Rigol HDO1000 and HDO4000 12bit oscilloscopes launched in China

[mawyatt]

Demonstration video about the visualization techniques, including the new ultra-acquire mode:

Nice!! Both videos well done and show off this new HDO4000, the large touch screen used in the video is nice 

Understand that one can utilize the firmware upgrades for the HDO4000 into the HDO1000 without any apparent issues!!

Much appreciated if someone could run the Two-Tone IMD at 100KHz, 1MHz & 10MHz to show the input channel linearity?

Best,

[markone]

-snip

Much appreciated if someone could run the Two-Tone IMD at 100KHz, 1MHz & 10MHz to show the input channel linearity?

Best,

Do you really want to ignite another discussion about measuring distortion with DSOs ? 

Jokes apart, I guess it would be necessary a quite high quality generator to discern DUT IMD from source IMD.

[David Hess]

Do you really want to ignite another discussion about measuring distortion with DSOs ? 

Jokes apart, I guess it would be necessary a quite high quality generator to discern DUT IMD from source IMD.

Oscilloscope inputs have poor linearity so the demands on the two-tone signal source are not great.

[markone]

Do you really want to ignite another discussion about measuring distortion with DSOs ? 

Jokes apart, I guess it would be necessary a quite high quality generator to discern DUT IMD from source IMD.

Oscilloscope inputs have poor linearity so the demands on the two-tone signal source are not great.

Ok, define "not great" with a number.

[David Hess]

Do you really want to ignite another discussion about measuring distortion with DSOs ? 

Jokes apart, I guess it would be necessary a quite high quality generator to discern DUT IMD from source IMD.

Oscilloscope inputs have poor linearity so the demands on the two-tone signal source are not great.

Ok, define "not great" with a number.

8 bits is roughly 51 dB SFDR and the analog front end linearity is unlikely to be even that good.  Good linearity is a tough problem in this case.

[mawyatt]

Do you really want to ignite another discussion about measuring distortion with DSOs ? 

Jokes apart, I guess it would be necessary a quite high quality generator to discern DUT IMD from source IMD.

Oscilloscope inputs have poor linearity so the demands on the two-tone signal source are not great.

Ok, define "not great" with a number.

8 bits is roughly 51 dB SFDR and the analog front end linearity is unlikely to be even that good.  Good linearity is a tough problem in this case.

Most modern quality AWGs will likely fit well within that range, since they originate the signal from 14~16 bit DACs and have decent buffer & scaling amplifiers. Some even support digital waveform combining within the instrument, at least our experience with the SDG2000X/6000X demonstrated this as an effective means of signal waveform addition/combining without significant linearity issues.

Best

[markone]

Do you really want to ignite another discussion about measuring distortion with DSOs ? 

Jokes apart, I guess it would be necessary a quite high quality generator to discern DUT IMD from source IMD.

Oscilloscope inputs have poor linearity so the demands on the two-tone signal source are not great.

Ok, define "not great" with a number.

8 bits is roughly 51 dB SFDR and the analog front end linearity is unlikely to be even that good.  Good linearity is a tough problem in this case.

Why do you mention 8 bits ?

[markone]

Do you really want to ignite another discussion about measuring distortion with DSOs ? 

Jokes apart, I guess it would be necessary a quite high quality generator to discern DUT IMD from source IMD.

Oscilloscope inputs have poor linearity so the demands on the two-tone signal source are not great.

Ok, define "not great" with a number.

8 bits is roughly 51 dB SFDR and the analog front end linearity is unlikely to be even that good.  Good linearity is a tough problem in this case.

Most modern quality AWGs will likely fit well within that range, since they originate the signal from 14~16 bit DACs and have decent buffer & scaling amplifiers. Some even support digital waveform combining within the instrument, at least our experience with the SDG2000X/6000X demonstrated this as an effective means of signal waveform addition/combining without significant linearity issues.

Best

I too own an SDG2042X and I'm aware it's now capable to internally combine channels but we have no specs about intrinsic IMD, so I do not see a lot of sense to source my scope with it and declare that everything "wrong" that I see is from the DSO, IMHO it would be necessary a signal generator with proved IMD specifications data.

[2N3055]

Do you really want to ignite another discussion about measuring distortion with DSOs ? 

Jokes apart, I guess it would be necessary a quite high quality generator to discern DUT IMD from source IMD.

Oscilloscope inputs have poor linearity so the demands on the two-tone signal source are not great.

Ok, define "not great" with a number.

8 bits is roughly 51 dB SFDR and the analog front end linearity is unlikely to be even that good.  Good linearity is a tough problem in this case.

Most modern quality AWGs will likely fit well within that range, since they originate the signal from 14~16 bit DACs and have decent buffer & scaling amplifiers. Some even support digital waveform combining within the instrument, at least our experience with the SDG2000X/6000X demonstrated this as an effective means of signal waveform addition/combining without significant linearity issues.

