySte screens...as for now there are pretty different, that is at list "confusing".
And still You are saying nothing left to show... ??

Could be right Your "theory" that it needs some "special kind of waveforms" to "trigger" it working, or high FPS Motion Pictures, to see anything , maybe. 
But I'm living in "illusion", question true or not, that 74dB SFDR should be easily seen at FFT's , even with simple sinewave.

Lot have been told.. and lot have been learned, that is very true... but again:
"One picture is worth thousand words".

So ...let me just ask again:
Any chance You could post any screens showing normal vs HR mode..??

Kind Regards
Rosendorfer


 

Offline HPerez

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Re: Rigol DS2072 Review
« Reply #28 on: August 20, 2012, 09:31:22 pm »
Some screenshots with the DS2102 and another with the DSA815-TG
 

Offline PA4TIM

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Re: Rigol DS2072 Review
« Reply #29 on: August 20, 2012, 09:54:31 pm »
The big question, is the hires mode the true signal or the normal mode. noise floor drops but amplitude alters too. Also the time domain signal looks different.

The scope is at 15MHz allmost 3dB different from the SA. But the peaks are all not alike (3dBm is 50% difference in power) is.

I made a small setup tonight for some Hameg FFT pictures. I first had to be sure my signal has the right frequency and amplitude. (using a GPS controlled thunderbird, a HP312B selective voltmeter, two SA's and My HP8640 and my maybe the R&S) They all agreed.

I am gonna use a 10Mhz -10dBm sinewave with -60dBc harmonics. (and probably a pulse too) The Hameg shows the harmonics nice but only decent at 65Kpts and some averaging. So for checking a signal this is usefull but for alighnment not, much to slow.But it was to hot in here so I hope tommorow it is a bit cooler.

Fred
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Offline Gunb

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Re: Rigol DS2072 Review
« Reply #30 on: August 21, 2012, 07:12:29 am »
Hi Fred,

The big question, is the hires mode the true signal or the normal mode. noise floor drops but amplitude alters too. Also the time domain signal looks different.

The scope is at 15MHz allmost 3dB different from the SA. But the peaks are all not alike (3dBm is 50% difference in power) is.


Absolutely right! That's why I mentioned it as a "nice-to-have" feature that will never replace a real 10 bit or 12 bit ADC.



I am gonna use a 10Mhz -10dBm sinewave with -60dBc harmonics. (and probably a pulse too) The Hameg shows the harmonics nice but only decent at 65Kpts and some averaging. So for checking a signal this is usefull but for alighnment not, much to slow.But it was to hot in here so I hope tommorow it is a bit cooler.


Exactly, that's what I'm thinking, too. In particular taking a few neighboured samples together and make one of it is also a kind of loss of information, especially when searching for outliers, i.e. spikes and so on. That's why I do not use HiRes-mode most of the time.


Kind regards
Gunb

 

Offline Gunb

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Re: Rigol DS2072 Review
« Reply #31 on: August 21, 2012, 08:24:24 am »
Hi Rosendorfer,


Lot have been told.. and lot have been learned, that is very true... but again:
"One picture is worth thousand words".


I'm working more outside than at home and preparing a special arbitrary signal takes more of my
spare time I'm prepared to offer - sorry, very busied developer.

And what do expect more from my screenshots than Agilent already has shown?


So ...let me just ask again:
Any chance You could post any screens showing normal vs HR mode..??

Kind Regards
Rosendorfer

The signals I have are of confidential use, no way of posting them. If I should find signals when I'm at home
I will post them, but I can't promise to do that during the next weeks.

On the other hand: I always said it's a "nice-to-have" feature that can be helpful for special cases but it will never
replace an ADC with higher resolution. Many people already posted screenshots and most of them revealed that
there will be no real advantage for standard signals - so, take it as it is: it's a feature, nothing else.

As mentioned month ago I would recommend to try to get test unit from a distributor and do your own measurements.
It will show you more than a screenshot and will answer your question if you can use it for your own projects or not.

