Author Topic: Building my own scope  (Read 18688 times)

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Offline py-bb

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Re: Building my own scope
« Reply #100 on: October 22, 2022, 02:34:17 pm »
[snip]

This is going to come across a bit snippy but I mean it pragmatically.

You're causing serious thread clutter with this.

I think you think you're informing me of stuff, I think you're ... spouting stuff you've heard without really understanding (again for the spirit of brevity) and you think you're doing something.

Spouting these facts does not help OP.

You had a good point with the "analogue is easy" without a CRT not being easy, but the rest isn't going to help.
 

Offline Mechatrommer

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Re: Building my own scope
« Reply #101 on: October 22, 2022, 02:36:45 pm »
Read more carefully. I think the DS1054 scope is a normal scope. The context you chose to omit indicates you think it isn't normal.
there you go strawman fallacy again. i never mentioned anything about DS1054. i bet you havent read this carefully... https://blogs.keysight.com/blogs/tech/bench.entry.html/2022/05/09/what_s_the_differencebetweenareal-timeandsamp-WuT8.html
Nature: Evolution and the Illusion of Randomness (Stephen L. Talbott): Its now indisputable that... organisms “expertise” contextualizes its genome, and its nonsense to say that these powers are under the control of the genome being contextualized - Barbara McClintock
 

Online tggzzz

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Re: Building my own scope
« Reply #102 on: October 22, 2022, 02:49:11 pm »
So you discount commercial scopes such as the HP54110A 1GHz bandwidth, 40MS/s? That was a "normal" scope in its day, albeit top of the range.
so you discount Shannon-Nyquist Theorem? circa 1915

The two options are that:
  • you don't understand those theorems as well as you think you do, or
  • HP manufactured and sold equipment that violated those theorems. Bear in mind that I used that scope and knew the engineer that designed the digitiser.
Which is more likely?

BTW, here's the manual from which I took the numbers: https://www.keysight.com/us/en/assets/9018-05874/user-manuals/9018-05874.pdf

To save you the irritation of giving a false email address, here are the two key specs from p3-1 and 3-2...
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
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Online tggzzz

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Re: Building my own scope
« Reply #103 on: October 22, 2022, 03:03:35 pm »
[snip]

This is going to come across a bit snippy but I mean it pragmatically.

You're causing serious thread clutter with this.

That's one opinion. In any case, it takes two to make clutter.

Quote
I think you think you're informing me of stuff, I think you're ... spouting stuff you've heard without really understanding (again for the spirit of brevity) and you think you're doing something.

You do not understand that you do not understand!

I wish I could repeat a PM I received about you a couple of hours ago. I can't since it is obviously private, and therefore I cannot unfortunately justify that statement. Sorry about that. The key observation was your first post was a simple question about scope input protection, followed by your being a microwave expert. I prefer not to jump to conclusions as fast as wryly and tentatively suggested in that PM.


Quote
Spouting these facts does not help OP.

That's not for you to say. Or do you know what he thinks and speak for him?

Quote
You had a good point with the "analogue is easy" without a CRT not being easy, but the rest isn't going to help.

I have never said "analogue is easy" or anything remotely similar. Analogue is subtle and complex; that's why there aren't so many analogue engineers and products nowadays.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Offline Mechatrommer

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Re: Building my own scope
« Reply #104 on: October 22, 2022, 03:05:20 pm »
the problem with my wife is.. apart from wandering off topic to defend her point, is she thinks i'm a fool, even if when talking about technical topic (she's a kindergarden teacher). ;D
Nature: Evolution and the Illusion of Randomness (Stephen L. Talbott): Its now indisputable that... organisms “expertise” contextualizes its genome, and its nonsense to say that these powers are under the control of the genome being contextualized - Barbara McClintock
 
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Online tggzzz

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Re: Building my own scope
« Reply #105 on: October 22, 2022, 03:13:43 pm »
Read more carefully. I think the DS1054 scope is a normal scope. The context you chose to omit indicates you think it isn't normal.
there you go strawman fallacy again. i never mentioned anything about DS1054. i bet you havent read this carefully... https://blogs.keysight.com/blogs/tech/bench.entry.html/2022/05/09/what_s_the_differencebetweenareal-timeandsamp-WuT8.html

Sigh.

