How to Trust FFT with Siglent SDS1202X
Вставка
- Опубліковано 4 лип 2024
- This video is about How to Trust FFT measurements, and we I'll demonstrate using the Siglent SDS1202X. The FFT is very powerful but it has to be setup correctly - then the measurements can be trusted.
I use a setup that JohnAudioTech uses in his videos. He has done a great job testing amplifiers and I hope to show how to set up the Siglent to take these measurements. See his link below:
JohnAudioTech: • Rigol DS1052 vs Siglen...
Siglent Oscilloscope link
amzn.to/2yrVkhA
Link to GW Instek
amzn.to/2ZattLT
Siglent Electronic Load
amzn.to/39zyK3S
You can support this channel with this link to Patreon - I really do appreciate your support?
Patreon.com/KissAnalog
Or on PayPal at: KissAnalog@gmail.com
Or by shopping on Amazon using one of my links:
Amazon Commercial 90DM030 multimeter: amzn.to/2Jl9yCT - Наука та технологія
Thanks for the video Eddie! Good stuff man. My attention kept going over to that tiny low frequency spike, I assume that is coming from the generator. We gotta build something and put this in practice! What about building up a little switcher or something? Maybe enough to drive a little lm386?
Jared Gray Thanks Jared - I appreciate the feedback! Yes I do have a project to actually build. I’ll build that and hope to post this weekend. Might have to be a two part video.
@@KissAnalog Awesome! Looking forward to it!
Thanks for a great dwelling into the FFT function on this scope.
You bet! Thanks for your feedback! I appreciate you!
Great video on the fft !! Thank you 🙏!!!
Debi Hansen Thank you for the great feedback!
thanks man just got this scope today and was curious about this!
Great Scope - so did you get the one I have or the -E?
Learned a lot from this video. Many thanks.
Glad it was helpful! Thanks for your feedback!
Thank you for the video. Much appreciated.
The Guitar Amp Tech You bet!
I love 2 see the community folk pen testing the ''new'' products!! thanks!! super big help 2 get up & running!!
Thank you! I hope so, we need to start using FFT more;)
Hi Eddie, Cool video Eddie, Great detail information. Thank you.
versace885 Thank you for the support!
versace885 Thank you - I appreciate you!
Thanks for the effory
You bet! Thanks for the feedback!
Really glad I found this, great explanation! I couldn't figure out how to get the FFT to work right, I was always zoomed in on the waveforms. Noob mistake! lol
Glad it helped! Happy to have you on the team;)
Thanks for the video Eddie! Just an idea, it would be interesting to see an FFT on a circuit you designed where you had to do some EMI filtering and the resulting improvement. Great work!
W4DXZ Signal Shack That’s a great idea - thank you!
Yes, Eddie, I would like to see that too.
Great info. Thanks for this. Explains why what i have doing has resulted in confusing results! Incidentally i want to thank you for your in-depth walk through on the MDO GW-Instek (visible front centre on the shelf in this video). I've ordered one based on your presentation swaying my decision from my local agent so be great having relied on a Tek TDS-420A so long now even though i just know desperately needs a restoration holiday.
Thanks for this great feedback! I’m glad I was able to help.
I just ordered a 2202x-e that has twice the samples of the 1200 series. Hoping the FFT is good, as its the main reason for purchase.. This video will help a lot to speed up the learning curve.
That 1M should be great! Also the problem that I found on mine has been corrected on yours. Let us know how you like it;)
Also the reason I bought mine
Cool Eddie
Adam L thanks Adam, great to hear from you!
Great Video! I hope it helps another UA-camr.
Brad Rich Thanks Brad! I hope so:)
Aweeeeeeesome
Thanks so much! I appreciate you!
Great video Eddie!
You did everything on a linear scale, what is good for an introduction. On the dB scale you have to be much more careful about the low amplitude harmonics.
I got into this trap as I was doing some simple THD measurements and every time I end up with a (relative) high peak on the 5th harmonic. I belief this is an artefact of the vertical amplifier itself.
after putting my distortion analyzer in between and only using the residual for the FFT, the harmonic bins became reasonable because I don't need that high dynamic range anymore.
