GDS-2000A series New economic oscilloscope by GW Instek comes to market

[Spike101]

I think that you will never get a real two channel signal generator.

I don't understand it. Why does it have two function gen outputs to begin with, if you can only enable one at a time?

[mikeselectricstuff]

RS232 rather than LAN is just ridiculous these days. 
Trigger in on front panel is useful on a 2-channel scope, less so with 4 channels.
The module thing is also rather dumb as it limits how many options can be used together - especially silly for those that already have dedicated connectors.
Would be very interested to see what's in those boxes.

   

[Hydrawerk]

Remember that GW instek is focused on Asia market - maybe they still use RS-232 there.

[SeanB]

I would guess a PCI interface chip and a basic DDS chip attached to a PGA stage, along with a switch set to select either the digital sine wave, the digital triangle or a simple square wave output. Quite a bit of overshoot on the square wave output there. Basic function gen, nice to have it integrated with a decent display and better UI though.

LA would be the FIFO, the 2 port RAM and the digital interfacing, the logic conversion being done on the pod, and the decoding being done by the main processor.

[roli_bark]

I think that you will never get a real two channel signal generator.

I don't understand it. Why does it have two function gen outputs to begin with, if you can only enable one at a time?

I'm not sure that is the case with Dave's review.
What can seen is basically 2 extension slots that can populate either: 2 Gens,or 1 Gen + 1 LAN, or 1Gen + LA, or 1 LA + 1 LAN, ...etc

2 Gens, because otherwise it would have had only 1 BNC for 1 Gen .

[Spike101]

I'm not sure that is the case with Dave's review.
What can seen is basically 2 extension slots that can populate either: 2 Gens,or 1 Gen + 1 LAN, or 1Gen + LA, or 1 LA + 1 LAN, ...etc

2 Gens, because otherwise it would have had only 1 BNC for 1 Gen .

Yeah, but look at the manual, that Hydrawerk posted. It says:

Note:
Even though it is possible to install two function
generator modules, only one function generator
option can be used at any one time.

??

[Hydrawerk]

Yes, one of my hesitations - if I was in the market - would be the industrial and GUI design; both the Rigol and Agilent series 'look' modern and sexy - it does not.

GDS-2000A's screen looks like Tektronix...  I am not familiar with those expensive Teks. The intensity gradation is really crap.
Dave, could you please test the Trigger output and maybe make a comparison table?

[Skimask]

Thanks in advance for what will be a fine and fun video no doubt!

Sorry, but it's not a "fine" video, nor a review. It's me playing randomly with the thing for an hour after opening the box.
I'll wait for inevitable complaints...

I'm reminded of that scene in Star Trek IV...where Spock has to make a guess, McCoy makes a comment, and Kirk has to explain to Spock that "he feels better about your guesses than most people's facts".
E.g.  I'd rather watch Dave twiddle knobs for an hour and get practically nothing accomplished vs. watching some marketing clown explain an item's operation.

[Hydrawerk]

And Dave, what do you think about the fact that this scope has no fine horizontal or vertical control? It's strange. Most scopes do have fine settings (at Rigol and Agilent you only must push the knob). Well, only Owon doesn't have fine settings, as far as i know.

[Yaksaredabomb]

Thanks for the first impressions Dave!  Noticed this just now in the Youtube comments and looking forward to it!

Matt Cysiewski 11 hours ago
going to do a? teardown?

EEVblog 3 hours ago
Of course. Likely tomorrow.?

[grego]

And Dave, what do you think about the fact that this scope has no fine horizontal or vertical control? It's strange. Most scopes do have fine settings (at Rigol and Agilent you only must push the knob). Well, only Owon doesn't have fine settings, as far as i know.

Again in Insteks defense this feature is on the firmware roadmap.  It's goofy for now but it will be added.  And thankfully Instek seems to be rather aggressive with their firmware update schedule.

Remember thus scope has only been on the market a couple of months.  That's not an excuse but we do need to take care about comparing it to more mature products.

[Hydrawerk]

Well, I am not sure. The expensive GDS-3000 from 2011 has no fine controls till today.
EDIT: http://www.gwinstek.com/en/product/productdetail.aspx?pid=3&mid=7&id=1290

[tinhead]

Well, I am not sure. The expensive GDS-3000 from 2011 has no fine controls till today.

that was 2yrs ago, the market was complettly different at that time.

[Hydrawerk]

Are you familiar with the GDS-3000 scope? Was there a better implemented digital phospor technology (aka intensity grading)?

[tinhead]

Was there a better implemented digital phospor technology (aka intensity grading)?

what do you mean with better? There is nothing wrong on GDS-2000A, use color grading and you a winner.

[marmad]

what do you mean with better? There is nothing wrong on GDS-2000A, use color grading and you a winner.

Sorry, tinhead, but even though I personally like color grading and would appreciate having it for certain kinds of signals - it's neither as intuitive as intensity grading (which is closer to the way we perceive things) nor as similar to analog oscilloscopes (which many people are used to).

But even more importantly, Dave's video raises the issue of how well GW-Instek is implementing their VPO technology - given their claimed wfrm/s rates. And poor implementation of VPO would affect both intensity AND color grading.

[grego]

Lets not read too much into it yet. Let Dave do his tear down and full review.