Go and re-read the context you snipped in order to make that (invalid) point. I never intimated you did initially mention the DS1054; I used it as an example to demonstrate the fallacy in one of your statements.

No, I didn't read that blog entry in detail. I stopped at "Rick Clark Product Marketing Manager".
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Offline Mechatrommer

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Re: Building my own scope
« Reply #106 on: October 22, 2022, 03:36:44 pm »
your prejudice and lack of insight caused your ignorance. what you dont realize is how many Keysight engineers and technical netizens are next to him to bash him if he write bullshit in Keysight blog. cheers.
Nature: Evolution and the Illusion of Randomness (Stephen L. Talbott): Its now indisputable that... organisms “expertise” contextualizes its genome, and its nonsense to say that these powers are under the control of the genome being contextualized - Barbara McClintock
 

Offline pcprogrammer

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Re: Building my own scope
« Reply #107 on: October 22, 2022, 03:44:17 pm »
I wish I could repeat a PM I received about you a couple of hours ago. I can't since it is obviously private, and therefore I cannot unfortunately justify that statement. Sorry about that. The key observation was your first post was a simple question about scope input protection, followed by your being a microwave expert. I prefer not to jump to conclusions as fast as wryly and tentatively suggested in that PM.

Let me do that for you :-DD

@py-bb

32 posts in a single day. The very first indeed being, an in my eyes, simple question about the protection of a scopes front end being the same for all the sensitivity settings.

https://www.eevblog.com/forum/beginners/oscilloscope-safe-to-use-any-scale-as-long-as-not-over-max-ratings/msg4475026/#msg4475026

And then you show up here as if you know all about how a scope works and that it is way easier to do in the analog domain, and then suddenly you know all about microwave technology for high frequency signals.

Further more you use Afghanistan as you country flag whilst you write here that you are proud of your British power plugs: https://www.eevblog.com/forum/chat/(youtube)-american-is-impressed-by-sensible-british-mains-plug-design/msg4477015/#msg4477015.

In your profile you write "Ashamed to say my real country ATM". https://www.eevblog.com/forum/profile/?area=summary;u=902560

So I assume that you are either treez or Faringdon or some other troll.
« Last Edit: October 22, 2022, 03:46:25 pm by pcprogrammer »
 

Offline py-bb

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Re: Building my own scope
« Reply #108 on: October 22, 2022, 04:41:26 pm »
I wish I could repeat a PM I received about you a couple of hours ago. I can't since it is obviously private, and therefore I cannot unfortunately justify that statement. Sorry about that. The key observation was your first post was a simple question about scope input protection, followed by your being a microwave expert. I prefer not to jump to conclusions as fast as wryly and tentatively suggested in that PM.

Let me do that for you :-DD

@py-bb

32 posts in a single day. The very first indeed being, an in my eyes, simple question about the protection of a scopes front end being the same for all the sensitivity settings.

https://www.eevblog.com/forum/beginners/oscilloscope-safe-to-use-any-scale-as-long-as-not-over-max-ratings/msg4475026/#msg4475026

And then you show up here as if you know all about how a scope works and that it is way easier to do in the analog domain, and then suddenly you know all about microwave technology for high frequency signals.

Further more you use Afghanistan as you country flag whilst you write here that you are proud of your British power plugs: https://www.eevblog.com/forum/chat/(youtube)-american-is-impressed-by-sensible-british-mains-plug-design/msg4477015/#msg4477015.

In your profile you write "Ashamed to say my real country ATM". https://www.eevblog.com/forum/profile/?area=summary;u=902560

So I assume that you are either treez or Faringdon or some other troll.

I asked a practical question about a very old scope that doesn't list the protections we'd expect of a modern scope & most PCB design is simulated these days and how they test/fix manufacturing duds is not something I deal with.

I work very hard to know where I'm fit to comment and I do not like your tone.
 

Offline pcprogrammer

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Re: Building my own scope
« Reply #109 on: October 22, 2022, 04:48:01 pm »
I work very hard to know where I'm fit to comment and I do not like your tone.

