New Rigol DS1054Z oscilloscope

[pascal_sweden]

(although no one has yet tested and posted a chart of the 50MHz roll-off).

Feel free to do so. Then we have facts on paper!

[Bert Camper]

Meltronics in Tel Aviv is the Rigol distributor for Israel.
http://www.meltronics.co.il/

[thisguy81]

Meltronics in Tel Aviv is the Rigol distributor for Israel.
http://www.meltronics.co.il/

Yes, allready looked into that. Besides the fact they done have this model yet,and dont know if they will, they offered me to buy the DS1052E for 500$US.

[iRad]

Too bad we can't roll the clock back on this one to message #37 and start over, where Dave says the following.

...people don't feel comfortable with this mathematical concept though.

As much as I enjoy Dave's posts, it's already been shown that he's incorrect in what he stated about the 100MHz bandwidth (although no one has yet tested and posted a chart of the 50MHz roll-off).

You deleted the part I was referring to... The mathematical concept of value for the buck.

I refuse to comment any further on this subject, as I'm not up to starting another unnecessary boxing match in this thread.   

[marmad]

You deleted the part I was referring to... The mathematical concept of value for the buck.

I refuse to comment any further on this subject, as I'm not up to starting another unnecessary boxing match in this thread.   

Yes... as you deleted the part directly before which it was referring to: the mathematical concept of bandwidth times sample rate. 

[edavid]

At least one of the two (of the worst offenders) finally realizes it...

Oh, I've realized it all along. The question is: would it better to just not respond when someone makes unsupported allegations about problems the DSO has?

YES

As the Talking Heads put it, Say something once, why say it again?   Of course it's always easier to apply this rule to someone else.

ETA: By which I mean, it's fine to disagree with someone, but try not to insist on having the last word.  Open minded people will get your point.

[pa3bca]

I also ordered the DS1054Z from Batronix a week ago. Unfortunately they were not in stock so I will have to wait at least another three weeks (according to their website). Bummer

You should have tried arBenelux, they had one in stock last week.

Yes, I have no affiliation with them, but if you live in the Netherlands and need a Rigol device do buy from them. I bought several Rigol devices there and their service is excellent.
Example: after about 3 months of use my DS2072 developed a problem on channel 1 (signals were 20+ dB down). No idea why, I don't think it was because I made a mistake. Anyway, they called me back the next day, telling me that they couldn't fix it themselves and we going to send the device back to Rigol. AND they were going to send me a new one the same day, at no cost and again with a full 3 years of warranty.
Recommended!

[marmad]

YES

As the Talking Heads put it, Say something once, why say it again?   Of course it's always easier to apply this rule to someone else.

Not to worry: I have a MSO1000Z arriving in a couple of days, so I'll start a separate thread discussing it's capabilities/limitations.

Of course, no Americans allowed (except Mark O!)

[pa3bca]

At least one of the two (of the worst offenders) finally realizes it...

Oh, I've realized it all along. The question is: would it better to just not respond when someone makes unsupported allegations about problems the DSO has?

YES

As the Talking Heads put it, Say something once, why say it again?   Of course it's always easier to apply this rule to someone else.

Hmm I know it it's always the ones with the outspoken / strong opinions your hear of. I am curious how the silent minority in this forum feels about this issue.
Anyway, I think that the end result of the discussion(s) is an enhanced insight in the performance of the scope & there are things to be learned and understood (for instance the leakage issue near Fnyquist was an eye-opener for me).

[rolycat]

As much as I realize there has been some off-topic (or close to off-topic) stuff, there has also been a serious discussion about the capabilities/limitations of the DSO.

And I for one am grateful for it. As Harry Callahan (almost) said, a man's got to know his scope's limitations.

As has been observed elsewhere, forum threads are not the best place for neatly packaged, predigested knowledge such as that found in textbooks or wikis. They are rather more like research notebooks; little nuggets of new information which may be available nowhere else, embedded in strata of less useful data.

