Gw Instek GDS2204E (200MHz 4 channel DSO) review

[nctnico]

I have not tried but I'm sure the span will be the same because 1Gs/s is the maximum samplerate either way.

[rhb]

Stretching the rope, I wish Santa could make FRA APP work with an external function generator so it could run on the GDS scopes.

It would be nice if the FRA app were usable on the units *with* AWGs.  A scan from 13-14 MHz at the maximum sampling of 90 samples per decade produces two points.  So no way to find the resonances of a crystal with that.

I was able to sync it with  a 33622A but not consistently.  Despite several hours of fiddling, I was never able to get the series response of a crystal such as an 8560A SA w/ TG will produce.  It's probably because the various operations are not operating in the same clock domains.

[Mortymore]

Oh well!!... An SDS1104X-E to marry with the SDG1032X would solve the Bode plot problem   

[rf-loop]

Oh well!!... An SDS1104X-E to marry with the SDG1032X would solve the Bode plot problem   

Yep.

SDG1032X -- Xtal---SDS1104X-E


Span 5kHz


Span 500Hz

[nctnico]

Stretching the rope, I wish Santa could make FRA APP work with an external function generator so it could run on the GDS scopes.

It would be nice if the FRA app were usable on the units *with* AWGs.  A scan from 13-14 MHz at the maximum sampling of 90 samples per decade produces two points.  So no way to find the resonances of a crystal with that.

I was able to sync it with  a 33622A but not consistently.  Despite several hours of fiddling, I was never able to get the series response of a crystal such as an 8560A SA w/ TG will produce.  It's probably because the various operations are not operating in the same clock domains.

You should be able to do this if you have a generator which can step through a range of frequencies with a certain dwell time. Most RF generators support this.

[Mortymore]

You should be able to do this if you have a generator which can step through a range of frequencies with a certain dwell time. Most RF generators support this.

Are you referring to something old school with sweep mode and trigger from a generator?
That actually works a bit better than I recall of my analog scope, with this digital 2000E, if the display is set to infinite persistence, because it will keep painting the screen, but that's to basic and calculation tedious comparing to the neat Bode plot of the Siglent scope (for instance).

Just for fun, placed a simple RC low pass filter on a bredboard with a cut-off frequency of 4KHz.
The generator 1032X sweeps from 10Hz to 100KHz on CH1, and on CH2 outputs a square wave of 1Hz, for triggering the scope on CH2.
Made 3 screen captures, one with a linear sweep, and the other 2 with logarithmic sweep, and the persistence in the last one was set to infinite, so after a minute or so the area to plot is filled. The vertical position on CH1 on the scope was deliberately set so roughly only the positive half of the wave is shown on screen... Bode plot alike.

This is just a "poor man" Bode plot. 

PS: installed the FRA APP but it kicks me off right from the start, stating that I don't have a generator in my scope, so I can't even take a look at it. Uninstalled the APP, since was of no use for me.

A side note: I came from a long "dark age" in electronic equipment and only recently acquired a decent digital scope and generator with some bells and whistles that many of you master here. Be forgiven if I say something idiot or don't quite get the picture here and there.

[nctnico]

You should be able to do this if you have a generator which can step through a range of frequencies with a certain dwell time. Most RF generators support this.

Are you referring to something old school with seep mode and trigger from a generator?

No, use the SA mode in peak hold mode (which can be set to averaging).

[Mortymore]

Having played a bit with the Spectrum Analiser option, after "re-upgrading" my 2074E from 200 to 300MHz, found that the higher frequency that can be set is 750MHz, but the span remains the 500MHz (so it has to start at 250MHz). Though it may seem a nice feature having the ability to shift the frequency range 250MHz up, it actually has no use since there's nothing shown in the display above 500MHz (see picture attached: GW2000E_SA_750MHz.PNG). Am I doing doing something wrong? Is that a bug? Or am I missing some useful point for this to be like it is?

Something that I find annoying with this scope is the "supra imposed windows", like with the feature "statistics" or a "table". Seems that Rigol and Siglent (series 1000) manage to re-arrange the windows so things fit or having some degree of transparency, don't block much the signal to be viewed. GW just place a opaque board, blocking everything (GW2000E_SA_Table.PNG). 

Even in the XY mode were half of the screen is empty, the window for statistics has to fell on top of what you are trying to see (GW2000E_XY_statistics.PNG). 

Just for comparison, attached 2 random images that can be found on this forum, posted by other members (hope they don't mind) from a Rigol and a Siglent (series 1000). I think they serve the purpose to show a better arrangement than in the GW2000E scope.

Even harder to get is the fact that the GW has an 8" screen and the other scopes on comparison are 7" (though with the same resolution), besides the fact that the Rigol has the icons associated to the side buttons always visible, stealing screen area. I believe there's some margin for improvement in the GW UI. But by all means, correct me if I'm wrong.

I love this scope, but I'd like it to be as prefect as possible. 

[nctnico]

GW Instek could improve the screen layout but then again the fonts used by Rigol and Siglent are much smaller which may affect readability.

BTW if you look at the SA screen you'll see it stops measuring at 500MHz.

