Magnova oscilloscope

[LoneWolf6912]

or this is the best the SDG can output at its highest frequency and you get the same presentation on both bandwidths.

That's what I'm saying, these relatively expensive AWGs often have worse rise times than the AWG built into my super cheap scope.

 <9ns for the SDG2000X

The measured value of 8.7ns therefore corresponds to the specifications of the AWG.
This is no problem at all for the scope.

You get rewarded with investment to real relatively expensive models, not hobbyist SDG2000X, expensive models are 1ns
SDG6022X risetimes are 2ns
SDG7000 are 1ns or better.

I have exactly the same AWG as yours. I didn't think about the time rise of the generator. My bad 

[Aldo22]

You get rewarded with investment to real relatively expensive models, not hobbyist SDG2000X, expensive models are 1ns
SDG6022X risetimes are 2ns
SDG7000 are 1ns or better.

Well, everything is relative. 
For me, an FY6900 is a hobbyist device for <$100 and it has a faster rise time than the 5x more expensive SDG2042X.
It's just not really good for the price in that regard. It certainly has other merits.

[tautech]

or this is the best the SDG can output at its highest frequency and you get the same presentation on both bandwidths.

That's what I'm saying, these relatively expensive AWGs often have worse rise times than the AWG built into my super cheap scope.

 <9ns for the SDG2000X

The measured value of 8.7ns therefore corresponds to the specifications of the AWG.
This is no problem at all for the scope.

You get rewarded with investment to real relatively expensive models, not hobbyist SDG2000X, expensive models are 1ns
SDG6022X risetimes are 2ns
SDG7000 are 1ns or better.

I have exactly the same AWG as yours. I didn't think about the time rise of the generator. My bad 

Maybe, maybe not.
Unhacked SDG6022X here.....

[nctnico]

It’s possible to select different measurement units. For the analog channels, you can choose between volts and amps. Honestly, too few. Being used to measuring physical signals, I would have liked to see more exotic units like Tesla or even candela. Regarding the math channels, they already have more units available, though still too few for my liking. I wonder why they don’t include a “custom” button to let users create their own units.

The unit selected for the channel also affects the calculation of the power (dBm, etc.) in the FFT. How should the power be calculated in the FFT for a user-defined unit of a channel?

In dB or dBr (see https://en.wikipedia.org/wiki/Decibel)

[Andre77]

In dB or dBr (see https://en.wikipedia.org/wiki/Decibel)

Okay, no power reference would be an alternative. I'll add this (along with other unit settings for the channels) to our update wish list.

[hpw]

....  I'll add this (along with other unit settings for the channels) to our update wish list.

As you would be the first on sky as adding:

- rtHz scales (level & dBc) 

- cross correlation & averaging (conj complex), as using 2 channels would/should show up 6dB lower noise floor

Hp

[KungFuJosh]

You get rewarded with investment to real relatively expensive models, not hobbyist SDG2000X, expensive models are 1ns
SDG6022X risetimes are 2ns
SDG7000 are 1ns or better.

The SDG1000X also has better square waves with ~4ns rise time, and up to 60MHz. It was a weird choice to degrade that for a better model. 🤷

[blackdog]

Hi

Here I show how I do rise time measurements with Leo Badnar's pulse generator and from a Low Cost Function generator the Siglent SDG 1032X.
For good risetime measurements, it is important to use good cables and BNC connectors, together with an attenuator on the input of the scope.
My measurements are for scoops up to about 500MHZ and I have little or no experience with scoops above 1GHz.

The setup shown here is intended to minimize refelections in the measurement system.

Make sure the scope is set to 50 Ohm input impedance.
Use at least a 50 Ohm attenuator of -6 dB, in my measurement it is -20dB and preferably with a bandwidth of 2GHz or more.

I used a -20dB attenuator in this measurement setup, one from MiniCircuits and the other is from Radial.
The lower trace is from the Radial attenuator and the upper trace is from the MiniCircuits attenuator.
I cannot see any difference in attenuation between these attenuators, there is only a small difference in attenuation between the two types.

