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  • Опубліковано 3 гру 2024

КОМЕНТАРІ • 283

  • @harbselectronicslab3551
    @harbselectronicslab3551 4 роки тому +52

    For years I have still been referring trainee's to this video.....that cutout demo is still the best teaching aid I have ever seen........

    • @ALEngineer30
      @ALEngineer30 2 роки тому

      it really is. brilliant and very simple.

    • @toxicricardo
      @toxicricardo Рік тому

      I’ve used spectrum analyzers for years and have always had to spend 30 mins remembering what VBW and RBW were now that’s I’ve seen this video I know I will only spend a max of 8mins and 37 seconds

  • @WizardVespian
    @WizardVespian 9 років тому +92

    This is the most concise, helpful explanation I have ever found for RBW and VBW filters. I've been using spectrum analyzers for years and I'm quite familiar with their setup and use, but I've never understood what those filters actually did under the hood so to speak... until today. Thank you, and please keep making videos. Those of us who take the time to search out this information (the small crowd that we are) really do appreciate the time and energy you put into making them. Thumbs up!

    • @w2aew
      @w2aew  9 років тому

      Thank you. Be sure to let me know if you have a topic you'd like to see in a future video.

    • @WizardVespian
      @WizardVespian 9 років тому

      I'm sure I'll have lots of questions when I start college. I intend to get into RF engineering, provided I can make the grades. For now I'm just a curious satcom tech with all together too much time on my hands, and I'm thoroughly enjoying the wealth of knowledge available on UA-cam, the EEVblog (thanks Dave) and other forums. I really enjoy the in depth technical focus of your videos. I do have one question about this video. Why do we have to convert Vpp to Vrms in order to do a dBv measurement? Is there a technical reason for it, or is it just convention?

    • @w2aew
      @w2aew  9 років тому

      It's because the dB values always relate to power, and power is computed from rms values.

    • @WizardVespian
      @WizardVespian 9 років тому

      That makes perfect sense combined with the tidbits I just learned from some other videos on the difference between Vpp and Vrms (specifically how Vrms is calculated, and why). Thanks!

  • @germibestia
    @germibestia 2 роки тому +8

    when somebody knows his stuff very well, he is able to explain it in a simple, easy to understand and yet complete way.
    Here we have the perfect example.

  • @ebarnes442
    @ebarnes442 4 роки тому +5

    I've been teaching people how to use a spectrum analyzer and what RBW and VBW filters do for a couple of decades. This is easily the best , simplest description of it I've ever seen. Thanks!

  • @Automotive-Velocity
    @Automotive-Velocity 2 роки тому +1

    These are the best electronics videos on YT. Concise and well presented.

  • @John_L
    @John_L 2 роки тому

    I finally scratched a very long-standing itch by buying my own spectrum analyser a few weeks back. It's fascinating to run it in the shack on wide bandwidth (up to 1.5GHz) with a small telescopic antenna and see all the spectrum mush in a modern home! Your videos are an excellent way for me to rediscover the nuances of my new toy some 40 years after I last used a spectrum analyser professionally. Thank you and 73 de G3WGV.

  • @jayeshsukumaran
    @jayeshsukumaran 6 років тому +1

    Thank you for very clearly explaining what the RBW and VBW filters are. Really appreciate the time and energy you put into making such wonderfully informative videos.

  • @chetangaonkar7251
    @chetangaonkar7251 6 років тому +1

    This is one of the best explanations of any RF fundamentals I have come across. Thank you!

    • @w2aew
      @w2aew  6 років тому

      Thanks - I hope you like more of my RF (and other) videos.

  • @rysend
    @rysend 11 років тому

    You are one of the best teachers on youtube. Clear, concise, zero BS, visual, interesting. Thanks for sharing your knowledge!!

  • @ka1wht
    @ka1wht 2 роки тому +3

    A very articulate and detailed explanation to help understand spectrum analyzer operation. Thank you, Alan.

  • @conesillyvalley7182
    @conesillyvalley7182 6 років тому +12

    Another great example of American way of teaching by super talented yet humble masters. Thank you!

    • @jimcervantes5659
      @jimcervantes5659 6 років тому +3

      What is "American way of teaching"?