Well that is your prerogative. As it is mine to make observations, and what I wrote is what my opinion is, based on what I have seen today.

Offline py-bb

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Re: Building my own scope
« Reply #110 on: October 22, 2022, 04:51:02 pm »
I work very hard to know where I'm fit to comment and I do not like your tone.

Well that is your prerogative. As it is mine to make observations, and what I wrote is what my opinion is, based on what I have seen today.

Well in my opinion you're a git, you should never mock someone for asking a question about how to operate equipment safely.

That's a very bad habit to have indeed.
 

Online tggzzz

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Re: Building my own scope
« Reply #111 on: October 22, 2022, 06:36:54 pm »
I work very hard to know where I'm fit to comment and I do not like your tone.

Well that is your prerogative. As it is mine to make observations, and what I wrote is what my opinion is, based on what I have seen today.

Well in my opinion you're a git, you should never mock someone for asking a question about how to operate equipment safely.

That's a very bad habit to have indeed.

If pcprogrammer had done that, I would agree with you.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Offline py-bb

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Re: Building my own scope
« Reply #112 on: October 22, 2022, 06:43:44 pm »
I work very hard to know where I'm fit to comment and I do not like your tone.

Well that is your prerogative. As it is mine to make observations, and what I wrote is what my opinion is, based on what I have seen today.

Well in my opinion you're a git, you should never mock someone for asking a question about how to operate equipment safely.

That's a very bad habit to have indeed.

If pcprogrammer had done that, I would agree with you.

Thanks for sharing your unique view of the world..... I guess.

Hopefully now you've got that out of the way we can get back on topic.
 

Offline pcprogrammer

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Re: Building my own scope
« Reply #113 on: October 22, 2022, 06:57:22 pm »
Well in my opinion you're a git, you should never mock someone for asking a question about how to operate equipment safely.

That's a very bad habit to have indeed.

Again your prerogative, but I did not mock you. I just questioned if you are a troll.

And I did this on making an observation on what you have posted here and in other threads. It is quite uncommon for a new member to go from a simple question to being a world class expert handing out advice in a single day. Most just ask a question and get their answers and ask maybe another question and that is it. Post count does not go up as fast as yours.

Online tggzzz

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Re: Building my own scope
« Reply #114 on: October 22, 2022, 07:06:36 pm »
I work very hard to know where I'm fit to comment and I do not like your tone.

Well that is your prerogative. As it is mine to make observations, and what I wrote is what my opinion is, based on what I have seen today.

Well in my opinion you're a git, you should never mock someone for asking a question about how to operate equipment safely.

That's a very bad habit to have indeed.

If pcprogrammer had done that, I would agree with you.

Thanks for sharing your unique view of the world..... I guess.

Hopefully now you've got that out of the way we can get back on topic.

There are solid grounds for stating it is not a unique view of the world.

I agree that your becoming the subject of a subthread is indeed distracting.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Offline py-bb

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Re: Building my own scope
« Reply #115 on: October 22, 2022, 07:09:33 pm »
I work very hard to know where I'm fit to comment and I do not like your tone.

Well that is your prerogative. As it is mine to make observations, and what I wrote is what my opinion is, based on what I have seen today.

Well in my opinion you're a git, you should never mock someone for asking a question about how to operate equipment safely.

That's a very bad habit to have indeed.

If pcprogrammer had done that, I would agree with you.

Thanks for sharing your unique view of the world..... I guess.

Hopefully now you've got that out of the way we can get back on topic.

There are solid grounds for stating it is not a unique view of the world.

I agree that your becoming the subject of a subthread is indeed distracting.

Hey I've been trying to drop hints I'm not interested for a while.

For some reason you seem to think you're worth listening to.

The post I am replying to, why did you feel the need for that?

All you're doing is making yourself look bad, the regulars might know you but I'm new! To me you look like this weird contrary loon arrogant enough to to think crap like that is worth posting.

Take 10 minutes, think before you press enter. Otherwise I don't see what good can come of interacting with you.
 

