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

[Hydrawerk]

It seems that this scope GDS-2000A is the same case as Tektronix DPO2000 series. The update rate is quite good (6200 waveforms/s) up to 100ns/div, and then at 20ns/div it drops dramatically down to only 160 waveforms/s.

How are you drawing that conclusion?  We don't have any numbers other than their "ideal" at this point.

According to the setting that I had in this video... But it is not a conclusion, it's only a hypothesis.

[icon]

It seems that this scope GDS-2000A is the same case as Tektronix DPO2000 series. The update rate is quite good (6200 waveforms/s) up to 100ns/div, and then at 20ns/div it drops dramatically down to only 160 waveforms/s.

Just to clarify, you're not saying that the GDS-2000A actually has comparable update rates to the Tek DPO2000, but that, like the Tek, there's a 'headline rate' (80k wfm/s, in the GDS-2000A's case) which rapidly (more rapidly than the Agilent) drops off as you move away from the optimum? Also, am I imagining things or does the Rigol DS2000 do a similar thing? I'm sure I saw a table somewhere, but I can't find it now.

Isn't it fun playing oscilloscope Top Trumps?

Cheers
John

[marmad]

Just to clarify, you're not saying that the GDS-2000A actually has comparable update rates to the Tek DPO2000, but that, like the Tek, there's a 'headline rate' (80k wfm/s, in the GDS-2000A's case) which rapidly (more rapidly than the Agilent) drops off as you move away from the optimum? Also, am I imagining things or does the Rigol DS2000 do a similar thing? I'm sure I saw a table somewhere, but I can't find it now.

Hi John,

Sure, all scopes have a wfrm/s rate that changes - always dropping towards the slower timebases because of the limiting factor of time: e.g. at 1ms/div, assuming the display is 10 divs, each sweep is 10ms - meaning the absolute maximum rate possible (with an impossible 0% dead time) is 100 waveforms per second. At the upper timebases, it appears that most DSOs (aside from the Agilent X series with their new ASICs) have a peak setting - and then begin to drop again to the smallest timebase setting. As far as the GDS-2000A series goes, we have no hard evidence of what it does in any range - except Instek's own demonstrations which appear to make it clear that it's peak setting is at 500ns/div.

[Hydrawerk]

Just to clarify, you're not saying that the GDS-2000A actually has comparable update rates to the Tek DPO2000, but that, like the Tek, there's a 'headline rate' (80k wfm/s, in the GDS-2000A's case) which rapidly (more rapidly than the Agilent) drops off as you move away from the optimum?

Yes, the top waveform update rate of GDS-2000A is better than Tek DPO2000.
Here is the waveform update rate as measured by marmad. It also drops down at shorter timebase settings, but it is although quite good.

Here are the results of a quick test I did measuring the Rigol DS2072 waveform update rates at all timebase settings and memory depths (also attached in Excel format). If you compare these to the Agilent 2000X series published rates, it's obvious the Agilent is the clear winner - although it doesn't have anything close to the possible memory depths.

Single channel - 1MHz square wave to Channel 1 - Trigger Out to frequency counter. I took best-case rate when it was fluctuating:

	14kPts	140kPts	1.4MPts	14MPts	56MPts
5ns	15,000	13,150	1,412	142	36
10ns	9,400	9,400	1,412	142	36
20ns	50,012	13,515	1,416	142	36
50ns	25,003	13,515	1,416	142	36
100ns	17,859	13,159	1,412	142	36
200ns	11,365	11,360	1,408	142	36
500ns	5,434	5,435	1,336	142	36
1us	5,263	2,890	1,126	139	35
2us	5,054	1,506	846	133	35
5us	4,425	1,176	733	130	35
10us	3,789	1,157	720	130	35
20us	2,945	992	442	117	34
50us	1,326	639	414	114	34
100us	683	421	306	94	32
200us	347	245	200	69	28
500us	140	109	97	39	21
1ms	70	56	52	29	15
2ms	35	29	27	19	10
5ms	~14	~13	~11	~9	~6
10ms	~7	~6	~6	~5	~3
20ms	~4	~4	~3	~3	~2
50ms	~2	~1	~1	~1	~1
100ms	~1	~1	~1	~1	~1

https://www.eevblog.com/forum/testgear/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/30/

[grego]

I've made a command decision and I will be getting the 2204A. My reasoning is price/performance.

