Instek GDS-1062A micro review

[cyberfish]

First some background -
The Instek GDS-1062A is in the same price range (or slightly more expensive) as Rigol 1052E. On paper it looks better with 2M long memory that can be used at 1GS/s. Bandwidth is 60Mhz, and of course no 100MHz hack. Otherwise very similar!

It was released only a few months ago, so reviews are still few and far between. The only one I found was this -
http://welecw2000a.sourceforge.net/docs/Hardware/GW_Instek_GDS-1152A.pdf
for the 150MHz version. It has some high quality photos of the internals (I don't want to take mine apart yet).

The Instek appears to be of higher build quality compared to Rigol's
http://home.comcast.net/~ajawam1/rigol/RIGOL_DS1102E_GUTS.html

One interesting thing to note is that Rigol uses 5xAD9288-40 dual ADCs to get 1GS/s (overclocking from 40MHz to 100MHz), while Instek uses 4xAD9288-100 dual ADCs to get 1GS/s (overclocking from 100MHz to 125MHz).

From Digikey,
AD9288BSTZ-40 = $6.32
AD9288BSTZ-80 = $10.09
AD9288BSTZ-100 = $17.09

The total cost of the 4 ADCs Instek is using (17.09 x 4 = 68.36) is much higher than Rigol's 5 ADCs (6.32 x 5 = 31.6). This is for single quantities, but the ratio should be similar at high quantity. The 100MHz parts cost almost 3 times as much as the 40MHz parts. We don't know what's the impact of this difference.

Now fast forward to yesterday... (most parts are copied and pasted from this thread https://www.eevblog.com/forum/index.php?topic=1189.15)

Just got my GDS-1062A. Have only been playing with it, and probing some few hundred kHz UART signal.

No major (or minor) complaints so far. I'm pretty happy with it, but then I don't have anything to compare it to (except the Tektronix in school lab).

Scrolling is smooth. Tried different time bases, etc. No noticeable lag any time.

I want to test it out for future potential buyers' benefit, but don't really know how. And I don't have a signal generator (I do have MCUs, passive components, diodes, transistors, common chips, etc). Any suggestions? I don't even have something that can generate short enough rise time to test the bandwidth!

Just a note before I forget - Yes, 1GS/s can be used with 2M long memory mode. 100us is the maximum timebase for 1GS/s (2ms recorded). It switches to 500MS/s at 250us.

For equivalent time sampling -
25ns -> 1GS/s
10ns -> 2.5GS/s
5ns -> 5GS/s
2.5ns -> 10GS/s
1ns (min) -> 25GS/s

So when the manual says the long memory cannot be used at <25ns, it just means it cannot be used with ETS. So yes, it is better than Rigol in this regard (1GS/s with 2M).

At 1x probe, DC coupling, averaging off, 1Gsps, probe shorted to ground clip, 2mV/div, 1ms/div, I am getting
Vavg = -117uV, Vp-p = 400uV
If that means anything (I'm curious. Anyone want to do the same on Rigol and see what you get?). PS. tried aluminum foil grounding with same result

Interestingly, if I switch to ground coupling, Vavg becomes 89.1uV, and Vp-p = 0.

From joelby:

The DS1102E registers Vavg 360uV, Vpp 2.00mV, which does seem a bit noisier than yours.

A comment from mojo-chan

I have an Instek with 2M memory and it is excellent.

One thing to watch with long memory scopes is how they display the waveform when zoomed out. The Rigol ones, and apparently even some older Tektronix models, only show one sample per pixel. In other words they show every nth sample of the waveform. The better ones, such as the Instek or newer Tektronix, are a bit cleverer. They show the maximum and minimum samples in the range covered by each pixel.

In practical terms what that means is that is that it is much easier to find interesting events. Say you are looking for a voltage spike or an out-of-band sync signal (such as video sync which is 0.3v lower than the main video part). On a Rigol you have to pan through the waveform while zoomed in looking for it. On an Instek you can see it when zoomed right out and zero in on it very quickly.

I can confirm it on my Instek. If you have different levels in the same pixel's time, it becomes a strip from maximum to minimum.

As for the subjective things -
Build quality is good. Nothing filmsy. User interface is well laid out. Didn't notice any peculiar sequences needed to access any function.
Responsiveness is good when scrolling without math. No noticeable lag any time. With FFT it starts lagging noticeably at high time bases. Gets to about 2 frames per second.
Fan noise I don't know. I am in a room with 5 computers and probably 20 fans =) It sounds like jet engine.

From alm:

Some complaints I've heard about the Rigol are that triggering is not terribly stable (the wave always dances around slightly, even with a stable and noise-free signal) and that the measurements are based on the image on the screen, not the original signal. Things like bad accuracy compared to precision, and measurements that change depending on the vertical position on screen. Since I don't have a Rigol scope, I can't give you specific examples. It would be useful to know if the Instek scope has the same issues.

