EEVblog #699 - Rigol DS1054Z Oscilloscope Jitter Fix Testing

[EEVblog]

Dave tries out the new DS1054Z firmware from Rigol that is supposed to fix the 5us delay jitter issue, and the AC Trigger Coupling jitter issues.
Have they fixed it, or is there still a problem?
What caused the 5us jitter issues to begin with, Dave also investigates the ADC PLL based sample clock with an e-Field probe and the Rigol DSA815 spectrum analyser.
Did Rigol also change the PLL coefficients?

ADF4360 PLL datasheet: http://www.analog.com/static/imported-files/data_sheets/ADF4360-7.pdf

[allikat]

Nice to see it fixed Dave.  You're absolutely right, that is a pretty horrible clock waveform.  Maybe they got a few out of spec parts sneak through the QC checks, or someone in management decided to order based on cost not spec.  You never know how these things happen.  Your previous teardown video did rather imply the design was cost focused, and that can mean some pretty tight requirements for parts when you're effectively trying to do things the hard way for cost reasons.

[SeanB]

Better performance for sure, though I doubt that the original filter is correct for this application. You are right that it likely will need "upgraded" component values, likely done in production as "after serial xxxxxxx". Looks like the PLL can do better, though I guess that that is only really obtainable at specific combinations of input and output frequencies with optimal layout. I would also guess that you would need close tolerance capacitors in that filter as well, and likely they might have been substituted with lower cost ones in production. Might be worth it to get the values in a NPO type and replace the on board versions and see if it helps the jitter, as it being temperature dependant seems to point to the capacitors being cheaper types.

[rob77]

it's nice to see that Rigol do care about their customers and they're able to fix issues      planning to buy a 2nd scope, and i think i made the decision now (and i like the looks of 1054Z and the big screen anyways )

[matt303]

Great video, nicely showed the PLL issue, does look like them making the best of a bad job but if it works and works reliably it's a fix. Looking forward to your review video now, looks a great scope for the money especially if the waveform update rate is as good as the spec sheet says.

[Chipguy]

Nicely done!

[JonR]

Would be interesting to measure the clock on the 2000 series too (and even the old 1054E!).

[maor]

The spectrum after the update is fine, the span around a central frequency generated from a PLL is referred to as phase noise, and the division goes as follows:
0-10Khz from offset : the quality of the of the input frequency.
10-100khz from offset : quality of the loop filter.
100khz-1Mhz from offset : issues with the PFD.
seeing that before the fix, the 100Khz offset was only -6.5 dBc, it would make sense how easily it could effect the signal and cause the jitter, going -37 dBc is more than enough  of a spectral clarity for these applications.

[nixfu]

With the amplitude of the extra components down 40db, that is probably good enough to not cause the problem anymore.  I am guessing you could use the old version and cycle through all the multipliers and see at which point it stopped having issues, eg its -6db at 5us, -12db at 15us, etc.. at some point you will see where the clock signals are down low enough to not affect it.  If someone has an unpatched scope, you could try and see at which multiple the jitter goes away, and that would allow you to calculate at what signal level (-db) the extra clock harmonic does not affect the scope anymore even before this fix.

And I am guessing that there is NO way to actually get rid of these components totally unless you add extra bandpass filtering, and that would require more LC filters or something and not just a simple ac coupling cap on the PLL output.

More than likely the scope math works fine as long as the level of those extra clock products are down below a decent threshold.  I mean -40db is 1/10,000th  less signal level than the main peak.  That is pretty damn good actually compared the original output where the first product was only -6db down, which means the first product was fully at 25% of signal level of the peak.

So you have gone from the first product being .25 of the primary to only having the power of 0.0001 of the primary signal. 

That would be considered extremely good oscillator output quality improvement, in the world of RF where we deal with oscillators, and multiplier products all the time.

I say good on Rigol, that is much better results than I would have expected to achieve without physically adding extra physical bandpass filtering.  At those levels, the software should now have zero trouble detecting the primary clock output and rejecting the spurious harmonics.


So, Dave, now is it time to get out that first hour of the review you already have shot?

[dmg]

Well, they are saved by the fact that the ADC is only 8 bit so the performance degradation due to jitter doesn't affect that much, as the limiting factor for performance is still the quantization noise up to above the required bandwidth of the scope. In any case that clock looks kinda crappy and the PLL seems to have locking issues. It seems that they use a too narrow loop filter for the application, and that means that cutoff frequency for VCO phase noise is too low so it lets most of it go through and prevents correct lock. In the previous firmware the loop was completely unstable and now it's at most borderline stable. For these applications when your reference is good you usually use a relatively wide (10's to 100's of kHz) loop filter because that minimizes overall phase noise and jitter.