I actually just got off the phone with the regional sales manager here in the US (a nice gent named Frank Paz) in Chino, CA.  I had a couple of questions for him which he answered satisfactorily to me.

1. Where is it serviced if there is a problem?

It's actually serviced here in the States.  They have a repair facility in Chino, CA to handle service.

2. If it needs recal where does it have to go?

Again, their US service facility will handle the recal. Negative for them is the recommended annual recal vs Agilents 2 or 3 year cycle but whatever. It's done here in the US and has a 2 week turnaround.

3.  CAN decode.

As I mentioned earlier its in their next firmware update I believe. Either way its coming and it's not an addon. I actually use this so it's kind of important if I have a LA that it can do CAN.

4.  Fine vertical (or lack thereof)

This is on their firmware roadmap with no scheduled release date.  Frank mentioned he had just heard back from the factory from my earlier query about this. Instek has a decent rep here in the US so I don't think he's blowing smoke up my ass. Then again there's no release date scheduled so it could be tomorrow or 2 years from now.  Not a deal breaker though.

From tequipment.net I can get this for $1765 and add in the LA a little later after I mess with the scope.  That's $100 less than the best price listed for then 2000x used on eBay, and when you add in all the upgrades for the Agilent to bring it to par with the Instek it's a significant amount (memory upgrade, segmented memory, decodes, etc).

Stay tuned.

Greg

[marmad]

I've made a command decision and I will be getting the 2204A. My reasoning is price/performance.

Good for you, Greg - early adopters rule!    I'm looking forward to hearing about it, and I hope you'll consider doing some kind of review here.

[tequipment]

If you want EEVblog price for this GDS unit drop me an email, salesteam@tequipment.net  Ref the EEVblog and me, Evan Cirelli.
I will authorize a discount.

One again everything thanks for the business.

Evan Cirelli

Vice President of TEquipment.NET

[dr.diesel]

If you want EEVblog price for this GDS unit drop me an email, salesteam@tequipment.net  Ref the EEVblog and me, Evan Cirelli.
I will authorize a discount.

One again everything thanks for the business.

Evan Cirelli

Vice President of TEquipment.NET

Does this apply to other manufactures as well?

[tequipment]

Yeah for the most part.  I think I am going to set up a EEBlog coupon or discount.  In the future we can give EEBlog pricing as a login but for now email us for a quote. 

I want to be as honest and open with you guys as possible with pricing.  We want your business.

Thanks
Evan

[dr.diesel]

Yeah for the most part.  I think I am going to set up a EEBlog coupon or discount.  In the future we can give EEBlog pricing as a login but for now email us for a quote. 

I want to be as honest and open with you guys as possible with pricing.  We want your business.

Thanks
Evan

You are my new best friend!   

[marmad]

While looking through the manual carefully, I noticed something which is buried in there (page 110):

The 2MPts of sample memory are only usable in single channel - single trigger mode (or as segments). When using normal/auto triggered modes, it's 1MPt for a single channel - or 500k when using 2 channels.

Granted, 1M/500k is adequate for most tasks so it's not necessarily a problem. It's just that GW-Instek perhaps should make this a little more clear in documents/adverts for the DSO - otherwise it seems slightly disingenuous.

[Hydrawerk]

Someone should measure the waveform update rate for more timebase settings. I am afraid it will be worse than Rigol DS2000. 

[grego]

Someone should measure the waveform update rate for more timebase settings. I am afraid it will be worse than Rigol DS2000. 

It's not.

http://www.ittsb.eu/GDS-2102A%20Wfms%20measurments.html

Just use table 3 as your data as we're discussing the validity of the other 2 tables.

