Test Equipment Anonymous (TEA) group therapy thread

[med6753]

Let me throw something out for discussion....

I have a fixed (5Khz, .5V p-p) Sine wave that I use as a quick check of scope function. It has a very small glitch on it. On the 2465 it shows up clearly, even with the scope set to 20Mhz bandwidth limit. (Pix 1). Now look at the Siglent DSO. (Pix 2) Do you see it? Yes, because you KNOW it's there. If you didn't know it you wouldn't have a clue. Granted, the Siglent is an entry level DSO with a somewhat limited sample rate. So maybe I'm comparing apples to oranges. But to me this gives the advantage to the CRO. Basically infinite sample rate to see glitches.   

[bd139]

Try single shot it. Also the intensity grading and persistence on a DS1054Z would show that

You have amplifier slew rate limitations instead of sample rate limitations.

Edit: an example - here's a particularly shitty unstable RF amplifier I built. Note the spikes captured. These have a very low cycle count only:

[Specmaster]

I know what you mean about watches, personally I would not grace my wrist with an Omega, Rolex or a Breitling for that matter, they would be sold, simple as that. I have had my fill of the el cheapo watches made from base metals that crumble away to nothing while your wearing them due to sweat causing them to corrode, also had my fill of the Casio's of the type you mention.


These days its Citizen or its cousin, Accurist that I wear, Citizen because of the Eco-drive and SS material used for the case, means that I have a watch that will last and last, not need batteries or servicing and will not corrode while I'm wearing it and is super accurate being as they claim, accurate to withing a few seconds per month, or in the case my radio controlled ones which are accurate to 1 second over 20 million years, don't cost the earth so I'm unlikely to be stabbed for them either so they are not really status pieces as the most expensive one I have costs only £700 new and the cheapest one I have cost me £20 so I'm safe. 


Now that thing in your pocket, if it happens to be one of the latest Apple products, on the hand could pose a possible threat to you as they are seen as status symbols , the logic behind it escapes me though, unlike a diamond encrusted solid 18ct gold Rolex which sends out all the wrong kind of messages

[bd139]

Citizen / Accurist are a good deal. They're functional over everything.

iPhone stopped being a status symbol years ago. Can get them on Tesco mobile. Mine's on giffnaff Literally crawling with them. The only status now is not having one with a broken screen

[Specmaster]

Quote from: med6753 on Today at 11:56:39 am

Let me throw something out for discussion....

I have a fixed (5Khz, .5V p-p) Sine wave that I use as a quick check of scope function. It has a very small glitch on it. On the 2465 it shows up clearly, even with the scope set to 20Mhz bandwidth limit. (Pix 1). Now look at the Siglent DSO. (Pix 2) Do you see it? Yes, because you KNOW it's there. If you didn't know it you wouldn't have a clue. Granted, the Siglent is an entry level DSO with a somewhat limited sample rate. So maybe I'm comparing apples to oranges. But to me this gives the advantage to the CRO. Basically infinite sample rate to see glitches.

To be fair to the Siglent, I think it has picked up the glitch but it is lost in the background noise. I believe it can be seen on the 3rd graticle line from the right and because CROs generally have a far lower noise level it is clearly visible.

[med6753]

Quote from: med6753 on Today at 11:56:39 am

Let me throw something out for discussion....

I have a fixed (5Khz, .5V p-p) Sine wave that I use as a quick check of scope function. It has a very small glitch on it. On the 2465 it shows up clearly, even with the scope set to 20Mhz bandwidth limit. (Pix 1). Now look at the Siglent DSO. (Pix 2) Do you see it? Yes, because you KNOW it's there. If you didn't know it you wouldn't have a clue. Granted, the Siglent is an entry level DSO with a somewhat limited sample rate. So maybe I'm comparing apples to oranges. But to me this gives the advantage to the CRO. Basically infinite sample rate to see glitches.

To be fair to the Siglent, I think it has picked up the glitch but it is lost in the background noise. I believe it can be seen on the 3rd graticle line from the right and because CROs generally have a far lower noise level it is clearly visible.

Yep, that's it on the 3rd graticle from the upper right. But if I didn't show the 2465 first would you know that's a glitch? My point is no, you wouldn't because it is lost in the noise. But I'll try single shot and see what happens...if I can figure this damn DSO out. This is my first DSO. Up until about 2 years ago I really knew nothing about them.

[tggzzz]

Please note I only said the interface of the 54600. The actual implementation is a different matter. Things have changed a lot since 1994. As with all gear you're looking at the abstraction of a problem, not the problem itself so you need to understand what happens between one and the other.