Anyway, this issue could be related to Rigol using Analog Devices' driver for the PLL. They offer linux and os-independent drivers for most of their synthesizers but they are pretty buggy and use an approach to calculate divider values that usually gives suboptimal results, at least for ADF4350/51 which is pretty similar to the ADF4360 they use but with integrated multiband VCO. We used them in a project and we had lots of trouble because of lots of annoying bugs, the worst one being that the documentation for device tree configuration parameters was not up to date and new versions of the driver used totally different parameter names, so it wasn't reading them properly so everything was being misconfigured. Even when that was solved we got even more issues from calculations that led to fractional operation when the frequency requested could be synthesized in less noisy integer mode, obsession with adjusting reference divider to 7 which led to a weird PFD frequency and made it fail to calculate values to generate exact 1 GHz from 25 MHz reference and things like those. So the PLL didn't properly lock at certain frequencies or the output wasn't exact and had lots of spurs.

We finally ended up ditching the driver and writing our own based on the code from the desktop application that analog devices gives to interact with the evaluation board, which was written in a much more sensible and failproof way (by different people), and everything worked well. They should look into the issue because it's unacceptable to have a bad clock on a high performance ADC, even when it "works".

[Chryseus]

It has not really fixed my jitter issue, although I had almost none before the update, perhaps even a little less it's hard to tell.


Isn't really that bad so I can live with it.

[rob77]

It has not really fixed my jitter issue, although I had almost none before the update, perhaps even a little less it's hard to tell.


Isn't really that bad so I can live with it.

and what would you expect from a $500 scope ? according to the pictures you attached, your scope was and is just fine.

[pickle9000]

That video turned out well. Short, useful, educational.

The update fixed my scope, it did have issues. It did not kill any of the key "hacks".

I bet Rigol will now include some more thorough production line testing. This particular fault should be a thing of the past. Siglent, Hantek are watching as well and probably changing their production testing as well. Although many may say how can this happen I always see it as beneficial. Rigol will certainly have a better product and more reliable scope because of it.

I have no doubt they will change the hardware slightly, that's usual. You can bet that many will be checking the hardware on this scope over and over. This scope is under a microscope (literally) and will be until another one breaks it's hold on it's place in the market.

I was asked by a friend the other day about where this scope belongs on the bench. I replied it's a good "beater" scope. Inexpensive, massive features, good for daily general purpose measurements.   

 

[Howardlong]

The video was shaking about all over the place at the start. Should've done it at 60fps 4k, isn't that what Hollywood uses these days? *








(*=joke)

[Chryseus]

and what would you expect from a $500 scope ? according to the pictures you attached, your scope was and is just fine.

The output of the PLL is pretty awful, for $500 I'd certainly expect it to be better than that in a piece of test equipment, while the actual effect on my scope can be pretty much ignored it still doesn't excuse the failure on Rigol's part to properly check the PLL and the associated components. 

[nixfu]

Isn't really that bad so I can live with it.

Are you sure that is jitter and not just persistance? Make sure persistence levels is turned to none.

[rob77]

and what would you expect from a $500 scope ? according to the pictures you attached, your scope was and is just fine.

The output of the PLL is pretty awful, for $500 I'd certainly expect it to be better than that in a piece of test equipment, while the actual effect on my scope can be pretty much ignored it still doesn't excuse the failure on Rigol's part to properly check the PLL and the associated components. 

my statement was related exactly to your very case, not the overall situation around the clock of Rigol scopes you were complaining about the patch not fixing your jitter issue - while you got jitter (if one could call that jitter) adequate to a $500 scope.

[Lightages]

Are you sure that is jitter and not just persistance? Make sure persistence levels is turned to none.

There is no "none" for persistence on the DS1004Z series. This I hate. There is always persistence, minimum and some intermediate settings, and infinite. If you want to see the raw signal you need to set to infinite.

[rob77]

Are you sure that is jitter and not just persistance? Make sure persistence levels is turned to none.

There is no "none" for persistence on the DS1004Z series. This I hate. There is always persistence, minimum and some intermediate settings, and infinite. If you want to see the raw signal you need to set to infinite.

and what would "none" do ? redraw the waveform many times a second with 100% intensity ? that would yield a flickering thick line => no added value in that (just my very opinion)

[michalK]

Yesterday I watched new Dave's video about software upgrade for DS1054Z.
As soon as I saw that it worked with Dave's unit I decided to write a firmware request to Rigol. Today morning I got a reply from Application Engineer from Rigol - do those people never sleep, it's Sunday 

First thing first, so I would like to show you how it worked with my scope.
I had the same problem with it as probably most of its users. The signal jitter on 5us trigger shift and AC trigger coupling.
Below you can see some screenshots BEFORE firmware upgrade. My firmware version was 00.04.01.SP2.

0 us


5 us


AC trigger coupling



AFTER firmware upgrade

0 us


5 us


AC trigger coupling


Also, I would like to note that at first (as suggested by Rigol engineer) I have upgraded the bootloader of my scope, then I upgraded firmware to version 00.04.02 SP3 and finally to 00.04.02 SP4.
I'm not sure if such procedure is necessary (Dave didn't do that on video) but that is what I got from Rigol and I have no reason not to listen to their advices.
At last I can enjoy my DSO as it is written on the screen after successful upgrade precedure 

[Monkeh]

and what would you expect from a $500 scope ?

I don't know, what would you expect from a $1200 scope?