Especially screenshots are even not a way to show any effects, especially not when "on the fly" calculation is
done as with Boxcar Averaging.

I think of you when I should find time to generate an example  ;)

Kind regards
Gunb


Besides: do you understand German? If yes, I could give a link to a technical paper in German (sorry, could not find translations) where HiRes and ERES are explained well.
« Last Edit: August 21, 2012, 08:33:47 am by Gunb »
 

Offline Rosendorfer

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Re: Rigol DS2072 Review
« Reply #32 on: August 21, 2012, 11:50:19 am »
Some screenshots with the DS2102 and another with the DSA815-TG

Hi HPerez

Thanks for posting Your screens, having Normal mode with HR mode and even comparison of DS2102 with DS815 is even more I could ask..!!!

Well..... 8)

Could You post some screens showing if at 12 bit HR mode the  74dB SFDR is real number..??

And what about noise floor of DS2102 at 500uV .. how low it actually is and if HR mode does anything to it..??

Thanks again...!!

Rosendorfer
 

Offline PA4TIM

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Re: Rigol DS2072 Review
« Reply #33 on: August 21, 2012, 04:45:00 pm »
I posted pictures in the Rigol-Hameg topic (FFT and Hires/normal mode)

Fred
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Offline Gunb

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Re: Rigol DS2072 Review
« Reply #34 on: August 22, 2012, 10:03:05 am »
Hi there,

you all take nice screenshots and press the Hires-button because Rosendorfer likes to see screenshots - no problem with that - but do you really know what you're measuring? What Hires-mode is really doing and what the fundamental basics are behind it?

Honestly I've got the feeling that you're not familiar with time discrete signal processing - no complaint, no accusation.

I mean, it's easy to switch on a scope and produce some nice colorful screenshots, but knowing how it works and what it shows is quite a different thing. And that's why I would argue that screenshots should no be the first chain link but the last.

Let me explain the mistake that I can see in all of your measurements and why you don't see any or only a small difference between normal mode and Hires-mode in most of the screenshots that you already have done.

As already explained to Rosendorfer in one of my previous comments the concept of Hires-mode is to take a few real samples and calculate one to be displayed. This is done at slower timebases where sample rate of the memory is limited and the ADC can provide more samples than can be stored with that speed.

Instead of throwing samples away as in normal mode the ADC runs with its fastest sample rate and takes a group of N samples to calculate 1 to be displayed in Hires-mode. The advantage is that more samples come into play, that the vertical resolution becomes higher depending on the ratio between the maximum sample rate of the ADC and the displayed sample rate and a lower noise floor because higher frequencies are filtered. The disadvantage is a slower signal refresh caused by averaging of the N samples per group and, most of all, that the bandwidth of the signals to be measured becomes lower with each extra bit of resolution!

This method is named "Boxcar Averaging" and the concept is: "don't throw away information, if you can use it".

Where's the limit?
-> It depends on the sample rate the scope is currently working with and that's depending on the selected timebase!

Example #1: you've got a scope with 4GSa/s ADC, the timebase is set to a value that the scope works 4GSa/s, too, that means, it works with its fastest sample rate -> pressing the HR-button has absolutely no effect because there are no samples left to average anything!

Example #2: same scope, but now working with 2GSa/s in normal mode. That means, that the ADC potentially throws every 2nd sample away. Pressing the HR-button now takes exactly 2 real sampled values and calculates exactly 1 displayed sample from it.

Example #3: only to make it crystal clear: My HMO2524 has got an ADC of 2.5GSa/ at max. When I choose a timebase where it samples with 625MSa/s, the ratio is  2.5GSa/s to 625MSa/s equals 4. It means that 3 of 4 samples are thrown away in normal mode. Pressing the Hires-button now takes all 4 samples and calculates the average "on the fly". The result - 1 sample - appears in screen then.

No you might ask: and what all of this has to do with HIGH RESOLUTION??????


Well, as mentioned many times the algorithm behind that is the "Boxcar Average" that can be implemented as a simple FIR filter algorithm on DSPs, microcontrollers, FPGAs ....
It's a so called one pole filter that takes N samples for 1 average value.