    • @conesillyvalley7182
      @conesillyvalley7182 6 років тому +1

      @@jimcervantes5659 glad u asked. American way Of teaching is: 1) spoken by someone with both theory and practical knowledge 2) taught using actual hardware and NOT text book or black board 3) spoken from years of personal experience and not just parroting 4) taught humbly, simply, and to the point using fewest words

    • @jimcervantes5659
      @jimcervantes5659 6 років тому +2

      Baki Pest - Why do you refer to it as American?

    • @conesillyvalley7182
      @conesillyvalley7182 6 років тому +1

      @@jimcervantes5659 because America is number 1 in high-tech. From moon landing to smart phones, and just about anything me/you use is invented in America, definitely much more advanced than mine (india) or your (Mexico, spain?) country

    • @jimcervantes5659
      @jimcervantes5659 6 років тому +4

      Baki Pest - I am a US citizen and have received all of my education in the US, including a BS in electrical engineering. Nothing in your description seems inherently American, nor necessarily optimal depending on the circumstance. I have seen a lot of American teaching and don't recognize what you are talking about. Oh well.

  • @WestCoastMole
    @WestCoastMole 11 років тому

    Well Done Alan...The new generation of entry level Spec Analyzers are priced down to a level where a whole new group of people can obtain them. This creates a need for tutorials for both the Theory of Operation and How to Use the device and get the most out of it. This video is an excellent example of how to clearly and concisely address the matter. Thanks again

  • @DucatiMTS1200
    @DucatiMTS1200 4 роки тому +1

    Today’s a better day sir because you helped clearly explain the workings of RBW and VBW filtering to me. I am most appreciative 🤗.

  • @aeronothis5420
    @aeronothis5420 7 років тому

    As a SATCOM guy, I thank you for the service these videos you make provide.

    • @w2aew
      @w2aew  7 років тому

      Your welcome - thank you for saying so.

  • @trumannevercry
    @trumannevercry 4 роки тому +1

    Great video. Explain the concepts of VBW and RBW in an easy way. Definitely recommend this video for anyone want to understand the spectrum analyzer more.

  • @cny02253
    @cny02253 11 років тому +1

    Alan, you really know how to come up with simple and elegant visual aids. Masterful, concise video showing the relatively simple concept behind the oblique phrase "Resolution Bandwidth" and the application of filters. I love filters. You can't do enough videos about filters, "Q", all that cool stuff.

  • @geperezg
    @geperezg 11 років тому

    Very good video. After 3 years in the instrumentation industry, I have finally found something to solidify these principles in my head.

  • @keena1326
    @keena1326 3 роки тому

    Man...best explanation of these two subjects I've come across yet.

  • @gonzik2675
    @gonzik2675 11 років тому

    Amazing videos! As a studying engineer seeing how things work in the real world is worth more than you can imagine. Thanks for your hard work and comprehensive tutorials!

  • @w2aew
    @w2aew  11 років тому +5

    K1MGY - good questions. I'll answer them using your numbers:
    1) It is an Advantest U3461
    2) VBW reduces the variation in the trace due to noise, it doesn't reduce the noise floor. It won't reduce the amplitude of the signals as long as the sweep speed is slow enough to allow the filter to fully charge. This is usually taken care of automatically.
    3) Reducing VBW will help uncover things that are standing "in the grass" by flattening the noisy grass around the signal. Reducing RBW will help even more by reducing the noise floor, uncovering signals that were buried below the noise.
    4) Sweep time (sweep speed) is typically linked to RBW and VBW. RBW is typically linked to SPAN. Narrow SPAN = narrow RBW = slower sweep speeds. Yes, slower sweep speeds in a swept analyzer make it easier to find transients.
    Alan

    • @DanielRojas-pf1pw
      @DanielRojas-pf1pw 9 років тому

      ***** Hey Allan,
      Thanks a lot for the great videos, as always. What practical difference is there between reducing the VBW and just plain averaging? I know that reducing the VBW is actually filtering the higher frequencies, as opposed to just plain averaging. Leaving the math aside, I notice that both approaches increase the sweep time and don't have an effect on the noise floor.
      Can you comment on the differences of both? When would I use one or the other?
      Thanks!