[radiogeek97]

Pickle and others
   Thanks for the post update info.  My scope has all of the hacks installed, would you folks that do have these "updatese" and have done th FW upgrade mind posting your hardware info.  I do have the jitter problem but would be more effected by loosing the "updates" than I would with the jitter problem.   I will post my hardware info when I get to my bench. 

[DanielS]

and what would you expect from a $500 scope ?

I would expect a PLL that performs close to its reference design capabilities through the application-specific operating range out of any properly designed product at any price point since there is practically no material cost difference between a good and bad PLL circuit based on the same crystal and PLL chip.

[tggzzz]

and what would you expect from a $500 scope ?

I would expect that they had checked that their phase locked loops were actually locked! If not just stuff an RC oscillaroe in there!

Ditto for a $200 scope.

If their engineering appears to be, um, "slapdash" in one area then it probably is in others too. Motto with software: the number of remaining bugs is proportional to the number of bugs already found.

[Lightages]

There is no "none" for persistence on the DS1004Z series. This I hate. There is always persistence, minimum and some intermediate settings, and infinite. If you want to see the raw signal you need to set to infinite.

and what would "none" do ? redraw the waveform many times a second with 100% intensity ? that would yield a flickering thick line => no added value in that (just my very opinion)

There is sometimes a bit of detail hidden in the displayed signal when there is any persistence. Try it. Look at a waveform and then turn persistence to infinite and you will see some hidden detail. This is only a partial solution as there is garbage on the screen from the infinite persistence. There should be a no persistence option, period. I don't want my scope hiding information from me if I want to see it.

[DanielS]

There should be a no persistence option, period. I don't want my scope hiding information from me if I want to see it.

Then you should turn off intensity grading as well since that is effectively short-term persistence.

Single-shot has nothing to persist or intensity-grade on either, so if you see "persistence" on those, you are looking at something else like a display formatting/scaling feature/glitch.

After all, unless your auto-trigger rate is slow enough that you have time to look at your signal before the next trigger, the scope will be blending the outputs from multiple trigger events on each display refresh to present to you as much of what happened since the last display refresh as it can to improve your chances of seeing glitches - that's what those 30k-200k wfm/s are for. If the scope presented only one waveform per display update, you would be losing 99.9% of the information.

[Phil_L]

Mine had no discernible offset jitter but did have AC trigger jitter pre-update. No jitter in either instance after update.
I took a 12Mpt FFT of a 16MHz crystal oscillator using  Alessandro's application before and after the update and I'm fairly certain I kept all other conditions consistent.
Maybe it's not particularly significant considering it's only a 40kHz span, but I just thought it was interesting that there was such a difference even though mine didn't seem to have problems initially. Was the AC triggering fix unrelated to the PLL? Or does the DS2000 series have the dodgy clock as well?

[rob77]

There is no "none" for persistence on the DS1004Z series. This I hate. There is always persistence, minimum and some intermediate settings, and infinite. If you want to see the raw signal you need to set to infinite.

and what would "none" do ? redraw the waveform many times a second with 100% intensity ? that would yield a flickering thick line => no added value in that (just my very opinion)

There is sometimes a bit of detail hidden in the displayed signal when there is any persistence. Try it. Look at a waveform and then turn persistence to infinite and you will see some hidden detail. This is only a partial solution as there is garbage on the screen from the infinite persistence. There should be a no persistence option, period. I don't want my scope hiding information from me if I want to see it.

that's why you have so many triggering options - to catch the detail in single shot.
btw... it's not possible to see a "hidden" detail in auto mode.... if the "hidden" detail is occurring in every single cycle, then you'll clearly see it even with persistence and your detail is not hidden anymore if it's not present in every cycle, then you got no chance to see it auto mode - you have to catch it in single shot
or is the "hidden detail" you talking about just a noise ? 

[cidcorp]

Sorry but is there a link to the new firmware, somewhere?

Thanks

Chris

[Lightages]

Yes, by saying detail I mean noise too, or even variations in the signal. With any persistence, this can get blurred and make the signal look cleaner than it is. Like said! Try it. You will see that the persistence s hiding detail, temporal detail.

Why is it a bad thing to see all the noise and changing detail in a signal? Really? Is that not one of the reasons for an oscilloscope?

[janoc]

I have done the update on my DS1074Z now and it seems to have fixed the AC trigger jitter just fine. Now all the trigger coupling modes work well. I didn't have the 5us offset issue before, so can't comment on that.

However, it seems to me that the scope now boots significantly slower post-update. Is that normal or is there something funny going on with my unit?

[Lightages]

Sorry but is there a link to the new firmware, somewhere?

Thanks

Chris

It is a bit strange that Dave did not provide a link with the original post.

http://beyondmeasure.rigoltech.com/acton/ct/1579/s-0518-1412/Bct/l-sf-lead-0006/l-sf-lead-0006:16888/ct2_0/1?sid=W41SWJyI3

[michalK]

However, it seems to me that the scope now boots significantly slower post-update. Is that normal or is there something funny going on with my unit?

I think my unit start up a little bit longer, too. I haven't checked the starting time before update so I can't compare it.