One effect is that the gain of resolution follows the formula: 0.5*log (base 2) N - VERY IMPORTANT to understand!!!
This formula tells you how many extra bits you can win the more N samples are taken into account to calculate your average!

Example #4: If you sample with the maximum sample rate of your scope's ADC, exactly 1 sample is taken into the filter algorithm, i.e. N=1, that is: 0.5*log (base 2) 1 = 0!!! No gain of resolution!

Example #5 :If you sample with half of the ADCs maximum sample rate, i.e., N = 2, the formula says: 0.5*log (base 2) 2 = 0.5!!! You will win 0.5 extra bits of resolution, that is 8.5 bits instead of physical 8 bit

Example #6: If you sample with a quarter of the ADCs maximum sample rate, that leads to 4 samples per group, i.e., N=4, the result will be 0.5*log (base 2) 4 = 1!!! No we're at 9 bit resolution.


Do you understand now why you don't see any difference when you press the HR-button when sampling with the ADC's maximum sample rate?!?!? Or there's nearly no effort if using half of it?!

And that's not all!

One disadvantage of the Boxcar average - the Hires-mode -  is that it works as a one pole filter where the -3dB bandwidth depends directly on the displayed sample rate.
It follows the 3 db bandwidth limit: 0.44 x displayed sample rate

So, if you're scope has got a 2.5GSa/s ADC, the display shows a sample rate of 625MSa/s depending on the chosen timebase, the filter limits the maximum signal frequency to 275MHz with a resolution of 9 bit.


If you really want to see the difference, you should follow these guideline:

 #1: calculate the ratio between the maximum sample rate and the actual displayed sample rate and assign it to N
 #2: set it into the formula: 0.5*log(base 2) N and you'll get the extra bits of resolution
 #3: depending on the displayed sample rate calculate the limiting bandwidth of 0.44 * sample rate and investigate if your signal frequency is below that
 #4: for demonstration use signals where noise is interfering a small vertical detail to see the difference
 #5: then take a screenshot to demonstrate the difference.

--> my explanations show:

- why all manufacturers speak about "up to x bits" extra resolution
- why it never can replace an ADC with real higher resolution
- why it absolutely makes no sense to post screenshots without understanding these fundamental basics, otherwise it's nice & colorful only.
- and most important, that High Resolution is not a constant for any chosen timebase. Now you can calculate yourself how to adjust the scope to reach it.

Beside that, look into Rigol's datasheet, they tell more precise than Hameg at which timebase and sample rate the resolution is.

And: I've also the DSA815 but comparing FFT with a real analyzer can be tricky in case of non-periodic signals and knowing nothing about smearing effects and how windows have to be used. But that's quite a different story  :)

Hope it's helpful for further measurements  :)


Kind regards
Gunb




« Last Edit: August 22, 2012, 10:06:12 am by Gunb »
 

Offline PA4TIM

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Re: Rigol DS2072 Review
« Reply #35 on: August 22, 2012, 11:37:09 am »
Nice explanation. I know a lot about analog scopes and SA's and how to measure, but I'm digital disabled. So nice to read more about this.
While making the pictures I noticed what you told about samplerate. And also that a bigger ratio made a bigger difference but i was measuring 10 and 100 MHz. I could not get a higher ratio and keeping useable resolution.

But according to your explanation  I do not understand why the 2nd and 3td harmonic are way of, while the higher harmonics in hires mode were closer to what they should be. That should the the other way around not ?

But the main problem is both methods do not give the right results. Hires result is a small differense if it changes samplerate but it does not seems to give more accurate results, hut other results.

Only the First harmonic is rather correct. Very good considering I used -40 dBm so we are talking about a fault from a few uV's and becausec how FFT works I understand higher harmonics are difficult in this case, we talk about very very small signals buried in a big signal. A harmonic of -80 dBm is a voltage a scope in theory can not even measure.