1. Measurements are done on the actual data. I can still get the 1kHz frequency reading from the compensation output even if I zoom out to 100ms/div (becomes big yellow band).
2. I have no way of measuring accuracy, but vertical offset (tried from -30V to 30V) does not change the readings appreciably (on the compensation output).
3. Used soundcard to generate 8kHz, 2.3Vpp sine wave. Appears to trigger reliably. I put it on continuous trigger mode, and moved the trigger from peak to peak. Waveform display is always very stable, and trace is thin. Tried manual triggering a few times, too. All images look identical.

Conclusion
From my very limited experience with the GDS-1062A, I believe it's well worth the extra $70 or so I paid for it. Main advantages are faster and deeper memory, higher build quality, and better firmware (and maybe analog frontend/triggering).

EDIT:
Another thing I noticed -
The Rigol has 1 set of vertical controls (volts/div and offset) shared between the 2 channels. Instek has 1 set for each channel. Should be easier to use?

[slburris]

Where did you get your GDS-1062A from?  Teequipment.net or somewhere else?

Scott

[cyberfish]

I am in Canada so I got it from http://www.tradeport.on.ca/. I think they are Instek's representative in Canada or something, since they answered an email I sent to Instek.

I was thinking about Tequipment, too (they have lower price), but they have 1 month lead time for this scope, and warranty would be less convenient.

[cybergibbons]

Good review - I agree with pretty much everything there (for my GDS-1162A).

The zooming UI is the one thing the Rigol does a lot better, but I can live with it.

[cyberfish]

First very minor complaint -
The channels are coloured yellow and blue, yet the 2 probes come with red, blue, and black rings.

I like to have the ring colour match the channel colour, so I don't need to try to figure out which channel is which every time. The probes that came with Tektronix scopes do have yellow rings.

I guess it's attention to tiny details like this that sets the big brands apart from these Asian brands.

Still very satisfied with the scope, though. Measured a few different things (UART signal, low frequency amplifiers, power supply ripple, and some audio frequency stuff from my soundcard). Everything works perfectly so far.

[Bored@Work]

Are you sure you got original Instek GTP-060A-4 probes? http://www.gwinstek.com/en/product/productdetail.aspx?pid=40&mid=171&id=265

[Mechatrommer]

I like to have the ring colour match the channel colour, so I don't need to try to figure out which channel is which every time. The probes that came with Tektronix scopes do have yellow rings.
I guess it's attention to tiny details like this that sets the big brands apart from these Asian brands.

Why keep blaming Asian? if you judge only base on that, then Rigol (Asian) will be at the same par as Textronix (or even better), since they got plenty of this yellow and blue rings, even better they got pink rings which i'm still trying to figure out for what? Think global, not local. and you are competing a jet with a car and keep complaining how shitty the car is.

[Kiriakos-GR]

Well I am blaming the Westerners for an change ... some of them they have not even learn,
how to use an digital camera ... and post pictures ..  

[TheWelly888]

I'm choosing between the Instek GDS1102A ( 100MHz BW ) and the GDS1152A ( 150MHz ) scopes.

They both have the same sample rates but I vaguely remember our Dave suggesting that one should get DSOs with a sample rate of at least 10x the bandwidth of the scope so should I avoid the 150MHz one that ground alone?

Edited to add: I've just read the sourceforge link mentioned above and the reviewer appear to think that the actual sample rate is 500Ms/s!? But the -3dB point of the scope's bandwidth is 173MHz by using a pure sine wave input.

[Mechatrommer]

why dont you just go with 200MHz? nice number... 2x 100MHz

[NiHaoMike]

The 10x is for the dominant fundamental. Your effective bandwidth is then 5x, which should be enough to capture up to the 5th harmonic. For most signals, that's enough to get a good view.
You only need twice the highest frequency in your signal to perfectly reconstruct it.

And then there's equivalent time sampling, a trick that only works with repeating signals.

[cyberfish]

Are you sure you got original Instek GTP-060A-4 probes? http://www.gwinstek.com/en/product/productdetail.aspx?pid=40&mid=171&id=265

Yeap. That's what it says on the 2 little bags the 2 probes come in. There are yellow and green rings in that picture, but no red. A new revision maybe?

Why keep blaming Asian? if you judge only base on that, then Rigol (Asian) will be at the same par as Textronix (or even better), since they got plenty of this yellow and blue rings, even better they got pink rings which i'm still trying to figure out for what? Think global, not local. and you are competing a jet with a car and keep complaining how shitty the car is.