[radiogeek97]

Just updated my scope and I had results just about like Dave had.   My jitter and ac trig coupling is noticeably better now   AND. Post update all my upgrades were retained      thanks again

[janoc]

However, it seems to me that the scope now boots significantly slower post-update. Is that normal or is there something funny going on with my unit?

I think my unit start up a little bit longer, too. I haven't checked the starting time before update so I can't compare it.

Mine now takes about 34 seconds to boot up from pushing the power button to the trace appearing. I didn't measure it before, but it was certainly faster - someone in the other thread on this scope commented that his boots in about 19 seconds, before and after the update. That sounds about right for what I had before.

[JackOfVA]

I wonder if some of the remaining noise sideband could be due to noise from the switching power supply or from the LCD display coupling into the PLL loop filter, where it becomes a modulating source (FM) to the loop.

Given the PLL multiplication factor, it wouldn't take a lot of unwanted noise leaking into the PLL to cause problems.
 

[DG5SAY]

Hi, in the Video I cant see any decoupling capacitor around the ADF4360. According the datasheet (page 7, table 4) there must be one on pin 2 and pin 6 to ground "as short as possible"!
Decoupling capacitors and their right positioning are very important. They must be on the same side like the IC, and no via allowed between the capacitor an the IC-pin.
I think that will significantly improve the PLL performance (noise, jitter).
And don´t forget a decoupling capacitor on the supply of the 25 MHz oszillator!

[Monkeh]

Hi, in the Video I cant see any decoupling capacitor around the ADF4360. According the datasheet (page 7, table 4) there must be one on pin 2 and pin 6 to ground "as short as possible"!
Decoupling capacitors and their right positioning are very important. They must be on the same side like the IC, and no via allowed between the capacitor an the IC-pin.
I think that will significantly improve the PLL performance (noise, jitter).
And don´t forget a decoupling capacitor on the supply of the 25 MHz oszillator!

They're on the other side of the board. Yes, they can be on the other side of the board. BGAs, dual row QFN, the reality of where your power and ground planes live..

That said, the decoupling is much less robust than used on the DS2000Z design.

[Guni]

Also, I would like to note that at first (as suggested by Rigol engineer) I have upgraded the bootloader of my scope, then I upgraded firmware to version 00.04.02 SP3 and finally to 00.04.02 SP4.
I'm not sure if such procedure is necessary (Dave didn't do that on video) but that is what I got from Rigol and I have no reason not to listen to their advices.
At last I can enjoy my DSO as it is written on the screen after successful upgrade precedure 

Can you explain "bootloader upgrade"? On the officially published Rigol's update there is only firmware. I first time listen about bootloader update.
BTW
Very nice illustration before-after update!

[michalK]

Honestly I was surprised when I read that bootloader needs to be updated.
To be 100% accurate below you can read an e-mail I got from Rigol:

"To be on the save side, I suggest to upgrade first to 00.04.02 SP3 and afterwards to 00.04.02 SP4
Therefore please start with the bootloader update... followed from the Firmware update 00.04.02 SP3
afterwards with the Firmware 00.04.02 SP4"

I had the same firmware version as Dave on the video, 00.04.01 SP2. As you could see he simply loaded 00.04.02. SP4 firmware without any additional steps. Probably method suggested by Rigol engineer is super safe way of doing the same thing.

[radiogeek97]

for those of us that have and want to retain "upgrades/hacks" i would be hessitant to update the bootloader unless absolutely necessary.  You may wind up with a locked instrument like the dsa815

[Jamieson]

The firmware update fixed both the 5us and AC trigger coupling issues on my DS1054Z.  This unit was ordered in November from TEquipment and delivered on December 24th.  Nice work Rigol!

[Guni]

Honestly I was surprised when I read that bootloader needs to be updated.
To be 100% accurate below you can read an e-mail I got from Rigol:

"To be on the save side, I suggest to upgrade first to 00.04.02 SP3 and afterwards to 00.04.02 SP4
Therefore please start with the bootloader update... followed from the Firmware update 00.04.02 SP3
afterwards with the Firmware 00.04.02 SP4"

I had the same firmware version as Dave on the video, 00.04.01 SP2. As you could see he simply loaded 00.04.02. SP4 firmware without any additional steps. Probably method suggested by Rigol engineer is super safe way of doing the same thing.

So, I think booloader update means - step by step upgrade from 00.04.01 SP2->00.04.02 SP3>00.04.02 SP4, not direct.
We (or only I) don't know Rigol's firmware version numbering and changelogs as well. Logically 00.04.01.SP2 -> 00.04.02 SP3 is more important update with bootloder upgrade. From 00.04.02 SP3 ->00.04.02 SP4 is just a minor update.

[dentaku]

Great video  and it wasn't too long at all. These types of videos are worth taking the time to do right.

[womai]

Tried the new firmware version. Below are the jitter pictures before and after the update (input: 20 MHz sine wave, looking at it 5 us after the trigger). As you can see my scope (DS1054Z) had a pretty bad case of "jitteritis", around 13ns pk-pk (see cursors), but the update cured it completely! Very happy about it.