[radiogeek97]

Thanks to dave's review and to all the helpful folks here!  I sold my trusty 1052E on Ebay for a very good price and ordered my 1054z last night from T-equipment.  Unfortunately they are on back order for atleast 2 weeks     Will post my first impressions/ findings when it arrives 

[David Hess]

Oops. My bad. The 10 MHz is indeed your blue line riding the wavecrests, not my (5 MHz) red line. Was not paying attention (and counting) as I was trying to reconcile the two signals (120 and 130) into a DSB waveform.

What kind of results do you get when averaging is used?

On my 2440 I can recover the original waveform at the wrong amplitude which is then rectified if I enable ETS.

[David Hess]

Two guys typing furiously:
"That is caused by non-linearity and sampling jitter in Rigol's digitizer."
"Uhh... no it isn't."
"Ok, THAT is caused by non-linearity and sampling jitter in Rigol's digitizer."
"No proof of that."
"Well, THAT is caused by non-linearity and sampling jitter in Rigol's digitizer."
"No, that's something else."
....
....
Rinse and repeat. 

I agree that I initially chased the wrong problem but none of the signal sources used in the tests would have revealed the non-linearity discussed in the Agilent document I linked.

The interleaving issue affecting non-linearity came back with your own post although I did not bring it up then.  The datasheet you linked for the HMCAD1511 specifically mentions and includes specifications for "interleaving spurs" leading to an 13 dB difference in SFDR at 71 MHz.

On the bright side, I now have a clearer understanding of the limitations of Rigol's DSOs and other DSOs and I know better what tests to do when evaluating them.

[David Hess]

If the filter was long enough, then the 130 MHz image would have been removed.  The filter however is shorter than this because of both performance reasons and because the filter length subtracts from the usable record length at the ends where a full set of samples is not available to calculate it.

Hm I think I can see how with (much) longer sampling you might get rid of the mirror (leaked) frequency, as the sampling points "move" over the fundamental. but, but... wouldn't that be ETS?? sounds like cheating?

It would not be ETS any more than triggering after reconstruction which happens now.  It would still work on a single acquisition.  Incidently, ETS works with single acquisitions by aligning the waveform with the trigger point producing the same result as triggering after reconstruction.

Longer FIR filters require both proportionally more processing and more memory so it is not surprising that the minimal acceptable size is used.  This is especially a problem with FPGA based designs where the reconstructed sample rate is higher than the FPGA multiplier cycle time so the logic for the filter would have to be duplicated multiple times.  The filter could be implemented after acquisition like older DSOs but then the beginning and end of the acquisition record would need to be truncated where the input to the filter is invalid and high waveform acquisition rates would be more difficult.

Even in the best case, what would be gained?  The difference between 100 MHz and the 125 MHz Nyquist frequency is only 25 MHz.  I could see having it as a post-processing option on a long record length DSO.

[marmad]

DSOs with longer and sharper reconstruction filters will display more accurate results up to their Nyquist frequency.

I have seen no evidence that any DSO manufacturer is doing this. Tek claims their FIR filters pass frequency components up to 80% of the Nyquist frequency - which, coincidentally, is 100MHz @ 250MSas/s rate - same ratio as what we see on the Rigol DS1000Z. Do you have have any specs or docs from any DSO that claim a higher percentage? It's all well and good to claim that something is mathematically possible - like travelling at just under the speed of light -  but it's quite another thing to realize it. 

[Fungus]

Oh, I've realized it all along. The question is: would it better to just not respond when someone makes unsupported allegations about problems the DSO has?

YES

As the Talking Heads put it, Say something once, why say it again?   Of course it's always easier to apply this rule to someone else.

What if somebody drops in here and only reads the last few posts? If the only person still posting is the idiot/moron then they might get completely the wrong idea.

You don't have to write essays, just say "Nope, you're still wrong - re-read previous answers".

[leppie]

BLAH BLAH BLAH BLAH ....

What if somebody drops in here and only reads the last few posts? If the only person still posting is the idiot/moron then they might get completely the wrong idea.

I agree. This thread puts some threads on XDA to shame ;p

FFS US$399!!!!

Works just fine on 8Mhz SPI signals and decoding/triggering 4 channels, what more do you need? 

