FFT vs Spectrum Analyzer w GW Instek MDO-2204EG Oscilloscope
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- เผยแพร่เมื่อ 30 ก.ย. 2024
- In this video I will demonstrate the difference between FFT and the Spectrum Analyzer option of the MDO2204EG Oscilloscope in the video FFT vs Spectrum Analyzer w GW Instek MDO-2204EG Oscilloscope.
4ch GW Instek MDO scope: amzn.to/3fATUnq
2Ch GW Instek MDO scope: amzn.to/3xsNg8E
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Siglent Electronic Load: amzn.to/39zyK3S
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Just FYI... I clicked your link and purchased mine yesterday based on your videos. I am very excited about doing these type of tests.
That is awesome - thanks! GW doesn't support my channel - but I am glad for you;)
I guess FFT is more suitable than a spectrum analyzer when measuring sporadic/"single shot" signals?
It really depends on the filter used. Some are better for more transient signals and some are better for more reoccurring spikes.
Hi Eddy I've never really used the FFT, on my Siglent DSO, but I will now, very interesting video, though I'm going to have to watch it again, to absorb all the information, Merry Christmas, Paul
You bet Paul! I'll use it more to show the advantages so there will be more opportunities to see it used.
Shopping for an oscilloscope. Appreciate your time and thoughts. Really helpful. Thanks. Loving it.
That’s great! Thank you! Let us know if you get a scope and how you like it;)
best demonstration I have seen
Thanks so much!!
Enjoy your videos and learning a lot. Have a great Christmas. Looking forward to you productions in 2021.
Thank you! I appreciate you and wish you happy holidays;)
I love those GWInstek scopes. At the office I use the MSO version of the MDO you have and I think it's got great "bang for buck".
Anyway, great video and a Happy Christmas Eddie and ALL my fellow subs :-)
Thank you! Merry Christmas to you as well;)
Merry Christmas Eddie. Thank you for a great video, a nice Christmas present for me.
Thank you! Merry Christmas to you too;)
Hi Ed, thanks for this video! Fantastic. Quick question if you have a moment. I’m looking at the 2102AG model. I don’t understand what the AG is ?( vs the EG). Any quick tips greatly appreciated .
Merry Christmas! What a great video. Do you think in the future we can go further with FFT and spectrum analyzers to use in troubleshooting? I'm thinking it would be helpful in eliminating distortion in an audio amp. One other thing. Check this free spectrum analyzer out www.sillanumsoft.org/. Great for audio analysis. I just use the mic jack on my computer.
Thanks Tron! I wish you a Merry Christmas as well;) I do plan to use the FFT more. I agree - I think it is a great tool to use. That software looks great. Do you use the mic input for a mic to bring in audio, or do you use it for electronic probing input? Have you seen this vid? th-cam.com/video/daGJEhuX_bQ/w-d-xo.html
@@KissAnalog Just watched the video good stuff. I made a crude probe out of an aux cable I hacked up that works ok. I have a BNC to aux converter on the way that will allow me to use regular Oscope probes with this software.
Look up JohnAudioTech on youtube he uses scope FFT a lot to test audio amps
@@researchandbuild1751 Thank you! I like John’s channel. He actually gave me credit recently in a couple videos in showing him how to use his new Siglent FFT;)
Merry Christmas to you and your family
Thanks! I appreciate you! I wish you and yours a Merry Christmas too;)
Of course, there is no difference between the results in FFT and spectrum analyzer modes on this scope! Because this "spectrum analyzer" is not a true spectrum analyzer here. It is only USER INTERFACE that is reminiscent of a spectrum analyzer . The spectrum shown is the same FFT in a different window. But this scope is perfect for my needs, because real spectrum analyzers go from 9kHz only. And I need it for audio mostly, which includes lower spectrum. By the way, I had purchased the GDS2072E model, and software upgraded it to include the spectrum analyzer functionality and the 300Mhz bandwidth. Way cheaper!
Thanks for the great feedback!! As you say - most spec-ans start at 9kHz for a low freq type. The MDO is supposed to have a dedicated processor that makes it better than most FFTs in scopes - and it does seem really good. I honestly think the Pico scopes that I've reviewed are better with their 14bit A/D front ends;) Does your GDS work the same as my MDO for the Bode plots? I've tried to find that out so that I can guide people on which scope to get...