[Smokey]

Great job on the video.  Putting some quantitative values (and plots) to the problem really helps hammer it home.

A suggestion:
Topics like this could really benefit from their own text page in addition to the video.  Something like a report that people could link to and reference.  The video is great, but not really something people can reference for details easily.  I bet you could get a lot more hits if you had a text blog post report of the findings in the video with some screenshots of the important parts. 

Also, maybe you could also use that page, or a section of it or something, as an up to date summary of the HUGE forum thread about the topic.  Once a forum thread takes off like this one, it becomes really had to keep up with it, and I know I personally give up really trying at some point.  I know some of the phone hacking sites dedicate the first post as the current summary of the thread.  That's really useful.

Just some thoughts.

[Daniel 74]

Looking at the video, I noticed that one inductor pair is placed in parallel and another pair is placed in-line. These should be placed in right angles with respect to each other.
This seems like asking for trouble in sensitive circuits like PLLs. Considering the tolerances on the parts, this could be the source of the problem and also could explain why the behavior is not consistent on all oscilloscopes.

[ConnorGames]

If anyone else has a spectrum analyzer and affected scope, it would be interesting to see if Rigol has just come up with a new set of hard-coded coefficients, or if they are doing some kind of "autotuning" on the PLL.

[Bud]

Follow blog #683, where the root cause of the problem was identified and which is where analysis was done on a pre updated scope and will be repeated on a post update one. We will not be cross posting in two threads. If interested in details of how the investigation developed, read the above blog from page 19 on.

[max666]

It is a bit strange that Dave did not provide a link with the original post.

http://beyondmeasure.rigoltech.com/acton/ct/1579/s-0518-1412/Bct/l-sf-lead-0006/l-sf-lead-0006:16888/ct2_0/1?sid=W41SWJyI3

Thanks for posting the link, Lightages.

My unit didn't actually show the 5µs jitter before and it also shows no clock jitter after the update (I checked lots of other delays too).
But my unit was really bad at AC Trigger Coupling (it didn't even trigger on the rising edge as it's supposed to). The firmware update fixed the whole AC Trigger Coupling completely 
I really like the AC Trigger Coupling. Sometimes if you have an AC signal with DC offset and the DC offset varies slowly and you want to look at the whole signal and not just the AC part, it's really handy to have AC Trigger Coupling so you don't have to constantly readjust the trigger level.

Boot-Time stayed practically the same before and after the firmware update.

before   Boot Time 32 s	0 µs	5 µs	AC Trigger Coupling
after   Boot Time 34 s	0 µs	5 µs	AC Trigger Coupling

EDIT: ns -> µs typo fixed

[aargee]

I've updated my firmware and all is good with the 5uS jitter and the AC coupled trigger.

Interestingly, bootup was 19 seconds before AND after the upgrade.

[vargoal]

I should be getting my DS1054Z this month, fingers crossed that it doesn't have jitter issue. But being that I am friends with Murphy I am sure it will.

[womai]

max666,

>>My unit didn't actually show the 5ns jitter before

Actually the worst-case position is 5 us (MICROseconds), not 5 ns (NANOseconds), since the timing modulation is 100 kHz. So looks like you checked a delay that was 1000x too short, no wonder you did not see any noticeable jitter...  :=)

[DanielS]

Actually the worst-case position is 5 us (MICROseconds), not 5 ns (NANOseconds), since the timing modulation is 100 kHz. So looks like you checked a delay that was 1000x too short, no wonder you did not see any noticeable jitter...  :=)

If you look at his actual screen dumps, they show 5µs as expected. His 5ns titles were just  brain farts.

[Lightages]

I just did the update and all went well. \there is zero evidence of jitter at 5us and none with AC trigger coupling. My boot time remains around 18 seconds. All upgrades remain enabled. System info show 00.04.02 SP4 and hardware 0.1.1

For me this is now a prefect perfectly functional scope, except for some personal gripes that I will cover another day in a video.

[mauroh]

Most probably is just me with a low knoledge of DSOs basics, but to verify the new firmware i was playing with a 20MHz oscillator and notice that if I enable 3 or 4 channels the signal jitters.

Is this just due to the 250MSa/s that the scope is only capable with 3 or 4 enabled channels?

I've tried with 9MHz and 4MHz with the same result.

Mauro

[Lightages]

Just tried with all four channels enabled and I saw nothing.

[DanielS]

Is this just due to the 250MSa/s that the scope is only capable with 3 or 4 enabled channels?

This is not jitter; this is noise and some of it is indeed attributable to the lower sampling rate when using two or more channels.

The clock jitter issue this thread is about is for the delayed sweep function - when you want acquisition to start a certain amount of time after trigger. Some people noticed that the 1000Z and 2000A series scopes had periodic jitter every 5µs worth of trigger delay. You would need to setup such a delayed sweep to see if yours has it. On your screen, the delay is set to zero, which means you are staring directly at the trigger. You will never see jitter (at least not the type this thread is about) there.

[mauroh]

Is this just due to the 250MSa/s that the scope is only capable with 3 or 4 enabled channels?

