Choosing between entry-level 12-bit DSOs

[tggzzz]

typical strawman fallacy, taking my words out of context. didnt i use question mark? or words possibly/probably?  where did i mentioned "analogue scope"? or even comparing it with DSO? i know the article is about why you should not use breadboard... which to some of us is pretty invalid anyway, just because of one FU scenario. but my highlight is on BW limited scope demonstrated in the article, not really anything to do with the main topic specifically.

Good to see you acknowledge the misrepresentation, even if you don't mention why you decided to do it.

If you specifically mention "DSOs" rather than "scopes", presumably you think the digitisation is important and relevant. It isn't - as I clearly stated in the article.

Why not address the other points I made? On second thoughts, don't; they are too off topic and I doubt anybody will be interested.

If you make something difficult to read then you shouldn't be surprised if people can't work out what you are trying to say. I suggest you reread at least the first post in a thread that was so timely and pointed that it became "sticky" stunningly quickly: https://www.eevblog.com/forum/beginners/why-writing-style-and-grammar-matters-in-posts/

[vk6zgo]

It's not (only) a bandwidth issue. It's the failure to interpolate the sample data points correctly.

EDIT: Rephrased the question.

@shapirus, assume that you probe an almost ideal square wave and a scope would show you either figure7 or figure8.
Which one would you prefer subjectively? [ I'll explain the difference later in order to get an unbiased vote. ]

Neither pictures are correct. They both show Gibbs ears which do not exist in the real world. If you want to prevent seeing Gibbs ears, you need to use extra bandwidth limiting so the sin x/x   reconstruction does not add the Gibbs ears. IOW, for the best view of a square wave you need to bandwidth limit it in respect to the oscilloscope's bandwidth.

Actually, they do, & analog 'scopes also see them.

The group delay for all frequencies which make up the transition varies with real world systems, so they are displaced in time, & some frequency components are time delayed enough w.r.t. others that they produce both overshoots & undershoots.

When we were using older BW type TV transmitters to transmit PAL colour TV signals, we used a sin ^2 pulse & bar to check for such problems, (within a limited bandwidth, this was much more useful than a squarewave).
We had a magic device called a transversal equaliser, which was used to shift the overshoots & undershoots around to fit the specification.
It was a very complex adjustable filter network, & was a pig to adjust.

[bdunham7]

What's your opinion between the two again? 😉

We're only 31 pages into the discussion--it's too early for conclusions. 

[vk6zgo]

This is why most DSOs have a "Default" button that completely (almost, anyway) restores the scope to an original configuration.  I use it routinely when I can't remember what I was using the scope for last and just want to start over.  This prevents me missing something like having turned up the holdoff time that won't immediately be obvious but might cause some issues.

I must admit to being lazy, and occasionally using the "beam find" button 

"Real" 'scopes don't need no steenkin' "beam find" button!

[tggzzz]

This is why most DSOs have a "Default" button that completely (almost, anyway) restores the scope to an original configuration.  I use it routinely when I can't remember what I was using the scope for last and just want to start over.  This prevents me missing something like having turned up the holdoff time that won't immediately be obvious but might cause some issues.

I must admit to being lazy, and occasionally using the "beam find" button 

"Real" 'scopes engineers don't need no steenkin' "beam find" button!

FTFY

My highest bandwidth scope, a truly strange and wonderful beast, doesn't have a beam find button.

It does have a "samples/cm" control in addition to the normal "time/cm" control, plus a "time magnification" control with a range of 1-100. It also has 200MHz BC107 transistors in the signal chain and a 1.7GHz bandwidth. And GR874 connectors, presumably because they thought that era's BNC connectors/cables weren't good enough for 2GHz.

I ought to do a thread on it, mainly to unsettle some of the more, um, traditional people here 

[vk6zgo]

Have you been paying attention to all the discussions in this thread about the theory and practice of sampling?

In general there are many significant erroneous beliefs about sampling, held by far too many people - beginners and professionals alike.

Sampling is not an easy topic to understand; at one of my previous employers we used a very simple question to weed out those that understood it from those that thought they understood it.

I am happy to report that I do not misunderstand it. I simply don't understand it at all! But I'm learning ...

My attitude is "Bah! Humbug!" It's just mixing in drag! 

But then again, RF people see mixers everywhere!

[tggzzz]

Have you been paying attention to all the discussions in this thread about the theory and practice of sampling?

In general there are many significant erroneous beliefs about sampling, held by far too many people - beginners and professionals alike.

