Products > Test Equipment

True analog scopes

<< < (57/84) > >>

tggzzz:

--- Quote from: james_s on December 22, 2022, 07:55:13 pm ---
--- Quote from: BillyO on December 22, 2022, 07:02:57 pm ---Y'all need to quit using this as the main reason to have a DSO.  It's not.

--- End quote ---

It's the main reason I use a DSO. Yes it's possible to do single sweep with a CRO and a camera, but that's a big pain. Doing a single shot capture on a DSO is trivial, it's the biggest advantage that the average user will see the most benefit in. They other perks they offer are nice too, but single sweep is the big one.

--- End quote ---

... Single sweep with the displayed waveform retained by more than the phosphors' persistence :)

Even so, it is somewhat surprising how useful that can be, if that's all you've got :)

TimFox:
An especially useful feature of DSOs is the ability to display the waveform in a single sweep before the triggering event.

tggzzz:

--- Quote from: TimFox on December 22, 2022, 09:16:59 pm ---An especially useful feature of DSOs is the ability to display the waveform in a single sweep before the triggering event.

--- End quote ---

Agreed, that's something which the unlamented analogue storage scopes couldn't do.

It is less compelling with repetitive waveforms, of course.

mag_therm:
ARRR..., But we had the original Hioki Hi-Corders, 4 channel, they could capture sub microsecond.
I forget how much pre-trigger but quite a lot, seconds even.
The chart paper would be spread across the engineering office floor so everybody could offer their learned opinion.

baldurn:

--- Quote from: tggzzz on December 22, 2022, 07:35:56 pm ---
Your list with my response...
Single shot capture The USP for storage scopes; agreed
Zooming on a captured waveform Analogue scopes have delayed trigger. (Some digitising scopes cannot zoom - useless!)

--- End quote ---

This is just so much easier on the DSO. Delayed trigger also does not exactly do the same thing. Segmented capture? Searching for events matching a pattern? Dual view of zoomed out and zoomed in view?


--- Quote ---Programable triggers of many kinds I've found those to be good when playing around, but insufficient for normal jobs

--- End quote ---

There is just stuff you can not do without. Runt triggering for example is not easy or impossible on many analog scopes. Means you are simply not going to get the job done. Or that you have do something contrived and complex instead of something easy on the DSO.


--- Quote ---Serial decoding Digital domain tools are much better: protocol analysers and printf(). Some digitising scopes only decode what's on the screen, which is useless
MSO Scope plus logic/protocol analyser is usually sufficient. Where not, there's a fair chance a digitising scope won't be either

--- End quote ---

You can always get more (digital!) instruments but the point is that the modern DSO is very versatile. It will usually do the job. It might not be the best for every job, nothing is. It is a function the analog scope simply does not do (again).


--- Quote ---Statistics displayed on screen Some analogue scopes display some stats on screen. While digitising scopes appear to have more complex stats, their accuracy in the context of the specific waveform has to be verified. Too many scope's firmware has been found to have subtle bugs

--- End quote ---

There is no comparison. The old cheap analog scopes do not display any stats at all (only more advanced expensive ones do). Talking about bugs in firmware is just handwaving. The stats a very useful. Not because you can't do without but because it is so easy and its just there. No need to calculate something yourself when the machine does it.


--- Quote ---
FFT 8bit ADCs are limited toys w.r.t. FFTs. 14bit is much better, and even then it would be better to use a sound card for audio or dedicated spectrum analyser for RF. Some digitising scopes only do an FFT of what's on the screen, which is useless

--- End quote ---

I just compared FFT on my new Siglent SDS2104X HD with my spectrum analyzer. It was damn impressive. But even with the cheaper entry level scope SDS1104X-E you get 1 Mpts FFT which will help the average HAM operator to verify his transmitter just fine. I also find it very useful for teaching.

Could you use a sound card? Possibly but when you are done spending the day setting that up, the guy with a DSO just pressed a few buttons on his DSO to the job done. Not to mention that the sound card is yet another digital solution, it is limited to audio frequencies and usually requires additional hardware anyway.


--- Quote ---Network connectivity In most cases a convenient feature rather than a sigificant benefit
Programability by scripting / remote control I don't know how you can usefully script looking at an analogue waveform to find something unexpected.

--- End quote ---

Not useless just because you have no need for networking. There has to be a reason that all modern instruments come with it. What might it be?


--- Quote --- For digital signals use a digital domain tool:  a decent logic analyser or protocol analyser will have far superior triggering and filtering[/b]

--- End quote ---

Again the DSO is a versatile tool. It might not be the best but it can do a lot of stuff for free. Even the entry level scopes have this stuff. And sometimes it is just important to have the analog and digital signals on the same screen - nothing does that better than the DSO. The analog scopes does not do it at all.


--- Quote --- Much better display Analogue displays are usually sufficient for analogue waveforms. For digital domain analysis, a digitising scope's screen quickly becomes a limiting factor; better to use the better triggering/filtering in a logic/protocol analyser, or offline post-processing in a computer

--- End quote ---

"sufficient" does not equal "good". Lets just admit that the small CRTs are horrible and that the new breed of entry level scopes with 10 inch touch screens are just so nice that you would think it came straight from Startrek... are there uses where an even bigger screen is better? Of course, that is why all new DSO are network connected so you can bring that right to your huge 30 inch desktop.


--- Quote ---Auto setup Ah, the "I don't know how to work it / I don't know what I'm expecting to see" button beloved of those that like the "Tesla full self-driving (beta)" way of using an instrument :)

--- End quote ---

That is right. Beginners love that button. Sure sometimes they love it too much. Someone here claimed the analog scope is so easy because every lever is visible and right there. Well tell you what - the beginner just presses that one hated button and usually he gets what he wants. Not sure why it should be hated when its helps people.


--- Quote ---Multiple acquisition modes, Math modes I've never found those necessary, but provided an 8bit ADC isn't a limitation then it could be an advantage
Mask tests useful for production tests, less so for exploratory design
Power analyses / other kinds of analyses I use a DMM or the relevant special tool for those
Bode plot Severely limited by 8bit DACs, not just a simple digitising scope, can be achieved other ways

--- End quote ---

That is pure rubbish. Bode plot is _very_ useful. It seems to be doing the job excellently for most purposes and 8 bit does not matter at all. Again the versatile tool DSO does it, but is not the only instrument or maybe the best instrument, but why should that take anything away if it solves the job?  Never seen an analog scope that could do bode plot.


--- Quote ---
--- Quote ---The list just continues. There is so much the analog scope can not do. Especially the analog scopes available cheaply.

--- End quote ---

The cheap digitising scopes are severely limited; they look enticing, but are disappointing when you look in detail.

Your other points are strawman arguments addressed previously.


--- Quote ---And THAT explains why nobody is producing analog scopes anymore.

--- End quote ---

No. The main reason is economic: it is now far cheaper to make a new digitising scope than a new analogue scope.

Good old analogue scopes are far cheaper than decent new digitising scopes.

--- End quote ---

The new entry level DSOs from Siglent and Rigol et al are fantastic devices. You are not going to find an analog scope + something that replaces all of what the DSO also does for anything less. That would be true even if the analog scope was free which is why everyone ends up with a DSO in the end.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod