Mr. Carlson is an encyclopedia of knowledge. He is a Canadian and really appreciated by many throughout the world. I wish I could visit your lab Paul. I would never leave!!!
I for one am Very appreciative of your time and teachings! I only wish I could have received this kind of education in my younger years but am So very appreciative that I can learn and apply these teachings now! Thank you Mr Carlson for sharing your knowledge, talent and time to insure we learn the correct ways along with the cautions that we are dealing with potentially high voltages. On behalf of all here, Thank you.
Paul, I say this freely and not because you mentioned me in the video, but there is just not enough tube related videos on TH-cam. This video IS the best one I have ever seen on TH-cam hands down. Very well explained and the confidence of your knowledge on this subject is simply outstanding. Being an old tube lover since my teens I really enjoyed this one.....Well Done and a huge thumbs up !Now I can say a big thanks for the mention of me and my channel and is very much appreciated. I feel very honored and going to post this one on my website for others to view and learn. Thanks my friend.
@@supersolex Check out Glasslinger on TH-cam sometime. He wears women's clothes, but he also does repair and restoration of tube equipment. He even makes some of his own tubes.
Paul: I'm an old NASA gate chaser from the 70s where I learned TTL. Lots of logic, lots of transistor theory, and just a little analog....probably just enough to figure out simple power supplies. Now that I'm an old retired guy, I have come back to ham radio, and my interests particularly lie in vintage tube equipment, particularly Collins, and some of the "Big Iron" AM broadcast transmitters. Your videos are wonderful in helping me transfer what I learned as a digital tech to tubes. Although you don't specifically mention it, as you go through your excellent signal chasing, I find myself saying, "oh, that works just like a transistor." Thank you so very much for videos just like this one....they are exactly right on the money for what I need.
I just came across this video (4 years late). I do understand how a triode valve system works but wanted see how you explained it for the beginner. Your explanation was spot on, very good. I saw an explanation by another TH-camr trying to explain how tubes (valves) work, their instruction video was full of errors and inaccuracies. They got very defensive when I commented on the errors in the video. Your explanation was excellent and flawless. Well done Paul, keep more great videos coming like this.
So glad you stressed that an amplifier stage swings the supply voltage across the plate resistor, that the output signal voltage comes from the supply, not the tube. I was years into things, without formal training, before I realized that. It’s too easy to visualize that the tube “turbocharges” the input signal applied to the grid, sends it through the vacuum and onwards to the plate. I better understood the term “valve” when I conceived of the tube as a valve that opens partially, in proportion to the input signal, to create a low-resistance path from B+ to ground, loading the supply, dropping the voltage across the plate resistor.
Mr Carlson, If you ever write a book (and you should). Put me down for one of the first copies. Your demonstrations are brilliant. Thanks again for your hard work and informative videos.
He is so right though sir. I have a feeling that any book that you would write would be up there in caliber with "the art of electronics." I cannot stress just how much I have learned from you and how much I appreciate the work that you are doing. Even your TH-cam videos alone have elevated my understanding Beyond what I would have imagined possible. I really really appreciate everything you do!
Man, I don't understand a lot of what you're saying but I've been binge watching for ages now. Love your explications and even though I'm just a muso, this all intrigues me and dig the way you go through things in depth, fast, but take your time to explain. I hope you keep up the great work man?!!!
Paul, Ahhhhhh! You have greatly clarified to me how tubes work in 18 short minutes. I especially like how you present theory, then assemble a circuit and prove it to be true. That really helps me absorb material. What kind of maniac gives a Mr. Carlson's video a thumbs down? Thanks, I know making videos (well, good ones) takes time and effort.
Ian Butler they probably get the video in their feed and by thumbing down think they are influencing the algorithm not to send anymore vids like this to them.
Where were you, when as a recent graduate of 6th grade in 1966, I attended a summer elective workshop program of beginner electronics which included DC theory and vacuum tube operation? We were given old High School text books and I recall having great difficulty wrapping my understanding around the very concepts you are teaching so clearly. You are helping many people.
Finally! A clear explanation as to why the output of the plate is out of phase, and from there a clear understanding of the push-pull mechanism in the output! Thanks! Great video, great channel!
A one man high tech technical school in each video presentation. For me your videos are great refresher courses. In my day I also taught electronics technology at a hands on level. Your methods and approach are the best I've seen in a long time.
I have to admit, you, and Forrest Mimms III make learning very user friendly. Taking text book content, and applying them to real world situations. And keeping it simple, while being in depth with information.
I really like what Mimms did with his books.The first of his that I saw was getting started in electronics.Easy to understand like you said and handy for a person wanting to learn
Found this older video on tubes as i am building my 1st amp from scratch. Well, its an Eico 147 Signal Tracer that i am converting to a Fender Champ 5F1. I just tried to power it up yesterday and pop the fuse and fried the rectifier 6X5 tube. Opps. Well back to the schematics and try see where i went wrong. i like the way you are able to explain then set up little demos. Appreciate all you work very much. Thank You hoping i can figure this baby out. Take care and stay safe. Dennis
After trying to study dozens of books and countless videos for years, your video was the simplest and best explaination in my entire quest to understand tube amps Thank you
Hey Paul; How did I ever forget that the last number on the right end of the tube label designated the number of useful elements in the tube? But I did... Thanks for the refresher. Also thanks for mentioning us for promoting your site to others. You deserve it, with the knowledge base that you possess and your ability to explain it to the masses out here in such a clear and concise manner. Thanks, and a big two thumbs up from all of us to YOU my friend. You have taught us all a lot! Cheers, Tom PS I subscribed to Peter's "TRXBench" a long time ago thanks to your suggestion. I have watched ALL his videos. I am having a blast watching him diagnose ham gear. His English has sure come a long way, hasn't it? "Achtung! Alles lookenpeepers, das instrumenten is nicht fer gerfingerpoken und hittengrabben. Ist easy schnappen der springerverk, poppen corken und blowen fusen mit spitz und sparken. Ist nicht fer geverken by das dumbkopf, alles rubbernecken sightseeren keepen hands in der pockets, relax und vatch der blinkin lights!"
+AntiqueRadioandTV LOL, I have that on a piece of piece of paper somewhere. Years ago I volunteered my time at a local radio museum, they had a few of those "saying's" here and there. Peter is great to watch, and I enjoy his English as well :^) Thanks again for the kind mention Tom!
We are the ones who have to thank you a lot for your work to deliver us great videos and great information. Double thumbs up for your humility. Thank you!
An excellent representation that is so well explained, it reminds me when I ran my own service shop for more than three decades repairing, modifying, and designing specific requirements for my customers. Well Mr. Carlson; you have inspired me to rekindle my love for electronics to the point that I now serve the public once again, for that you have my deepest gratitude.
I wish you the best of luck also. You bring a tube amplifier to a tech around here, if you can find one, you are liable to pick it up six month later without it ever getting it looked at, or never see it again.
When I was 15 my father brought me home an old PA amplifier with a pair of 6L6s. At the time, I wasn't sure what to do with it or how to use it. The rectifier tube was missing also. My dad told me to ask his friend Emil Rudat who lived down the street and worked for RCA at Harrison, NJ. Emil had a 5V4 and it worked after he showed me how and where to hook things up. Anyway, I ignorantly started poking around the underside with the chassis laying on it's side on top of a metal topped cabinet I had used for my rock collection. I had my hand on the top and grabbed the B+ on a capacitor and had my first whack from 400+ VDC. It felt like two people gave me a yank on each arm to pull them out of my body, I was thrown on the floor and shaky. Wow, I knew I was lucky to be still alive. I have heard many engineers and technicians consider that a "right of passage" in the field, but it's a "right of passage" that you want to avoid. Wear gloves or keep one hand in a pocket or both, I was told. I think I got a lesser one again later from a charged capacitor. Even when the unit is off, I learned to discharge caps. It was the last time and I'm still around at the age of 71. Whew! Emil became my early "Mister Wizard" for electronics and he was a life long friend from the WWII generation. My dad had a saying about using power tools, such as a circular saw, which applies to many potentially dangerous things we work on. "Don't be afraid of it. Just RESPECT it." I got it!
Honestly, I get more info from your hard work than anyone else. That is not to discredit anyone else. I just really really get it when you delve into the subject. Sometimes I must watch the video a half dozen times; but I know what it is you are saying when I am done.keep them coming, I can't get enough.Thank s to everyone who has helped as well. It is what makes it fun.
Excellent work. Easy to understand. I know all this stuff already from my professional background in vacuum tube equipment back in the 50's and I retired in 2010. Nevertheless I really enjoyed your presentation. Best quick written electronics lessons back in my day were in the back of the old RCA Receiving Tube Manual of the 50s &60s. Besides taking this stuff in high school and college, I learned it first from that RCA manual. Another great book was the ARRL ham radio Handbook.
Great vid, well done. I've been restoring radios for around 30 years, and I had no idea that the last number in a tube designation identified the amount of elements it has.
Thank you for the kind mention, Paul. I have lots of vacuum tube radios, record players, and test equipment to fix when I have time for it. Most problems will be solved by recapping, but this video will be especially helpful. Other than the filament voltage spec, I had no idea there was any rhyme or reason to vacuum tube part numbers. No worries on my name. It is commonly mispronounced. Should be WAH-sah-TON-ic. Thanks for the thumbs up!
All of your warnings of electrocution bring me back to my childhood. When I was around 9 or 10 I became interested in electronics, I would go out and bring home discarded radios, TV's and any thing electronic and play with them. I always had my hands in something that was plugged in, and the only tools I had were my mom's kitchen knives ( which didn't please her). In all that time I only got one good shock and that was when I found out that a flyback transformer can make you flyback. I love your videos, you are a true inspiration.
+Mr Carlson's Lab Here's another story about the bench that I played with the tube radios and such. The bench was in the basement of the house we lived in, it was constructed with 2x8s with a small gap in between. I had gone to the neighborhood store and bought a sharp knife for carving and such. Being proud of my newest possession the first thing I wanted to do was show my dad, he happened to be in the basement at the time. My dad took the knife and with the smoothest action I'd ever seen (it had to be purely muscle memory from years of fatherhood) inserted the gleaming blade into the gap and with a flick of his wrist snapped the blade off and handed me the handle. Funny he never gave thought to the voltages I was playing around with, but he just may be responsible for my retention of all ten of my digital low impedance voltage probes.
Thanks for a very informative video very easy to understand very concise I am delving into valve amplifiers at the ripe age of 65 for my retirement years although i love electronics and have been since building my first crystal set back in the late late 50's Kind regards Steven King
Everytime your hand went near the 300v I broke out into a sweat. I do hobby work in tube radios and amps but am ultra paranoid. Great explanation and a pleasure to watch. Thanks.
That was excellent, I'm a complete novice who plays guitar and have several tube amps. I never understood how the tubes amplified the input single and after watch this explanation I understand how they work. Thank you...
Enjoyed the video a lot. You are really good at explaining. If you could do a video explains in laymen terms how a tube amp works from input to speaker would be extremely helpful for us amateurs. Thanks for an excellent video.
Thank you so much for the awesome lessons. I look forward to every new video you post, they have helped me immensely. I repair tube guitar amplifiers, as a hobby mostly, because there are very few good repair shops in my area, and the few that are charge more than most gigging musicians can afford. I also test my repairs by playing the amp at performance volume for an hour or so, this helps to ensure that the musician doesn't experience a failure at the worst possible time, during a gig. So far I am 100% with this method. Thanks again and God bless!