Perhaps that is a good place for the analogue scope; when you need to intimately understand the difference between input and eyeballs without delving into sampling theorem. You can model an analogue scope as a low pass filter.

There are, apparently, still as many "mere implementation" problems in low-end DSOs as there were 20 years ago.

The problem with the 54621 wasn't with the sampling theorem but with the "helpful" reconstrution done on the screen - it made the signal look far far worse than it was in reality. Turning off the reconstruction and the signal "magically improved" back to reality.

Of course all that shenanigans was (and is) buried deep in the menuing structure, so you would only find it if you knew what you were looking for. Beginners certainly wouldn't and (from experience) most engineers wouldn't either.

[tggzzz]

Quote from: med6753 on Today at 11:56:39 am

Let me throw something out for discussion....

I have a fixed (5Khz, .5V p-p) Sine wave that I use as a quick check of scope function. It has a very small glitch on it. On the 2465 it shows up clearly, even with the scope set to 20Mhz bandwidth limit. (Pix 1). Now look at the Siglent DSO. (Pix 2) Do you see it? Yes, because you KNOW it's there. If you didn't know it you wouldn't have a clue. Granted, the Siglent is an entry level DSO with a somewhat limited sample rate. So maybe I'm comparing apples to oranges. But to me this gives the advantage to the CRO. Basically infinite sample rate to see glitches.

To be fair to the Siglent, I think it has picked up the glitch but it is lost in the background noise. I believe it can be seen on the 3rd graticle line from the right and because CROs generally have a far lower noise level it is clearly visible.

Has the "quote" button stopped working in your browser? I can't be bothered to guess what you/med6573 are trying to say!

[tggzzz]

I have a fixed (5Khz, .5V p-p) Sine wave that I use as a quick check of scope function. It has a very small glitch on it. On the 2465 it shows up clearly, even with the scope set to 20Mhz bandwidth limit. (Pix 1). Now look at the Siglent DSO. (Pix 2) Do you see it? Yes, because you KNOW it's there. If you didn't know it you wouldn't have a clue. Granted, the Siglent is an entry level DSO with a somewhat limited sample rate. So maybe I'm comparing apples to oranges. But to me this gives the advantage to the CRO. Basically infinite sample rate to see glitches.

Indeed, but the problem isn't the sampling rate per se.

The problems are centred around the screen's resolution and the DAC's resolution.

Try delving deep into the menuing system to see if there is something like "peak display" or "high resolution" mode.

N.B. that's a problem in itself for teachers: each DSO can do similar things in several different ways - but they all call it something different and it is located somewhere different in the menuing system.

[bd139]

14 bit DAC does help on this. The very low resolution of the 8 bit scopes doesn’t give you a whole lot of dynamic range. Also when they apply averaging across several sweeps the DAC errors which are quite significant tend to mask smaller problems and glitches. One of the reasons I was looking at the higher end Keysight scopes actually.

Yes. I think it is important that teachers use the same kit across the board in these circumstances and actually understand it. When I was at university we just got some of the earlier Hp digital scopes and the students knew more about them and the limitations than the lab and tutors did. While people bitch about the longevity of the TI83 calculator, it’s the same problem.

Also it takes you months to learn and understand a piece of equipment before it becomes an extension of your mind and body. A lot of mistakes are made by not second guessing your assumptions about it up front.

[Specmaster]

Quote from: bd139 on Today at 12:13:59 pm

Citizen / Accurist are a good deal. They're functional over everything.

iPhone stopped being a status symbol years ago. Can get them on Tesco mobile. Mine's on giffnaff Literally crawling with them. The only status now is not having one with a broken screen

Yep, I've tried Lorus, Casio, Rotary (I have my fathers old watch which is a Rotary and very precious to me) but none of them hold a candle to Accurist/Citizen watches.

When it comes CRO/DSO I want both, if I could get an affordable DSO tomorrow, I would, just like my watches, the most accurate are the Atomic Controlled ones, but I also have 5 others that aren't radio controlled but still accurate to a few seconds a month.  I view them in the same way that I view a CRO and the Radio Controlled ones like a DSO 

Not so sure about Apple Phones and similar top end ones from other makers, there what these moped gangs start of with snatching from people who they have spied flashing them in public probably before graduating on to lightening raids in Jewelers, bastards.

[Specmaster]

N.B. that's a problem in itself for teachers: each DSO can do similar things in several different ways - but they all call it something different and it is located somewhere different in the menuing system.

Thats exactly right, not just for teachers though but for all users. Just as you get used to doing things in a certain manner with functions clearly assigned to a particular group of controls etc, along comes a newer model and hey presto, not only has the function been moved elsewhere but the method of implementing it has also been altered.

