literally the best video I have seen on this topic. going to a top engineering institution is not for learning, it's just for connections and opportunity. TH-cam is for learning.
8 years after you made this video, it's still helping people like me understand dB's. I followed the reasoning easily but may have to watch a few times more to get the maths to sink in. Thanks for making the video.
When I saw the handheld camera going from the scope to the paper I thought “oh boy, here we go another junky video” but after I watched the whole presentation I was so pleasantly surprised: There was the math … and up here you can see the real world. Awesome explanation, very clearly done! Hats off to you sir, best dB explanation I have ever seen anywhere.
I am an electrical engineer but I have NEVER heard the topic explained as well as this. THANK YOU for the refresher as well as many new things you taught me! I need to watch this again!
Allan: As I have remarked previously several times, your speech level never varies, your articulation & grammar are as close to perfect as anyone can reasonably expect, & your descriptions & explanations are without peer. The number of people who subscribe to your videos speaks for the quality of same. I have steered many of my colleagues to your "channel" ' & they are all impressed. It is a rare occasion that I don't learn something from each video ( imagine Allan....I am 80 years of age & I don't know everything !) You will move from pencil & paper to oscilloscope to spectrum analyser ( yes, I know Americans spell the word analyser with a "Z", but at 80 years of age I don't plan on changing Her Majesty's English spelling) & concepts that may not have been completely clear suddenly become so. BRAVO! I have never encountered any other person who displays your level of competence for conveying technical information to a host of followers of doubtless widely varying levels of education with such ease & aplomb. We are privileged to have access to your videos Allan. With admiration & respect Sir, Brian Hind
Excellent work, and a refreshingly clear, intuitive teaching style! Kudos, mon ami … 41 years later, and I STILL enjoyed those fundamental concepts of “WHY dB?!?” In the FIRST PLACE!! 😇😇😇
Alan One of the best explanations I have heard on the subject. You have a magic way of cutting through the nonsense with the most practical explanations. Many Thanks.
It's been many many moons ago since I've reviewed this. You did and outstanding job as always. Clear, precise and to the point along with the examples you provided. Kudos to you for your teaching skills. I must say you laid this out much better than any textbook I've ever studied. I look so forward to every video you post. I either find a new way at looking at electronics or just down right learn something new.
So good to finally be able to differentiate whats what with the various slang's of Dbm's that have been past erroneously around the horn for years and every engineer seems to have a nuance of their own!! Thank you for sharing your insights on this matter!! 73's , Gary Grove Minneapolis, MN
How I explain it: a decibel is a tenth of a Bel, and 1 Bel stands for "an order of magnitude". So when you make the signal 70 dB weaker, that's 7 Bel, or 7 orders of magnitude, or 10 million times as you say.
man, your channel is a masterpiece...i consider myself a quialified systems engineer, but it appears that sometimes I'm missing in depth understanding of some basic concepts...and you've got a talant of explaining things in a simple and structured way...wrap your videos in a book format and launch a crowdfounding compaing...I'll be the first to support it...
Easily the best explanation of the various DB's I've ever seen or read. Seriously, the explanation and math on your graph paper complemented with examples on the scope are simply brilliant!
You just wouldn't believe how many things you've cleared up in my mind through the explanations of the subject matter! I mean, outside of the video topic, I've now been able to make sense and/or have a better understanding of what had seemed confusing to me in electronics and radio frequencies when it came to the oscilloscope and the spectrum analyzer. I'm strictly an entry-level hobbyist and couldn't even begin to speak intelligently on the 'real-world' applications of most of these points but I'm determined to grasp the basics through videos like this and through various test/hobby kits. I own several scopes, (my most recent is digital), though nothing as advanced as the Techtronic scope/SA you have here. Of course I have a signal frequency generator and recently purchased a small Spectrum Analyzer, (the "Tiny SA"). I wanted to understand how the SA works and how to apply its functions to an oscilloscope and vice/versa. Once I'm sure that I understand the use of a Spectrum analyzer, I'll buy one that is considerably more versatile and accurate. Thanks again for the great video and this is one that I'll be referring back to in the weeks & months ahead. Rich
Excellent channel! Sir, I have my parents and my grandfather's slider rulers. My grandfather worked at the radio-telegraph station, in Rio de Janeiro, and during the 1940s he did the first SSB transmission from Brazil to France. My father says slider rulers gave engineers a magnitude perception that is much better than calculators.