    • @w2aew
      @w2aew  9 років тому +1

      Daniel Rojas You can think of the VBW as a trace smoothing filter. Thus, if you had a low level signal buried in the grass, the smoothing would likely hide the signal - while averaging would smooth out the grass but not clip the tiny signal.

    • @ernieschatz3783
      @ernieschatz3783 6 років тому

      This is excellent. "Yes, slower sweep speeds in a swept analyzer make it easier to find transients." I have to take periodic measurements of pulsed microwave (RADAR transmitters to be exact) signals. With one of our handheld analyzers (Agilent N9344C), I have to play with the sweep speed, or the signal will pop in and out of view, or it won't display at all. The analyzer is basically DC to 20GHz and has no problem reading CW signals at any of the frequencies we check (anywhere from 700MHz to about 9 GHz). We sometimes borrow a Rohde and Schwarz FSH20 handheld that displays any signal we want to see without touching any settings. I'm wondering if there was something I missed in the spec sheet when I acquired the Agilent, or is the Rohde and Schwarz just more refined?

  • @buffteethr
    @buffteethr 6 років тому

    Excellent video. I am currently debugging my DUT for CE compliance and this is the best explanation I have seen for VBW and RBW. Good job.

  • @jonesthesteamuk
    @jonesthesteamuk 9 років тому

    Best UA-cam video I've seen on how a spectrum analyser works. Clear simple description. Great stuff keep it coming!

  • @nickpenacl
    @nickpenacl 2 роки тому +1

    This is just the video that I was looking for a long time ago . Wonderful

  • @mjlorton
    @mjlorton 10 років тому +9

    Brilliant explanation Alan...just starting to play with my MDO analyser..searched for "frequency analyzer rbw" and look who I find?! ;-)
    Cheers, Martin.

    • @w2aew
      @w2aew  10 років тому

      Martin, while the principles are largely the same, the SA in the MDO operates differently. There is no "sweep". It uses a discrete Fourier Transform (actually a Chirp-Z transform to be exact) to compute the spectrum from direct sampled data. Thus, there is no VBW function, and 'sweep time' is replaced with 'spectrum update rate.' The RBW determines the time-duration of the data record that is sent to the Chirp-Z transform.

    • @mjlorton
      @mjlorton 10 років тому

      *****
      Thanks for the info Alan.

  • @robertsomerset6630
    @robertsomerset6630 3 роки тому

    I think this just helped me understand why my duplexer tuning was never as good as it could've been. Lowering the RBW would help me see the filters individually when they are right next to each other. Thank you!!!

  • @davidbeauchesne7399
    @davidbeauchesne7399 10 років тому

    Just purchased my first spectrum analyzer and was confused by the difference between RBW and VBW. Your video explained it very well. Thank you!

  • @omgkingdano
    @omgkingdano 8 років тому

    These are excellent fundamental refresher videos. Very well thought out and explained. Backed by excellent examples on real world equipment. Very nice.

  • @goldfisch9199
    @goldfisch9199 9 років тому +2

    Your videos are amazing. I don't understand why teachers can't expalin it that well

    • @JohnRaschedian
      @JohnRaschedian 6 років тому

      Teachers can usually only teach. They usually don't understand the real meaning of what they teach. Most of them time, they simply memorize things.

  • @lorimeyers3839
    @lorimeyers3839 Рік тому

    Im familiar with RF and spec ans and I’ll tell you what - it’s a very good video for a novice to watch. I think repetition and doing so every so often (it’s easy to forget setups/applications).
    In my line of work, I try to familiarize myself with Markers, Min and Max holds. Measuring channel and composite power. Eb/no, signal to noise, etc. Runnings sweeps on cables. Spec ans are also used in conjunction with signal generators (sig-gen) when testing RF equipment, fiber shelves or RF antenna paths. Blah blah.

  • @dougn7bfs
    @dougn7bfs 6 років тому

    your visual examples coupled with your explanation as you go makes this a great tutorial, thanks!!

  • @garysavage4121
    @garysavage4121 7 років тому +1

    I had never seen a description of RBW using a mask (to represent the RBW filter) over a drawing of the measured spectrum. It was very easy to understand.

  • @berkol1407
    @berkol1407 8 місяців тому +1

    thanks for the great explanation 10 years ago!

