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Rigol HDO1000 and HDO4000 12bit oscilloscopes launched in China

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rf-loop:

--- Quote from: David Hess on December 07, 2023, 12:12:35 pm ---
--- Quote from: 2N3055 on December 07, 2023, 06:26:30 am ---
--- Quote from: David Hess on December 07, 2023, 05:34:05 am ---...

Older DSOs tend to be worse, especially those with interleaved ADCs because of greater non-linearity in the digitizer.  On these instruments the "wobulation" goes away when random equivalent sampling is used because the equivalent time sample rate is so much higher so there can be no aliasing.  Modern instruments which lack equivalent time sampling can use averaging (HP/Agilent/Keysight recommended this in an application note), but I do not think this is as effective.
--- End quote ---

Siglent scopes have dot mode where they practically perform RIS (random interleaved sampling), although it is not marketed as such. If signal is triggering fast enough you get nice waveform reconstruction on repetitive waveforms, even when severely undersampled. So they don't market ETS or RIS but it still works as such.
--- End quote ---

That is effectively what HP/Agilent/Keysight recommended for DSOs which lack equivalent time sampling.  The problem is that even in dot mode, (sin x)/x reconstruction must still be used to determine the trigger point, so the aliasing moves the trigger point around corrupting the result.  Averaging helps, but it does not produce as accurate a result as equivalent time sampling.

As a practical matter, the difference should be irrelevant.  In both cases the bandwidth of the instrument is insufficient to accurately represent the signal.

--- End quote ---


Display mode dots, interpolation x
( I have reduced memory for get enough low samplerate for demonstrate this)

In this image Zoom window sample interval is 2 div (10ns)

Rise time here is <0.5*sample interval. I can not see big problems with trig position...

Of course can say that it is not accurately trig'd but...  how big problems you see there...  and this is not ETS.
There on screen is sequential acquisitions randomly interleaved (overlaid)

However, this method has limitations, although it is useful in some situations. Most of the time, our real-time sample rate is sufficient because the full 2GSa/s can be kept up to 10ms/div (SDS2000X Plus)
But as can see trigger position is still ok even when in this case sample interval is 2 div in this Zoom window (4000x Zoom ). Digital trigger engine after ADC can still handle this quite well.

core:

--- Quote from: rf-loop on December 07, 2023, 01:34:04 pm ---
--- Quote from: David Hess on December 07, 2023, 12:12:35 pm ---
--- Quote from: 2N3055 on December 07, 2023, 06:26:30 am ---
--- Quote from: David Hess on December 07, 2023, 05:34:05 am ---...

Older DSOs tend to be worse, especially those with interleaved ADCs because of greater non-linearity in the digitizer.  On these instruments the "wobulation" goes away when random equivalent sampling is used because the equivalent time sample rate is so much higher so there can be no aliasing.  Modern instruments which lack equivalent time sampling can use averaging (HP/Agilent/Keysight recommended this in an application note), but I do not think this is as effective.
--- End quote ---

Siglent scopes have dot mode where they practically perform RIS (random interleaved sampling), although it is not marketed as such. If signal is triggering fast enough you get nice waveform reconstruction on repetitive waveforms, even when severely undersampled. So they don't market ETS or RIS but it still works as such.
--- End quote ---

That is effectively what HP/Agilent/Keysight recommended for DSOs which lack equivalent time sampling.  The problem is that even in dot mode, (sin x)/x reconstruction must still be used to determine the trigger point, so the aliasing moves the trigger point around corrupting the result.  Averaging helps, but it does not produce as accurate a result as equivalent time sampling.

As a practical matter, the difference should be irrelevant.  In both cases the bandwidth of the instrument is insufficient to accurately represent the signal.

--- End quote ---


Display mode dots, interpolation x
( I have reduced memory for get enough low samplerate for demonstrate this)

In this image Zoom window sample interval is 2 div (10ns)

Rise time here is <0.5*sample interval. I can not see big problems with trig position...