Only channel-1 was used, the attenuator on channel-2 is there to show you what types I used.


.

Both measurements with the two difference attenuators imaged.

.

But what does the block look like from an affordable feature generator....
Below the Siglent SDG1032X set up to reproduce the best block wave on the output.
This generator has a special circuit internally for that.
If you stay below 1V PP at 50 Ohm load, almost no abberations are visible.
The cable between the Siglent generator and the -20dB attenuator on the scope input is a BNC cable from Huber and Suhner.


.

And for completeness a picture when the Siglent generator is set above 1V, in this picture it is then 2V PP at a 50 Ohm load.

.

I hope this helps a little with showing rise times on a scope.

Kind regards
Bram

[LoneWolf6912]

Hello,

Thank you, Blackdog, for your guidance. I followed your instructions closely.

I used my Siglent SDG2042X (not hacked), along with a low-noise Keithley 4801 BNC cable, connected to a Tekbox 50-ohm feedthrough termination (DC-1 GHz). Unfortunately, I didn’t have an attenuator available, but I believe this setup was a reasonable alternative.

The oscilloscope was set to a 50-ohm termination. I tested a 10 MHz square wave, 1Vpp, with a 50-ohm load on the AWG.

Attached is the result from the Magnova. As other members suggested, the limiting factor was indeed the AWG. I apologize for jumping to conclusions too quickly in my previous message.

[blackdog]

Hi, LoneWolf6912, :-)

You are lucky, that my scope was still on the Bodnar was still in memory.
Below the Siglent SDG 2042X which I also have on the shelf, with the same settings as the SDG 1032X.

The difference in rise time is nil, there is always a difference between generators, bandwidth of the scoops and how the manufacturer “tuned” the upper end of the frequency range.
For example, the max bandwidth or e.g. phase behavior.


.
Just a moment...searching, I must have a KeySight paper that deals with this....
This is not quite the Application Note I was referring to, but does provide a lot of info.

www.bramcam.nl/Diversen/RiseTime-KS.pdf

If I still come across the Application Note on tuning the Scoop inputs, I will post the .pdf here.

Greetings,
Bram

[tautech]

You get rewarded with investment to real relatively expensive models, not hobbyist SDG2000X, expensive models are 1ns
SDG6022X risetimes are 2ns
SDG7000 are 1ns or better.

The SDG1000X also has better square waves with ~4ns rise time, and up to 60MHz. It was a weird choice to degrade that for a better model. 🤷

New technology faster slew rate output stages improved risetimes in SDG1000X that weren't around when SDG2000X was released.

One also need remember that pushing to higher frequencies makes faster risetimes more difficult to accomplish.

[Tomki]

Hello,

@Tomki: have fun with the BM350.

Too bad it will be another six months or so before you have the BMO logic probe set and the function generator hardware module.
Have you ordered two BMO logic probe sets?

I'm interested to know why you chose the BM350?

Best regards
egonotto

No, so far I ordered only one logic probe. But we‘ll see 🥸.
Maybe I get the chance to serve as Beta-tester. I‘ll keep you posted.
In regard to the BM350 - it‘s a simple calculation: I had originally ordered the BM200. Then I asked if an upgrade to BM350 was also possible at the introductory price (30% discount), which was confirmed. But: the upgrade from BM200 to BM350 (even at the regular price) does not include the better 500MHz Testec probes, which are significantly more expensive than the 350MHz probes that come with the BM200. So I switched to the BM350 straight away

[Tomki]

In regard square waves of the Siglent SDG6022x I got a screenshot of an 80MHz square and a sinus including math function. Ch1 sould be the squre. That‘s as good as the Siglent can be at it‘s maximum freq for squarewaves…
I‘ll add some more screenshots tomorrow. However, the slightly corrupt rectangular shape is not a fault of the Magnova 😎

[tautech]

In regard square waves of the Siglent SDG6022x I got a screenshot of an 80MHz square and a sinus including math function. Ch1 sould be the squre. That‘s as good as the this Siglent can be at it‘s maximum freq for squarewaves…
I‘ll add some more screenshots tomorrow. However, the slightly corrupt rectangular shape is not a fault of the Magnova 😎

FTFY.