This is not jitter; this is noise and some of it is indeed attributable to the lower sampling rate when using two or more channels.

To Lightages: do you have a DS1054z? Mine is a DS1104z and I guess 100MHz bandwidth is "too much" if the scope is acquiring only 250MSa/s.

Thanks DanielS for the clarification, but I'm not totally convinced that it is just "noise". I'll search some nice literature online about Sample Rates vs Bandwidth and i guess I'll find our friend Nyquist introducing me again her daughter Aliasing 

Limiting the bandwidth to 20MHz the signal is much more stable

Mauro

[Lightages]

I have a DS1054Z "upgraded" to 100MHz.

[tggzzz]

I'll search some nice literature online about Sample Rates vs Bandwidth and i guess I'll find our friend Nyquist introducing me again her daughter Aliasing 

And I'm quite sure you will see that it is perfectly reasonable (in theory and in practice) to sample, say, a waveform with 3GHz components at 100MS/s.

Of course there is the proviso that the signal you wish to extract has a bandwidth <50MHz

[mauroh]

I have a DS1054Z "upgraded" to 100MHz.

Well this is strange... I have a DS1074Z "upgraded" to 100MHz
Have you tried with a sine wave or square?
I'm using some crystal oscillators and I expect all DS1104Z will behave in the same way under the same condition...

[rf-loop]

Most probably is just me with a low knoledge of DSOs basics, but to verify the new firmware i was playing with a 20MHz oscillator and notice that if I enable 3 or 4 channels the signal jitters.

Is this just due to the 250MSa/s that the scope is only capable with 3 or 4 enabled channels?

I've tried with 9MHz and 4MHz with the same result.

Mauro

It is one form of aliasing.
Your signal have frequency components over Nyquist and these produce classic "corner wobbling".  It is well explained in many places, example in some Agilent(Keyshit) papers.  (also there is Rigol  very poorly  implemented "Sin(x)/x" fake in DS1000Z, as described previously, example here: https://www.eevblog.com/forum/testgear/rigol-ds1074z-weird-signal-level-problem/msg563208/#msg563208 )

[mauroh]

It is one form of aliasing.
Your signal have frequency components over Nyquist and these produce classic "corner wobbling".  It is well explained in many places, example in some Agilent(Keyshit) papers.  (also there is Rigol  very poor implementation if "Sin(x)/x" fake)

Yes, in this few minutes I had a very pleasant reading of the following paper:

http://cp.literature.agilent.com/litweb/pdf/5989-5732EN.pdf

Thanks to everyone for the quick and friendly feedback.

Mauro

[max666]

Actually the worst-case position is 5 us (MICROseconds), not 5 ns (NANOseconds), since the timing modulation is 100 kHz. So looks like you checked a delay that was 1000x too short, no wonder you did not see any noticeable jitter...  :=)

If you look at his actual screen dumps, they show 5µs as expected. His 5ns titles were just  brain farts.

Ooops, must have been looking at my scope upside down

Most probably is just me with a low knoledge of DSOs basics, but to verify the new firmware i was playing with a 20MHz oscillator and notice that if I enable 3 or 4 channels the signal jitters.

Is this just due to the 250MSa/s that the scope is only capable with 3 or 4 enabled channels?

I've tried with 9MHz and 4MHz with the same result.

Mauro

Interesting, I took a look myself.
Picture 1 at 1000MSa/s looks fine, note that it says sin(x)/x=ON. Funnily you can't disable sin(x)/x on 1000MSa/s and 500MSa/s.
Picture 2 at 250MSa/s ... oh boy!
But watch what happens when I disable sin(x)/x in Picture 3   

[Agent24]

and what would you expect from a $500 scope ?

I would expect that they had checked that their phase locked loops were actually locked! If not just stuff an RC oscillaroe in there!

Ditto for a $200 scope.

If their engineering appears to be, um, "slapdash" in one area then it probably is in others too.

Like the awful quality CapXon capacitors all through the power supply?

[Neddie]

where can I get a copy of the new firmware?
Cheers
Ned

[tautech]

and what would you expect from a $500 scope ?

I would expect that they had checked that their phase locked loops were actually locked! If not just stuff an RC oscillaroe in there!

Ditto for a $200 scope.

If their engineering appears to be, um, "slapdash" in one area then it probably is in others too.

Like the awful quality CapXon capacitors all through the power supply?

Really. 
Oh dear.

Can others confirm this?
Agent24 can you post a photo?

[Agent24]

and what would you expect from a $500 scope ?

I would expect that they had checked that their phase locked loops were actually locked! If not just stuff an RC oscillaroe in there!

Ditto for a $200 scope.

If their engineering appears to be, um, "slapdash" in one area then it probably is in others too.

Like the awful quality CapXon capacitors all through the power supply?

Really. 
Oh dear.

Can others confirm this?
Agent24 can you post a photo?