5:12 - "Factory Designation Letters" - Are these 'designated' AFTER the tube is manufactured? In other words, are the tubes 'binned' into different performance profiles once they are manufactured? Example a run of 'A' type tubes would be sorted based on gain to either 'AU', AX' or 'AY'.
Awesome explanation sir .I am new to tubes,so it helped me a lot to understand how it works in real .I am a tech and have my own repair shop all i do is cell phone repair and all kind other electronics repair but all modern one but some time people come with old power amps with tubes witch is hard for me a bit but now after watching your videos it seem easy.Thanks again.
This video hit the spot !!! I work almost exclusively on Tube Amps and there were some true nuggets in this one, thank you so much. BTW - I was directly to your awesome channel by JOERNONE so glad he got a shout out !!! THANK YOU Paul !!!
I have subscribed and see I will learn quite a bit here. My first question, since the cathode is connected to ground, where, or should I say how, is it getting its three to five volts. I have electrical engineers here at work, but whenever I have a tube question their eyes go blank and they start drooling. I will be retiring soon and always wanted to do this. I have bought my self a scope and signal generator and other equipment and am learning how to use it. I have fixed a few amps with it but it was more luck than skill. Once I retire I will be signing up for some help. I always keep one hand in my pocket, I have gotten zapped a few time.
Current is flowing in the cathode resistor, and if current is flowing in a resistor, Ohm's law demands that there must be a voltage dropped across it (V = I x R). If the voltage drop across the cathode resistor is 3V and one end is connected to ground (0V) then the other end and therefore the cathode must be at +3V.
I'm a guitar player trying to diagnose some humming vibration on my tube amp, but this presentation seriously makes me feel like a complete idiot. Kinda humbling actually to know there are people out there intelligent to understand this stuff.
Thank you Paul for your videos !! I have learned quite a bit from you and consider you as my online Elmer !! I do tube radio and phonograph repairs and restos here on the West Coast. Keep the good work coming !! Best Regards, Dennis
Thank you so much for explaining how tubes work I've often wondered that my whole life it is interesting to work with the circuitry. I have worked on electronics my whole life but I always been intrigued by old antique radio gear. always been my thing. Thanks
Hello Paul, thank you very much for sharing such an interesting video. Could you please give an estimate about the Max and Min frequencies which we can achieve in this type of tube amplifier video, assuming no restriction on capacitors frequency response? Many Thanks.
+esmaeil nam Hello Esmaeil. The 6C4 is a general purpose triode. This can be used through the entire audio range, right into the VHF region (to 150MHz or so). Of course, the circuit that surrounds the tube will limit it's usable amplification range. You find this tube widely used as a phase inverter, and an oscillator in receivers. Here is a data sheet for you: www.mif.pg.gda.pl/homepages/frank/sheets/093/6/6C4.pdf
I am designing a valve preamp for myself at the moment. This is very helpful information, and much better explained than most sources I have used so far. Thank you for your videos :)
LOVE your channel!!! Thank you! I learned enough about Tube HF amplifiers to actually build a simple zero bias 3-500z amp, it works great!! Although I did this, for some reason I can not grasp the concept of tube bias, I have had people explain it, and I have even worked on some 811 amps that are biased. But I am just copying other people without having a full understanding. When people start talking about negative voltage and voltage above ground, for some reason my brain shuts down. I would love to see a video explaining just that aspect. Thank you for everything you do!
Around the 15 min mark, Paul is discussing how the AC audio signal causes larger fluctuations at the plate by drawing on the high voltage, thereby creating an inverted DC signal. To my untrained ear, it sounds as though he's saying that the audio signal is translated into DC voltage at this point. But then his schematic shows what appears to be a capacitor at the output of this stage, which suggests some sort of RC coupling between stages. Wouldn't this capacitor block DC? Is that the intention, to attenuate DC before the next stage? Thanks for the help.
Excellent video, many thanks. I always learn from watching and listening to you. [and re-watching!] I find the use of analog meters far less stressful in my work, as the movement of the needle is stone-axe simple, and can be seen out of the corner of one's eye. The digital meters are quite amazingly designed, with auto this and auto that, but a bunch of numbers is a bunch of numbers. One must 'READ' the numbers, then apply logic to evaluate the trend. I guess this could be old age creeping up on me huh? This analog/digital differential affects one in driving and flying, as with an analog display, the angle can be seen peripherally, and one knows without thinking about it, where one is on the speed scale. With digital, from 11 mph to 99 mph, that is just two digits. Take your eyes off the road/sky and focus on the instrument, read, analyse, deduct, apply, return to driving/flying... Even worse, with flying, from 100mph to 999mph, it is still only three digits. PS:I haven't been Nine Hundred Ninety-Nine miles per hour! [Yet?]
+av8bvma513 Thanks for your input! I like both types of meters myself, but in some cases, an analog meter makes things easier, especially when peaking circuits. Lets hope you never see 999 on that instrument!
Great video content. I found this video 5 years after ,you post it but never is to late. I have a question,and I really appreciate your opinion. Do you recommend to use a fan trying to cool down a guitar tube amplifier? Does that have a bad effect on the tone of the amp? By lowering the temperature of an amplifier ,you increase the life of the tubes? Thanks for any given answers. Cheers.
If the guitar amplifier is designed properly, there should be no need for fan cooling. Tubes run hot, and they are supposed too. In some cases fan cooling tube circuits (VFO's, BFO's and so on) will make the circuits unusable as they need temperature stability.
Paul, please keep making videos on troubleshooting audio tube type amplifiers. I love your clear and professional explanations. Do you have any videos on proper cleaning and lube of common carbon based turn pots and slide type potentiometers? Also, are all tonal controls on say a guitar amp linear or audio (logarithmic) taper type potentiometers? I believe volume turn-pots are always audio taper type. A video just on potentiometers and proper maintenance and replacement of would be of great help. Thank you sir. 🙂👍👍
Such a great episode! Really well explained, you have cleared for me few things about tubes which I have struggled with. I would love to see an episode on solid state audio equipment, I'm sure I could learn something new!