Of course can say that it is not accurately trig'd but...  how big problems you see there...  and this is not ETS.
There on screen is sequential acquisitions randomly interleaved (overlaid)

However, this method has limitations, although it is useful in some situations. Most of the time, our real-time sample rate is sufficient because the full 2GSa/s can be kept up to 10ms/div (SDS2000X Plus)
But as can see trigger position is still ok even when in this case sample interval is 2 div in this Zoom window (4000x Zoom ). Digital trigger engine after ADC can still handle this quite well.



--- End quote ---


Very interesting, indeed. Thanks !

All we can get with sinc is below. Rigol doesn't like x and dots.

Fungus:

--- Quote from: thm_w on December 07, 2023, 01:31:17 am ---Anyone see with 2 channels on it seems to get way more vertical jitter? The waveform looks terrible, even at lower frequencies. Maybe an issue with my source or cable, odd it doesn't show up when on single channel though. Will try again later with a proper source.

--- End quote ---

The problem is trying to trigger at 2ns/div horizontal when you have 1GS/sec sample rate.

rf-loop:

--- Quote from: core on December 07, 2023, 01:48:19 pm ---
--- Quote from: rf-loop on December 07, 2023, 01:34:04 pm ---
--- Quote from: David Hess on December 07, 2023, 12:12:35 pm ---
--- Quote from: 2N3055 on December 07, 2023, 06:26:30 am ---
--- Quote from: David Hess on December 07, 2023, 05:34:05 am ---...

Older DSOs tend to be worse, especially those with interleaved ADCs because of greater non-linearity in the digitizer.  On these instruments the "wobulation" goes away when random equivalent sampling is used because the equivalent time sample rate is so much higher so there can be no aliasing.  Modern instruments which lack equivalent time sampling can use averaging (HP/Agilent/Keysight recommended this in an application note), but I do not think this is as effective.
--- End quote ---

Siglent scopes have dot mode where they practically perform RIS (random interleaved sampling), although it is not marketed as such. If signal is triggering fast enough you get nice waveform reconstruction on repetitive waveforms, even when severely undersampled. So they don't market ETS or RIS but it still works as such.
--- End quote ---

That is effectively what HP/Agilent/Keysight recommended for DSOs which lack equivalent time sampling.  The problem is that even in dot mode, (sin x)/x reconstruction must still be used to determine the trigger point, so the aliasing moves the trigger point around corrupting the result.  Averaging helps, but it does not produce as accurate a result as equivalent time sampling.

As a practical matter, the difference should be irrelevant.  In both cases the bandwidth of the instrument is insufficient to accurately represent the signal.


--- End quote ---


Display mode dots, interpolation x
( I have reduced memory for get enough low samplerate for demonstrate this)

In this image Zoom window sample interval is 2 div (10ns)

Rise time here is <0.5*sample interval. I can not see big problems with trig position...

Of course can say that it is not accurately trig'd but...  how big problems you see there...  and this is not ETS.
There on screen is sequential acquisitions randomly interleaved (overlaid)

However, this method has limitations, although it is useful in some situations. Most of the time, our real-time sample rate is sufficient because the full 2GSa/s can be kept up to 10ms/div (SDS2000X Plus)
But as can see trigger position is still ok even when in this case sample interval is 2 div in this Zoom window (4000x Zoom ). Digital trigger engine after ADC can still handle this quite well.



--- End quote ---


Very interesting, indeed. Thanks !

All we can get with sinc is below. Rigol doesn't like x and dots.



--- End quote ---

Of course you get around same but as you can see in my image samplerate was 100MSa/s  when you use 2GSa/s.
Now try to do same using 100MSa/s but same signal. Or if not possible set oscilloscope and signal so that sampling interval is least 2x longer than risetime.  Whole thing was just this... sampling speed far below fNyquist (risetime).


Naturally this below using 2GSa/s as is your image for same signal is just easy.. all can do it.
Sinc, and 2GSa/s. (yes but this is not 12bit scope)
As can also see there is now 100M bandwidth, so risetime bit reduced.. (because 8 bit scope run in 10bit mode)

RobbiOne:
Inside that web page:

https://int.rigol.com/products/detail/DHO1000

I just see a tech features of the scope and 3 links for manual, datasheet and demo request.
No firmware or download link.

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