Also: It's a difference if you use the coarse steps for your vertical, or the fine ones. With one I read higher 3rd harmonic contend, with the other 5th and 7th and nearly no 3rd. Any idea why? ( I was tweaking from 2 V/Div to about 1,6V/Div for the better resolution)
BeamFinder You are right! I normally use log scale but I was hoping to make a point using linear for easier reading. Thanks for that great feedback!
@@KissAnalog Eddie, I thank you for your appreciation of my comments or hints. I enjoy your videos and straight forward approach. Sharing my experience and ideas is a thing of joy.
You absolutely did make a point by using linear. It's the best way to understand what all that magic is about.
Hi Eddie,
Thanks for the video. Really interesting. I will have to watch it slowly while trying things on my scope (with only 30 kpts of memory).
Questions:
1. Would you show us FFT on the GaN class D amp?
2. It would be great to better understand how you were manipulating the generator to inject the 1 Khan and the other components.
3. What would it look like if you used a different waveform.
Cheers
Mark
Those are great questions! I will do a video soon to see if I can answer this. You might find this video interesting: ua-cam.com/video/97p6BkAMTik/v-deo.html
Would be interesting to compare with a spectrum analyzer. With FFT you also catch eventual AD acquisition and/or amplifier nonlinearities of the scope. Also, the windowing choice greatly impacts your spectral representation. Nonetheless, if you are familiar with the limitations of the DFT (as I can see you are :)) you should not have a problem with the interpretation of the results. Nice video by the way :)
Hi Lutz, you are right - I’ve been meaning to do this for awhile;) Thanks for this feedback!
Some day I will set up my AWG with a spectrum analyzer and two scopes daisy chained. It will be cool to compare the same signal on the SA in the frequency domain, as well as in the time domain with and without FFT. And by the way, Siglent's scopes FFT function is amazing. There is a difference between the SDS1202X-E and the SDS1204X-E though, as the FFT is enhanced in the 4 channel version. Probably due to Siglent's firmware updates. It's a shame the FFT in the 1202X-E is not updated as well in this matter.
Thanks for the great feedback! The firmware is different in these 2 scopes. I like the FFT in the Micsig though as can be seen in this video: ua-cam.com/video/bFWJUmgs_8M/v-deo.html
This scope has prob very rudimentary FFT and memory, but you could simply zerofill to 1k or 2k points apply your window function and get sufficient digital resolution. You could show what happens if you do discrete fourier transform of a sine without smoothing things out with a window function and show sinc truncation artifacts. Also you can show what happens when multiple freq are mixed and separate them out with FFT.
Thank you! Great ideas!
Liked and subscribed. Thanks for the video Eddie ! have you done a video where u used the 1202x to calculate thd? (Some of us can't afford the Keithly)
Thank you! Great to have you on the team;) Thanks for reminding me about this. I meant to do this awhile back. I'll get to it very soon;) I got a great deal on that Keithly
Greetings friend. First of all, thank you for your work and thank you for all your contributions to the community, you are helping us a lot. I would like to ask you a question if it is not too much trouble.
I have a question about oscilloscopes. I've been looking for weeks to buy one with 2 channels. I'm between a Siglent or a Rigol.
Both are 200Mhz and 1Gsa/s. The most notable differences between them are: The Siglent SDS1202X-E has 14Mpts and up to 400,000 Wfm/s, while the Rigol DS1202Z-E has 24Mpts and 30,000 Wfm/s.
The question is, what should I get, more Mpts or more Wfm/s?
And in your opinion, which one do you think is better and which one would you choose?
Thanks again, thank you for your contributions to the community.
A strong hug.
Thanks so much! I appreciate you!
OK, so honestly - both those scopes are a generation old now, and only 2 channel. I chose the Siglent over Rigol as there are other features where Siglent is better (non - E and the -E version GUI is not as clean).