Best

I too own an SDG2042X and I'm aware it's now capable to internally combine channels but we have no specs about intrinsic IMD, so I do not see a lot of sense to source my scope with it and declare that everything "wrong" that I see is from the DSO, IMHO it would be necessary a signal generator with proved IMD specifications data.

It was tested and documented here on EEVBLOG...

[David Hess]

8 bits is roughly 51 dB SFDR and the analog front end linearity is unlikely to be even that good.  Good linearity is a tough problem in this case.

Why do you mention 8 bits ?

Because if the input signal conditioning has great difficulty achieving 8 bits of linearity, then 12 bits is much harder even than that.  This is one of the reasons that 8 bits has been considered largely sufficient for DSOs.

[markone]

Do you really want to ignite another discussion about measuring distortion with DSOs ? 

Jokes apart, I guess it would be necessary a quite high quality generator to discern DUT IMD from source IMD.

Oscilloscope inputs have poor linearity so the demands on the two-tone signal source are not great.

Ok, define "not great" with a number.

8 bits is roughly 51 dB SFDR and the analog front end linearity is unlikely to be even that good.  Good linearity is a tough problem in this case.

Most modern quality AWGs will likely fit well within that range, since they originate the signal from 14~16 bit DACs and have decent buffer & scaling amplifiers. Some even support digital waveform combining within the instrument, at least our experience with the SDG2000X/6000X demonstrated this as an effective means of signal waveform addition/combining without significant linearity issues.

Best

I too own an SDG2042X and I'm aware it's now capable to internally combine channels but we have no specs about intrinsic IMD, so I do not see a lot of sense to source my scope with it and declare that everything "wrong" that I see is from the DSO, IMHO it would be necessary a signal generator with proved IMD specifications data.

It was tested and documented here on EEVBLOG...

What do you mean, maybe that now SDG2KX  have official IMD numbers for channels combine function valid for entire frequency ranges ?

[markone]

8 bits is roughly 51 dB SFDR and the analog front end linearity is unlikely to be even that good.  Good linearity is a tough problem in this case.

Why do you mention 8 bits ?

Because if the input signal conditioning has great difficulty achieving 8 bits of linearity, then 12 bits is much harder even than that.  This is one of the reasons that 8 bits has been considered largely sufficient for DSOs.

Sorry but I miss the point, here we have a 12 bits scope and a request for a dual tones IMD test, my point was that without a signal source with a known IMD specification is not possible to proceed to test the DSO under that aspect.

Do you mean that is useless test ?

[mawyatt]

It was tested and documented here on EEVBLOG...

What do you mean, maybe that now SDG2KX  have official IMD numbers for channels combine function valid for entire frequency ranges ?

All joking aside, do your homework as suggested 

Best

[markone]

It was tested and documented here on EEVBLOG...

What do you mean, maybe that now SDG2KX  have official IMD numbers for channels combine function valid for entire frequency ranges ?

All joking aside, do your homework as suggested 

Best

 

[mawyatt]

As suggested there is lots of info on these measurements, just do a diligent search and you'll find it!!

Regarding the SDG2KX as a potential source for doing the DSO IMD testing. This sort of parameter may not be directly specified (maybe indirectly) but our AWG is not bad, maybe you should test yours with a good instrument (Spectrum Analyzer). Then you'll know if the major source of the IMD is the AWG or DSO, or both. Please remember this is Root Sum Squared result, so you may need to "back out" the IMD if the source and measurement are not >10dB apart.

Here's a quick SDG2KX test we did with a SSA3021X+ operating in it's "Sweet Spot". We used a Mini-Circuits 10dB PAD (always keep this N type PAD in place to protect the SA), and set the AWG CH1 and 2 to 0dBm (50 ohm reference), and frequency CH 1MHz, Ch2 1.01MHz. AWG Wave Combine is used, with output directed to Ch1.

SA center F of 1MHz with 100KHz span, and RBW & VBW of 1Hz. Judge for yourself the results shown below.

Edit: Added a couple more plots at 100KHz and 10MHz Center Frequency.

The point here is if the AWG is measuring this level of IMD on the SA, then you "know" the AWG is at least this good a source for use with such measurements, which as mentioned should be at least 10dB better than what your intended DUT is.

As always, KTI (Know Thy Instrument) and YMMV.

Best,

[mawyatt]

Believe the SDG2KX utilizes Quad-Oversampling, so the 1.2GSPS spec is somewhat misleading (please correct if this isn't true, don't want to spread any mis-information). This begins to show when producing a 100MHz based 2 Tone waveform, as artifacts begins to show up along the baseline noise floor likely caused by various "mixing" processes going on since each DAC update rate is only an effective 300MHz (1.2GSPS/4). With this in mind we wouldn't recommend our SDG2000X for a IMD source for 100MHz use.

We did check our SDG6000X at 100MHz. This has a 2.4GSPS, so if the Quad-Oversampling assumption is correct, then each DAC is 600MHz updated, and should produce less waveform artifacts. As expected it does at better job at 100MHz than the SDG2000X we have.