Patricia, that is a good question. In Mr Carlsons experimental setup this cap is not needed, he is slowly changing the voltages in the circuit to demonstrate the amplifying of a triode. In an audio amp you need this cap to stabilize or smooth out the cathode potential because of the fluctuation due to the varying frequencies and volume of the signal to be amplified. Otherwise the signal would distort somewhat.
Strange one I ran across was on a particular guitar amp where half of a 12AX7 was biased with cathode direct coupled to the second section grid. The heater to this cathode had over 100 volts relative to the heater. Several tubes would not work due to heater cathode leakage at this voltage and biasing. Manufacturer had specially selected tubes that would work in the circuit tested for low leakage..
Let me guess, Hiwatt? A good mod to do in this case is to raise the filament supply on a DC bias of around 50V (voltage divider from B+, with a smoothing cap, connect to center of hum pot or filament winding CT)
Paul, very good explanation for the novice. People these days seem to have such a problem understanding the basic functions of a tube and how they work. Great practical application demonstration. What is the equipment in your opening picture. Reminds me of my old HP 460BR broadband fast pulse amplifiers. Basically just 13 tubes running in distributed amplifier operation. Nothing quite like a couple rows of tubes to keep you warm on a cold day. Mike
Very well explained! So, the phase inverter would be used to drive a push-pull output stage, while the triode pre-amplifier would be used to drive a single ended output stage, right? It is now surprisingly simple. Never though I would understand vacuum tubes.
Hi, I have watched quite a few of your videos, I am a novice to electronics, I love vacuum tube amplifiers, and build quite a few of them for me and my friends, but the one thing I can’t understand is how to troubleshoot and remove him from few of my amps .. You explain things really well is there any way you can use a prop and show us novices how to find the hum and get rid of it… Thanks in advance
I really love your videos! You have such a great way to explain electronics. Thx so much for doing these videos. As said by others, if you one day release a book on vacuum tube audio I'll buy it straight away!!
Thank you for all of your hard work and I'm learning more at this point than I can really understand, I only wish that I would have learned more before watching your posts, I will be watching your videos over and over again.
Mr.Carlson I have one question ... I bought a two NOS tubes, one 12at7 Brimar and one 12at7 RFT, and both of them have the flash on the filament when I turn on the amp. They show a different kind of filament flash, the Brimar is smaller and kind of faster and the RFT is just like the one you made your video about filament flash (Rogers - mad in Holland). When I wanted to return them to be replaced by the vendor, they said: "Hallo, you are wrong. A flash is mostly seen with tubes from east Europe and is not a problem or failure. The quality of these tubes is high. " I would be very grateful if you could please shed some light on this as I am confused as to how to resolve this and what to learn from this experience.
Excellent series of videos, Paul--so well spoken, planned out and clear! Thank you for posting them. But please share how you get >330V on the 6C4 plate in this circuit if the B+ is only 300VDC w.r.t. ground, if I'm reading your Agilent DVM correctly around 17:40?
You bet! I've been watching daily now; some videos I'm re-watching because as I'm learning I'm understanding better so the second time around I'm picking up on something(s) I missed the first time.
I had my hands into old radios way back when I was young boy around 12 if remember right.And I guess had enough sense to know what to touch an what not to! Because i'm still here, and always seemed the manage to get them(tube radio's) working even if though trial and error.some of the funnest times in school was a electronics class I took in high school, it was just at the time of switch over from tube to transistor,so they taught both, the instructor was more of a tube guy! As to teacher to student, we got along great,so much some called me his pet! I could have cared less the man taught me allot.!And I'm grateful. For our class end of year project we had to build a super heterodyne am radio that would pick up 5 stations on a perfboard. Tune and make play.Mine picked up 7 some thought I cheated! Really the only cheating i did was helped others to get theres working that was against the rules! I think teacher knew but looked the other way!I love your videos keep them coming please! Dave wd8mbz
thanks for your vídeos. my question is: when you puts the volume at max in your radio and can ear the noise is because is a static noise ok and no radio station is over your point of the dial. could be measured the static noise? your stick glass pointer could be used to check? thanks in advance.
Thanks for taking the time to do these Paul. This may sound odd but I knew how a tube worked but now, thanks to this video, I UNDERSTAND how it works :) 73 NE5U Mike
I remember the days in electronics school (NRI) tube operation wasn't explained this well. We had to think hard where it made our brains hurt LOL. Great videos! Frank Ferraro--Audio Craft Electronics :)
Good video education for the tube beginners. Many thanks. Do you have any further video plan to show more superb tube explanation?Again awesome good job.
awesome video. taught me a lot. I have a few tube radios and test equipment to fix and you explain the theory so well. very easy to understand. Thank youvery much
Hi, I am working on a clone of a Vox guitar amp and wanted to use thermal flow simulation to assess the 60's cab design and orientation of the amp chassis. In the Vox amp the tubes face down (like many amps) inside the cabinet. I am not sure how to apply a value for the tubes in the chassis which for the simulation is input as Watts. Forgive my obvious lack of electronics knowledge but is there a relation ship between the Watts and external Temperature reached by a tube. The tube data sheets dont show a working temperature range. The flow simulation should show if the heat convection to the components in the chassis is better or worse depending on its orientation, which is the aim of the study. Some people have added fans to their old amps as they have a concern about heat, and some swear that the hotter an amp runs the better it sounds. However there must be an ideal temp range or at least max that a tube should run before its life span is dramatically reduced. I can also use the simulation to see if adding a fan will improve the air flow and therefore heat dissipation. There is also transfer of heat through the chassis from the tubes to other components on the turret board and I have often wondered if the amp is better off in an 'upright' config whereby the heat from the tube rises up and out of the cab, without passing over the rest of the components as apposed to the 'upside down' config.