I'd go with the new Uni-T that has the memory - speed - and a better GUI as well as a great FFT (not perfect, but much better). Also starts off with 2GSa/s vs 1GSa/s from the others - and 4 channels. Both the Uni-T and the Siglent can go down 500uV/div vs 1mv with Rigol. Here's the link to Uni-T: amzn.to/3v5GsTz
The 2 channel Picoscope cost a bit more but is a far better scope with awesome software. You can download the software and give it a try. Here's the link to the scope. I'd go with the 2206 or higher: amzn.to/3wOl3Pb
Hello Eddie, I am beginner in more advanced scope functions. I''ve already build few projects and tube amps however I never thought about FFT, and measuring THD etc. Now I bought myslef as a self gift a Siglent SDS1202X-E :-) It is so exciting and looks like a totally new chapter in my development in electronics . I am wondering however what are other best ways to use such advanced scope in amp builds. THank you for advices.
Thanks for sharing that! It sounds like you are learning a lot and having fun. That’s a great scope! I’ll be getting more videos out very soon and I’ll show how to use those more advanced features;)
Hello, thanks for very good video explaining FFT application on Siglent oscilloscope.
But I have a question. How do you generate a 1kHz signal and at the same time as 4.5kHz "pilot" signal on same output of a function generator?
I do own an Signent SDG function generator and I wish to learn how can I also trigger different "pilot" signals.
Do you have different files made and saved in the funciton generator that contains the 2 different frequencies?
Thank you,
1k buddy
What do you mean?
So I have the HP 85532 and the HP 85632 and the 141a
Hi and thanks for the great videos.. I am trying to setup my Siglent for a test of the kit amp I have and it says the Vrms is 1.01 measured but on the FFT graph is saying .8 something. My siglent smd 3045 multimeter agrees with the scope and the output from the siglent sdg1025 reads 2.8 vpp hi-z out. I ran a self cal on everything but still shows up low on the FFT graph.. I wonder if I did something wrong.??
Sorry, I'm just catching up on comments. I've been starting with subs and then trying to work thru them all but I've been getting behind... Those are interesting measurments. The 1.01 should have showed up on the FFT. It might be an impedance mismatch between the generator and the scope. When the scope was connected to the generator, did you measure with the multimeter? What freq is it that you were looking at? IS the multimeter capable of the same bandwidth?
This is excellent video. How did you mix your 1kHz, 4.5kHz and 4.6kHz test tones? Were you simply feeding the scope signals from 3 generator channels? At 17:50 you said you had "him" add a 4.6kHz signal; are you playing a file? Brother, I have wasted a lot of time trying to be confident with an FFT with which I'm experimenting, but amplitude measurements of my harmonics compared to the fundamental are making no sense 😕.
Thanks for the great question! I want to do a series on FFT to really start with the beginning and go as far and deep as we can. I want to do a number of videos showing how to do different things that anyone can try and get familiar with. Your comment has made me realize the methods that I think I need to use. Please let me know what you think as they come out;)
You could turn on the markers on the FFT display which precisely tells you magnitude and frequency. Looks like you do not have the latest firmware maybe?
You are right - I got an early update - now I’m sure I’m out of date. I was afraid that I’d lose something that the early release gave me;)
great video, would you go for this one or the Rigol DS1202Z-E 2ch? thanks!
Thank you! I'd actually go with the new GWInstek. I'm hoping to do a video on it this weekend. The price and specs should be better.
@@KissAnalog any luck finishing the video review? cant wait to press buy!
hi, which is the maximum frequency of the signal measuring fft with Siglent Oscilloscope 100 MHz Bandwidth? can I measure fft of a 21 MHz signal? thanks
That's a great question! Generally, a good FFT on a 100 MHz scope should not have a problem showing the voltage of a generator at 21 MHz. It isn't so much the bandwidth but the sampling rate that matters.
@@KissAnalog thanks for the response, I´m interested in 21MHz, 15 meter hf cw ham band, so it will do the job.
How would u compare the 1202 fft to like a HP 85532 3 series spectrum analyzer
Wow that's a great question. That HP is from the 70s;) The BW starts at 1 kHz and BW resolution only goes down to 100 Hz. Other than that, it would be interesting to see the difference. I think the 1202 FFT would give good results and easier to see, but the HP is an actual spectrum analyzer, so it would be interesting. The HP module that you mention also needs the monitor that it plugs into.
