Rigol HDO1000 and HDO4000 12bit oscilloscopes launched in China

[mawyatt]

Thanks for the plots

Can you keep the span for each frequency the same at roughly 50KHz? You will need to increase the sweep time to improve the frequency resolution. Using a slower sweep time will allow better frequency resolution and allow the 3rd order IMD products to be shown a little better, as they should stand out above the FFT noise floor which is helped with FFT averaging as shown.

Here's an example at 100KHz with 50KHz span, and added a 1MHz version.

Thanks again!!

Best,

[tomud]

Personally we haven't seen much Rigol bashing here (actually more Siglent bashing), mostly just folks trying to gather information on this very interesting new HD DSO from Rigol.

Disclaimer, we don't own any Rigol equipment (yet), mostly Siglent and HPAK, also Keithley, GW Instek, Hioki, Tonghui, and Tek.

Because to tell the truth, there is probably no Siglent fanatic here.

Martin72 changed MSO5000 to Siglent - I am not surprised reading his posts and what were the problems with the MSO5000 after they were launched on the market.

Personally, apart from products of renowned companies (R&S, HP/Agilent, etc.), I have more Rigol equipment than Siglent. The purchase of SSA from Siglent convinced me a bit to this company. Although the recent purchase of the SDM3065X and its firmware has spoiled this good Siglent picture a bit. In fact, I would kick the ass of the manager who is responsible for this product. On the other hand, I read on the forum about SDM and knew what I was getting into, so I can't blame anyone. Here, a much lower price and the lack of Keysight 34465A equipment on the market and the increase in its price decided on the choice.

As a forum hobbyist, I want to learn about hardware, whether it's Rigol or Siglent, but from people who are able to write about hardware and have hands-on experience with it. This always allows you to make a purchase decision and reduces the likelihood that the equipment will be returned to the seller.

However, the fact that there are internet storytellers who know everything about the equipment mainly after seeing its photos on the internet will no one can change that 

Only Tautech is a seller and promotes Siglent equipment a bit, on the other hand, at least he tries to help everyone when they have a problem with Siglent equipment - even if you didn't buy this equipment from him. So you can forgive him to some extent 

[tautech]

Mawyatt, I don't know if it is good enough, but I own a SDG 2K AWG that work with wave combine.
If you suggest me a setup(delta F) I can try to show a FFT on HDO1K.

Thanks!!

Recently we did some IMD tests with our SDG2K on here with the Combine Mode, but can't remember where.

Here ?
https://www.eevblog.com/forum/testgear/two-tone-test-with-scope-and-sa/

[tautech]

Only Tautech is a seller .............

Be very afraid, there are a few more of us here. 

[mawyatt]

Personally, apart from products of renowned companies (R&S, HP/Agilent, etc.), I have more Rigol equipment than Siglent. The purchase of SAA from Siglent convinced me a bit to this company. Although the recent purchase of the SDM3065X and its firmware has spoiled this good Siglent picture a bit. In fact, I would kick the ass of the manager who is responsible for this product. On the other hand, I read on the forum about SDM and knew what I was getting into, so I can't blame anyone. Here, a much lower price and the lack of Keysight 34461A equipment on the market and the increase in its price decided on the choice.

Agree about the SDM3065X, this is our least favorite Siglent equipment and has been relegated to just measuring lab temperature, we rely on the three KS34465A, DMM6500, AG34401A and HP34401A for DMM measurements.

Also agree tautech has been very helpful for folks with Siglent equipment, however haven't seen anyone as helpful with Rigol tho!!

Best,

[Martin72]

But there must be "rigol people" here....
When I still owned the MSO5000 I was in contact with Rigol support almost weekly.
Every time I wanted to send a link to something, the answer was you don't need it, we know the thread...

[skander36]

Thanks for the plots

Can you keep the span for each frequency the same at roughly 50KHz? You will need to increase the sweep time to improve the frequency resolution. Using a slower sweep time will allow better frequency resolution and allow the 3rd order IMD products to be shown a little better, as they should stand out above the FFT noise floor which is helped with FFT averaging as shown.

Here's an example at 100KHz with 50KHz span, and added a 1MHz version.

Thanks again!!

Best,

These are the best I can get, I think.
Unfortunately, over a certain sweep time, the signal don't offer good results.

[mawyatt]

We don't have the Rigol HD DSO, so not sure how the FFT works.

Can you scale the Vertical axis with Ref and Scale/div?

Can you select the time sweep to improve noise floor?

Is FFT averaging available to drive down the noise floor and show the IMD products better?