Most of the heat in a tube is generated by the heater elements which operate at a specified voltage (in most audio equipment 6.3v) the current drawn by the tube heaters is always specified on the appropriate data sheet. The bias voltage/current applied to the tube also adds to the operating temperature. The air temperature within the cabinet will not effect the operation of the tubes so adding a cooling fan will remove hot air but have no sonic impact. The heaters can be operated at a slightly lower voltage than specified. Some people believe that doing so will improve tube life although a more likely reason for tube failure is heat cycling, ie switching them on and off. The reason that the data sheets do not give maximum operating temperatures is that as long as the tubes are operated within their electrical limits they will not become "too hot". There are exceptions such as high power radio transmission tubes some of which are water cooled. Some transmitter tubes dissipate as much as 10000 Watts so are in a different league to our humble domestic tubes.
Thanks, that helps a great deal with my understanding. I have noted that keeping capacitors to within there max temp range is important to their life, so I do intend to turn the clone chassis over so that heat from the tubes rises out of the cab and not through the chassis and onto the turret board. Intuitively I think it must be better to run the circuit resisters, caps and electrolytic caps as cool as possible by ideal orientation and layout of the chassis and avoid any unnecessary heat from the tubes whether by convection or conduction. I have post on the SW sight showing my work so far. forum.solidworks.com/message/666048?et=watches.email.thread#comment-666048
Mr. Carlson is an encyclopedia of knowledge. He is a Canadian and really appreciated by many throughout the world. I wish I could visit your lab Paul. I would never leave!!!
I for one am Very appreciative of your time and teachings! I only wish I could have received this kind of education in my younger years but am So very appreciative that I can learn and apply these teachings now! Thank you Mr Carlson for sharing your knowledge, talent and time to insure we learn the correct ways along with the cautions that we are dealing with potentially high voltages. On behalf of all here, Thank you.
Paul, I say this freely and not because you mentioned me in the video, but there is just not enough tube related videos on TH-cam. This video IS the best one I have ever seen on TH-cam hands down. Very well explained and the confidence of your knowledge on this subject is simply outstanding. Being an old tube lover since my teens I really enjoyed this one.....Well Done and a huge thumbs up !Now I can say a big thanks for the mention of me and my channel and is very much appreciated. I feel very honored and going to post this one on my website for others to view and learn. Thanks my friend.
+The Radio Shop
Thanks for the very kind words Buddy! Glad your enjoying the video's, and thanks again for the kind mention!
been struggling with that too! nothing Tube related to find on YT
@@supersolex Check out Glasslinger on TH-cam sometime. He wears women's clothes, but he also does repair and restoration of tube equipment. He even makes some of his own tubes.
@@AcmeRacing Eww lol. He does have good repairs!
Paul: I'm an old NASA gate chaser from the 70s where I learned TTL. Lots of logic, lots of transistor theory, and just a little analog....probably just enough to figure out simple power supplies. Now that I'm an old retired guy, I have come back to ham radio, and my interests particularly lie in vintage tube equipment, particularly Collins, and some of the "Big Iron" AM broadcast transmitters.
Your videos are wonderful in helping me transfer what I learned as a digital tech to tubes. Although you don't specifically mention it, as you go through your excellent signal chasing, I find myself saying, "oh, that works just like a transistor." Thank you so very much for videos just like this one....they are exactly right on the money for what I need.
Thanks for your feedback, and your kind comment too!
I just came across this video (4 years late). I do understand how a triode valve system works but wanted see how you explained it for the beginner. Your explanation was spot on, very good. I saw an explanation by another TH-camr trying to explain how tubes (valves) work, their instruction video was full of errors and inaccuracies. They got very defensive when I commented on the errors in the video. Your explanation was excellent and flawless. Well done Paul, keep more great videos coming like this.
So glad you stressed that an amplifier stage swings the supply voltage across the plate resistor, that the output signal voltage comes from the supply, not the tube. I was years into things, without formal training, before I realized that. It’s too easy to visualize that the tube “turbocharges” the input signal applied to the grid, sends it through the vacuum and onwards to the plate. I better understood the term “valve” when I conceived of the tube as a valve that opens partially, in proportion to the input signal, to create a low-resistance path from B+ to ground, loading the supply, dropping the voltage across the plate resistor.
Mr Carlson, If you ever write a book (and you should). Put me down for one of the first copies. Your demonstrations are brilliant. Thanks again for your hard work and informative videos.
+Todd Anonymous
Your welcome Todd! Thanks for the very kind words!
He is so right though sir. I have a feeling that any book that you would write would be up there in caliber with "the art of electronics." I cannot stress just how much I have learned from you and how much I appreciate the work that you are doing. Even your TH-cam videos alone have elevated my understanding Beyond what I would have imagined possible.
I really really appreciate everything you do!
I agree 100% to your comment
Man, I don't understand a lot of what you're saying but I've been binge watching for ages now. Love your explications and even though I'm just a muso, this all intrigues me and dig the way you go through things in depth, fast, but take your time to explain. I hope you keep up the great work man?!!!
Paul,
Ahhhhhh! You have greatly clarified to me how tubes work in 18 short minutes.
I especially like how you present theory, then assemble a circuit and prove it to be true. That really helps me absorb material.
What kind of maniac gives a Mr. Carlson's video a thumbs down?
Thanks, I know making videos (well, good ones) takes time and effort.
Ian Butler they probably get the video in their feed and by thumbing down think they are influencing the algorithm not to send anymore vids like this to them.
Where were you, when as a recent graduate of 6th grade in 1966, I attended a summer elective workshop program of beginner electronics which included DC theory and vacuum tube operation? We were given old High School text books and I recall having great difficulty wrapping my understanding around the very concepts you are teaching so clearly. You are helping many people.
Finally! A clear explanation as to why the output of the plate is out of phase, and from there a clear understanding of the push-pull mechanism in the output! Thanks! Great video, great channel!