Can you imaging learning to drive and the car you learnt on had a conventional accelerator pedal but the new car you purchased had this foot pedal relocated  and in the process it had transformed into a hand operated control on the centre console??? What we need is a proper convention where controls are sort of standardized and extra new one could be also incorporated in a sensible co-orderinated fashion, then we would all gain something and could move onto newer ideas much quicker and feel at home with it. Its the man - machine interface thats a radical overhaul IMHO.

[tggzzz]

Quote from: bd139 on Today at 12:13:59 pm

Citizen / Accurist are a good deal. They're functional over everything.

iPhone stopped being a status symbol years ago. Can get them on Tesco mobile. Mine's on giffnaff Literally crawling with them. The only status now is not having one with a broken screen

Yep, I've tried Lorus, Casio, Rotary (I have my fathers old watch which is a Rotary and very precious to me) but none of them hold a candle to Accurist/Citizen watches.

When it comes CRO/DSO I want both, if I could get an affordable DSO tomorrow, I would, just like my watches, the most accurate are the Atomic Controlled ones, but I also have 5 others that aren't radio controlled but still accurate to a few seconds a month.  I view them in the same way that I view a CRO and the Radio Controlled ones like a DSO 

Not so sure about Apple Phones and similar top end ones from other makers, there what these moped gangs start of with snatching from people who they have spied flashing them in public probably before graduating on to lightening raids in Jewelers, bastards.

bd139 didn't write that! You are putting words into his keyboard.

[bd139]

He's only quoting badly due to the blockquote bug. Context is maintained by big gap

Regarding conventions: feature differentiation is done via breaking conventions. With conventions there is limited innovation possibility.

Regarding motorcycle theives: if I lose my phone to one, meh. I'd just buy another one. The real comms robbers here are the insurance companies who wouldn't pay out if it did get nicked. Up on their fees already. However if I see one in action I might accidentally flatten the fucker.

Currently disappointed because I bought salty popcorn instead of salt and sweet popcorn for lunch 

[Specmaster]

He's only quoting badly due to the blockquote bug. Context is maintained by big gap

Regarding conventions: feature differentiation is done via breaking conventions. With conventions there is limited innovation possibility.

Regarding motorcycle theives: if I lose my phone to one, meh. I'd just buy another one. The real comms robbers here are the insurance companies who wouldn't pay out if it did get nicked. Up on their fees already. However if I see one in action I might accidentally flatten the fucker.

Currently disappointed because I bought salty popcorn instead of salt and sweet popcorn for lunch 

Yeah, your spot on with the bug thing, switched off the Wysiwyg option, it sucks. At the end of the day it is the insurance companies that are in the main the biggest robbers out there, next to the banks.

As to innovation, it can still be done by following certain conventions in the control layout. Are the basic controls of a Fiat or Skoda any different to those on a Rolls Royce or Aston Martin, you or I could trade up and be able to drive them away and slowly learn the other features as we go.

From mobile device so predictive text might have struck again [emoji83]

[tggzzz]

... switched off the Wysiwyg option, it sucks....

Now there's a statement that is true in a much wider context

[bd139]

I couldn't agree more. LaTeX FTW.

[med6753]

Tried single shot. Unless I'm doing something wrong made no difference.

Here's a capture using the Siglent Easy Scope program. The glitch is right at the top on the center. As you can see...if the 2465 didn't tell you what is actually there you wouldn't know it.

[PA0PBZ]

Here's a capture using the Siglent Easy Scope program. The glitch is right at the top on the center. As you can see...if the 2465 didn't tell you what is actually there you wouldn't know it.

The amplitude of the glitch is about 4mV, the screenshow has 50mV per division, so the glitch is about 1/12th of a division. Seems right...?

[med6753]

As I said before.....DSO's are a new animal to me. I did some more playing around and I got the glitch.

[mnementh]

Tautech, I skimmed over Defpom's video on your 1202X-E; I like it overall.

While it does appear quite responsive, I don't see a lot of difference in the usability of the UI vs my 1054Z. I really only notice responsiveness issues on mine when I'm working with multiple signals and decoding; for the usual daily driver stuff, it's pretty much right there with me. For folks who need the extra BW, your 1202X-E is clearly a better choice in this price range; but I think part of what makes it more responsive is it only has to contend with 2 channels and 10K less memory depth. For most of what I need a DSO for, 4 channels is a minimum and I sometimes still wind up dragging out the Salae and my tablet.

So it's nice to have a choice in the bottom bracket, depending on what your primary needs are.