Thank you so very much. I've struggled with this for so long. I get the theory. However, I couldn't apply it, I'd end up tying myself in knots. This has truly lifted the scales from my eyes. This video is going to be my reference until I can explain it to someone else (or point them here).
I finally have a good understanding of db measurements. This is a great, and underrated channel for those of us coming into ham radio without formal education in electronics and RF theory.
This is an excellent explanation of dBs and their uses. It's at last helped me get my head better around this subject. I'm particularly grateful for the derivation of the voltage equation from the power equation. You're the only one on YT I've found showing and explaining this. Many thanks for another great tutorial Alan
I'm so glad it's relatively easy to record a presentation these days, because I will be watching this about 4 more times before I have it fully in hand. But it's clear and complete, so I won't be wasting your time or mine. Thank you.
Thanks, great video. I first learned the decibel in 1977 during satcom school in the Army and continue to use them daily as an engineer. Have taught a lot of folks how to work with dB of various flavors over the years and this is going in my bookmark file for a nice link to point people to. Well done.
Hey, great video, you inspired me. I am about to be pedantic, my old RF lecturer who was Marine Radio Officer is standing looking over my shoulder. He never forgot the caveat, "In a matched condition". Please everyone, remember to specify the source and load impedance and the system must be matched.
Thank you for this channel! I'm working on trying to repair an HP 8557A which is my first introduction to using SAs (probably bit off more than I can chew in that regard). Really struggling with an issue I'm having calibrating the lin/log relationship settings. This was compounded by a lack of understanding of dB scale and reference level. This video helped explain the fundamentals in such a clear/concise and easily understood manner. It gave me some confidence to continue working on this repair. Thank you!
The wise adage says that to learn is never too late. Your movies are for me the proof that this phrase tells the truth. Every time I learn a lot from your movies. Thanks a lot.
why cant they explain like this in engineering courses, its mind boggling. All EE college professors need to watch this and learn. i want to go back in engineering college all over again,
My instructors just assumed you knew. I had no idea what they were talking about. It should be standard across the board to introduce it in an intro course.
That's why I used to look for better textbooks back in the days or jump lectures to a better professor. Nowadays, TH-cam my friend. I stumble on this video for my young cousin because I suck at explaining and quite lazy... I just point to youtube video nowaday once I find a good one
Yes and if you did ask your professor about it, would he start trowing other terms at you, that you had never heard of! And of course, containing advanced theoretical physics with high level math, or something. Ending with you know even less!! :-)
@@burgerking220 Or the classical: Professor: "This part will you learn much more about in next semester, so I'll just jump over it here" Next semester professor: "I'll just jump this part over because you should already know all about this from last semester" :-)
Excellent simple explanation of dB. In fact with BODE100 impedance analyser, i recognized the unit dbohm. I was trying to measure ESR of capacitors. I have forgotten what was the definition of db. I knew it was a ratio of two units but i was uncertain if it was to be multiplied by 20 or 10. With time, I have almost forgotten all i learned at school and how analog electronics is important and rich. I work for a multinational company, electronic is only one of their border subject and they don't give any importance(even though all their products are based on algorithm and very often on important some analog technologies) when it comes to electronics and even more when it comes to analog electronics. Anyway , many thanks for your crystal clear explanation.
A very clear explanation of each unit. I really appreciate that people like you, take the time, to teach and help others. Warm greetings and my respects from Puerto Rico and God bless you.
I don't know how to thank you.... I have been gone watching your videos once after the other... The concepts are becoming clear to me after a long long time... I wish you could do more such videos. Perhaps on concepts of electromagnetic field theory and antennas. Great work! Thank you!
I used to work in an acoustics lab, where the important measurement is dBA. This is the noise or sound level relative to the threshold of hearing, ie. 0 dBA is the quietest sound that anyone can hear. (There are a few caveats on that, but that's basically it.) Here are some typical values: 40 dBA - a soft whisper 60 dBA - conversation at 3 ft. away 90 dBA - legal workplace limit for extended periods in many countries 110 dBA - rock band 130 dBA - jet engine at 200 ft. 140 dBA - the threshold of pain 235 dBA - the estimated sound level of the volcanic explosion at Krakatau Remember these are logarithmic values!