[Fungus]

FFS US$399!!!!

Yep, I can't believe anybody is nitrpicking over a $400 oscilloscope that can do as much as this one can. Demanding proof that the hack version really does have 100Mhz, because it's a ripoff if it doesn't (or something). I dunno what their point is to be honest, this thing's a total bargain even at 50MHz.

     

[Mark_O]

On my 2440 I can recover the original waveform at the wrong amplitude, which is then rectified if I enable ETS.

Full-wave or half-wave?   

[DanielS]

Yep, I can't believe anybody is nitrpicking over a $400 oscilloscope that can do as much as this one can.

While it is incredible for the price, apparent oversights and rounded corners are still apparent oversights and rounded corners though.

This is just like any tool: once you know one of your favorite tools has a quirk you do not like, it will always be on the back of your mind regardless of how great it is otherwise.

[aargee]

Seems to me a psychological problem rather than a problem with the tool.

Can it be fixed? Yes - make it so. No - oh well, that's life. Move on, nothing to see here.   

I'm just amazed at the bang per buck of this stuff, it just kills pro stuff I've worked with in the not too distant past.

Maybe a "Pushing the Rigol 1000Z series to the limits" thread is needed?

 

[EEVblog]

FYI those in Oz who have been asking.
Emona will have stock on the 11th Nov.
I suspect they might sell out.

[pa3bca]

What kind of results do you get when averaging is used?

On my 2440 I can recover the original waveform at the wrong amplitude which is then rectified if I enable ETS.

Averaging has (as I expected) no effect on the displayed waveform. That is, if triggering is on the top of the highest wave so the display is stable in normal mode. See attachments.
If I have the trigger level on 0 volt the display is of course not stable, and in that case averaging shows a somewhat constant amplitude that is, indeed, the average of the amplitude(s)

The frequency counter is totally lost here The counter is not a HW counter as in the DS2000 series.

[David Hess]

What kind of results do you get when averaging is used?

On my 2440 I can recover the original waveform at the wrong amplitude which is then rectified if I enable ETS.

Averaging has (as I expected) no effect on the displayed waveform. That is, if triggering is on the top of the highest wave so the display is stable in normal mode. See attachments.
If I have the trigger level on 0 volt the display is of course not stable, and in that case averaging shows a somewhat constant amplitude that is, indeed, the average of the amplitude(s)

Thank you for checking this.  It is what I expected as well.  I thought Rigol might have some special trick for handling this usage case but there really is no reason to.

Old DSOs with analog triggering behave differently because the trigger sees the original waveform without the aliasing and not what is shown when single shot acquisitions are made.  Both return misleading but different results.  If the signal source is a fast edge instead of a high frequency sine wave which is a more typical application, then both should return the same non-misleading results when averaging is used.

The frequency counter is totally lost here The counter is not a HW counter as in the DS2000 series.

I did not know the DS2000 series has a hardware counter.  Those are very nice to have sometimes.

[marmad]

There are now so many DS1000Z threads that it's difficult to know where to post, but since we've been discussing the subject of sample rates and aliasing here, I figured I'd post it here (with a link over from the main DS1074Z thread).

Until now, the only info about the 20MHz BW limit roll-off I've seen was this graph made by seronday (which I used earlier in this thread when making a possible overall BW graph for the DS1000Z). Well, I don't have the necessary equipment to do a proper BW graph (no signal generator that goes high enough), but my simple test seems to indicate that either seronday's graph is wrong - or there is a lot of difference among the various models (I've got a MSO1074Z). Perhaps some other owners would like to test this as well?

In seronday's graph, he shows 100MHz as being attenuated to about -11.3dB when the 20MHz BW limit is turned on.   Edit: I think I stayed up too late working that night  - seronday's graph pretty well matches my own measurement.

My test shows a 100MHz 400mV sine being attenuated to ~-7.8dB.

First, here is a 100MHz sine on the DS2000, with and without the 20MHz limit on (-13.2dB down):






And here is a 100MHz sine on the MSO1000Z, with and without the 20MHz limit on (-7.8dB down):