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.
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!
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.
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.
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
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)
@@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.
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 :)
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
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: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-97p6BkAMTik.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.
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: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-bFWJUmgs_8M.html
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
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,
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;)
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;)
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 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
@@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
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
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?
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.
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.
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;)
@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
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. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-awZLvTRtoiI.html Their newer and more price-friendly models, are getting solid feedback.
@@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.
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;)