@@w2aew Yes indeed - it startled people 3000 miles away, caused a pressure peak corresponding to 2.5 inches of mercury (8.5 kilopascals) at 100 miles away and the pressure wave went round the globe several times. It's just unimaginable.
I'd love to see you do a video on a VSA. I worked for 6 years as an RF Test Engineer on Cable Modems and Cable headends. I loved the power of the VSA, giving me the capabilities to look at signals in so many different ways. Time domain, freq domain, constellations, eye diagrams, etc. Great stuff you're doing. Kudos!
I think you've discovered that I do have some videos using a VSA. More precisely I am using a realtime spectrum analyzer, which is a VSA with realtime capability. I've got several videos using the RSA.
Another superb instructional video, Alan! Not only do you cover the material as clearly as, I think, is humanly possible but your voice quality and intonation are spot on. Even your use of graph paper and a scope lead as a pointer contribute to the clarity of your presentation. BTW, Tektronix makes some super scopes, don't they! :-)
This is what I meant a good teacher is , explaining confusing idea (at least to me) using simple explanation and easy to understand example. Good Good Video. Thanks Alan
4:25 and following: Having just learned that 10dB (or 1B) is an increase of decrease of _power_ by a factor of 10^1, or just plain 10, we might find the display of 10dB reduction to be rather unimpressive or puzzling. The unspoken assumption here is that the signal source is providing a voltage into a resistive load, and that therefore the power is proportional to V^2. So a factor of 10 reduction in power corresponds to a SQRT(10) reduction in voltage. SQRT(10) = 3.16. So whereas the original voltage is about 9.6 units p-p on the screen, the -10dB display would be 9.6 x 3.17 = 3.13 units p-p, which indeed it appears to be. Similarly for subsequent steps. Mr W2aew does discuss voltage ratios at 11:55, and goes on to show the single 10MHz signal measurement on the spectrum analyzer relative to dBmV. However, one example that would have been illuminating is what happens when you adjust the attenuator in 10dB steps (like in the first spectrum analyzer exercise), when the spectrum analyzer is set to display dBmV (ie: a voltage-based reference). Turns out that the analyzer will still show those as 10dB steps, because it still assumes that dBs of any kind are about power ratios (into a fixed resistor), even though it's showing absolute values relative to a reference specified as a voltage.
I dont mean to be so offtopic but does anyone know a method to get back into an instagram account?? I somehow forgot my account password. I love any tricks you can give me.
@Chris Allen I really appreciate your reply. I found the site thru google and im waiting for the hacking stuff atm. Takes quite some time so I will reply here later with my results.
Great knowledge... Glad to see that some great electronics youtuber also watch your videos and give positive vibes... Lots. Of respect from India.. De vu3ict..
Nice explanation. Was just reading about this topic and amplitude dB was stated as 20 log10 vice 10 log10 and this explained that well. Seeing the math really helps. Also cleared up the differences in types of dB measurements.
Absolutely brilliant explanation with great examples! So nice to get a refresher on this knowledge that I didn't quite understand fully before. (I have that "now I get it!!!" moment)
I'm going for my Extra class test on Nov 10. This video sure cleared up allot of confusion for me about where some of these equations came from in the ARRL manuals. I suppose part of the problem is that, in my career, I did not have to work with decibels. So remembering when to use 20*Log vs 10*Log didn't make much sense to me ... UNTIL NOW! Thanks very much. Don, KC3MBK
Ok my praises are getting old as I repeat them for every one of you videos. You have the right paper, have impeccable writing dexterity, know-how and the ability to explain complex subjects, simply. When can we expect the publishing of Alan's Engineer's Notebook? "hi hi", but I'm serious.
I must say that this video is amazing. I also must follow up by saying, "You have mastered this area of study!!!!!" I know the math, overall, is fairly basic, but it is nonetheless fascinating. I hope that it is somewhat normal to perhaps need to watch this a time or two more to fully grasp what you are explaining. I get it, but I have to review for a greater awareness...
All the parts of your tutorial are connected and the sequencing is wonderful .. thank you sir I really wanted to understand this topic for a long time. So dB basically deals for audio and signal transmission.
dB can be used with audio, RF, and many other applications where RATIOs of quantities are important, especially when the range of ratios can be large and small.