A one man high tech technical school in each video presentation. For me your videos are great refresher courses. In my day I also taught electronics technology at a hands on level. Your methods and approach are the best I've seen in a long time.
I have to admit, you, and Forrest Mimms III make learning very user friendly. Taking text book content, and applying them to real world situations. And keeping it simple, while being in depth with information.
I really like what Mimms did with his books.The first of his that I saw was getting started in electronics.Easy to understand like you said and handy for a person wanting to learn
Found this older video on tubes as i am building my 1st amp from scratch. Well, its an Eico 147 Signal Tracer that i am converting to a Fender Champ 5F1. I just tried to power it up yesterday and pop the fuse and fried the rectifier 6X5 tube. Opps. Well back to the schematics and try see where i went wrong. i like the way you are able to explain then set up little demos. Appreciate all you work very much. Thank You hoping i can figure this baby out. Take care and stay safe. Dennis
After trying to study dozens of books and countless videos for years, your video was the simplest and best explaination in my entire quest to understand tube amps
Thank you
Hey Paul;
How did I ever forget that the last number on the right end of the tube label designated the number of useful elements in the tube? But I did... Thanks for the refresher.
Also thanks for mentioning us for promoting your site to others. You deserve it, with the knowledge base that you possess and your ability to explain it to the masses out here in such a clear and concise manner.
Thanks, and a big two thumbs up from all of us to YOU my friend. You have taught us all a lot!
Cheers,
Tom
PS I subscribed to Peter's "TRXBench" a long time ago thanks to your suggestion. I have watched ALL his videos. I am having a blast watching him diagnose ham gear. His English has sure come a long way, hasn't it?
"Achtung!
Alles lookenpeepers, das instrumenten is nicht fer gerfingerpoken und hittengrabben. Ist easy schnappen der springerverk, poppen corken und blowen fusen mit spitz und sparken. Ist nicht fer geverken by das dumbkopf, alles rubbernecken sightseeren keepen hands in der pockets, relax und vatch der blinkin lights!"
+AntiqueRadioandTV
LOL, I have that on a piece of piece of paper somewhere. Years ago I volunteered my time at a local radio museum, they had a few of those "saying's" here and there. Peter is great to watch, and I enjoy his English as well :^) Thanks again for the kind mention Tom!
We are the ones who have to thank you a lot for your work to deliver us great videos and great information. Double thumbs up for your humility. Thank you!
+Damian Vieira de Castro
Thanks for the kind words Damian!
An excellent representation that is so well explained, it reminds me when I ran my own service shop for more than three decades repairing, modifying, and designing specific requirements for my customers. Well Mr. Carlson; you have inspired me to rekindle my love for electronics to the point that I now serve the public once again, for that you have my deepest gratitude.
+John Cunningham
Wow! That's a compliment! Great to read John, I'm glad I was your inspiration. I wish you the best of luck with what your doing.
I wish you the best of luck also. You bring a tube amplifier to a tech around here, if you can find one, you are liable to pick it up six month later without it ever getting it looked at, or never see it again.
When I was 15 my father brought me home an old PA amplifier with a pair of 6L6s. At the time, I wasn't sure what to do with it or how to use it. The rectifier tube was missing also. My dad told me to ask his friend Emil Rudat who lived down the street and worked for RCA at Harrison, NJ. Emil had a 5V4 and it worked after he showed me how and where to hook things up.
Anyway, I ignorantly started poking around the underside with the chassis laying on it's side on top of a metal topped cabinet I had used for my rock collection. I had my hand on the top and grabbed the B+ on a capacitor and had my first whack from 400+ VDC. It felt like two people gave me a yank on each arm to pull them out of my body, I was thrown on the floor and shaky. Wow, I knew I was lucky to be still alive. I have heard many engineers and technicians consider that a "right of passage" in the field, but it's a "right of passage" that you want to avoid. Wear gloves or keep one hand in a pocket or both, I was told. I think I got a lesser one again later from a charged capacitor. Even when the unit is off, I learned to discharge caps. It was the last time and I'm still around at the age of 71. Whew! Emil became my early "Mister Wizard" for electronics and he was a life long friend from the WWII generation.
My dad had a saying about using power tools, such as a circular saw, which applies to many potentially dangerous things we work on. "Don't be afraid of it. Just RESPECT it." I got it!
Thanks Jim for taking the time to write, and share your story. One day I will share the story of the 1cm hole in my left hand.
Mr Carlson's Lab save that story for the Patreon members. I get nightmares easily as I lucid dream more nights than I slumber.
Holy cow! That is huge! I'd like to hear the story.
Honestly, I get more info from your hard work than anyone else. That is not to discredit anyone else. I just really really get it when you delve into the subject. Sometimes I must watch the video a half dozen times; but I know what it is you are saying when I am done.keep them coming, I can't get enough.Thank s to everyone who has helped as well. It is what makes it fun.
+James Lucas
Great to read James! Glad your enjoying the video's.
Thanks for the short and clear explanation how a triode is used as a phase inverter and how it works
Your welcome!
Excellent work. Easy to understand. I know all this stuff already from my professional background in vacuum tube equipment back in the 50's and I retired in 2010. Nevertheless I really enjoyed your presentation. Best quick written electronics lessons back in my day were in the back of the old RCA Receiving Tube Manual of the 50s &60s. Besides taking this stuff in high school and college, I learned it first from that RCA manual. Another great book was the ARRL ham radio Handbook.
Great vid, well done. I've been restoring radios for around 30 years, and I had no idea that the last number in a tube designation identified the amount of elements it has.
+justsomeguytoyou
Thanks! Glad you enjoyed.
I absolutely love your presentations. This video on the tube amp was the most concise and clear explanation that I have heard. Thank you. Al
Thank you for the kind mention, Paul. I have lots of vacuum tube radios, record players, and test equipment to fix when I have time for it. Most problems will be solved by recapping, but this video will be especially helpful. Other than the filament voltage spec, I had no idea there was any rhyme or reason to vacuum tube part numbers.