  • @ronaldlijs
    @ronaldlijs 11 років тому

    EXCELLENT explanation Alan!!! Much appreciated on this end. I have just bought a spectrum analyzer off eBay and I think I will love it!! Keep it up!!!

  • @keithcoltron3171
    @keithcoltron3171 3 роки тому

    Wish I'd bumped into w2aew years ago, great teacher, great content, many, many thanks for all.

  • @dhananjayw502
    @dhananjayw502 3 роки тому +1

    Wow ! .... Very nicely explained. It cleared my doubts and will definitely help me. Thanks a lot.

  • @jipra
    @jipra 9 років тому +2

    Such a brilliant demonstration video! Very informative! Thanks w2aew, you're the best!

  • @DAVET38
    @DAVET38 11 років тому

    Hello Alan. Another very useful, clear video. Found it very helpful in the use of my new spectrum analyzer; allowing me to use the equipment more effectively and more 'knowingly'. Thanks

  • @gus_siles
    @gus_siles 2 роки тому

    What a brilliant explanation!! Congratulations!.. this goes straight to my classroom and lab.

  • @bachger4289
    @bachger4289 5 років тому

    The best explanation I've ever heard before. Thanks.

  • @randydireen3566
    @randydireen3566 5 років тому +2

    Love how clear this was

  • @shivbhalodia9711
    @shivbhalodia9711 6 років тому

    Thank you for such clear & concise explanation! You've saved me so much time and effort at work.

  • @thumbsup3096
    @thumbsup3096 2 роки тому +1

    Hey there,
    Insanely good.
    Your video just helped me out a lot.
    Good work man, and thanks.
    Greetings from Germany

  • @satyamjayanti2642
    @satyamjayanti2642 6 років тому

    Amazing explanation. I have never seen such a great tutorial of a SpecAn. Thanks !!

  • @wxfreak
    @wxfreak 11 років тому +1

    Great demonstration really helped me understand what is happening! Thank you!

  • @richarddomingos1423
    @richarddomingos1423 10 років тому +1

    Thanks from Brazil, i'm working with BK Precision by micronix, and that video helps me a lot!!!!
    I´ll see the others videos to learn more about it!!! Thank you!

  • @positivevibes179
    @positivevibes179 9 років тому

    Very nice presentation & explanation of the resolution bandwidth

  • @raindrop2407
    @raindrop2407 8 років тому

    Thank you so much. It's helping me a lot in my EE courses. Your videos are so unique and informative!

    • @w2aew
      @w2aew  8 років тому

      Very glad to hear that my videos are helping in your coursework!

  • @paulamiroy953
    @paulamiroy953 6 років тому +1

    Very innovative way of explaining ! Great work !

  • @jeffj2010
    @jeffj2010 3 роки тому

    Excellent video to detail how RBW works.

  • @petepnut
    @petepnut Рік тому +1

    Very useful and concise information, and very applicable to modern SA's such as Rigol and Siglent. Thanks! Peter G6EPN

  • @Sam-lc1lo
    @Sam-lc1lo 2 роки тому +1

    This is an awesome explanation

  • @BinaBhatt
    @BinaBhatt 7 років тому

    Very helpful explanation, particularly with the paper prototype (Wide Band and Narrow Band). Thank you.

  • @jianjiao542
    @jianjiao542 8 років тому

    Thank you! Very clear both in theory and practical. Solved my confusion for a long time.

  • @raccoonnyc
    @raccoonnyc 11 років тому

    I've never seen this explained so well.

  • @marcosbarros8069
    @marcosbarros8069 4 роки тому

    Excellent explanation; concise and clear: direct to the point. Thank you!

  • @perrooceaniko2005
    @perrooceaniko2005 5 років тому

    yes, you deserve 10 times more views …. my respect !

  • @vladorlov1207
    @vladorlov1207 4 роки тому

    Thank you from Russia! More happiness to your life!

  • @NexxuSix
    @NexxuSix 6 років тому

    Thank you for the explanation. I’m still learning a few tips and tricks from you combined with my operator’s manual on my newly acquired SA (HP8560E). I have learned a lot from you =)

  • @sudhansunithmr
    @sudhansunithmr 9 років тому

    This is a pretty decent knowledge bank video. Thanks for uploading and so lucidly explaining the concepts.