So considering that it is still a rather good achievement, but from an instrument we want usable accurate results, not wrong results we like because they are clever made or the pictures look great. ( i placed a HP SA picture as compare and measured the signal on serveral other ways like a HP selective voltmeter and an other SA)

The reason I made the pictures was first for myself to see if FFT on the Hameg is a usable function because i found it rather useless on my DS1102e. And i must say i'm impressed by the low noisefloor and i think results are usable to check an oscillator on harmonics for instance. But it is often to slow to make adjustments ( but i use a VNA for filters and check output on the analog SA)

I checked  the hires mode only because Rosenberger asked in the hope someone could comment them.

Fred

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Offline Gunb

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Re: Rigol DS2072 Review
« Reply #36 on: August 22, 2012, 11:56:38 am »
Hi PA4TIM.

I think, it's absolutely legal to make screenshots, didn't want to criticise that  ;)

I could not get a higher ratio and keeping useable resolution.

But according to your explanation  I do not understand why the 2nd and 3td harmonic are way of, while the higher harmonics in hires mode were closer to what they should be. That should the the other way around not ?


 #1 Higher resolution: I haven't studied all the details of your measurements, only a rough view. But you should consider not to forget the manufacturer's datasheet. They restrict the maximum of resolution opposed to the formula. Hameg says "up to 10bits" for my HMO2524, Rigol "up to 12bits" for my DS4012. The formula is open for everything   ;)

 #2 Harmonics: First of all I my explanation did not consider FFT at first place. I will have to study the results first and think about it. Hires-mode is not introduced for FFT in the first place but to get more details from signals. But indeed it should work with FFT, too.


Kind regards
Gunb
 

Offline M0pmz

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Re: Rigol DS2072 Review
« Reply #37 on: September 06, 2012, 04:21:43 pm »
Anyone good with audio/SNR-testing: is my DS2072 is performing good data capture?

Interesting question here: how well can DS2072 perform at analysing Audio system noise -
I'm aiming for better than 80dB SNR 70Hz - 20kHz (which I reckon is 40dB in terms of the volts datapoints).

Here's the resulting Volts spectrum, performed on the data captured by the RIGOL - see attached JPG file.

This test is a simple 2-level, 2-tone test:
Big signal at 1kHz PLUS second v. low level signal 250Hz <300uV... straight into Ch1 of DS2102.
Use PC to grab 1400 points - one display memory -  then look at spectrum (FFT using PC software).
Check spectrum as a means of recording real system SNR.

I love what this scope can do for the price - maybe it can help me here too..  I'd really appreciate views from people who've done decent quality audio testing and know what tests are out there...

Does this get me towards a decent audio system SNR-test method?

Many thanks!
Dave.
 

Offline Dread

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Re: Rigol DS2072 Review
« Reply #38 on: September 07, 2012, 11:47:51 pm »
Love the review but one thing I find disturbing is that so many of the features are trial features and are disabled soon after you buy it.  How much money does it cost to get the average feature re-enabled? Is there a webpage that list the prices?
« Last Edit: September 08, 2012, 09:52:39 pm by Dread »
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Offline M0pmz

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Re: Rigol DS2072 Review
« Reply #39 on: September 08, 2012, 08:23:36 pm »
Last time I checked the price for DS2000 decodes (SD-DS2) was £157

Gives you RS232, I2C, SPI - this was from the RIGOL-uk sales engineer folks. See http://www.rigol-uk.co.uk/rigol-ds2000-series-digital-oscilloscope/
They got me some useful extra help on working with data (see back 2-posts).

PLEASE - audio gurus look at my SNR results - PLEASE could you give me an honest view on my test results: SNR spectrum is pictured 2 posts earlier?

My displayed sample rate was around 100kSa/s for the data above. (I've read Grunb's excellent notes and I can see why slower rate might cause HF-roll-off, but using the 0.44 rule I think I'm OK with this rate for my test to 20kHz, yes??)

Thanks,
Dave.

P.S. The machine was a DS2072 (not a 2102 as stated above - was thinking of upgrading my machine and had 200MHz DS2202s on my mind too!)
 