[tinhead]

i don't see any problem with color grading implementation, all you need is to set base color (and maybe have way to invert them,
e.g. from blue to red spectrum). This seems to work on GDS-2000A good. The benefit of color grading  you need only these
256 colors and not waveform intensity crap (yes, on analog scope there is no color, but hey, wh cares? my TV is color since
40yrs already ...)

Where is maybe (Dave or grego need to test it) something worng is how fast the intensity is
changing when turning the knob, all i saw was Dave turning wild knob to right, to left and back and beeing complained
about the waveform colors 

However, for a fraction of second you can see good picture (like in the middle picture of the link below), even with single color.

Check here http://www.gwinstek.com/vpo/
on the bottom the intensity pictures, on Daves video i saw only max or min^^

So when this is an error, then only in way how fast the intensity is changing (and i can clearly see that on Rigol you need to
turn the knob for an hour ^^ to get from min to max).

Lets not read too much into it yet. Let Dave do his tear down and full review.

right, it was first touch only.

[marmad]

Lets not read too much into it yet. Let Dave do his tear down and full review.

A) I'm not saying it's impossible that Dave's settings were off - and better results might be gotten - but honestly, Greg, the intensity grading in the video you posted doesn't look very good to me (and that was at a time base that the Instek supposedly does ~13,000 wfrm/s).  You could help sort this out by posting an image from the Instek which is similar to this one I just captured from my Rigol:



B) I doubt whether Dave will ever do a full review - he never went back and did one of the Rigol DS2000 (which is a DSO he likes quite a lot). He did a 1'12" impressions video - so I would suspect we will see a teardown and little else (although I could be wrong).

[marmad]

i don't see any problem with color grading implementation,

Color grading uses a lookup table from the intensity values - if the intensity values are coarse, the color grading will be as well..

...and i can clearly see that on Rigol you need to turn the knob for an hour ^^ to get from min to max).

Again, you're spouting nonsense about the Rigol which is untrue. There is rarely a time when you have to turn a knob very long on the Rigol - it uses TWO knobs (slow/fast) for any variable that has a wide range - plus it has software acceleration implemented on it's encoders - which the Instek seems to be lacking.

[Hydrawerk]

There is some DPO... But yes, these were quite slow-changing signals
But the AM modulation in Dave's video looks definitely crap.
EDIT: See the Agilent screenshots. This is how AM should look like.
Not like this: http://youtu.be/cRe9b7iV6Kc?t=42m53s

[tinhead]

i don't see any problem with color grading implementation,

Color grading uses a lookup table from the intensity values - if the intensity values are coarse, the color grading will be as well..

ehm you don't know how it is implemented on GDS in detail, me either. All i can see is that it works as it should when
set to color grading.

...and i can clearly see that on Rigol you need to turn the knob for an hour ^^ to get from min to max).

Again, you're spouting nonsense about the Rigol which is untrue. There is rarely a time when you have to turn a knob very long on the Rigol - it uses TWO knobs (slow/fast) for any variable that has a wide range - plus it has software acceleration implemented on it's encoders - which the Instek seems to be lacking.

well, i can clearly see on video, Dave turning for seconds knob from min to 3/4 (video 43:02 to 43:35) and then
from min to max on GDS in shorter time (at 48:50). I don't give a shit if there is acceleration or 20 knobs and 6 buttons
for super fine intensity on Rigol - all i need to see is there on video - meaning how long it takes and what he is doing.

For sure the grading looks better (no, i don't like it, not on Rigol nor Agilent, but it looks better as on GDS with single color,
it is somehow analog-blur kind of. However, i prefer anyway the color grading, so what.

[Hydrawerk]

B) I doubt whether Dave will ever do a full review - he never went back and did one of the Rigol DS2000

Maybe because you did before him? Why not.

[marmad]

ehm you don't know how it is implemented on GDS in detail, me either. All i can see is that it works as it should when
set to color grading.

I know how any sane programmer would code it - but no, I don't know if they did it a different way than that - but possibly they did, given some of the stupid things they've done in the firmware. And if by, 'it works as it should' you mean it displays colors - yes, you're right, it does  - but in the video it looks coarsely done to me - as does the intensity grading. Again, it might just be that Dave has things set incorrectly - I don't know - but it would be nice to see it demonstrated more.

I don't give a shit if there is acceleration or 20 knobs and 6 buttons for super fine intensity on Rigol - all i need to see is there on video - meaning how long it takes and what he is doing.

I guess you don't have to give a shit because you're full of it. Dave is clearly PLAYING with the intensity setting on the Rigol during those 33 seconds of video - turning it up and down, taking his hand from the knob, then turning it up and down again, etc. - to demonstrate the grading for the camera. Then you post this ridiculous shit about those 33 seconds:

...and i can clearly see that on Rigol you need to turn the knob for an hour ^^ to get from min to max).

...when in reality, it takes exactly 3.5 rotations of the knob to get from minimum to maximum (you can do it in ~2 seconds).

[jahonen]

To me it looks like GDS-2000A is unable to do shading in "density"-fashion (something that velocity modulation of electron beam produces in analog oscilloscopes). That prevents it working for AM modulated signal. For example, I get the attached image with my Agilent MSO6034A when singleshotting an AM modulated signal. From advertisements, it looks like the shading/color-grading works only on subsequent sweeps.

Regards,
Janne