@@KissAnalog No, my scope does not do bode plots, as it does not have a generator built in. Actually, software shows it has it (I can select the generator in the menus after the software upgrade, but it does not have the hardware needed for that, so it freezes). SA functionality, on the other hand, is no problem. Everything works fine. Concerning a separate processor for SA, I doubt it has any. My scope is not supposed to include SA functionality and that is what the GW Instek said to me when I had personally inquired them about it (and they lied). So, they would not have installed separate hardware and then do not use it! But someone on the net posted a way to upgrade the software and that is what I did and it works fine (also, the BW upgrade to 300MHz). SA is just a software thing in all of these scopes - GDS, MDO, MSO - as firmware is exactly the same in all of them.
"Real spectrum analyzers go from 9 Khz only" - Absolutely incorrect. Spectrum analyzers designed for RF work generally start at 9Khz. However, there are such things as general purpose or "low frequency Spectrum Analyzers" which are designed to cover from 0.1 Hz (and lower) to 100 Khz. These analyzers are extremely useful for audio frequency work, and vibration analysis in the frequency ranges below 20 hz. I suggest you check out Stanford Research Systems, their SR760 and SR770 spectrum analyzers which are multi-thousand-dollar analyzers. I have their SR760 which has a range of below 0.1 Hz to 100 Khz and a frequency resolution in the milli-Hz range... Now THAT's a REAL spectrum analyzer as you put it. But I also have the GW-Instek MDO-2204-EX and it does an excellent job for audio analysis work, and has some great features like the BODE plotting. But it's not in the same class as Stanford Research and was not designed to be. The MDO-2204 series is a great product and well worth the price.
Merry Christmas
Merry Christmas to you too;)
Isnt rectangular window actually a bit less accurate? I know you have to use a specific thpe of window for different circumstances. Dont want rectangular always.
That’s right. Rectangular is good for more accurate freq info but amplitude is not as accurate.
Merry Christmas, Eddie, and thanks for the comparison. Indeed I bought the scope based on your recommendation, from Conrad, the only shop in Germany which had it available at a reasonable price. I think I should not have watched the vid late on Christmas eve, though, as it made me dream of you as the captain of a small freight ship in a futuristic version of a flooded city of Hamburg (to which I have no relationship whatsoever). Must have been that Santa look of yours, or I have worked too much lately...
LOL I know what you mean Gunnar - I've been putting in too many hours too;) Let us know how you like your scope along the way...
Great Scope, retired a few years ago and getting back into Electronics, specifically audio. Thanks to your recommendations I added the MDO-2204EX to my workbench along with my existing Tektronix 2467, it is my first experience with digital scopes. From watching the spectrum analyzer mode in your video, it looks like I could use the peak table to manually calculate THD. Since I don't want to spend what it would cost to get a Keithley THD meter, is there a simpler way to use the scope to come up with THD or maybe even a custom math function to continuously display THD.
Thanks for the great question. It is not a simple answer or I didn’t find one yet. But, I think I can make a video on this great subject!
All the best Ed for the up coming New year & another spin around the Sun! I hail from New Zealand & can vouch that back in April when my country did its 1st lockdown i started to work from home and updated my hobby bench to something a bit better, starting with one of these scopes, my decision based in major part on Ed's previous videos. The machine arrived in the country just days before the border closure went into force & my delivery from Taiwan just squeaked through our main airport before it closed.... So far the machine has been used to fix a lot of gear from TV cameras to tube guitar amps in my rough'n ready home 'sort-of' Lab. Bit of a learning curve this instrument but you get there & you can always look up TH-cam & go to Ed's videos for a bit of tutorial! The machine doesn't have that seriously pin sharp extreme resolution style of LCD screen that say a $8000 plus (say top end Siglent) 'scope offers but that reflects in the price. At the my bench at work i use a Rhode&Schwartz RTM3004 & that is a serious 'scope but it cost my employer more than what i paid buying my last new car i drive daily! All the best everyone!
Thanks for the great feedback peteb2;) It is great to hear from our friends in New Zealand! These shutdowns have been good for home lab work, but I'm ready to get out a bit;) I used a Rhode&Schwartz for a bit until I left my last job. We had a top scope from 3 vendors and all were nice in their own way, but the price is nuts. This Instek scope provides a lot of bang for the buck. Cheers!