Online David Hess

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Re: Building my own scope
« Reply #116 on: October 23, 2022, 12:40:13 am »
Thanks. You seem to be remarkably knowledgeable. Do you work in the field of oscilloscope manufacturing?

I never have, but I have studied oscilloscope design for years, and am considering doing a similar project based on the Tektronix 2232.

With digital ones the problem is that you need to have 1 amplifier (at least for each channel) and one thing sampling it (the ADC). This is because if you had 2 and switched between them (say taking it in turns) they'd be slightly different in gain and sampling. We often don't expect channels to be exactly the same so you can get away with it but still.

The Tektronix 2230 and its predecessor, the 468, use a single digitizer for two channels with analog channel switching without any problems.  The 2230 even weirdly supports chop or alternate mode when operating as a digital storage oscilloscope.  Of course it would be silly to design a DSO this way today, and the 2232 which replaced the 2230 uses one digitizer per channel.

Most DSOs even now use analog channel switching to support more than one channel per digitizer, or more than one digitizer per channel, but it is done internally as part of the ADC.  This has been done for a long time to support higher sampling rates when fewer channels are in use.  It is not difficult to do, but is an unneeded complication.

A low sampling rate sampling oscilloscope could be made for bandwidths above 1 GHz but that entails several other design disciplines and is less generally useful.

Correct. Take equivalent time sampling, but for that to work you need a reliable fine scaled delay, or more useful for spectrum analysis a heterodyne mixer to bring your signal down in frequency. But these require a lot of additional electronics to make it work.

I was thinking in terms of a sampler and the timing circuits.  Neither are a trivial exercise at GHz bandwidths and picosecond resolution.

I have been looking into the requirements to design a modern "sampling DSO" based on the random sampling capability of the Tektronix 7T11.  This would combine 4+ GHz sampling bandwidth with conventional operation from the user's perspective without a delay line.

Quote
Last year I figured there should be standard interface ADCs and processors to allow for a high sample rate design without an FPGA or custom logic, and there are, but they are incredibly expensive.

You mean the FMC based systems?

I do not remember if that was it, but there is a standard for high speed ADC interfacing and I did a search for ARM microcontrollers which support it.  The cost of the ADC and microcontroller were much higher than the cost of a more conventional ADC and microcontroller and an FPGA to interface them.

Well most likely money. High speed ADC's are expensive and using two that are capable of half the speed might cost way less than the single high speed one.

There are plenty of reasonably priced sampling ADCs now that are fast enough to make a useful DSO.

Delay isn't too much of a problem: see the very simple circuits in the Tektronix 1502 TDR.

A TDR has the advantage of operating synchronously and generating its own trigger.  A sequential sampling oscilloscope has two triggers, one for the external signal and one for the sampling strobe.  A random sampling oscilloscope in addition has to measure positive and negative delay, and includes a rate generator.

Quote
Triggering from the signal is more challenging. The Tek 1502 avoids that by having an, ahem, external trigger that is generated internally :)

In most cases the triggering does not need to have as high a bandwidth as the input signal.  What does matter however is trigger noise which requires careful design to minimize.  The required performance was easier when tunnel diodes were available, but there are some modern comparators which are good enough.  What is missing now however are fast PNP transistors.
 
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Offline Mechatrommer

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Re: Building my own scope
« Reply #117 on: October 23, 2022, 01:17:18 pm »
now i found the guy (apart from the Ted Yapo OSHW thread). 12GHz $300 Kickstarter was no go... official website out of stock. the BOM should be lesser than $300 in case somebody want to follow the trail, or implement the concept into slower MHz much cheaper, much fewer like maybe 200 Sa/s? i think we can push arduino to 2KSa/s so GHz frontend with arduino sampler should not be improbable ;D jk..

https://www.kickstarter.com/projects/1855991221/10-ghz-usb-oscilloscope
http://www.fastsampling.com/
https://www.eevblog.com/forum/crowd-funded-projects/10-ghz-usb-oscilloscope/

if you want to get fancy $35K sequential ETS PicoTech:
https://www.picotech.com/oscilloscope/9300/picoscope-9300-sampling-oscilloscopes



and here recap from not a marketing manager, the Tek.. to whoever missed the bus... befriending Al Zimmerman alone will not make you right..
https://w140.com/tekwiki/wiki/Sampling_oscilloscope
here quoted to get into context:
Quote
Equivalent time sampling requires repetitive signals
thats the Tek's saying, not me.