  • @famossfla
    @famossfla 11 років тому +1

    Thanks Alan
    Another great informative video. Nice explanation of interaction of RBW and VBW..

  • @Rcschim
    @Rcschim 6 років тому

    Super well explained with just a pen and cutout cardboard. Like it a lot! thanks!

  • @jojojoy4395
    @jojojoy4395 3 роки тому

    Great presentation and illustrations. Thank you very much.

  • @luisaruquipac.381
    @luisaruquipac.381 10 місяців тому +1

    Best video ever! You are a hero !

    • @luisaruquipac.381
      @luisaruquipac.381 9 місяців тому

      It was the last question in my last oral exam of my master degree. Thanks for sharing your knowledge.

  • @saintlouis999
    @saintlouis999 5 років тому

    Amazing video!!! Simple, concise and super clear!!!!! Thanks a lot.

  • @mklengel
    @mklengel 6 років тому

    Great tutorial. Thanks for producing this videos. Please keep on with it.

  • @TruongNguyen-yo8qr
    @TruongNguyen-yo8qr 3 роки тому

    The block diagram, teaching materials and your way of explanation are very succinct. You are very knowledgeable. I am hoping for Oscilloscope operating tutorial video clips when you have a chance. Thank you very much.

    • @w2aew
      @w2aew  3 роки тому

      I have MANY videos on operating oscilloscopes. Here's a playlist:
      ua-cam.com/play/PL746BF38BC2E068E0.html

    • @TruongNguyen-yo8qr
      @TruongNguyen-yo8qr 3 роки тому

      @@w2aew Thank you very much for the information. Please excuse me for not searching about Oscilloscope tutorials thoroughly before requesting. No matter how complex a piece of equipment, you make it so simple to understand

  • @volcanowb
    @volcanowb 6 років тому

    I get so much from your sessions!
    Thank you!

  • @AM-uw6br
    @AM-uw6br 7 років тому +1

    Excellent video! Both precise and coherent

  • @alvaropalomonavarro6177
    @alvaropalomonavarro6177 10 років тому +1

    I just shared this with my students. Great job.

    • @w2aew
      @w2aew  10 років тому

      That's great! Feel free to share any of my videos with them that you might find useful. I have lots of circuit tutorials, component tutorials, test & measurement topics, and much more on my channel.

  • @bhavemanojs
    @bhavemanojs 4 роки тому

    Thanks for the clear and concise explanation!

  • @rohinparkar
    @rohinparkar 10 років тому

    Hi w2aew .. Excellent explanation .. Nobody ever explained it this way to me.

  • @ianchong7422
    @ianchong7422 2 роки тому +1

    THANK YOU!!! Now I understand the different.

  • @cskillet2003
    @cskillet2003 5 років тому

    5:44 What does he mean by "give the narrower filter time to charge"? What determines that charge time?

  • @dougspurell2387
    @dougspurell2387 8 років тому

    Very concise and nicely conveyed. Well done.

  • @JohnSmith-he5xg
    @JohnSmith-he5xg 7 років тому +2

    Great videos. Thanks for taking the time to make these :)

  • @hiranthini1
    @hiranthini1 5 років тому

    Excellent explanation, well presented

  • @yTb2801082331
    @yTb2801082331 3 роки тому +1

    Thank you veeeeery much for this very useful video!!!!!

  • @tarun5632
    @tarun5632 11 років тому

    Fascinating, Knowledgeable and clears all doubts Thanks

  • @hercai10
    @hercai10 6 років тому +2

    Awesome explanation!

  • @RojoKiller
    @RojoKiller 4 роки тому

    Thank you so much for this ilustrative explanation, it helped me a lot!

  • @khangau4844
    @khangau4844 11 місяців тому +1

    just 1 word: beautiful !!!!

  • @sciottos
    @sciottos 5 років тому

    Wonderful explanation and demonstration of R&V BW...3 Cheers!

  • @g0fvt
    @g0fvt 10 років тому

    Someone below asked why spectrum analysers are so expensive, my one uses basically an oscilloscope mainframe but with a spectrum analyser "plugin". One of the expensive to replace parts of a spectrum analyser is the mixer, they are easily destroyed but probably the most vulnerable component. The mixers have to have a broad, flat frequency response and tend to use exotic diodes within them. Sadly I have seen spectrum analysers effectively written off due to mixer damage.
    I am sure the precision attenuators are not cheap either!