@@w2aew But is it specifically in electronics and telecommunication ? For example in mechanics how would they use it, maybe measuring the loudness of a motor, engine ... etc. So that's means measuring sound which is physics. So dB is in general a physics measurement method, is my conclusion correct ?
It is used outside of electronics, RF, EMI/EMC, and telecommunications. Acoustics is a another area where it is used extensively - sound pressure level is measured in dB.
@@w2aew Thanks a lot 🙂 if you allow me to ask you something out of the subject, I'm actually lost in power electronics and wanting to design SCR triggering circuit, where the best area to start from ? I've watched a lot circuits online but people on edaboard forum told me that I don't have any idea of what I'm doing ! Do you know a professional forum that would help me to learn about it ?
@@PerchEagle Online forums are really not the best way to learn about electronics, since there are many trolls and lots of mis-information. Books, professional video series (like the courses offered by MIT and Kahn Academy) are much better to learn from. I did do a video on the basics of SCRs, maybe that will help you: th-cam.com/video/lSqCiCc7jQc/w-d-xo.html
I can put it no better than bain5872. Simply excellent, using the SA versus the `scope to show how the dB is so useful makes it very easy to see the merits. Superb presentation, thank you.
Probably the best dB explanation video I've seen
Oh yes, totally agree - thanks!
I agree. 100%
Probably the best dB explanation video I've seen (2)
I agree too. 👍🏻
Great Job!!!
literally the best video I have seen on this topic. going to a top engineering institution is not for learning, it's just for connections and opportunity. TH-cam is for learning.
8 years after you made this video, it's still helping people like me understand dB's. I followed the reasoning easily but may have to watch a few times more to get the maths to sink in. Thanks for making the video.
Yes, there's a wealth of information in these K2AEW videos. They never get old. AEW = Always Educational and Worthwile.
When I saw the handheld camera going from the scope to the paper I thought “oh boy, here we go another junky video” but after I watched the whole presentation I was so pleasantly surprised: There was the math … and up here you can see the real world. Awesome explanation, very clearly done! Hats off to you sir, best dB explanation I have ever seen anywhere.
So glad you liked it. I hope you find that my other videos impress you as much as this one did.
Excellent video! All lecturers should teach like you, the students would love it.
I will write without hesitation - the Internet was invented for such amazing leśons and teachers. 👍
Best regards from Warsaw!
I am an electrical engineer but I have NEVER heard the topic explained as well as this. THANK YOU for the refresher as well as many new things you taught me! I need to watch this again!
Allan: As I have remarked previously several times, your speech level never varies, your articulation & grammar are as close to perfect as anyone can reasonably expect, & your descriptions & explanations are without peer. The number of people who subscribe to your
videos speaks for the quality of same. I have steered many of my colleagues to your "channel" ' & they are all impressed. It is a rare occasion that I don't learn something from each video ( imagine Allan....I am 80 years of age & I don't know everything !) You will move from pencil & paper to oscilloscope to spectrum analyser ( yes, I know Americans spell the word analyser with a "Z", but at 80 years of age I don't plan on changing Her Majesty's English spelling) & concepts that may not have been completely clear suddenly become so. BRAVO! I have never encountered any other person who displays your level of competence for conveying technical information to a host of followers of doubtless widely varying levels of education with such ease & aplomb. We are privileged to have access to your videos Allan.
With admiration & respect Sir,
Brian Hind
Thank you Brian - this is very much appreciated!
Going over the calculations was incredibly helpful. It's like most content creators don't think someone searching for explanations of dB is nerdy.
Excellent work, and a refreshingly clear, intuitive teaching style! Kudos, mon ami … 41 years later, and I STILL enjoyed those fundamental concepts of “WHY dB?!?” In the FIRST PLACE!! 😇😇😇
This video is timeless.
I find myself coming back to watch it again and again.
Alan
One of the best explanations I have heard on the subject. You have a magic way of cutting through the nonsense with the most practical explanations. Many Thanks.
This was epic. You are a wonderful teacher. God bless.
It's been many many moons ago since I've reviewed this. You did and outstanding job as always. Clear, precise and to the point along with the examples you provided. Kudos to you for your teaching skills. I must say you laid this out much better than any textbook I've ever studied. I look so forward to every video you post. I either find a new way at looking at electronics or just down right learn something new.