No need, it's all here in Dave's teardown: http://youtu.be/kb9P1Am9aFU?t=13m36s

Quite sad since the old model used Nichicon. It's a total nosedive in quality. I've seen so many blown CapXons on Badcaps.net and replaced many myself, mostly in LCD monitors.  I don't know which brand Dave thinks is worse than CapXon, maybe Samxon, but AFAIK they are actually better, though the Samxon GF series seem to be pretty horrible.

[Towger]

where can I get a copy of the new firmware?
Cheers
Ned

You can apply on their website. When I did it, I got a reply back within a hour or so. Depending on your current firmware version they may recommend that you update the bootloader as well, with an another update, before updating to the latest firmware. However, if you don't want to contact Rigol there are links in pervious posts to the latest update and I have seen no complaints from those who skipped the bootloader update.

For the record, my boot time from 'switch on' to 'trace display', with only ch1 on and no probes connected are:

00.02.01.SP1 - 29.6 seconds
00.04.02.SP3 - 33.7 seconds -> This is the update with the latest bootloader. File name 'DS1000Z(boot)Update_00.04.02.zip' containing folder 'Sparrow(boot)Update_00.04.02.03.00'.  For those complaining there are no release notes, this file also contains a Word document with 18 pages of changes in both Chinese and English.
00.04.02.SP4.07 - 33.7 seconds
00.04.02.SP4.07 After Self  - 33.8 - No difference.

I was also sent a 'DS1000Z(ARM)Update_00.04.02.zip', but this appears to contain the same update as the 'DS1000Z(boot)Update_00.04.02.zip' without the bootloader, so I did not bother installing it.

BTW. My scope is an early *real* DS1104Z and I could not reproduce either of the two bugs.

[Orange]

and what would you expect from a $500 scope ?

I would expect that they had checked that their phase locked loops were actually locked! If not just stuff an RC oscillaroe in there!

Ditto for a $200 scope.

If their engineering appears to be, um, "slapdash" in one area then it probably is in others too.

Like the awful quality CapXon capacitors all through the power supply?

Really. 
Oh dear.

Can others confirm this?
Agent24 can you post a photo?

It's probably not going well with your Siglent sales is it ? 

[Neddie]

Found the firmware link , thanks.

[DanielS]

I've seen so many blown CapXons on Badcaps.net and replaced many myself, mostly in LCD monitors.  I don't know which brand Dave thinks is worse than CapXon, maybe Samxon, but AFAIK they are actually better, though the Samxon GF series seem to be pretty horrible.

To be fair, the majority of blown CapXon caps are put in applications they are grossly under-spec'd for in the first place, so a large part of their failure is due to negligent design from the downstream product engineering: if you take the best caps ever made and run them at 4-10X their rated ripple current in an environment where they may be exposed to temperatures over 80C, as is often the case in poorly designed SMPS, they will fail prematurely too. The products could also be engineered for failure: stress the caps just enough to guarantee the PSU will fail soon after the warranty expires.

In the 1000Z's case, the caps likely see less than 1A ripple since there are 2-4 of 'em per supply output. The whole unit only consumes 40W including PSU losses and the enclosure has a fan guaranteeing airflow, so the caps' operating temperature will be hardly anything over ambient.

Rigol wants to earn market share and they are not going to earn much respect if they design products that systematically fail after 3-4 years due to shaving $1 on the BoM that could have let the products last a more reasonable 10 years. I would expect that Rigol has done their job and concluded that those CapXon will be good enough to give the scope service life comparable to the major-league manufacturers they want to compete with.

[Neddie]

Is this firmware update suitable for the DS2000 series of scopes?
Does not seem to have been mentioned in this thread.
Cheers
Neddie

[vinicius.jlantunes]

It is one form of aliasing.
Your signal have frequency components over Nyquist and these produce classic "corner wobbling".  It is well explained in many places, example in some Agilent(Keyshit) papers.  (also there is Rigol  very poor implementation if "Sin(x)/x" fake)

Yes, in this few minutes I had a very pleasant reading of the following paper:

http://cp.literature.agilent.com/litweb/pdf/5989-5732EN.pdf

Thanks to everyone for the quick and friendly feedback.

Mauro

Very nice document this one from Agilent. Interesting to see them showing the problems on the LeCroy and Tek scopes 

[Agent24]

I've seen so many blown CapXons on Badcaps.net and replaced many myself, mostly in LCD monitors.  I don't know which brand Dave thinks is worse than CapXon, maybe Samxon, but AFAIK they are actually better, though the Samxon GF series seem to be pretty horrible.

To be fair, the majority of blown CapXon caps are put in applications they are grossly under-spec'd for in the first place, so a large part of their failure is due to negligent design from the downstream product engineering: if you take the best caps ever made and run them at 4-10X their rated ripple current in an environment where they may be exposed to temperatures over 80C, as is often the case in poorly designed SMPS, they will fail prematurely too. The products could also be engineered for failure: stress the caps just enough to guarantee the PSU will fail soon after the warranty expires.

It's possible, but I am not sure they are overstressed. In the same LCD PSUs I repaired where all the CapXons where blown, there were also a couple of Taicon capacitors on the PSU outputs that were still just fine with ESR well in spec and everything.