BTW does the FFT allow cursors? This really helps with evaluating signals, especially if they have a relative measurement.

Anyway, thanks so much for the effort and measurements,

Best,

[Fungus]

Do we listen because "You don't have to own something to know anything about it", or "Sorry, but unless you own one you can't possible know anything about them. Reading things in forums doesn't count. That's just the way it is."

So which is it

One of those is sarcasm for the guy simultaneously telling me I know nothing because I only read about them in forums but that he knows something because he read it in a forum.

Me? I only mentioned the user interface, not anything technical, and I added a disclaimer. Apparently that was enough to enrage a lot of people and derail an entire thread. 

I'm still not sure why people think you can't learn anything about a user interface by watching videos. Martin72 seems to be able to post official Rigol "marketing" videos and get away with it so I figure it's something personal.

[skander36]

We don't have the Rigol HD DSO, so not sure how the FFT works.

Can you scale the Vertical axis with Ref and Scale/div?

Can you select the time sweep to improve noise floor?

Is FFT averaging available to drive down the noise floor and show the IMD products better?

BTW does the FFT allow cursors? This really helps with evaluating signals, especially if they have a relative measurement.

Anyway, thanks so much for the effort and measurements,

Best,

This are the FFT settings.
No averaging in FFT menu, only for the aquisition, but does not impove. I can use vrms instead of dB.
If I scale the signal will also scale.
There are cursors availabe to measure the FFT.

[mawyatt]

For the 100KHz FFT, set the Center Freq to 100KHz and Span to 50KHz. For the Amplitude set the offset to 0dBv and the scale to 20dB/Div. This should produce a good FFT.

For cursers, set 1 to 100KHz, 2 to 110KHz, 3 to 90KHz and 4 to 120KHz, then show the curser table if possible.

Edit: I see cursers are only two A and B, so set A to 100KHz and B to 90KHz.

Thanks for the efforts

Best,

[Martin72]

Btw, do the math traces have different colours ?

[skander36]

Btw, do the math traces have different colours ?

Yes.

[Martin72]

Ah, that was something I´ve missed badly on the MSO5000....
Multi-windows...That´s really cool. 
Which rigol you have, DHO1000 or 4000 ?

[skander36]

Ah, that was something I´ve missed badly on the MSO5000....
Multi-windows...That´s really cool. 
Which rigol you have, DHO1000 or 4000 ?

the least expensive    :  DHO1000 2 channels.

[skander36]

For the 100KHz FFT, set the Center Freq to 100KHz and Span to 50KHz. For the Amplitude set the offset to 0dBv and the scale to 20dB/Div. This should produce a good FFT.

For cursers, set 1 to 100KHz, 2 to 110KHz, 3 to 90KHz and 4 to 120KHz, then show the curser table if possible.

Edit: I see cursers are only two A and B, so set A to 100KHz and B to 90KHz.

Thanks for the efforts

Best,

0 offset does not seems good.
24 dBv offset is better.
EDIT: and the cursors.

[mawyatt]

Ok Offset is not at top but in middle, so set offset to -80 dBv and 20dB/div.


BTW nice display with 4 FFT windows!!

You changed your two tones above from 100 & 110KHz to 90 & 100KHz, set them back to 100 & 110KHz and leave cursers at 100KHz and 90KHz, this will show the one sided IMD.


Best,

[skander36]

Ok Offset is not at top but in middle, so set offset to -80 dBv and 20dB/div.


BTW nice display with 4 FFT windows!!


Best,

Now with 80 dBv offset.

P.S. Maybe a remote session will be better 

[mawyatt]

This doesn't look right, you should only have two dominate tones at 100 & 110KHz, not three, and two lesser tones at 90 & 120KHz. Is your AWG setup properly?

Also, the cursor reading at 100KHz should be about -9dBv (1VPP = -9dBv rms). Raise the sample rate to something >2MSPS, with 400KSPS you might seeing aliasing.

Check the plots we posted earlier.

Best,

[skander36]

You changed your two tones above from 100 & 110KHz to 90 & 100KHz, set them back to 100 & 110KHz and leave cursers at 100KHz and 90KHz, this will show the one sided IMD.


Best,

nope. just cursors have changed (90 & 100).

[skander36]

This doesn't look right, you should only have two dominate tones at 100 & 110KHz, not three, and two lesser tones at 90 & 120KHz. Is your AWG setup properly?

Also, the cursor reading at 100KHz should be about -9dBv (1VPP = -9dBv rms). Raise the sample rate to something >2MSPS, with 400KSPS you might seeing aliasing.