From my experiments with my Siglent, the resolution also depends on the timebase you have set for the actual waveform display on the scope itself. You have to get a larger amount of cycles on the screen and the go into FFT and then you will be able to "zoom in" further for greater resolution
The FFT depends entirely on the current view on the oscilloscpe screen. If you want more detail you need more sine wave cycles on the screen to begin with, meaning a shorter timebase before you switch to FFT
That sounds right! Nice job! I did a video on this;) How to Trust FFT with Siglent SDS1202X th-cam.com/video/VSCoAX2aJ2M/w-d-xo.html
I think you should build an amplifier pcb I sent you :P then use FFT on the amplifier !
That would be cool! Thanks!
Instead of all the jagged vertical lines, I'm used to seeing a nice smooth line (bell curve). Can that scope do that in FFT mode?
Do you mean like the Bode Plot? FFT or spectrum should be vertical lines, but Bode Plot is a horizontal line. Thanks for the question!
Can you do a video using the spectrum analyzer on an audio amp displaying the frequency response.
You bet! Thanks for asking! I plan to do a lot more of this. I did do this video where I show the FFT: th-cam.com/video/daGJEhuX_bQ/w-d-xo.html
I get the sense the SA is still using math to derive the signal. What do you think?
I think it has s separate processor, but I think you are right, but it can focus on the bandwidth of choice versus the whole bandwidth of the scope.
i.imgur.com/i5Kh1OU.mp4 (the highest K-point I can get in FFT-math mode seems to be 88k though with a lower sample-rate but what this value actually refers to, I don't know)
with a 72USD DDS FY6900 60mhz delivering the signal i.imgur.com/9Poj4WQ.jpg )
i.imgur.com/Xfub6A8.jpg
But are not planning to be using FFT that much, got some of these relative cheap PC-based spectrum analyzers/explorers that go up around 6.8GHZ and usually turn to those when I wanna get an idea of an RF signal, sadly spectrum analyzers that will play along up in those regions, are pricey.
also tried with one of these relatively cheap 1Hz to a tad under 7Ghz half-duplex / with an inbuild signal generator feature + RF waterfall and stuff i.imgur.com/SuaRN6y.mp4
also tried with an FPV signal.. i.imgur.com/4gLFe8h.mp4
and simply just slap a 50cent wifi antenna-zzzzzz on top of the scope and see what RF signal it picks up from this RF signal generator
- as crude as it gets i.imgur.com/VlNmDzR.jpg
from like a few hz up to 500mhz the FFT on the scope took clear notice, it's a 100mhz BW 4ch scope..
but I'm a newcomer on a strict budget trying to learn electronics and RF - so I'm likely messing a lot of these approaches up to test certain things.
i.imgur.com/lHaSyLi.jpg /
Also took a look at the wfps values..I do get around 95.000 to 100.000 waveform pr sec. on the above Micsig with the ext. out. i.imgur.com/wFNDOf0.mp4
setup i.imgur.com/5EsWZrM.jpg
(its spec says 80k wfps) but it gives 95k to 100khz in my testing, though the scope I'm testing as the freq-reading source is very crude and it's this DSO unit from MiniWare, so not sure if that flukes my reading?
i.imgur.com/TZvrYOY.jpg
But its very likely I'm doing something wrong or misunderstood something fundamental.
Thx for the vids, helping one to evolve...
What's the bandwidth of the spectrum analyzer part. does it simply correspond with the scopes 200Mhz bandwidth so max 200Mhz or does it reach fx 1Ghz or 1.5Ghz like some of the others?
Are the spectrum analyzer able to show a waterfall 2 or 3D, perhaps on a matching GW PC software?
In today's world, a lot of RF everyday-gear is in the higher values, not least phones, Wifi 2.4 and 5Ghz Wifi, RC gadgets, so would be great for support up in those higher values, though such instruments get expenive very fast for the average hobby-user..
Also pretty unreal how one can take down satellite RF data and get infrared heatmaps of the world.
Merry Christmas, I have a 70 mhz one, in principle fft and spectrum function are the same only the spectrum function mimics a real spectrum analyser. But the really difference is that fft is limited to the scope max frequency whereas the sa function supports 500mhz on all versions. Really great. So the scope can measure till 500mhz, but is limited by software. The signal generator is a nice feature but not a real tracking generator but anyhow, I like this scope. And learned some new tricks from your video. Thanks!