[Hydrawerk]

Thanks for the link. http://www.ittsb.eu/GDS-2102A%20Wfms%20measurments.html The Trig Out is quite weird, but it might not be a problem... Unless you want to use it synchronise another instrument... It should be like 0...5V signal.

c) The Trigger-Out has an voltage range not higher than 200 mV AC, which varies significantly depending the time base of the scope and usually ranges from 120 mV to 5 mV and even less than that.
The only multimeter which had the proper sensitivity as frequency counter due their low mV range, plus the Min/Max/Average function, is the U1270A Series.
(...) 3) Avoid using a multimeter if possible, very few are capable for this task, if you have a sensitive and fast dedicated frequency counter capable for 4-5 measurements at the 100 KHz range … Use it.

What? Marmad used his multimeter to measure waveform update rate of his Rigol DS2000 and it was OK. http://youtu.be/gAY1GQEjrfc?t=2m51s

[marmad]

What? Marmad used his multimeter to measure waveform update rate of his Rigol DS2000 and it was OK.

Well, I can't find any specifications from either Rigol or GW-Instek about what the levels are for their Trigger Output terminals on those DSOs. I wonder if they might be optically-coupled, requiring a pull-up resistor to get a decent higher level voltage. But in any case, my Fluke 87 III doesn't seem to have much trouble reading the Rigol's output.

[Hydrawerk]

Rigol doesn't specify the Trigger output level, but it will be maybe 0 to 5V?
At Agilent it is like this:

[Hydrawerk]

At a normal /non GW Instek/ scope it is no problem to measure the Trig Out with a low-end counter or multimeter... You've probably seen this my video.

[marmad]

c) The Trigger-Out has an voltage range not higher than 200 mV AC, which varies significantly depending the time base of the scope and usually ranges from 120 mV to 5 mV and even less than that.

Just measured the Rigol and it appears to have a Trigger Out voltage level of ~3.5V DC into 1M; ~1.5V into 50 Ohm.

[grego]

Well it's moot for me now.  I just finished ordering mine from tequipment.net -- great pricing.

I should have it in my grubby little hands by the middle of next week.

[marmad]

I should have it in my grubby little hands by the middle of next week.

Well, if you dare take it apart, I'm sure there are loads of members who'd love to see what's inside 

[Hydrawerk]

Just measured the Rigol and it appears to have a Trigger Out voltage level of ~3.5V DC into 1M; ~1.5V into 50 Ohm.

That's how it should be. I suspect that there is a hardware bug in early batch of GDS-2000A. The manufacturer knows it. The Taiwanese businessman at the trade fair told me not to use a multimeter to measure the Trig Out.
I will not buy any GW Instek product, because the company has no subsidiary in Europe.  Are you from USA, grego? Then it's OK. The scope is nice and feature rich. Suitable for those who need the mask pass/fail test.

[marmad]

Well, I like the feature set of the Instek - especially some things sorely missing from the DS2000. But I don't care about the expandability because I would never buy any of that stuff (I like a separate LA and AWG). I definitely prefer the design and interface of the Rigol by a large margin - even the type and method of displaying screen information, IMO, is better on the Rigol (the GW-Instek doesn't even show you the sample rate on the screen). And I love the low-noise 500uV front end and large memory of the Rigol.  So I think if I was choosing 2-channels today, I would probably still go with the Rigol.

But as far as 4-channels goes, the GW-Instek is significantly cheaper than the DS4000 for a similar DSO - so it's much more attractive.

[grego]

Just measured the Rigol and it appears to have a Trigger Out voltage level of ~3.5V DC into 1M; ~1.5V into 50 Ohm.

That's how it should be. I suspect that there is a hardware bug in early batch of GDS-2000A. The manufacturer knows it. The Taiwanese businessman at the trade fair told me not to use a multimeter to measure the Trig Out.
I will not buy any GW Instek product, because the company has no subsidiary in Europe.  Are you from USA, grego? Then it's OK. The scope is nice and feature rich. Suitable for those who need the mask pass/fail test.

Yep.  I'm outside Chicago here in the US of A.

[Hydrawerk]

GDS-2000A has no High resolution mode, only 8 bit all the time.

[grego]

GDS-2000A has no High resolution mode, only 8 bit all the time.

Correct - that was a known for me.  Not a huge deal for me considering the other options that are of use to me.