No worries on my name. It is commonly mispronounced.
Should be WAH-sah-TON-ic. Thanks for the thumbs up!
+Eric Wasatonic
Glad you enjoyed the video Eric. I look forward to some of your future restorations. Thanks again!
All of your warnings of electrocution bring me back to my childhood. When I was around 9 or 10 I became interested in electronics, I would go out and bring home discarded radios, TV's and any thing electronic and play with them. I always had my hands in something that was plugged in, and the only tools I had were my mom's kitchen knives ( which didn't please her). In all that time I only got one good shock and that was when I found out that a flyback transformer can make you flyback. I love your videos, you are a true inspiration.
+wgenerotzky
Great story! Thanks for taking the time to write.
+Mr Carlson's
Lab
Here's another story about the bench that I played with the tube radios and such.
The bench was in the basement of the house we lived in, it was constructed with 2x8s with a small gap in between. I had gone to the neighborhood store and bought a sharp knife for carving and such. Being proud of my newest possession the first thing I wanted to do was show my dad, he happened to be in the basement at the time. My dad took the knife and with the smoothest action I'd ever seen (it had to be purely muscle memory from years of fatherhood) inserted the gleaming blade into the gap and with a flick of his wrist snapped the blade off and handed me the handle. Funny he never gave thought to the voltages I was playing around with, but he just may be responsible for my retention of all ten of my digital low impedance voltage probes.
I find your videos really helpful. You have that ability to teach that is rather rare
Thanks for a very informative video very easy to understand very concise I am delving into valve amplifiers at the ripe age of 65 for my retirement years although i love electronics and have been since building my first crystal set back in the late late 50's Kind regards Steven King
Everytime your hand went near the 300v I broke out into a sweat. I do hobby work in tube radios and amps but am ultra paranoid. Great explanation and a pleasure to watch. Thanks.
+mbaker335
Glad you enjoyed!
Understanding the method of amplification in tubes is a real eye opener, and a very ingenious idea!
That was excellent, I'm a complete novice who plays guitar and have several tube amps. I never understood how the tubes amplified the input single and after watch this explanation I understand how they work. Thank you...
Enjoyed the video a lot. You are really good at explaining. If you could do a video explains in laymen terms how a tube amp works from input to speaker would be extremely helpful for us amateurs. Thanks for an excellent video.
Thanks for your input Jan!
Your teaching style is first rate. Thanks for all your work.
Glad your enjoying the video's Ian!
That was the clearest explanation of amplification through a tube I have ever heard. I have subscribed to you for more. Thank you.
Glad you enjoyed the video, Thanks!
By far the best explanation of the behavior of a triode i've ever seen...
Very good tube refresher course took me back 40 years to my days at electronics vocational school!
Thank you so much for the awesome lessons. I look forward to every new video you post, they have helped me immensely. I repair tube guitar amplifiers, as a hobby mostly, because there are very few good repair shops in my area, and the few that are charge more than most gigging musicians can afford. I also test my repairs by playing the amp at performance volume for an hour or so, this helps to ensure that the musician doesn't experience a failure at the worst possible time, during a gig. So far I am 100% with this method. Thanks again and God bless!
+flockoglock
Glad your enjoying! Sounds like you know what you doing!
+Mr Carlson's Lab sometimes it's more about what not to do.:)
Another one out of the park!!!! In 27 years of being a ham, I never understood tubes this way! 73's de w1rmd
5:12 - "Factory Designation Letters" - Are these 'designated' AFTER the tube is manufactured? In other words, are the tubes 'binned' into different performance profiles once they are manufactured?
Example a run of 'A' type tubes would be sorted based on gain to either 'AU', AX' or 'AY'.
Awesome explanation sir .I am new to tubes,so it helped me a lot to understand how it works in real .I am a tech and have my own repair shop all i do is cell phone repair and all kind other electronics repair but all modern one but some time people come with old power amps with tubes witch is hard for me a bit but now after watching your videos it seem easy.Thanks again.
I enjoy your clear explanations, thanks
This video hit the spot !!! I work almost exclusively on Tube Amps and there were some true nuggets in this one, thank you so much. BTW - I was directly to your awesome channel by JOERNONE so glad he got a shout out !!! THANK YOU Paul !!!
+Ron C
Your welcome Ron! Glad you enjoyed.
I have subscribed and see I will learn quite a bit here. My first question, since the cathode is connected to ground, where, or should I say how, is it getting its three to five volts. I have electrical engineers here at work, but whenever I have a tube question their eyes go blank and they start drooling. I will be retiring soon and always wanted to do this. I have bought my self a scope and signal generator and other equipment and am learning how to use it. I have fixed a few amps with it but it was more luck than skill. Once I retire I will be signing up for some help. I always keep one hand in my pocket, I have gotten zapped a few time.
Current is flowing in the cathode resistor, and if current is flowing in a resistor, Ohm's law demands that there must be a voltage dropped across it (V = I x R). If the voltage drop across the cathode resistor is 3V and one end is connected to ground (0V) then the other end and therefore the cathode must be at +3V.
@@silasfatchett7380 Thank you Silas
I'm a guitar player trying to diagnose some humming vibration on my tube amp, but this presentation seriously makes me feel like a complete idiot. Kinda humbling actually to know there are people out there intelligent to understand this stuff.
Good explanation, it's been many years since I studied vacuum tubes in school. Nice simple presentation.
+Oldbmwr100rs
Glad you enjoyed!
Thanks for another great video Paul. I will be watching this several times to absorb all this valuable information.
+Shaun Merrigan
Your welcome Shaun!
Yet another superb video Mr Carlson! I'd really love to see more of those tube amp troubleshooting tips/construction vids! Keep up the good work!
