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REVIEW - Rigol DS2072 - First Impressions of the DS2000 series from Rigol
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Teneyes:

--- Quote from: Teneyes on July 11, 2014, 09:21:08 pm ---"Which is Better??? ":-//

--- End quote ---

As you can see by the flat traces that I manually created the data for the waveforms and re-loaded the sample data into the DSO and the DSO created the Traces, always with SinX/X interpolation.

 
1.  In the first display the sample data is at one level and then jumps to  the Higher level in one sample period (500ps).
 NOTE how the SinX/X interpolation displays  a pre and post step ringing.

To explain in more detail. I saved a waveform file from the DS2000 (at 140pts/disp)) to a USB Stick.
I then transfered this file to a PC. I then used a Hex Editor to put in the Sample data into the files that I wanted the DSO to Display. , There is NO real voltages measurement Data.
I set the first 70 data samples for 1 div above the bottom of the display
then
I set next 70 data samples for 1 div below  the top of the display.
I then loaded the waveform file into the DSO (w/USB)
The ringing you see is the result of the DSO trying to make a sine wave with the SinX/X interpolation function. between the 140 Data Points at 500ps intervals


2. In the second display the step change of level was created for a smoothly change to resrtiction the SinX/X effect.
   See the Dot Samples in this Display.
You can see the Dots are a gradual curve at the bottom and top of the Step change in the Sample Data.

I think a lot of the overshoot when displaying a step change is the SinX/X function. A user has to look at where the sample dots are to determine if there was a real indication of overshoot.
The #1 display shows a 10% overshoot when there was absolutely Zero overshoot !

As for the Front end BW of the DS2000 we know that there is a Programmable BW Amplifier that has the selections of 20,100,200,350,650 and 750 MHz so I assume 300MHZ option opens up the BW to 350MHz

Teneyes:
I hope the last 2 posts were Helpful. I'm not getting any questions or comments??

See pix for OLD wfm data for #2 display.  x'1B'=1 div,   x'B1'= 7 div
miguelvp:
I think you explained it so well, no one has questions  :-+

I agree on the phantom ringing, and dot mode usually shows you what is real vs what is extrapolated in vector mode.
Orange:

--- Quote from: Teneyes on July 11, 2014, 09:30:44 pm ---
--- Quote from: Teneyes on July 11, 2014, 09:21:08 pm ---"Which is Better??? ":-//

--- End quote ---

As you can see by the flat traces that I manually created the data for the waveforms and re-loaded the sample data into the DSO and the DSO created the Traces, always with SinX/X interpolation.

 
1.  In the first display the sample data is at one level and then jumps to  the Higher level in one sample period (500ns).
 NOTE how the SinX/X interpolation displays  a pre and post step ringing.

To explain in more detail. I saved a waveform file from the DS2000 (at 140pts/disp)) to a USB Stick.
I then transfered this file to a PC. I then used a Hex Editor to put in the Sample data into the files that I wanted the DSO to Display. , There is NO real voltages measurement Data.
I set the first 70 data samples for 1 div above the bottom of the display
then
I set next 70 data samples for 1 div below  the top of the display.
I then loaded the waveform file into the DSO (w/USB)
The ringing you see is the result of the DSO trying to make a sine wave with the SinX/X interpolation function.


2. In the second display the step change of level was created for a smoothly change to resrtiction the SinX/X effect.
   See the Dot Samples in this Display.
You can see the Dots are a gradual curve at the bottom and top of the Step change in the Sample Data.

I think a lot of the overshoot when displaying a step change is the SinX/X function. A user has to look at where the sample dots are to determine if there was a real indication of overshoot.
The #1 display shows a 10% overshoot when there was absolutely Zero overshoot !

As for the Front end BW of the DS2000 we know that there is a Programmable BW Amplifier that has the selections of 20,100,200,350,650 and 750 MHz so I assume 300MHZ option opens up the BW to 350MHz

--- End quote ---

I  made test already a year ago; see post
https://www.eevblog.com/forum/testgear/sniffing-the-rigol%27s-internal-i2c-bus/msg247223/#msg247223

first picture.

This is NOT due to Sin X/ X interpolation. Besides that, the sin interpolation is only done between sample points.....
The first picture in this post was done running the scope bandwidth at 200MHz. you can already see how much overshoot it has. Test done at 300MHz show even more overshoot. NOT due to sin interpolation.
Another point is that if this was due to sin interpolation you would see the same overshoot/undershoot on the start of the pulse. This is clearly not the case on picture from my earlier post.

I'm not sure why people want to believe that that a $850 scope can measure 300MHz without severe signal distortion.....

For people that doubt my signal generator, it was checked with other equipment (1 GHz sampling system).
I have seen similar responses from a guy from Finland and those screen shots look very similar also with the same generator a Tektronix 284.

So as far I'm concerned this myth has been busted for the DS2000 series  :)
Orange:

--- Quote from: Teneyes on July 12, 2014, 03:37:17 pm ---
--- Quote from: Orange on July 12, 2014, 09:37:15 am ---This is NOT due to Sin X/ X interpolation. Besides that, the sin interpolation is only done between sample points.....
The first picture in this post was done running the scope bandwidth at 200MHz. you can already see how much overshoot it has. Test done at 300MHz show even more overshoot. NOT due to sin interpolation.
.......
So as far I'm concerned this myth has been busted for the DS2000 series  :)

--- End quote ---

Thanks Orange.
I think you tested on the DS2072 Non-A , with older Firmware
My displays indicate nothing about the Analog specifications of the DSO.

Yes the vector display follows thorough the sample points and (SinX/X is used between data points)

I may have missed the post, is there any difference in the front end of the DS2000A to improve the spec.? (higher BW)  Although the latest FW allows the option for DS2302 (300MHz), was there any changes to the frontend in the DS2000A hardware for a faster response (with what overshoot??)

Besides Rigol sales , I doubt anyone has both DS2000 and DS2000A to do a test with same pulse.
and with only a few sample points/div  I think it would be hard to determine any difference when testing at the limits of the DSO specifications.

Just thinking,why I like 1ns/div?   I am old  :( and slow to multiple by 2, for 2ns/div   ;D

--- End quote ---
Well that's a good question. I would assume that Rigol has adapted the front-end of the new DS2000A to compensate for the excessive overshoot with the 300MHz model. But I don't know for sure, I don't own one.

Reading lately other attempts of using the old firmware I think Rigol has changed the boot loader on the very latest production.  A new patched firmware is needed to get the serial number out of the 'dark places' of the scope.
Hopefully the guy's that did the patch of the firmware are still reading this, and will consider a newly patched firmware based up-on 3.01SP1

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