Cheers,


mnem
*Toddles off to ded*

We thought the 1202X-E was pretty neat when it came out in April last year and as an entry level unit it was a big step forward on what Siglent had produced in this class before. However the new 4ch X-E's blow them out of the water in terms of capability by virtue really only of much more added functionality. Some of this is stuff many might not need but it's there should you do so these new 4ch  X-E's are a DSO that you can really grow into.

But back to the 1202X-E for a mo....Dave got sent one of the very first and it was a 1102X-E and Dave being Dave when he had it apart for the compulsory teardown decided it would be good form to eyeball the JTAG at boot where he logged it all for all to see and guess what, it was pretty simple to see it was of a series that was BW limited in the boot code. 
Siglent took one look at Dave's vid and then only released the top of the range 200 MHz model. 
The vid is #985 if you want to take a look.

So with another 8mths of development they released the 1004X-E models and that's where the 1054Z becomes seriously challenged, two 1GSa/s ADC's with 14M mem for each plus that same fast processor and the additional functionality over the 2ch models. Again, a sharp responsive DSO.

Anyways, enough of the sales pitch, you can hunt out any further info if you're interested.
Nighty night mnem.

The only problem there is that these scopes aren't exactly in the same price category anymore. I bought my 1054Z for $329 shipped from TEq on sale (actually, they price-matched a loss-leader sale Arrow was having, then hooked me up with a 50-ohm feed-thru terminator to sweeten the deal); street price is $350-379. The SDS1104X-E street price is $479-499 shipped, and the SDS1204X-E is $749-799.

It looks like you do get more for your money with the 1104X, but it's on average $150 more, and the 1204X is twice the price. Just to put things in perspective.

That said... buying a 'scope is like buying gaming computer gear or buying a big-screen TV; in order not to be obsolete by the time you get it home, you should dig deep in your wallet... so deep it makes your gonads ache... and buy as high on the food chain (while still shopping carefully with an eye towards bang:buck ratio) as you can with every penny you can scrape up, beg or borrow. 6 months down the road when you see the newest models coming out you won't regret the extra money spent, and you'll be wishing you had if you don't.


Cheers,


mnem
Money hurts.

[bd139]

Siglent have no reliable UK reseller so I'd buy a better Rigol over a Siglent if I wanted to spend more money.

I don't buy that scopes really go obsolete. Better ones come out but that doesn't mean the old ones are less useful than before. The interface between them and the universe is quite stable

[Specmaster]

Siglent have no reliable UK reseller so I'd buy a better Rigol over a Siglent if I wanted to spend more money.

I don't buy that scopes really go obsolete. Better ones come out but that doesn't mean the old ones are less useful than before. The interface between them and the universe is quite stable

Yep, that interface would be the users and we have been stable for centuries 🤣

From mobile device so predictive text might have struck again [emoji83]

[GerryBags]

Yep, that interface would be the users and we have been stable for centuries 🤣

Well, stable-ish.

[mnementh]

... switched off the Wysiwyg option, it sucks....

I couldn't agree more. LaTeX FTW.

Now there's a statement that is true in a much wider context

Mmmmm.... LaTeX...

Quote from: bd139 on Today at 12:13:59 pm

Citizen / Accurist are a good deal. They're functional over everything.

iPhone stopped being a status symbol years ago. Can get them on Tesco mobile. Mine's on giffnaff Literally crawling with them. The only status now is not having one with a broken screen

Yep, I've tried Lorus, Casio, Rotary (I have my fathers old watch which is a Rotary and very precious to me) but none of them hold a candle to Accurist/Citizen watches.

When it comes CRO/DSO I want both, if I could get an affordable DSO tomorrow, I would, just like my watches, the most accurate are the Atomic Controlled ones, but I also have 5 others that aren't radio controlled but still accurate to a few seconds a month.  I view them in the same way that I view a CRO and the Radio Controlled ones like a DSO 

Not so sure about Apple Phones and similar top end ones from other makers, there what these moped gangs start of with snatching from people who they have spied flashing them in public probably before graduating on to lightening raids in Jewelers, bastards.

I used to be a diehard Timex ironMan wearer; until they got bought out by the Chinese factory that used to make them and it all turned into plastic body/plastic lens/plastic band crap. Since then I've worn the 00s vintage Fossil SS Diver watches and Arkitekts pretty much exclusively, when I wear a watch. I have a very good, inexpensive pocketwatch that keeps better time, and does all that "connected" crap too; mine is Android simply because anything fApple with a usefully-sized screen is still obscenely overpriced.

mnem
I tried single-shot on my club sandwich; The results, while quite spectacular, were less than optimal.