Offline playfsx

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Re: Rigol DS2072 Review
« Reply #40 on: September 14, 2012, 10:36:34 am »
Here you can see the performance of the scope in XY mode:

 
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Offline Sparky

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Re: Rigol DS2072 Review
« Reply #41 on: October 13, 2012, 12:15:15 am »
Hello everyone!

I recently found the EEVblog and this forum, and I must say it is excellent!  :)  The product reviews and forum comments from end-users is a tremendous resource, especially for EE hobbyists like myself who are researching for a nice capable 'scope, and trying to get great value for money.  I've seen there are a number of cheap Chinese DSO's on the market, and so it is important to know the good from the bad when making a purchase choice.

I've been researching and reading for a few days through these pages and the Rigol DS2000 series are looking mighty nice!  I love that big screen, and other features that have been previously mentioned, and the options seem reasonably priced (seems like you can't escape paying for software unlock these days...), especially compared to Agilent and others.  I've read there are some firmware bugs on the DS2000, and Dave's recent review (EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around), highlights a few usability issues, but Rigol is not Agilent, and so while I hope for the best, I'm willing to accept a few "issues".  But, from my reading, the DS2000 looks great on paper and from peoples opinions the general consensus seems to be that its excellent value!

So, being keen on this 'scope, I'm wanting to hear a little more of its short-comings before I commit to it.  I wonder if we can hear from users about the "dual time base" feature, which in Dave's video blog on the DS2000 he shows by recording a waveform and then trying to zoom in...but he can't get it working properly.  In fact, it looks like a major problem and the scrolling of the waveform doesn't appear to work at all.  Have any of the users here (JimmySte, playfsx, ...) been able to try this out?  I'd love to know whether this feature is broken, as seems to be the case in Dave's video, or whether there is something else needed to get it working.

Thanks for your comments folks!
Cheers!
 

Offline george graves

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Re: Rigol DS2072 Review
« Reply #42 on: October 13, 2012, 01:05:21 am »
I really impressed with the UI and resolution.  Just wish it was 4-channel. I just can't see upgrading from a rigol ds1052e to another 2-channel scope for 3 times the price.

Offline EV

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Re: Rigol DS2072 Review
« Reply #43 on: October 13, 2012, 06:01:31 am »
I have also this DS2202 scope. I have not this time base issue about what Dave told, but I have the old firmware. Maybe this issue is the problem of the new firmware.


.

  I've read there are some firmware bugs on the DS2000, and Dave's recent review (EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around), highlights a few usability issues, but Rigol is not Agilent, and so while I hope for the best, I'm willing to accept a few "issues".  But, from my reading, the DS2000 looks great on paper and from peoples opinions the general consensus seems to be that its excellent value!

So, being keen on this 'scope, I'm wanting to hear a little more of its short-comings before I commit to it.  I wonder if we can hear from users about the "dual time base" feature, which in Dave's video blog on the DS2000 he shows by recording a waveform and then trying to zoom in...but he can't get it working properly.  In fact, it looks like a major problem and the scrolling of the waveform doesn't appear to work at all. 
« Last Edit: October 13, 2012, 07:49:03 am by EV »
 

Offline Sparky

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Re: Rigol DS2072 Review
« Reply #44 on: October 16, 2012, 01:56:17 am »
Thanks, EV, for contributing your experience with the DS2202 'scope.  From what you say, it seems likely the bug was introduced by the new firmware (when correcting the X-Y mode issue Dave talked about in his video).

I'm thinking it would be valuable to compile a list of DS2000 firmware versions, and the reported problems from users.  The DS2000 series are relatively new so I doubt there are many firmwares available yet, but in the long run it would be a good resource for people when considering firmware upgrades.  What do users think about an "RIGOL DS2000 Series Firmware" thread on this topic?

On the topic of firmwares, it seems the only way to get new releases is by emailing RIGOL technical support.  Is this true?  It seems a slow/inconvenient way to get updates...  Is there an "automatic check for firmware update" available on the scope?
 