If u could message me personal I have some questions and some stuff id like tomshoenya
Thanks - if you could email me that would be great!
Hi, I would like to ask you a question. Do you know if I can do a bode plott with the SDS1102X+?
I don’t think that model has it built in, but there are ways you could do it I think. Do you have this scope or are you considering it.
@Kiss Analog Thank you for your answer. I have the oscilloscope and was wondering how I could do a bode plott. I would really appreciate it if you could do a video about it how to create them manually? Thank you for your help
Thank you
Do we can use this scope as logic analyser?
There are very similar models to mine that do come with options for logic analysis. I think they are typically 16 channel.
@@KissAnalog thanks dear
Did you explain it be for
How can i use it ?
For this scope
Eddie loved your knowledge on FFT but you lost me when you added the second signal and said it wasn’t a harmonic so did you modulate another signal in? Wish you would have shown the change to the generator to get the second signal
Thanks Greg! Yes, I did add a second signal. I'll do a video soon showing how to do this;)
You gave that dmm to Mr Jack Sound, your deputy minister of GaN propaganda. The poor fellas had to repair it. Haha good video man. I can pay more attention to the buttons you press as I shall be able to do it soon 28mpts
Hope you like your new scope. Let us know how it goes after you get a chance to play with it;)
@@KissAnalog yeah man. For sure I'm hoping I can sell the old one and pick up a dual output rigol I've been looking at. I could cheese a simple dual 12v rail if I need but I'd like a more permanent solution. I had to get a guy looking to buy it last night to check your videos to see if I was real.... I hung up on him. An Australian guy who wasn't our beloved David told me I didn't sound Canadian. I should've spoke like Terrance or Phillip from south park lol
LOL what was he doing checking to see if you were real?
I used a scope for 40 yrs. And if I had go through this process for every measurement, I would have been fired 1000x over.
LOL yes the Siglent does take a minute to setup, but it actually goes much faster once you have done it a few times. The FFT can give some great info though. It has only been found common on scopes in recent years. But handy when you don't have a spectrum analyzer around;)
Hi I'm new to electronic and no idea about scope but just bought (micsig STO1104C) i wonder why no see any videos about using scope to check and repair problems or defects device, but only showing waves and features of the scope itself?
Hi ... If you are that new yo Electronics then why did you choose this oscilloscope brand and model no. MICSIG TO1104 and on what bases did you take that decision initially ??
@@ahmedalshalchi likely because it's one of the best entry scopes on the market.
one of the only partable scopes, that will also work as a bench scope without driving you nuts.
mike electric stuff has a video about it and the board and components are of surprisingly good quality, when you have the price in mind.
Micsig makes nice portable scopes, but they were usually very expensive some of their first portable models and cost many grands, particularly those that were isolated and for potent voltage.
ua-cam.com/video/awZLvTRtoiI/v-deo.html
Their newer and more price-friendly models, are getting solid feedback.
Jakob ... Thanks for your feedback about Micsig ... May I ask which oscilloscopes are you using new ?
You are right - I’ll do a video showing some debugging. Nice scope!
@@ahmedalshalchi I'm new and zero knowledge about oscilloscope but I bought micsig sto1104c because of touch screen and with battery power other than that i don't know look like it nice big screen. I looking around videos learning how to use oscilloscope.
Why does it not just fill the screen horizontally? Ugh it bothers me so much
Thanks for the feedback! Are you talking about the menu buttons using part of the screen? I wish Siglent would allow these to be turned off.
@@KissAnalog no i mean the fft is seems to always start partially in the screen and ot always on the very left unless you fiddle with it
Do you see that in this video? ua-cam.com/video/uTirYr_y5u8/v-deo.html
Al of those spikes signals are just harmonic's on the basic signal. Your chasing ghoste.
pulesjet Yes you are right - at one point when I had the two large amplitude spikes up together they added together in the time domain and must have flat topped a bit to get those little spikes to pop up. Good eye;)
That's the power of frequency domain visualization vs time domain.
...or parasitic modulations of the signal source ...
Ihr seid was bitte? "Ernährungsexpert.....innen"? Echt jetzt?
Nutrition expert? I’m sorry - I don’t understand.