So good to finally be able to differentiate whats what with the various slang's of Dbm's that have been past erroneously around the horn for years and every engineer seems to have a nuance of their own!! Thank you for sharing your insights on this matter!! 73's , Gary Grove Minneapolis, MN
Very long time I Search teaching with real time example finally I got one of the best teacher. Thanks a lot sir..
How I explain it: a decibel is a tenth of a Bel, and 1 Bel stands for "an order of magnitude". So when you make the signal 70 dB weaker, that's 7 Bel, or 7 orders of magnitude, or 10 million times as you say.
I've been looking for this for a very long time.
That is an absolutely perfect and intuitive explanation of this term.
Even after 6 years, do you comment help others! Thanks!! :-)
I took a screenshot of your comment!
This is gold right here!
:-) I like how how he said goodbye -- "Thanks for watching and oscillator" -- classic! Thanks for a great explanation of dB!
man, your channel is a masterpiece...i consider myself a quialified systems engineer, but it appears that sometimes I'm missing in depth understanding of some basic concepts...and you've got a talant of explaining things in a simple and structured way...wrap your videos in a book format and launch a crowdfounding compaing...I'll be the first to support it...
How to teach is one thing and you do it well. I think that the real brilliance here is in the "What to teach domain".
Easily the best explanation of the various DB's I've ever seen or read. Seriously, the explanation and math on your graph paper complemented with examples on the scope are simply brilliant!
You just wouldn't believe how many things you've cleared up in my mind through the explanations of the subject matter! I mean, outside of the video topic, I've now been able to make sense and/or have a better understanding of what had seemed confusing to me in electronics and radio frequencies when it came to the oscilloscope and the spectrum analyzer.
I'm strictly an entry-level hobbyist and couldn't even begin to speak intelligently on the 'real-world' applications of most of these points but I'm determined to grasp the basics through videos like this and through various test/hobby kits.
I own several scopes, (my most recent is digital), though nothing as advanced as the Techtronic scope/SA you have here. Of course I have a signal frequency generator and recently purchased a small Spectrum Analyzer, (the "Tiny SA"). I wanted to understand how the SA works and how to apply its functions to an oscilloscope and vice/versa.
Once I'm sure that I understand the use of a Spectrum analyzer, I'll buy one that is considerably more versatile and accurate.
Thanks again for the great video and this is one that I'll be referring back to in the weeks & months ahead.
Rich
After so many years this is still the best video on this subject.
Very helpful!
Excellent channel! Sir, I have my parents and my grandfather's slider rulers. My grandfather worked at the radio-telegraph station, in Rio de Janeiro, and during the 1940s he did the first SSB transmission from Brazil to France. My father says slider rulers gave engineers a magnitude perception that is much better than calculators.
Thank you so very much. I've struggled with this for so long. I get the theory. However, I couldn't apply it, I'd end up tying myself in knots. This has truly lifted the scales from my eyes. This video is going to be my reference until I can explain it to someone else (or point them here).
I finally have a good understanding of db measurements. This is a great, and underrated channel for those of us coming into ham radio without formal education in electronics and RF theory.
This is an excellent explanation of dBs and their uses. It's at last helped me get my head better around this subject.
I'm particularly grateful for the derivation of the voltage equation from the power equation. You're the only one on YT I've found showing and explaining this.
Many thanks for another great tutorial Alan
I'm so glad it's relatively easy to record a presentation these days, because I will be watching this about 4 more times before I have it fully in hand. But it's clear and complete, so I won't be wasting your time or mine. Thank you.
Thanks, great video. I first learned the decibel in 1977 during satcom school in the Army and continue to use them daily as an engineer. Have taught a lot of folks how to work with dB of various flavors over the years and this is going in my bookmark file for a nice link to point people to. Well done.
Hey, great video, you inspired me. I am about to be pedantic, my old RF lecturer who was Marine Radio Officer is standing looking over my shoulder. He never forgot the caveat, "In a matched condition". Please everyone, remember to specify the source and load impedance and the system must be matched.