350 & 500 MHz SDG6000X models can provide squarewares to 120 MHz.

[egonotto]

Hello,

I was just disappointed by the filter function of the Siglent SDS3000X HD. I wanted to demodulate a PWM signal (1 kHz square wave with 50 % duty cycle) with a low-pass filter. I couldn't do that because I couldn't set the cut-off frequency low enough.

What about the Magnova? What is the minimum possible cut-off frequency for a low-pass filter?

Best regards
egonotto

[KungFuJosh]

What about the Magnova? What is the minimum possible cut-off frequency for a low-pass filter?

And do we need to jump through any hoops to get to specific filter frequencies?

[LoneWolf6912]

Hello,

I was just disappointed by the filter function of the Siglent SDS3000X HD. I wanted to demodulate a PWM signal (1 kHz square wave with 50 % duty cycle) with a low-pass filter. I couldn't do that because I couldn't set the cut-off frequency low enough.

What about the Magnova? What is the minimum possible cut-off frequency for a low-pass filter?

Best regards
egonotto

Here's the différente option of filter.

[nomead]

I'm not familiar with Siglent's user interface but is your reference waveform using 1 ns timebase while AWG waveform uses 10 ns timebase?

You are lucky, that my scope was still on the Bodnar was still in memory.
Below the Siglent SDG 2042X which I also have on the shelf, with the same settings as the SDG 1032X.

The difference in rise time is nil, there is always a difference between generators, bandwidth of the scoops and how the manufacturer “tuned” the upper end of the frequency range.
For example, the max bandwidth or e.g. phase behavior.

[blackdog]

Hi,

Yes that's a bit unclear, I think the waveform you capture is just the image memory.
It obviously does not scale with the active channel, and so that gives ambiguity to the gen who did not do the measurement, sorry about that.

But to make up for it, I took two more measurements.
These are done separately, so error is no longer possible, (I hope)

First up again is the Lao Bodnar pulser.
The measurement conditions are the same as the previous measurements.

I used the Zoom function to display the waveform as well as the rise/fall time.
The measurements line also displays the fall time.

Bodnar Pulser, the Zoom mode here is 1ns/Div.

.

Siglent SDG2042 Generator, the Zoom mode is here 10ns/Div.

.

I visualized the Zoom function so that the rise time fits nicely within two divisions.
Which of course means that you take into account the time base settings of the scope.

It is also about the quality of the displayed pulse.
Another user showed that his generator could generate an 80MHz “square wave signal.”
But that's not much use if the generator itself doesn't have the bandwidth to make it look like a square wave.

And for an 80MHz square wave, you need at least a scope bandwidth of 1GHz and preferably a bit more.
This together with excellent cables and connectors, e.g. SMA.

Kind regards,
Bram

[LoneWolf6912]

André, do you have on your wishlist some power measurement system ? It would be a fine addition to the tools already offered by your machine.

[Andre77]

André, do you have on your wishlist some power measurement system ? It would be a fine addition to the tools already offered by your machine.

Yes, that's already on our wish list. But thanks for the suggestion anyway! As it is a comprehensive feature, it will still take some time before it is available.

[egonotto]

Hello,
...

What about the Magnova? What is the minimum possible cut-off frequency for a low-pass filter?

Best regards
egonotto

Here's the différente option of filter.

Hello,

thanks, is there an LP filter for the math channels? If so, how low can the cut-off frequency be?

Best regards
egonotto

[KungFuJosh]

Here's the différente option of filter.

That's a channel filter to limit bandwidth. We would like to know if there's (HP, LP, BP) filtering set for Math or Trigger Coupling, and how it can be set.

[Andre77]

What about the Magnova? What is the minimum possible cut-off frequency for a low-pass filter?

We would like to know if there's (HP, LP, BP) filtering set for Math or Trigger Coupling, and how it can be set.

There are not yet any independent filters for the maths channels or triggering.