Sampling is not an easy topic to understand; at one of my previous employers we used a very simple question to weed out those that understood it from those that thought they understood it.

I am happy to report that I do not misunderstand it. I simply don't understand it at all! But I'm learning ...

My attitude is "Bah! Humbug!" It's just mixing in drag! 

But then again, RF people see mixers everywhere!

Yes, I've gradually learned the wisdom of that fact and the observation of the fact!

Multiplication rulez

[wasedadoc]

When we were using older BW type TV transmitters to transmit PAL colour TV signals, we used a sin ^2 pulse & bar to check for such problems, (within a limited bandwidth, this was much more useful than a squarewave).
We had a magic device called a transversal equaliser, which was used to shift the overshoots & undershoots around to fit the specification.
It was a very complex adjustable filter network, & was a pig to adjust.

In the lab where 'pulse and bar' was invented we called those equalisers 'fairy fingers boxes'.

[KungFuJosh]

What's your opinion between the two again? 😉

We're only 31 pages into the discussion--it's too early for conclusions. 

Only 16 pages into the discussion with my settings. 😉

We've got to be at least half way there, then Martin can share what he already knows. 🤣

[vk6zgo]

When we were using older BW type TV transmitters to transmit PAL colour TV signals, we used a sin ^2 pulse & bar to check for such problems, (within a limited bandwidth, this was much more useful than a squarewave).
We had a magic device called a transversal equaliser, which was used to shift the overshoots & undershoots around to fit the specification.
It was a very complex adjustable filter network, & was a pig to adjust.

In the lab where 'pulse and bar' was invented we called those equalisers 'fairy fingers boxes'.

In the wonderful world of vestigial sideband transmission & reception, they were worth their weight in gold, back in the days of Marconi & AWA high level modulated beasts, as were the other, equally messy tweakers for "Differential Phase & Gain".

Along came the next generation, which were, in the main, NEC low level modulated Tx, & all those wonderful devices were retired.
The NECs were that good that you could receive them, chuck 'em together, install them test them & the results would be "near as dammit" to what NEC got at the factory on their pre-delivery tests.

The LGT ones, were, let's say, not so good, but still had all the tweaks built in.

[Mechatrommer]

I must admit to being lazy, and occasionally using the "beam find" button 

"Real" 'scopes don't need no steenkin' "beam find" button!

at least now i know he got sense of humor.. maybe earlier talk about rigol gui being like ancient egyptian hygrogliphs and too much tools in a toolbix being bad was only meant as a joke... and err, the 'breadboard is bad due to 'purposedly excessive' parasitics inductance' too is a joke that i mistakenly interpreted as seriously written article..

[Harrow]

What if someone wanted to go one better than the DHO800/900 or SDS800X? What would be the best choice for the next step up?

[Grandchuck]

https://siglentna.com/digital-oscilloscopes/sds1000x-hd-digital-storage-oscilloscope/

[BillyO]

What if someone wanted to go one better than the DHO800/900 or SDS800X? What would be the best choice for the next step up?

What do you need most?  Vertical resolution (1) or bandwidth (2)?

1) SDS1000X-HD

2) SDS2000X-P

[tautech]

What if someone wanted to go one better than the DHO800/900 or SDS800X? What would be the best choice for the next step up?

So so many things might decide which, display size, mem depth, sampling rate (single or all channels active) and a myriad of other features available beyond entry level DSO's.
And of course budget.

Now we have had a small range of the X HD models on the bench while doing PD checks, SDS1000X HD models are quite nice to use especially with the uprated knobs that offer a quite nice feel however that is of course subjective as others might prefer a different style.
With their 10" display the top ribbon menu layout is the same as the more upmarket models and larger too which makes for a better touch experience......not that we leave fingerprints on the display of a new DSO when we can use a mouse instead. 

[Antonio90]

What if someone wanted to go one better than the DHO800/900 or SDS800X? What would be the best choice for the next step up?

The feature set of the 800X-HD is virtually identical to the 1000X-HD. The latter is just much nicer AFAIK. Better ADCs (EDIT: I thought that was the case, seems it isn't), screen, encoders and build quality. The 50R input path is integrated and it has more USB ports. It's a bit like a thinkpad (the older models) vs a regular laptop.
The 2000X-Plus is just higher class. Twice the memory, bandwidth, sample rate, true MSO, AWG, better timebase... But older, a bit slower in general and not 12 bits.
The "real" next step is the 2000X-HD, but it's a leap in price.