  • @willzhao640
    @willzhao640 7 років тому +1

    fantastic!! such great explanation!

  • @jancenj2218
    @jancenj2218 4 роки тому +1

    Can I ask you a few questions? In measuring the output power of a radio transmitter, which will give me a more accurate measurement? A power meter or a Spectrum Analyzer? Also, is the power I'm measuring peak or average? I was told using a zero span will give a better peak power measurement instead of a bigger span. Why is that?

    • @w2aew
      @w2aew  4 роки тому +1

      In general, a proper RF power meter will give you a more accurate power result than a spectrum analyzer. They are available for both average and peak power measurement. Zero span on a spectrum analyzer will give you a decent result as long as the RBW is wider than the bandwidth of the signal you're measuring.

  • @martinmassitti9791
    @martinmassitti9791 7 років тому

    Excelente video! Muy completo, y gracias a esto me permitio reforzar conocimientos. Gracias

  • @pmblsmft2
    @pmblsmft2 8 років тому

    Absolutely superb explanation. Thank you!!

  • @ericntsama5833
    @ericntsama5833 10 років тому

    Excellent !, thank you for the detailed explanation and live demonstration

  • @Aligreta
    @Aligreta 3 роки тому

    Very very smart explanation :).
    Btw did u have any issues with these advantest sa's? Mine was similar model but some day noise appeared around all carriers even the LO leakage was noisy and the level droped all down... I suspect mixer said enough for this life, i wish yours last long because advantest people does not share any service manual

  • @k1mgy
    @k1mgy 11 років тому

    Alan, fascinating. A few questions from this presentation:
    1. What is model of analyzer for demo?
    2. If video bandwidth is reduced the amplitude of noise is also reduced and as it is a low pass filter is there a slight reduction in overall amplitude (and therefore accuracy)?
    3. You mentioned reducing video bandwidth might uncover stuff that would be masked in the noise. You mean a transient that does not go above the noise floor (of previous wider bandwidth)?
    4. Would reducing the sweep span (I should watch prior video as term is not known) reduce horizontal sweep time and therefore increase resolution of transients?
    Many thanks for considering my questions!
    /k1mgy

  • @SoddingaboutSi
    @SoddingaboutSi 5 років тому

    So is the video bandwidth similar to the averaging on a digital scope? Very informative video, thankyou.

  • @montecri
    @montecri Рік тому

    Wow! What an explanation! Thank you sir!

  • @mostlypostie1
    @mostlypostie1 Рік тому +1

    Sensational videos. 73!

  • @ironic4love
    @ironic4love 3 роки тому +1

    This was great , Thank you so much

  • @phillipng7331
    @phillipng7331 10 років тому

    Very intuitive demo

  • @shardulvelapure
    @shardulvelapure 11 років тому +2

    really good video, thanks a lot.

  • @eddyfontaineyoutu100
    @eddyfontaineyoutu100 6 років тому

    Excellent explanation ! Thank you ! 👍

  • @rpbale
    @rpbale 7 років тому

    Love you videos. Along the lines of filters, Tek made a notch filter plugin for calibrating their low noise oscillator years ago. The notch filter attenuated the target Freq by about -60db with a very sharp Q factor. I’d like to make one of these but don’t really I stand how to get such a narrow but deep attenuation. I bet you could make this into a great video. The Tek device was the Tektronix 067-0938-00 Notch Filter Calibration Fixture for calibrating the Tek SG505 low freq oscillator.

    • @w2aew
      @w2aew  7 років тому

      High Q narrowband notch filters are tricky to make. Resonant cavities are one way - check out my video on tuning a notch type duplexer.

  • @geevnahal7926
    @geevnahal7926 4 роки тому

    Thank you for the clear explanation, would you please also explain how these can implemented with real components? I am imagining for RBW we need a variable Q band pass filter, or switching between many band pass filters. I was wondering if you can refer to some actual components or evaluation board for implementing this. Many thanks,

  • @damianlawrence8430
    @damianlawrence8430 4 роки тому

    Thanks for sharing mate. Good job