Thank you for this channel! I'm working on trying to repair an HP 8557A which is my first introduction to using SAs (probably bit off more than I can chew in that regard). Really struggling with an issue I'm having calibrating the lin/log relationship settings. This was compounded by a lack of understanding of dB scale and reference level. This video helped explain the fundamentals in such a clear/concise and easily understood manner. It gave me some confidence to continue working on this repair. Thank you!
The wise adage says that to learn is never too late.
Your movies are for me the proof that this phrase tells the truth.
Every time I learn a lot from your movies.
Thanks a lot.
You are the best teacher in the whole world for RF engg
BEST dB explanation!!!
why cant they explain like this in engineering courses, its mind boggling. All EE college professors need to watch this and learn. i want to go back in engineering college all over again,
My instructors just assumed you knew. I had no idea what they were talking about. It should be standard across the board to introduce it in an intro course.
That's why I used to look for better textbooks back in the days or jump lectures to a better professor. Nowadays, TH-cam my friend. I stumble on this video for my young cousin because I suck at explaining and quite lazy... I just point to youtube video nowaday once I find a good one
Yes and if you did ask your professor about it, would he start trowing other terms at you, that you had never heard of! And of course, containing advanced theoretical physics with high level math, or something. Ending with you know even less!! :-)
I was gonna say the same thing.
@@burgerking220 Or the classical:
Professor: "This part will you learn much more about in next semester, so I'll just jump over it here"
Next semester professor: "I'll just jump this part over because you should already know all about this from last semester" :-)
🤯🤯🤯🤯🤯 Absolutely the most cogent explanation of dB ever attempted. Thank you.
You have a gift. Found your channel a week ago and have become addicted! Thank you for your time and effort, and please keep them coming.
Excellent simple explanation of dB. In fact with BODE100 impedance analyser, i recognized the unit dbohm. I was trying to measure ESR of capacitors. I have forgotten what was the definition of db. I knew it was a ratio of two units but i was uncertain if it was to be multiplied by 20 or 10.
With time, I have almost forgotten all i learned at school and how analog electronics is important and rich.
I work for a multinational company, electronic is only one of their border subject and they don't give any importance(even though all their products are based on algorithm and very often on important some analog technologies) when it comes to electronics and even more when it comes to analog electronics.
Anyway , many thanks for your crystal clear explanation.
Thank you for such a clear & well explained video that got straight to the topic without any fluff & waffle, excellent! God bless, Bill.
I have never seen or experienced - as long as i can think of - better explaination. Thanks and big admire of you.
You're a better teacher than most of my engineering professors.
Your videos are great!
Your explanation is very clear and you have clarified now why we are using DB on SA. As always thanks Alan!
Very great video ever 8 years later! Thanks a lot!
The best explanation ever on dB with practice illustrating theory and vice versa. Brillant !
A very clear explanation of each unit. I really appreciate that people like you, take the time, to teach and help others. Warm greetings and my respects from Puerto Rico and God bless you.
I don't know how to thank you.... I have been gone watching your videos once after the other... The concepts are becoming clear to me after a long long time... I wish you could do more such videos. Perhaps on concepts of electromagnetic field theory and antennas.
Great work! Thank you!
Brilliant.Guys like you are desperately needed in universities. :)
Those who can't - teach....
I used to work in an acoustics lab, where the important measurement is dBA. This is the noise or sound level relative to the threshold of hearing, ie. 0 dBA is the quietest sound that anyone can hear. (There are a few caveats on that, but that's basically it.) Here are some typical values:
40 dBA - a soft whisper
60 dBA - conversation at 3 ft. away
90 dBA - legal workplace limit for extended periods in many countries
110 dBA - rock band
130 dBA - jet engine at 200 ft.
140 dBA - the threshold of pain
235 dBA - the estimated sound level of the volcanic explosion at Krakatau
Remember these are logarithmic values!
WOW - Krakatau was LOUD! Nearly 100dB above threshold of pain. Devastating!
@@w2aew Yes indeed - it startled people 3000 miles away, caused a pressure peak corresponding to 2.5 inches of mercury (8.5 kilopascals) at 100 miles away and the pressure wave went round the globe several times. It's just unimaginable.
@@chrisengland5523 Fascinating!
You have best and most relevant videos about electronics. You pick great topics to talk about.
I'd love to see you do a video on a VSA. I worked for 6 years as an RF Test Engineer on Cable Modems and Cable headends. I loved the power of the VSA, giving me the capabilities to look at signals in so many different ways. Time domain, freq domain, constellations, eye diagrams, etc. Great stuff you're doing. Kudos!