Sorry I wasn't clear. What I really meant is, that's the difference between major oscilloscope brands and small brands. It just happens that all the major brands right now are Western, and all the small brands right now are Asian. Hence the (incorrect) generalization.

I feel like I can blame Asians and Asian qualities for everything because I am Asian myself and my family owns a manufacturing business in Taiwan . Truth is, in general, quality of Asian products cannot match that of Western products, yet. It has to do with values and cultures. When you make US$100 a month, you develop a very different set of values than if you made US$10000. And it passes on. I've found the average income of a nation to largely correlate with the quality of products they produce, on average. That's why Taiwanese products tend to be of higher quality than mainland China's, but still inferior to those from Korea and Japan. When you make $100 a month, you want the things you buy to just work. You don't want someone to polish it up and charge you twice as much. Who needs build quality? Just use it carefully. Low income also makes clones and such much more appealing, so much that it becomes part of the culture (that thinks balant copying of everything is okay).

Well I am blaming the Westerns for an change ... some of them they have not even learn,
how to use an digital camera ... and post pictures ..  

You'll have to go find a Westerner elsewhere .

And the reason why I didn't post pictures is because you can find higher quality pictures in many other places. Instek's site for example.

I'm choosing between the Instek GDS1102A ( 100MHz BW ) and the GDS1152A ( 150MHz ) scopes.

They both have the same sample rates but I vaguely remember our Dave suggesting that one should get DSOs with a sample rate of at least 10x the bandwidth of the scope so should I avoid the 150MHz one that ground alone?

Edited to add: I've just read the sourceforge link mentioned above and the reviewer appear to think that the actual sample rate is 500Ms/s!? But the -3dB point of the scope's bandwidth is 173MHz by using a pure sine wave input.

Sample rate doesn't have to be 10x the BW of the scope. It just has to be 10x the bandwidth of the highest frequency signal with rich harmonics (eg. square wave) that you want to see clearly. It all depends on what you want to see.

For a DSO, BW and sampling rate are pretty much independent. The 150MHz scope is better.

The total sample rate is 1GS/s. Or 500MS/s if you use 2 channels. You can use all 1GS/s for one channel if you disable the other one.

[Bored@Work]

Are you sure you got original Instek GTP-060A-4 probes? http://www.gwinstek.com/en/product/productdetail.aspx?pid=40&mid=171&id=265

Yeap. That's what it says on the 2 little bags the 2 probes come in. There are yellow and green rings in that picture, but no red. A new revision maybe?

Strange. You could ask Instek what is going on. In the past they had the order code PA-105 for a set of blue, pink, green and yellow rings, two each. If you can't get some from Instek, hopefully for free,  maybe the Tektronix 016-0633-00 clips fit ($7, which is of course a ripoff for a few grams of worthless plastic) .

[cyberfish]

Strange. You could ask Instek what is going on. In the past they had the order code PA-105 for a set of blue, pink, green and yellow rings, two each. If you can't get some from Instek, hopefully for free,  maybe the Tektronix 016-0633-00 clips fit ($7, which is of course a ripoff for a few grams of worthless plastic) .

I painted a pair yellow already .

[Mechatrommer]

Are you sure you got original Instek GTP-060A-4 probes? http://www.gwinstek.com/en/product/productdetail.aspx?pid=40&mid=171&id=265

I feel like I can blame Asians and Asian qualities for everything because I am Asian myself and my family owns a manufacturing business in Taiwan . Truth is, in general, quality of Asian products cannot match that of Western products, yet. It has to do with values and cultures. When you make US$100 a month, you develop a very different set of values than if you made US$10000. And it passes on. I've found the average income of a nation to largely correlate with the quality of products they produce, on average. That's why Taiwanese products tend to be of higher quality than mainland China's, but still inferior to those from Korea and Japan. When you make $100 a month, you want the things you buy to just work. You don't want someone to polish it up and charge you twice as much. Who needs build quality? Just use it carefully. Low income also makes clones and such much more appealing, so much that it becomes part of the culture (that thinks balant copying of everything is okay).

the culture, the quality, the income and finally the knowledge... that will depend on you brother, will depend on you. i cant blame you if you are hired, (ie not self employed). But remember, Asian is really a big peaces of lands and has some of the largest companies on earth eventhough not in Ee industry. if you specify China, then the scope will be much smaller. If you keep with the mindset that Asian is poor quality, then there will be no change for now, future and at anytime, esp for you.
most major (both western, eastern) companies have targetting most small and low income Asian countries to become their production plant due to low labor cost, but i think they hire one guy (probably pay him big money) just to ensure quality among the (cheap) workers.i'll call it exploitation. well, i can type more, but... thats it. Cheers

[cyberfish]

By Asia, I really mean the less developed parts of it, ie. China and India. Japanese and Korean quality is just as good if not better than Western. Taiwan is somewhere in the middle.