[rf-loop]

What if someone wanted to go one better than the DHO800/900 or SDS800X? What would be the best choice for the next step up?

The feature set of the 800X-HD is virtually identical to the 1000X-HD. The latter is just much nicer AFAIK. Better ADCs, screen, encoders and build quality. The 50R input path is integrated and it has more USB ports.

It would be nice if you explain what facts this claim of better ADC's is based on.

Since quite often beliefs start to spread as truths and take on a life of their own, it would be good to mention what the claim is based on, unless it, or the information referring to it, appears in a public datasheet.

[Antonio90]

What if someone wanted to go one better than the DHO800/900 or SDS800X? What would be the best choice for the next step up?

The feature set of the 800X-HD is virtually identical to the 1000X-HD. The latter is just much nicer AFAIK. Better ADCs, screen, encoders and build quality. The 50R input path is integrated and it has more USB ports.

It would be nice if you explain what facts this claim of better ADC's is based on.

Since quite often beliefs start to spread as truths and take on a life of their own, it would be good to mention what the claim is based on, unless it, or the information referring to it, appears in a public datasheet.

Hello Rf-loop,
I don't know. I thought the 800X-HD had a lower-end ADC and it was shown on a teardown. I cannot find it, and I might have wrongly inferred it. I was "sure" it was the ADC12D500, and the 1000X-HD had the ADC12D1000, like the 2000X-HD.
In any case, the claim is baseless.
¿Could you confirm the 800X-HD also has two ADC12D1000?
I will edit my post removing the claim in any case.

[Martin72]

Hi,
You may have had this in mind:

https://www.eevblog.com/forum/testgear/siglent-new-sds800x-hd-first-bactch-unboxing-and-noise-compare-with-dho800/msg5248878/#msg5248878
Although a teardown, it was not clarified which ADCs are used.

[Antonio90]

Yes, that had to be it. If the 800X-HD has the same ADC, well, I don't know how Siglent managed to fit the whole package and features on €409.

[tautech]

Defpom SDS814X HD teardown:

https://youtu.be/XLC1CPWznTE?t=217

[Martin72]

Doesn't help the matter either.

[mawyatt]

What if someone wanted to go one better than the DHO800/900 or SDS800X? What would be the best choice for the next step up?

The feature set of the 800X-HD is virtually identical to the 1000X-HD. The latter is just much nicer AFAIK. Better ADCs, screen, encoders and build quality. The 50R input path is integrated and it has more USB ports.

It would be nice if you explain what facts this claim of better ADC's is based on.

Since quite often beliefs start to spread as truths and take on a life of their own, it would be good to mention what the claim is based on, unless it, or the information referring to it, appears in a public datasheet.

Hello Rf-loop,
I don't know. I thought the 800X-HD had a lower-end ADC and it was shown on a teardown. I cannot find it, and I might have wrongly inferred it. I was "sure" it was the ADC12D500, and the 1000X-HD had the ADC12D1000, like the 2000X-HD.
In any case, the claim is baseless.
¿Could you confirm the 800X-HD also has two ADC12D1000?
I will edit my post removing the claim in any case.

Mouser has the ADC12D1000 @ $1000 each, as mentioned above by Antonio90 how can Siglent sell the SDS800X HD at the price point they offer 

Suspect Siglent has a agreement with all the line up of TI related IC products and gets a really good deal from them, otherwise they'd be heading for Bankruptcy 

Best,

[tautech]

Mouser has the ADC12D1000 @ $1000 each, as mentioned above by Antonio90 how can Siglent sell the SDS800X HD at the price point they offer 

Suspect Siglent has a agreement with all the line up of TI related IC products and gets a really good deal from them, otherwise they'd be heading for Bankruptcy 

Yeah well if we put 2 and 2 together I believe we have a simple answer.

Data points
Considerable reduction in cost of SDS2000X HD models
Introduction of SDS800X HD and SDS1000X HD

If and if they all use the same 12bit ADC, buy price is not each but by the 1000's or possibly 10k or even larger lots.
Mike, you of anyone will know how large orders of expensive IC's can dramatically reduce BOM costs.

It's all about quantity......

[mawyatt]

Mike, you of anyone will know how large orders of expensive IC's can dramatically reduce BOM costs.

It's all about quantity......

Exactly, but even so, selling a DSO of this calibre and maturity at this price point is like getting a Porsche for the price of a Kia

And we know what the Porsches cost

Best,