#119 

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........

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!

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.

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!

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

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.

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

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

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.

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

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

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

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.

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.

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

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

thanks for the great explanation 10 years ago!

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!

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

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

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

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

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.

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

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.

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

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

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.

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!!!

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

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

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

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

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

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!!!

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.

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

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

Excellent video to detail how RBW works.

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

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

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

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

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!

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

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

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

Great presentation and illustrations. Thank you very much.

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

Very innovative way of explaining ! Great work !

Love how clear this was

Very nice presentation & explanation of the resolution bandwidth

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

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

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 =)

Thanks for the clear and concise explanation!

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

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

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

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

This is an awesome explanation

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

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?

THANK YOU!!! Now I understand the different.

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

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.

I get so much from your sessions! Thank you!

Excellent video! Both precise and coherent

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

it looks like the narrow rbw filter would generate some plateaus, since the given tones stay in it for a while when it sweeps them, so the graph at the bottom would not be sharp at the top, but rather flat, but still narrower than the graph above it.

Very concise and nicely conveyed. Well done.

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

Amazing video!!! Thank you

I've never seen this explained so well.

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

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

It is an excellent explanation. Would you please explain about the effect of the ratio VBW to RBW on uncertainty of power measurement (eg channel power)? for example why it is necessary to set VBW >=3*RBW for having negligible bias that arises due to log power averaging . Thanks a lot.

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

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

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

I just shared this with my students. Great job.

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

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

Best video ever! You are a hero !

Fascinating, Knowledgeable and clears all doubts Thanks

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,

Hi there Any chance for a help here I want to measure EMF There is a device that produces an EM radiation and I wanted to find out all the details about it Any chance what tools I would need Thx Also For radio frequency measuring Thx for getting back to me

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!

Wow! What an explanation! Thank you sir!

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

Excellent explanation, well presented

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

Thank you for the wonderful video. However, I have a question. 1) What does it mean/imply if the IF bandwidth is set as 70kHz? In this case, if the incoming signal were at 840MHz, how would the Spectrum analyzer/Network analyzer perform?

Sensational videos. 73!

Very intuitive demo

This was great , Thank you so much

Thank you from Russia! More happiness to your life!

Awesome explanation!

This is a superb explanation of RBW and VBW. Chapeau! I have one question though: am I right in understanding that a smaller RBW lowers the noise floor simply because the detector is integrating the power over a smaller frequency range, or is there some other effect in play?

Hi W2aew i was actually measuring the GSMLB 900 Second harmonics(1800) and if i decrease the RBW the second harmonic power is coming down and if increase the RBW the second harmonic power level is more , i do know that RBW affects the DANL but why RBW is affecting the second harmonic power level (can you plz explain)