I think you've discovered that I do have some videos using a VSA. More precisely I am using a realtime spectrum analyzer, which is a VSA with realtime capability. I've got several videos using the RSA.
Yes. Thank you!
Even though it has been 6 years since this post, it helped me, I'm very happy to find this post.
Thx Sr.
Brilliant can clear explanation that does not shy away from maths or practical demonstration. Many thanks for this.
Came back to watch this again. Thank you- for your useful and careful explanation of why we want dBs.
All I can say is I wish I came across this video years ago.. thank you for making me feel confident about this topic💪
Another superb instructional video, Alan! Not only do you cover the material as clearly as, I think, is humanly possible but your voice quality and intonation are spot on. Even your use of graph paper and a scope lead as a pointer contribute to the clarity of your presentation. BTW, Tektronix makes some super scopes, don't they! :-)
Man, these videos of yours are pure gold. Seriously. GOLD.
I’m enjoying this while taking my wired, optical and wireless class at DeVry at the moment. Class similar as your teaching is more of n depth.
This video really sums up everything I wasn't taught correctly at my degree. Wish I could have stumbled this earlier! thanks a lot!
This is what I meant a good teacher is , explaining confusing idea (at least to me) using simple explanation and easy to understand example. Good Good Video. Thanks Alan
You are officially the king of the explanation!!!
Excellent video as usual. You have the knack of making difficult concepts seem easy. I have learnt a lot from you over the past year. Many thanks.
Absolutely the best explanation. The demo makes it fantastic.
I learn something new every time you post a new video. So well explained and demonstrated. Keep up the fantastic work and look forward to many more.
You are a very good teacher. Excellent presentation, simple to understand and concise. Thank you.
Awesome, so much better than reading a book, your scope examples make it easy to visualize and understand.
Your explanations are great. You make me even more interested in RF than I already am.
Amazing explanation ,AND with clear examples. Beautiful thing. Thank you.
thanks a lot for producing such „easy to understand“ videos of quite complex subjects. Like your channel a lot
Cant imagine a better explanation of dB than this. Excellent, love it!
Alan, really excellent explanation, simple to understand and concise. Thanks for posting. Gerry
I Agree, but your videos are great too
lechu lsk Thats kind to say, thank you :)
You're welcome
BTW: It's me thank YOU
A super fine tutorial.. so simply explained.. thank you
An absolute incredible example for students and rf beginners. Thank You
4:25 and following: Having just learned that 10dB (or 1B) is an increase of decrease of _power_ by a factor of 10^1, or just plain 10, we might find the display of 10dB reduction to be rather unimpressive or puzzling. The unspoken assumption here is that the signal source is providing a voltage into a resistive load, and that therefore the power is proportional to V^2. So a factor of 10 reduction in power corresponds to a SQRT(10) reduction in voltage. SQRT(10) = 3.16. So whereas the original voltage is about 9.6 units p-p on the screen, the -10dB display would be 9.6 x 3.17 = 3.13 units p-p, which indeed it appears to be. Similarly for subsequent steps.
Mr W2aew does discuss voltage ratios at 11:55, and goes on to show the single 10MHz signal measurement on the spectrum analyzer relative to dBmV. However, one example that would have been illuminating is what happens when you adjust the attenuator in 10dB steps (like in the first spectrum analyzer exercise), when the spectrum analyzer is set to display dBmV (ie: a voltage-based reference). Turns out that the analyzer will still show those as 10dB steps, because it still assumes that dBs of any kind are about power ratios (into a fixed resistor), even though it's showing absolute values relative to a reference specified as a voltage.
Excellent refresher , thanks W2aew ....keep up the great work in 2016. Always look forward to your new postings.
Thank you, Thank you, Thank you, Thank you, Thank you! Every minute filled with goodness. Now back to my HP 8566B, with extra understanding.
Excellent video, which explains these concepts in an easy to understand way with nice examples. I wish all teachers were that good!
Another fantastic video Alan! This must be the best explanation of the different dB references I've ever seen. Thank you very much! 73
Great Video! Learned a lot! As a hardware EE your videos are invaluable. I am grateful for the time you spend on producing such quality material.