Here's the SDG2000X (#24) and SDG6000 (#23) at 2 Tone 100MHz Waveforms. Note both of these plots are using the Delta-Marker Function to show the 3rd Order IMD Products as dBc relative to the main two tones, we should have done this in the above plots 

As always, YMMV.

Edit: This thread is about the new Rigol HD series DSOs. Let's all hope they did a good job on the input amps and attenuators, and not degrade the 12 bit ADC. Others have shown a good job on the input referred noise, now lets hope the same for the linearity!!

Best

[David Hess]

Sorry but I miss the point, here we have a 12 bits scope and a request for a dual tones IMD test, my point was that without a signal source with a known IMD specification is not possible to proceed to test the DSO under that aspect.

Do you mean that is useless test ?

The signal source just has to be better than the possible performance of the DSO, but I have seen the transient response of "12 bit" DSOs, and none of them have 12 bit analog or noise performance.

[Fungus]

The signal source just has to be better than the possible performance of the DSO, but I have seen the transient response of "12 bit" DSOs, and none of them have 12 bit analog or noise performance.

Seems to me like you're asking the wrong questions.

The question is: Are they better than "8 bit" DSOs. In the case of these Rigols the answer seems to be a resounding "yes!"

[David Hess]

The signal source just has to be better than the possible performance of the DSO, but I have seen the transient response of "12 bit" DSOs, and none of them have 12 bit analog or noise performance.

Seems to me like you're asking the wrong questions.

The question is: Are they better than "8 bit" DSOs. In the case of these Rigols the answer seems to be a resounding "yes!"

They are better than the 8 bit Rigols, but *not* better than all older 8 bit DSOs or even analog oscilloscopes.  The 8 bit Rigols are particularly bad, so it is not difficult to improve on their performance.

Where the 12 bit DSOs do always perform better is FFT dynamic range; low RBW (resolution bandwidth) from a large FFT size minimizes the contribution from front end noise so performance is limited by quantization noise, although that does nothing to improve the SFDR which depends on the linearity.

[dreamcat4]

so does this make the siglent sds2000 plus a better overall / all round scope at the same price then?

[Fungus]

They are better than the 8 bit Rigols, but *not* better than all older 8 bit DSOs or even analog oscilloscopes.

 

so does this make the siglent sds2000 plus a better overall / all round scope at the same price then?

You're going to base a purchasing decision on a single person's claim that "all older 8 bit DSOs" are better than these?

(Edit: And using an incredibly narrow definition of definition of "better" that has nothing at all with user interface, noise levels, feature set, or ... anything else that will affect you in day-to-day life)

[markone]

The signal source just has to be better than the possible performance of the DSO, but I have seen the transient response of "12 bit" DSOs, and none of them have 12 bit analog or noise performance.

Seems to me like you're asking the wrong questions.

The question is: Are they better than "8 bit" DSOs. In the case of these Rigols the answer seems to be a resounding "yes!"

They are better than the 8 bit Rigols, but *not* better than all older 8 bit DSOs or even analog oscilloscopes.  The 8 bit Rigols are particularly bad, so it is not difficult to improve on their performance.

Where the 12 bit DSOs do always perform better is FFT dynamic range; low RBW (resolution bandwidth) from a large FFT size minimizes the contribution from front end noise so performance is limited by quantization noise, although that does nothing to improve the SFDR which depends on the linearity.

I remember very noisy Tek & Agilent 8 bits DSOs, much worse than current Rigol MSO5K, so I do not get your point, especially because is not supported by measured data.

This new Rigol 12bits line has nothing to do with previous ones under a lot of aspects, input noise and scope responsiveness are the first two things that you notice at first glance.

[Fungus]

This new Rigol 12bits line has nothing to do with previous ones under a lot of aspects, input noise and scope responsiveness are the first two things that you notice at first glance.

It's obviously a complete redesign. New hardware, new OS, new everything...

[markone]

so does this make the siglent sds2000 plus a better overall / all round scope at the same price then?

Do you really think that Rigol 12bits DSOs have inferior analog performance than Siglent SDS 2000x plus based on the fact that someone has expressed a personal opinion that is not supported by fact ?

[dreamcat4]

i have not taken any such position either way... it just seemed like a relevant question to ask. but such heated exchanges.

there is plenty of time to clear up those question. but it seems upon reviewing the last couple of pages there was some derailment between talking about difficulties measuring with the distortion from awg. which is a seperate matter itself

so the actual input distortion of these respective scopes. so no, i dont see how that has been sufficiently answered yet...

totally fine and no, i dont base my decisions based on just thin air. there has to be some real meat behind. its just a genuine case of:

well let me rephrase: if were true, (as a hypothetical). then what would it mean. because the sds2k has mixed signal, and perhaps less broken bugs in firmware etc.

but i had forgotton that the thing boots twice as long. its 1 minute boot time for the sds2k+, and only 30s for these new rigol hdo. so that alone i think would bother me to still prefer the rigol (all else being taken out of the equation)