Thanks Paul - that is great feedback;) Nice scope. I am sure I would have been just as happy with the 70 MHz one as well.
@@KissAnalog yes, the point for me was that for frequencies above 70mhz I use the spectrum analyse function. Working on radio's and transmitters that's the main function. So you have 500mhz for 70 MHz price
🤔👍🛠️🏆
LOL love it!
Hard time choosing between the SIGLENT SDS1204X-E with MDO Options or the GW Instek MDO-2204EX, I am a digital person, but did not find a logic analyzer probe for the GW, but did email them to ask, I know you are not much of a Digital person at the start of the series, but it is hard to compare these two since they do not have all the same features, but without the probes for GW I cannot compare them cost-wise, there is an $800 difference without them, but the GW has was more features, things I like about both of them over the other, so I was wondering if the Siglent FFT mode compares to GW, since that we can compare, and at a savings is the spectrum analyzer worth it alone, what are your thoughts?
That's a great question, and Sigent isn't a bad choice, but I do think the GW Instek has features that are really nice, and a larger display. I think what you might want to look at is the MSO1204EA that comes with probes and the generator option. Then you can do FRA analysis (Bode Plots). This is if you need the 16 channels. The FFT is great on all of these, but the GW Instek does have some extra features. Here is a contact that will most likely help you with a discount connection. He will find the right distributor for you. Just tell him that I sent you and he will help you with the price/contact.
Johnson Huang
INSTEK America Corp
Office: 909-399-3535
EMail: johnson_huang@instekamerica.com
@@KissAnalog I email him and he got back to me and the manual he sent me shows the 16 Logical probe cable breaks out into two 8 channel logic probes, and you can use this to do Bus Logic decoding, very nice, with all the options this seems like a much better option for R & D when you have no idea what you need in advance so you are trying to cover all the needs you know about now, but also the future needs that will pop up down the line and you wish you would have got something else, this has so many options compared to other scopes, I do not see me outgrowing this one any time soon, from what I see the option can be added, but much cheaper to order with it, plus for digital, you have that ratio of 2 to 2.5 times more frequency capability for digital compared to analog due to how you measure the leading edge, so thanks for the great advice, your channel has help me decide a lot easier and the contact to GW was great.
I have two TH-cam accounts, not sure why, but the picture is the same, and I know how hard it is to put out videos, and mine are not like any you will find anywhere on TH-cam, I did not notice the account name change till after I replied to the first one.
That sounds great! Instek is really one of the better brands I think. Thanks for giving me an update.
Instek was trying to figure out a way to give me some kind of credit for sending them a number of customers. But they are old school and don’t know how, but I still send people to them. I wish they had more models on Amazon so I could get some credit, but oh well...
I’ll have to check it out! Thanks!
What's the difference between a) signal generator and 2) signal tracker?
That's a great question! A signal generator does just that, it generates a signal. A generator could generate something as simple as a sign wave. A signal tracker comes in different types, and there is also a tracking generator, which is used with a spectrum analyzer.
@@KissAnalog Thanks for your reply ... but what does a signal tracker and/or a tracking generator actually do? Also, assuming it's some function between signal creation and signal analysis, is it always built into a signal generator or spectrum analyzer ... or does it also exist as a stand alone unit?
Sorry, let me restate the last question: Is the signal tracker and/or tracking generator always built into a signal generator on one end or the spectrum analyzer (or oscilloscope) on the other end? Or does it also exist as a stand alone unit?
Sorry, I don’t get good notifications sometimes for comments under the first comment. Also, I’ve had so I try to hit subscribers first, so it takes me awhile sometimes to catch up. A tracking generator is used with a spectrum analyzer, so the signal generator will track the SA (spectrum analyzer) and sometimes it comes built into the spectrum but not always. So, you will see the spectrum sitting on top of the generator as they are typically made to work with each other. Does that make sense?
i paid $1,700 for this same GwInstek spectrum analyzer 2 years ago on amazon. today, they list it for $1,900. why? because the US dollar has gone to dick-n-balls.
How have you liked it? Thanks for the feedback! Here is a nice Option (maybe the best) at under $1400: amzn.to/4eayDNv