not the best guy i can find explaining to prejudice, but best demonstration i can see in my top google list for those who are lazy to read texts...


talk about Compressive (Random Time) Sensing but link is broken..
Shannon also mentioned theory of lossless reconstruction through subsampling...
https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem#Sampling_of_non-baseband_signals
https://en.wikipedia.org/wiki/Compressed_sensing

for those who want to dig into the math and hence to the possibility of application... i can barely understand, but my ignorance doesnt make me right when bragging fallacies :-DD fwiw..
« Last Edit: October 23, 2022, 01:21:06 pm by Mechatrommer »
Nature: Evolution and the Illusion of Randomness (Stephen L. Talbott): Its now indisputable that... organisms “expertise” contextualizes its genome, and its nonsense to say that these powers are under the control of the genome being contextualized - Barbara McClintock
 
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Online David Hess

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Re: Building my own scope
« Reply #118 on: October 23, 2022, 01:59:28 pm »
now i found the guy (apart from the Ted Yapo OSHW thread). 12GHz $300 Kickstarter was no go... official website out of stock. the BOM should be lesser than $300 in case somebody want to follow the trail, or implement the concept into slower MHz much cheaper, much fewer like maybe 200 Sa/s? i think we can push arduino to 2KSa/s so GHz frontend with arduino sampler should not be improbable ;D jk..

An Arduino easily has the processing power, but significant external hardware is required for the sampler, triggers, and time-to-digital conversion.

Quote
https://www.kickstarter.com/projects/1855991221/10-ghz-usb-oscilloscope
http://www.fastsampling.com/
https://www.eevblog.com/forum/crowd-funded-projects/10-ghz-usb-oscilloscope/

if you want to get fancy $35K sequential ETS PicoTech:
https://www.picotech.com/oscilloscope/9300/picoscope-9300-sampling-oscilloscopes

All modern sampling oscilloscopes use sequential sampling which further limits their general applicability.  Past instruments which were more general purpose include the Tektronix 7T11, 7S14, and 3T2 which provided either random sampling, or in the case of the 7S14, a delay line, allowing them to sample the leading part of a signal like a conventional oscilloscope.

Quote
and here recap from not a marketing manager, the Tek.. to whoever missed the bus... befriending Al Zimmerman alone will not make you right..
https://w140.com/tekwiki/wiki/Sampling_oscilloscope
here quoted to get into context:
Quote
Equivalent time sampling requires repetitive signals
thats the Tek's saying, not me.

Sampling oscilloscopes require a repetitive signal, but it is possible to sample a repetitive but irregular signal.
 
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Offline Mechatrommer

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Re: Building my own scope
« Reply #119 on: October 23, 2022, 03:15:05 pm »
All modern sampling oscilloscopes use sequential sampling which further limits their general applicability.  Past instruments which were more general purpose include the Tektronix 7T11, 7S14, and 3T2 which provided either random sampling, or in the case of the 7S14, a delay line, allowing them to sample the leading part of a signal like a conventional oscilloscope.
but random sampling still needs repetitive (any shape) signal to show meaningful display. glitches, close loop control system, noises and many other areas (non-repetitive) cannot be shown correctly.
Nature: Evolution and the Illusion of Randomness (Stephen L. Talbott): Its now indisputable that... organisms “expertise” contextualizes its genome, and its nonsense to say that these powers are under the control of the genome being contextualized - Barbara McClintock
 

Offline tautech

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Re: Building my own scope
« Reply #120 on: October 23, 2022, 07:37:07 pm »
OP, balnazzar, you have mail.
Avid Rabid Hobbyist.
Some stuff seen @ Siglent HQ cannot be shared.
 