Check the plots we posted earlier.

Best,

Not too much to setup for the AWG. Freq - 100 kHz and 110 kHz, Amp. 0,775 mVpp and output set to wave combine .
This is how the signal look.

[mawyatt]

You changed your two tones above from 100 & 110KHz to 90 & 100KHz, set them back to 100 & 110KHz and leave cursers at 100KHz and 90KHz, this will show the one sided IMD.


Best,

nope. just cursors have changed (90 & 100).

This is showing 400KSPS and likely the "extra large" 90KHz tone is due to aliasing (it should be much much smaller that the two input tones) and swamping out the IMD tone which should be about 60dB down from the tones at 100 & 110KHz. The AWG should be set to 100 & 110KHz. Your setting of 0.775mvPP is -11.25dBv rms, 1VPP is -9dBv, either should be fine as the IMD is referenced in dBc, or below the input tone levels.

You should be seeing something like -60 to -70dB between the A and B cursers if things are correctly setup and the HD is responding as expected.

Please look at our earlier post for what the FFT should look like, this the same as on a Spectrum Analyzer shown here (added the previous DSO FFT for comparisons) Note the small IMD tones at 90 and 120KHz on the SA, which shows the SDG2000X AWG is good enough for the test at hand (this is in dBm since the SA is a 50 ohm based instrument). Also note how these plots, the DSO FFT and the SA plot, look similar as they should. Of course the SA will be superior to the DSO since this is the type of task they are designed for, whereas the DSO is mainly a Time Domain instrument and the FFT is an "extra" Frequency Domain feature we get 

Best,

[skander36]

This is showing 400KSPS and likely the "extra large" 90KHz tone is due to aliasing (it should be much much smaller that the two input tones) and swamping out the IMD tone which should be about 60dB down from the tones at 100 & 110KHz. The AWG should be set to 100 & 110KHz. Your setting of 0.775mvPP is -11.25dBv rms, 1VPP is -9dBv, either should be fine as the IMD is referenced in dBc, or below the input tone levels.

You should be seeing something like -60 to -70dB between the A and B cursers if things are correctly setup and the HD is responding as expected.


Best,

The AWG was set to 100 si 110 KHz. Other freq. appear due to different timebase. See here : https://youtu.be/EdaNDG3ke-I
Can I help you with more?

[rf-loop]

You changed your two tones above from 100 & 110KHz to 90 & 100KHz, set them back to 100 & 110KHz and leave cursers at 100KHz and 90KHz, this will show the one sided IMD.


Best,

nope. just cursors have changed (90 & 100).

This is showing 400KSPS and likely the "extra large" 90KHz tone is due to aliasing (it should be much much smaller that the two input tones) and swamping out the IMD tone which should be about 60dB down from the tones at 100 & 110KHz. The AWG should be set to 100 & 110KHz. Your setting of 0.775mvPP is -11.25dBv rms, 1VPP is -9dBv, either should be fine as the IMD is referenced in dBc, or below the input tone levels.

You should be seeing something like -60 to -70dB between the A and B cursers if things are correctly setup and the HD is responding as expected.

Please look at our earlier post for what the FFT should look like, this the same as on a Spectrum Analyzer shown here (added the previous DSO FFT for comparisons) Note the small IMD tones at 90 and 120KHz on the SA, which shows the SDG2000X AWG is good enough for the test at hand (this is in dBm since the SA is a 50 ohm based instrument). Also note how these plots, the DSO FFT and the SA plot, look similar as they should. Of course the SA will be superior to the DSO since this is the type of task they are designed for, whereas the DSO is mainly a Time Domain instrument and the FFT is an "extra" Frequency Domain feature we get 

Best,

It is bit weird, how Riglol have done this?

Here @skander36  attached image

FFT info display 400kSa/s

Main timebase (H) info display 2.5ms/  and  (A) 200kSa/s and 10kpts acquisition length.

Fun that this extremely high 90kHz peak in FFT looks like just 110kHz alias. (if sampling is 200kHz 110kHz signal is folded back to 90kHz, if this is case, it also explain its displayed level.

But, FFT window info tell 400kSa/s. If this is real truth then it must not fold back (alias). Is it (400kSa/s) real truth or is it just Rigolism.
If they have different sampling for FFT it is then nice to see what is display if normal oscilloscope and freq.axis displays are both displayed same time and just input single sinewave, say example 100.5kHz. 
Perhaps @skander36 can show it to us.

[skander36]

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