Thanks Alan, great post.
Thankyou for this post at last someone who can explain the fundamentals urco
I dont mean to be so offtopic but does anyone know a method to get back into an instagram account??
I somehow forgot my account password. I love any tricks you can give me.
@Derrick Alexander Instablaster :)
@Chris Allen I really appreciate your reply. I found the site thru google and im waiting for the hacking stuff atm.
Takes quite some time so I will reply here later with my results.
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Thank you so much, you really help me out !
Great explanation! Thank you for taking the time to make this tutorial.
Great knowledge... Glad to see that some great electronics youtuber also watch your videos and give positive vibes... Lots. Of respect from India.. De vu3ict..
Helpful equations & practical applications.
Nice explanation. Was just reading about this topic and amplitude dB was stated as 20 log10 vice 10 log10 and this explained that well. Seeing the math really helps. Also cleared up the differences in types of dB measurements.
THE ABSOLUTE BERST EXPLANATION I HAVE EVER SEEN OR READ. THANKS!!!!
Alan you are the best teacher ever .... thanks
Absolutely brilliant explanation with great examples! So nice to get a refresher on this knowledge that I didn't quite understand fully before. (I have that "now I get it!!!" moment)
The best explanation I have seen. Your examples were great!
The best explanation of db. Thank you!
I'm going for my Extra class test on Nov 10. This video sure cleared up allot of confusion for me about where some of these equations came from in the ARRL manuals. I suppose part of the problem is that, in my career, I did not have to work with decibels. So remembering when to use 20*Log vs 10*Log didn't make much sense to me ... UNTIL NOW! Thanks very much.
Don, KC3MBK
Useful 17.40 minutes ever spent. Very well eplained
The best tutorial on the subject that I've seen.
this just cleared up 40 years of confusion, thanks!
Excellent! I have always struggled as it wasn't explained properly for my brain to understand. Thank you! :)
Very informative. Clear concise explanations, and easy to follow even with the math. Thank you for taking the time to make this video!
Ok my praises are getting old as I repeat them for every one of you videos. You have the right paper, have impeccable writing dexterity, know-how and the ability to explain complex subjects, simply. When can we expect the publishing of Alan's Engineer's Notebook? "hi hi", but I'm serious.
Thanks for the really nice comments! I guess you can call this channel "Alan's Engineering Video Notebook" !
Very nice tutorial. Excelent and clear explanation. Recomended for all. I will share this video in my facebook.
I must say that this video is amazing. I also must follow up by saying, "You have mastered this area of study!!!!!" I know the math, overall, is fairly basic, but it is nonetheless fascinating. I hope that it is somewhat normal to perhaps need to watch this a time or two more to fully grasp what you are explaining. I get it, but I have to review for a greater awareness...
All the parts of your tutorial are connected and the sequencing is wonderful .. thank you sir I really wanted to understand this topic for a long time. So dB basically deals for audio and signal transmission.
dB can be used with audio, RF, and many other applications where RATIOs of quantities are important, especially when the range of ratios can be large and small.
@@w2aew But is it specifically in electronics and telecommunication ? For example in mechanics how would they use it, maybe measuring the loudness of a motor, engine ... etc. So that's means measuring sound which is physics. So dB is in general a physics measurement method, is my conclusion correct ?
It is used outside of electronics, RF, EMI/EMC, and telecommunications. Acoustics is a another area where it is used extensively - sound pressure level is measured in dB.
@@w2aew Thanks a lot 🙂 if you allow me to ask you something out of the subject, I'm actually lost in power electronics and wanting to design SCR triggering circuit, where the best area to start from ? I've watched a lot circuits online but people on edaboard forum told me that I don't have any idea of what I'm doing ! Do you know a professional forum that would help me to learn about it ?
@@PerchEagle Online forums are really not the best way to learn about electronics, since there are many trolls and lots of mis-information. Books, professional video series (like the courses offered by MIT and Kahn Academy) are much better to learn from. I did do a video on the basics of SCRs, maybe that will help you: th-cam.com/video/lSqCiCc7jQc/w-d-xo.html
Very interesting. Boy how much I have forgotten over the years. Thanks
I can put it no better than bain5872. Simply excellent, using the SA versus the `scope to show how the dB is so useful makes it very easy to see the merits. Superb presentation, thank you.