Offline EEVblog

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Re: Rigol DS2072 Review
« Reply #45 on: October 16, 2012, 11:27:24 pm »
So, being keen on this 'scope, I'm wanting to hear a little more of its short-comings before I commit to it.  I wonder if we can hear from users about the "dual time base" feature, which in Dave's video blog on the DS2000 he shows by recording a waveform and then trying to zoom in...but he can't get it working properly.  In fact, it looks like a major problem and the scrolling of the waveform doesn't appear to work at all.  Have any of the users here (JimmySte, playfsx, ...) been able to try this out?  I'd love to know whether this feature is broken, as seems to be the case in Dave's video, or whether there is something else needed to get it working.

I can also confirm that the same problem occurs in regular dual timebase mode when STOPed, not just in waveform capture/replay mode (a.k.a segmented memory).
Dual timebase works fine in regular updating mode.
But I have been assured that this is not normal, so the verdict is still out, I'm waiting on a response.

Dave.
 

Offline TP

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Re: Rigol DS2072 Review
« Reply #46 on: December 16, 2012, 06:41:08 am »
I just bought a Rigol DS2072 to replace my 35 year old Phillips PM3212 that just died.  I've been evaluating the High Res mode and it does work.  I programmed my computers 16 bit DAC to produce a sine wave with a tiny 0.7 LSB blip on it, much like the Agilent video posted earlier.  The Rigol could easily resolve the blip in High Res mode despite the fact that it was only 0.7 LSB of the 8-bit ADC.  The first figure (assuming it will allow me to attach images) shows the High Res trace blown up.  This trace was taken 100 mV/div and 2 ms/div and blown up post acquisition to 5 mV/div.  Of course, for a repetitive signal you could also just turn up the sensitivity to 5 mV/div and hunt for the blip with the offset and time/div and this is shown in the second figure. 

Of course, the extra resolution you get from boxcar averaging doesn't mean much if the DNL (differential non-linearity) of the ADC is not good, so I used the ramp and histogram method to measure DNL.  The results are that it's pretty good: only +-0.15 LSB.

Finally I measured the noise on the 500uV/div scale as 80uV RMS in Normal acquisition mode and 40uV RMS with the High Res mode, both with the 20MHz BW limit on.  With the 20MHz BW limit off and Normal mode I got 100uV RMS.  These are all with the input shorted with a 50 ohm terminator.

PS remember when calculating LSB remember that the 8 vertical divisions are not the full range of the ADC; it's actually 10.24 divisions with headroom off the top and bottom of the screen plot region.

[Edit: replaced HP with Agilent- shows hold old I am.]
« Last Edit: December 16, 2012, 07:59:31 pm by TP »
 

Offline marmad

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Re: Rigol DS2072 Review
« Reply #47 on: December 16, 2012, 07:07:53 pm »
Hi TP - thanks for your interesting info. You might want to move (or repost) it to one of the newer threads we're using for discussing features, bugs, and software for the DS2000 series:

https://www.eevblog.com/forum/reviews/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/

https://www.eevblog.com/forum/projects/software-tips-and-tricks-for-rigol-ds200040006000-ultravision-dsos/
 

Offline TP

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Re: Rigol DS2072 Review
« Reply #48 on: December 16, 2012, 07:44:12 pm »
Hi TP - thanks for your interesting info. You might want to move (or repost) it to one of the newer threads we're using for discussing features, bugs, and software for the DS2000 series:

https://www.eevblog.com/forum/reviews/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/

https://www.eevblog.com/forum/projects/software-tips-and-tricks-for-rigol-ds200040006000-ultravision-dsos/

Thanks.  I was responding to Rosendorfer who seemed interested in a screen shot that shows if High Res mode actually works.  The DNL measurement was also relevant to that question.  Should I also post in the "first impressions" thread?
 

Offline marmad

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Re: Rigol DS2072 Review
« Reply #49 on: December 16, 2012, 08:05:07 pm »
Should I also post in the "first impressions" thread?

Yes, I think your tests, measurements, and conclusions would be very pertinent there. I haven't had any time yet to explore the Hi-Res option of the scope.
 


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