That scale, curiously, reflects average income.

If you keep with the mindset that Asian is poor quality, then there will be no change for now, future and at anytime, esp for you.

I don't see how it concerns me, but anyways, denying inferiority is not the way to go forward. Admitting it and improving it is. If you go on to Chinese forums for example, you'll see that they do realize Chinese products are way inferior, and, in the case of oscilloscopes, recommend imported products for any serious work.

most major (both western, eastern) companies have targetting most small and low income Asian countries to become their production plant due to low labor cost, but i think they hire one guy (probably pay him big money) just to ensure quality among the (cheap) workers.

There is a difference between made-in-China and made-by-a-company-based-in-China, for precisely this reason.

[Mechatrommer]

There is a difference between made-in-China and made-by-a-company-based-in-China, for precisely this reason.

sorry if i misunderstood you. made-in-China and made-by-a-company-based-in-China still includes China people to work there (low level operators), and most probably Chinese work in Instek got the same salary as Chinese who work in Fluke (China Branch) if not less just by a bit. but the quality are different due to the way they treat their QC policy which mostly handled by higher level supervisors or engineers or managers. and which the Design (Fluke) comes from its Original (western) country but company based in China, as we cannot deny and must improve, "mostly inferior". So, its not the low income the workers get there makes the product inferior as you mentioned. That actually my point. Cheers

And when you mention Asia, you are talking about more than half the population of earth. If you be more specific, you just could save those 60% people who are innocent by stating only China (1/3rd of Asia). Cheers

[cyberfish]

sorry if i misunderstood you. made-in-China and made-by-a-company-based-in-China still includes China people to work there (low level operators), and most probably Chinese work in Instek got the same salary as Chinese who work in Fluke (China Branch) if not less just by a bit. but the quality are different due to the way they treat their QC policy which mostly handled by higher level supervisors or engineers or managers. and which the Design (Fluke) comes from its Original (western) country but company based in China, as we cannot deny and must improve, "mostly inferior". So, its not the low income the workers get there makes the product inferior as you mentioned. That actually my point. Cheers

That is exactly what I meant . It's not the workers that matter. It's the management level.

[Mechatrommer]

It has to do with values and cultures. When you make US$100 a month, you develop a very different set of values than if you made US$10000. And it passes on. I've found the average income of a nation to largely correlate with the quality of products they produce, on average. That's why Taiwanese products tend to be of higher quality than mainland China's, but still inferior to those from Korea and Japan. When you make $100 a month, you want the things you buy to just work. You don't want someone to polish it up and charge you twice as much. Who needs build quality? Just use it carefully. Low income also makes clones and such much more appealing, so much that it becomes part of the culture (that thinks balant copying of everything is okay).

i agree with the "different value and culture". from my experience as a "underpaid freelance photographer" maybe the point is, we seldomly find people who realy cares about quality, most people care most on the price, most of them couldnt afford Tektronix quality and price. Thats why maybe for Instek, their main target is just for these abundant of hobbiest and normal users, but for brand like Tektronix, their target is to these "very seldom" professional geeks with load of money. Thats the thing that make them apart. And i think it is intentional for the survival of their business. So for your case, its one of the unlucky consequences that you got the whole black rings, they maybe have missed it due to less number of workers less paid etc.

Its must be pointed out that due to the difference in "value and culture" in politics and economy of Asia, that cause this inferiority. Not that we are that stupid to intentionally miss the yellow and blue rings. We can do it, we can do better, but our environment just doesnt support it. Cheers

[Bored@Work]

You know, the fun and ideological "different values and cultures" stops when outright dangerous devices, with faked safety marks, are produced. There is a level of not caring for quality from where it starts to become criminal. Do not excuse delivering deadly devices as being a cultural thing.

[Mechatrommer]

maybe they got their own version of "By Law" or "Standard" Manual.

[blackdog]

Hi,
For you Girls en Guys who want to test there scope, build a scope tester!!
Follow this link => http://www.hamforum.nl/viewtopic.php?f=50&t=1384&p=5473#p5473
It is build with low cost components and the origional is from Tektronics... 

It wil be my next evening project, and YES Kiriakos, i will make some pictures 

Regarts,
Bram

[cybergibbons]

Mine came with blue, yellow, black, red and green rings.

[cyberfish]

Good to know they fixed that.

Mine was probably old stock then (they have a stock in Canada because they need to be modified to comply with Canadian regulations or something).

[sonicj]

For you Girls en Guys who want to test there scope, build a scope tester!!
Follow this link => http://www.hamforum.nl/viewtopic.php?f=50&t=1384&p=5473#p5473
It is build with low cost components and the origional is from Tektronics... 

cool!