Same goes for a certain Delta Electronics PSU from an HP Proliant server. A mixture of UCC, LTec and a CapXon. Guess which one was blown?

In the same environment, where one brand of capacitor fails while the others do not, and that brand fails consistently in many other devices, it does not suggest to me that the design is the problem.

[tautech]

and what would you expect from a $500 scope ?

I would expect that they had checked that their phase locked loops were actually locked! If not just stuff an RC oscillaroe in there!

Ditto for a $200 scope.

If their engineering appears to be, um, "slapdash" in one area then it probably is in others too.

Like the awful quality CapXon capacitors all through the power supply?

Really. 
Oh dear.

Can others confirm this?
Agent24 can you post a photo?

It's probably not going well with your Siglent sales is it ? 

The Fact that a major Asian manufacturer is using these famous caps might not concern you but is sure as hell concerns me.
Let's hope others don't follow. 

@ Orange
I have supplied Rigol product, that's the reason I have an interest.

[DanielS]

In the same environment, where one brand of capacitor fails while the others do not, and that brand fails consistently in many other devices, it does not suggest to me that the design is the problem.

You need to check the actual specs of the capacitors and the actual current going through them if you can actually find the specs. Just the brand does not say much - if your mixed-bag PSU with various brands in various stages of blowing up are on different rails at different stages of power filtering (separated by inductors for example) then the ripple they get exposed to can be drastically different.

I have seen flyback power supplies with only a pair of caps rated at 900mA each for decoupling on a 25A output; clearly not intended to run anywhere near 100% load for any length of time. Many of the cheap PSUs I have repaired had caps that I cannot identify due to unfamiliar logos (if any) and model tag (if any) that do not match the brand so most likely do not match the spec they appear to be intended to be spoofs of.

[jeroent]

The board version on my DS1054Z jumped from 0.2.3 to 0.1.1 after the firmware upgrade. Weird...

[Neddie]

Done the upgrade to my hacked DS2072A (ie 2302A :0) )  FW now reads 03.03.sp1 HW 2.0
AC trigger issue fixed.
5uS Jitter issue not fixed :0( , better , but not fixed.

[Neddie]

Sorry , my bad. Jumped the gun a little there.
No 5uS jitter , just a crap sig gen 
Thanks Teneyes for making me check again !!!
Neddie

[Dutch RC]

Hi Way more skilled friends,

I'm Jasper a RC fan and I'm looking for a scope, yes I can go to ebay and try to find a analog scope instead of the DSO Nano I was looking for first. No I'm not going those ways, on ebay or our national trading website there aren't many scopes for sale, when I find one it's 150€ plus 70€ shipping. That's without probes.

So I think I want this Rigol DS1054Z Oscilloscope, why? Don't know because many say it's a good scope for beginners. And that's exactly what I am, a complete noob with some really basic electronics knowledge.

Then why do I want a scope? Well because I want to measure noise on drone power systems and latency on FPV camera's and systems.

I probably can use something more basic, though I want to get something I can use for many years, I can only spend each euro once so better do it right the first time..

Now why do I come here? Because I need to know if this can be done and where to find more information on what else I can use it for in my RC hobby, life whatever.

So please, is this suitable and future proof for a complete noob like me?

I'm open for any suggestions,

Best regards,

Jasper

[Dutch RC]

So I went through the some local shops websites and came across this Owon XDS3064E

It's the same price as the Rigol DS1054Z and because I'm a noob I don't know which one is the better one to get.

Please any help would be appreciated, for me it's all a bunch of numbers without meaning. The Owon has a larger screen but I can't find reviews about it.

[Brumby]

If the numbers don't mean anything to you, then I have to wonder if you are really ready to buy a scope.  IMO, you should at least know what the main specifications are all about before parting with funds.

Also, you might be better off posting your questions in the Beginners section.  Not every member here reads every thread.

You might also want to try using the forum's Search feature to see what has already been said.  Sometimes reading over a previous discussion on a subject can provide useful information - and sometimes that is information you didn't know you needed to know.

[Dutch RC]

Hi Brumby,

You are right I should learn the numbers, I didn't want to make a new thread because I thought this already was the one i was going to buy.
I want to measure latency and noise on power systems so I think i need a scope, Best way for me to learn is "hands on" and not by reading tons of posts with numbers that don't mean anything for me because I can't see, feel and smell what's going on.

I will watch the basics again on youtube and start another thread, Probably the ###no for beginners wanting a scope, I went through several already but like I said, I don't know which numbers "I" need for what "I" want to do.

I will try to search for "Latency'and "Noise" and maybe I learn something new.

THANKS!! 

Regards,

Jasper

[Brumby]

This thread is more for discussion about Dave's video, as mentioned in the title.  What it presents and what is discussed here can be helpful in deciding if the scope mentioned is worthy of your consideration - but that's not the primary reason for this thread's existence.

To cut a long story short, the 1054Z would likely be a good choice that would take care of your basic needs ... and for when you start getting a handle on stuff.   By the time you work out that you need something better, you will know what features and specifications to look for - but it is not impossible that the specifications of the 1054Z will serve you for many years.