[Mortymore]

GW Instek could improve the screen layout but then again the fonts used by Rigol and Siglent are much smaller which may affect readability.

Yes, the fonts in GW look written in Bold format. Good for those like me that start to need glasses to read. But even then, cases like the screen in XY mode could have better display placement, some windows without border, some transparency or unnecessarily big size of the window. Cases that only a line of data is represented on a table, and the windows fills most of the screen. Well, maybe it's just me being picky, but i like to see data side by side with an image to get a better interpretation of graph vs data. Even an HP39GS graphing calculator has similar feature.

BTW if you look at the SA screen you'll see it stops measuring at 500MHz.

That's exactly my point. What's the purpose of extending the SA up to 750MHz if it's useless above 500MHz? I would call it a bug. Reminds me a speedometer with a scale up to 220Km/h in a car that only reaches 160. 

[rhb]

Having played a bit with the Spectrum Analiser option, after "re-upgrading" my 2074E from 200 to 300MHz, found that the higher frequency that can be set is 750MHz, but the span remains the 500MHz (so it has to start at 250MHz). Though it may seem a nice feature having the ability to shift the frequency range 250MHz up, it actually has no use since there's nothing shown in the display above 500MHz (see picture attached: GW2000E_SA_750MHz.PNG). Am I doing doing something wrong? Is that a bug? Or am I missing some useful point for this to be like it is?

The 750 MHz label is a FW bug.  It cannot go above the 500 MHz Nyquist frequency.  And the anti-alias filter limits it to around 350 MHz *if* they designed it properly.  It gets quite difficult to devise test cases. 

FWIW the step response using a 40 ps rise time square wave is exactly the same for the 200 & 300 MHz settings.

I need to do some more testing, but at the moment I'm playing with a Tek 11801 sampling scope in preparation for measuring actual clock skew in the Zynq vs what Vivado calculates.  The SD-26 heads sitting at the post office have a 20 GHz BW. So I'll be able to look at the skew of all the 8 data lines in a PMOD port to a resolution of 2-3 ps.

[nctnico]

BTW if you look at the SA screen you'll see it stops measuring at 500MHz.

That's exactly my point. What's the purpose of extending the SA up to 750MHz if it's useless above 500MHz? I would call it a bug. Reminds me a speedometer with a scale up to 220Km/h in a car that only reaches 160. 

It is not a bug. How can you get the maximum frequency in the center of the screen otherwise? Regular spectrum analysers usually allow similar settings.

@rhb: I have measured an increase in bandwidth on my GDS2204E after the 300MHz upgrade (IIRC from 270MHz to 320MHz) but it is probably too small to really see in the step response.

[rhb]

BTW if you look at the SA screen you'll see it stops measuring at 500MHz.

That's exactly my point. What's the purpose of extending the SA up to 750MHz if it's useless above 500MHz? I would call it a bug. Reminds me a speedometer with a scale up to 220Km/h in a car that only reaches 160. 

It is not a bug. How can you get the maximum frequency in the center of the screen otherwise? Regular spectrum analysers usually allow similar settings.

@rhb: I have measured an increase in bandwidth on my GDS2204E after the 300MHz upgrade (IIRC from 270MHz to 320MHz) but it is probably too small to really see in the step response.

My 8560A sets the center frequency  to 2.9 GHz, but issues an error message that 30 Hz RBW is incompatible and basically does nothing.  It's an analog instrument, so a bit different.  An upper limit above Nyquist on a DSO is just simply silly.  It's neither possible nor useful.  Like the Instek FRA app, it's a demonstration that the programmer didn't have a clue what they were doing.

Were those the -3dB points?   I've not tested it with my 8648C calibrated against my 438A.

[nctnico]

These are the -3dB points I measured (the numbers are from the top of my head so please look up a previous post to verify).
And again I don't think it is silly to end the trace half way the display. On spectrum analysers the center frequency is often used to have the frequency of interest in the middle of the screen so it is very easy to see where a frequency component is at. If the trace would be stuck to the right side of the screen you'd have to 'count squares' or or use the cursors to figure out what frequency you are looking at. The way GW Instek has implemented it is just convenient to use. The scope isn't trying to measure anything over Nyquist.

[Mortymore]

Thanks for your clarification nctnico.

Let it be this then:

.. Or am I missing some useful point for this to be like it is?
...

[Krisztián]

It would be nice if the FRA app were usable on the units *with* AWGs.  A scan from 13-14 MHz at the maximum sampling of 90 samples per decade produces two points.  So no way to find the resonances of a crystal with that.

Last weekend my buddy and me measured a 9 MHz crystal in FFT mode with the help of a BG7TBL noise source. Persistence was set to infinite. I think you'll not get the necessary resolution until switching to 1M record length. Spectrum averaging by oscilloscope would be nice. That was a GDS-2104E oscilloscope.

[nctnico]

If you use the key generator (see the GDS1054B thread) then you can use the SA mode which does support averaging multiple FFT traces.

[Krisztián]

In SA mode you'll get only 5kHz resolution at 9MHz because record length is fixed at 10k.

[nctnico]

Not on my GDS2204E. It seems in spectrum analyser mode the record length is fixed to 100kpts.


This image was created using the max-hold function and using an RF generator to step through the frequencies. Yes, this is a slow process... but it works.

Edit: the record length may be bound to the RBW.

[rhb]

I used an AWG (don't recall if it was the 2204EA or the 33622A) to sweep a 40 MHz 3rd overtone xtal from 13.2 to 13.6 MHz.  The Instek SA function displays the series notch as a peak. 

I'll add a screen shot to this post later.  I *think* I saved one, but I'd have to root around to find it and it was fairly tedious to set up if I have to do it over.

The Instek record length is fixed at 100 Kpts.  The RBW then depends upon the frequency span.

I plan eventually to get a Siglent SDS1104X-E and do a series of head to head comparisons for the same measurements with the Instek MSO2204EA, Owon XDS2102A and Rigol DS1102E.  All accompanied by the correct answer using my HP and Tek gear.

But at the moment I am having far too much fun with a Tek 11801 using the calibrator and an SD-26 sampling head.  In particular, I've been doing TDR on cables, connectors, terminators etc. I'm amazed at how much detail I can see with 20 GHz of BW.

[Mortymore]

Something that I find annoying with this scope is the "supra imposed windows", like with the feature "statistics" or a "table". Seems that Rigol and Siglent (series 1000) manage to re-arrange the windows so things fit or having some degree of transparency, don't block much the signal to be viewed. GW just place a opaque board, blocking everything (GW2000E_SA_Table.PNG). 

Actually GW-Instek have windows transparency, but in the 2000A series.

It can be seen at 6m30s on this video when the statistics option is enabled. Or for instance in the submenu options, scroll down windows. (buttons on the right side of the LCD, when they have submenu options)



On Dave's video "EEVblog #474 - GW Instek GDS-2000A Series Oscilloscope Unboxing & First Impression" it can be seen also throughout the video.

So why not on the 2000E?

[Mortymore]

New firmware update to Version 1.39 (7 Nov 2019)

Version 1.39
1.The SPC function is supported under roll mode now.
2.Added new erase disk function that can empty all the saved image files which located on the DSO.
3.Fixed UART parity bugs.
4.Fixed ¡§Adv math¡¨ operation issue.

EDIT: Why "Erase Disk" and "1 of 3" has a different font?

[Mortymore]

I was to put this info here earlier, but only now it goes.   

Some posts ago I complained that there's a lot of free space in the screen when in XY mode. It turns out that it can be filled if cursors are used.

BC547C: hFE=575



Did some experiments using the XY mode to trace some BJT transistor curves, taking advantage of a 2 channel AWG.

TUT had a 100k base resistor and a 50 (100//100) at emitter.
Generator CH1 connected to the TUT collector and X (ch1) on the scope.
Generator CH2 connected to 100k base resistor.
TUT emitter connected to 50 and Y (ch2) on the scope.

For NPN
CH1: Ramp up, 8kHz, 10Vpp, 5V DC offset
CH2: Stair up, 1kHz, 4Vpp, 2V DC offset


BD139: hFE=292



For PNP
CH1: Ramp down, 8kHz, 10Vpp, -5V DC offset
CH2: Stair down, 1kHz, 4Vpp, -2V DC offset
EDIT: CH1 and CH2 on scope were inverted

BD140: hFE=298



Took advantage of the fact that it can be selected a current probe for input, and so on  channel2 (Y) of the scope, current values can be shown, instead of Volts.

EDIT: Edited to replace images along the post

[Vytautas]

Hi, guys. Do we have a high resolution image of the AWG board used in any of the GDS-2000E scopes? Could anyone post it, pleeeaaase...

[Mortymore]

New firmware v1.40

1.Added German menu
2.Added Portuguese menu (I didn't ask for this) 
3.Fixed UART minor bug

Haven't tested yet. But would like to see at least a uniform font style.

And since I'm here, I'll ask a couple of things that I probably now the answer for, but...
Is there a GW scope/AWG pair to do a Bode Plot being the instruments independent, like Siglent has?
And following what I think is more or less the Vytautas idea: It could be added an internal AWG board to a GDS-2000E? (I realize that the case has no holes for the output BNCs)

EDIT:
They changed the font of "Erase Disk" 



But as I suspected, the menus in Portuguese... 



In some cases they had to change the font size to fit, in other, almost out of the box, some text was not translated as the "Erase Disk" (Apagar Disco)... I never intended to change the language from English, but it's good to see the effort to reach other markets.
Does anyone knows if GW has a good market on Brasil? When I see stuff like this in Portuguese language, it's never actually because of the tiny market in Portugal, but because of an eventual much bigger market on Brasil that justifies the effort of translation.

EDIT2:

Wile browsing through the scope I don't recall I've seen the Function Module "Fixed 4 Measurement" before.
Have I been distracted or something?  What does this do? Anyone has this unlocked?



EDIT3: The font type and style of the information above the horizontal menu buttons (yellow lettering) is different in the English to the Portuguese layout. In this regard I prefer the arial (maybe) font and not being bold, as seen in the Portuguese layout.
GW, can we have that font style in the English layout in the next firmware version?