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Online David Hess

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Re: Building my own scope
« Reply #121 on: October 24, 2022, 03:01:46 pm »
All modern sampling oscilloscopes use sequential sampling which further limits their general applicability.  Past instruments which were more general purpose include the Tektronix 7T11, 7S14, and 3T2 which provided either random sampling, or in the case of the 7S14, a delay line, allowing them to sample the leading part of a signal like a conventional oscilloscope.

but random sampling still needs repetitive (any shape) signal to show meaningful display. glitches, close loop control system, noises and many other areas (non-repetitive) cannot be shown correctly.

Sure, and the same applies to equivalent time sampling when used by a digital storage oscilloscope.  Sampling oscilloscopes can capture the same thing, but it takes longer because of their lower sample rates.  I once measured the rise time of a coaxial relay type of pulse generator operating at 120 Hz.  With a general purpose digital storage oscilloscope using 500 MS/s equivalent time sampling, this takes only a fraction of a second.  With a random sampling oscilloscope, it took half an hour.  The advantage of the sampling oscilloscope was 10+ GHz bandwidth and predictable transient response versus 100s of MHz.

Glitches and the transient response of closed loop control systems can be repetitive.  In many applications, including eye diagrams, a histogram is desired anyway, but histogram will not distinguish between noise and non-repetition.
« Last Edit: October 24, 2022, 03:05:26 pm by David Hess »
 
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Offline rob77

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Re: Building my own scope
« Reply #122 on: October 24, 2022, 03:16:51 pm »
Glitches and the transient response of closed loop control systems can be repetitive.  In many applications, including eye diagrams, a histogram is desired anyway.

"can be"  doesn't mean that all glitches are repetitive, in wast majority of cases glitches are non repetitive.

each tech has it's own use case... but if you're hunting a bug on a 40MHz SPI bus then all your sampling scopes and the 1GHz bandwith scope with 40MS/s are useless....
 

Online tggzzz

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Re: Building my own scope
« Reply #123 on: October 24, 2022, 05:10:26 pm »
Glitches and the transient response of closed loop control systems can be repetitive.  In many applications, including eye diagrams, a histogram is desired anyway.

"can be"  doesn't mean that all glitches are repetitive, in wast majority of cases glitches are non repetitive.

each tech has it's own use case... but if you're hunting a bug on a 40MHz SPI bus then all your sampling scopes and the 1GHz bandwith scope with 40MS/s are useless....

40MHz? Do you mean 40Mb/s? A 100MHz scope (say) with 1GS/s (or 10GS/s for that matter!) would be hard put to spot signal integrity issues or create a useful eye diagram.

As you say, each tool has its own use cases. That means it is unwise to make global statements without reference to use cases or preconditions for the statement's validity.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Offline rob77

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Re: Building my own scope
« Reply #124 on: October 24, 2022, 05:47:36 pm »
Glitches and the transient response of closed loop control systems can be repetitive.  In many applications, including eye diagrams, a histogram is desired anyway.

"can be"  doesn't mean that all glitches are repetitive, in wast majority of cases glitches are non repetitive.

each tech has it's own use case... but if you're hunting a bug on a 40MHz SPI bus then all your sampling scopes and the 1GHz bandwith scope with 40MS/s are useless....

40MHz? Do you mean 40Mb/s? A 100MHz scope (say) with 1GS/s (or 10GS/s for that matter!) would be hard put to spot signal integrity issues or create a useful eye diagram.

As you say, each tool has its own use cases. That means it is unwise to make global statements without reference to use cases or preconditions for the statement's validity.

i meant 40MHz because it's 40MHz...  it's pretty common to specify the SPI speed by it's clock frequency.

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A 100MHz scope (say) with 1GS/s (or 10GS/s for that matter!) would be hard put to spot signal integrity issues or create a useful eye diagram.

your sampling scope would not even catch the runt pulse, and your 1GHz bandwidth 40MS/s scope you love so much would not even notice half of the data... so what to use ? Mr. Tggzzz with a sharp pencil and a paper roll will do the trick i guess... while everyone else is happily using the 1GS/s scopes which are in fact not usable because the almighty omnipresent and omnipotent Mr. Tggzzz said so  :-DD

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it is unwise to make global statements without reference to use cases or preconditions for the statement's validity

that's exactly what You were doing in this thread  :-DD

peace for everyone ! i'm signing off  ;D
 


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