+Magnus Karlsson
Thanks Magnus!
Very helpful! Thanks so much for your whole video series.
+Applied Science
Thanks for the kind words Ben! Always look forward to your video's as well.
Your videos are extremely clear and concise. They will be very good for people new to electronics.
+Aron Gooch
Thanks Aron!
Thank you Paul for your videos !! I have learned quite a bit from you and consider you as my online Elmer !! I do tube radio and phonograph repairs and restos here on the West Coast. Keep the good work coming !! Best Regards, Dennis
+lionelguy
Thanks for the kind words Dennis! Your "Elmer" won't let you down :^)
Thanks! I now visualize what is going on in the circuit. You are outstanding with your teaching! 73, AA4EZ
That video was excellent it gives you a better understand of Valves. When we are tuning valve radios this all comes into play. Cheers and beers mate.
Thank you so much for explaining how tubes work I've often wondered that my whole life it is interesting to work with the circuitry.
I have worked on electronics my whole life but I always been intrigued by old antique radio gear. always been my thing. Thanks
Hello Paul, thank you very much for sharing such an interesting video. Could you please give an estimate about the Max and Min frequencies which we can achieve in this type of tube amplifier video, assuming no restriction on capacitors frequency response? Many Thanks.
+esmaeil nam
Hello Esmaeil. The 6C4 is a general purpose triode. This can be used through the entire audio range, right into the VHF region (to 150MHz or so). Of course, the circuit that surrounds the tube will limit it's usable amplification range. You find this tube widely used as a phase inverter, and an oscillator in receivers. Here is a data sheet for you:
www.mif.pg.gda.pl/homepages/frank/sheets/093/6/6C4.pdf
+Mr Carlson's Lab Thank you very much.
I am designing a valve preamp for myself at the moment. This is very helpful information, and much better explained than most sources I have used so far. Thank you for your videos :)
+Róbert Valdimarsson
Thanks Robert! Glad your enjoying the series.
Very clear explanation how cathode following and phase inversion works on a preamp tube👍
One of the most informative videos I have seen on how a tube works! Awesome.
+Richie Testa
Glad you enjoyed Richie, thanks for your comment!
LOVE your channel!!! Thank you! I learned enough about Tube HF amplifiers to actually build a simple zero bias 3-500z amp, it works great!! Although I did this, for some reason I can not grasp the concept of tube bias, I have had people explain it, and I have even worked on some 811 amps that are biased. But I am just copying other people without having a full understanding. When people start talking about negative voltage and voltage above ground, for some reason my brain shuts down. I would love to see a video explaining just that aspect. Thank you for everything you do!
Thanks for your input Dan.
These are really good little demonstrations. Very well explained.
+Bill Moran
Thanks Bill!
Very helpful and easy to understand for us old guys,,thanks for all the great videos on tubes!
Very enjoyable and educational. I always learn something from Mr. Carlson's Lab.
Glad you enjoyed it!
Around the 15 min mark, Paul is discussing how the AC audio signal causes larger fluctuations at the plate by drawing on the high voltage, thereby creating an inverted DC signal. To my untrained ear, it sounds as though he's saying that the audio signal is translated into DC voltage at this point. But then his schematic shows what appears to be a capacitor at the output of this stage, which suggests some sort of RC coupling between stages. Wouldn't this capacitor block DC? Is that the intention, to attenuate DC before the next stage? Thanks for the help.
Excellent video, many thanks. I always learn from watching and listening to you. [and re-watching!]
I find the use of analog meters far less stressful in my work, as the movement of the needle is stone-axe simple, and can be seen out of the corner of one's eye. The digital meters are quite amazingly designed, with auto this and auto that, but a bunch of numbers is a bunch of numbers. One must 'READ' the numbers, then apply logic to evaluate the trend.
I guess this could be old age creeping up on me huh?
This analog/digital differential affects one in driving and flying, as with an analog display, the angle can be seen peripherally, and one knows without thinking about it, where one is on the speed scale.
With digital, from 11 mph to 99 mph, that is just two digits. Take your eyes off the road/sky and focus on the instrument, read, analyse, deduct, apply, return to driving/flying...
Even worse, with flying, from 100mph to 999mph, it is still only three digits.
PS:I haven't been Nine Hundred Ninety-Nine miles per hour! [Yet?]
+av8bvma513
Thanks for your input! I like both types of meters myself, but in some cases, an analog meter makes things easier, especially when peaking circuits. Lets hope you never see 999 on that instrument!
Great video content.
I found this video 5 years after ,you post it but never is to late.
I have a question,and I really appreciate your opinion.
Do you recommend to use a fan trying to cool down a guitar tube amplifier?
Does that have a bad effect on the tone of the amp?
By lowering the temperature of an amplifier ,you increase the life of the tubes?
Thanks for any given answers.
Cheers.
If the guitar amplifier is designed properly, there should be no need for fan cooling. Tubes run hot, and they are supposed too. In some cases fan cooling tube circuits (VFO's, BFO's and so on) will make the circuits unusable as they need temperature stability.
@@MrCarlsonsLab Thank you very much.
Excellent tip video! How about similar tips videos on transistor amps, transmitter and receiver stages, etc.
+Paul Clay
Good ideas for a future video. Thanks for your input!
Paul, please keep making videos on troubleshooting audio tube type amplifiers. I love your clear and professional explanations. Do you have any videos on proper cleaning and lube of common carbon based turn pots and slide type potentiometers? Also, are all tonal controls on say a guitar amp linear or audio (logarithmic) taper type potentiometers? I believe volume turn-pots are always audio taper type. A video just on potentiometers and proper maintenance and replacement of would be of great help. Thank you sir. 🙂👍👍
what a ripper video. man i need to watch this video over & over every few months as more knowledge sinks in.
Take me back to Purdue's Lab back in the late 60's... Great Stuff!!
+llsdigitek
Glad you enjoyed!
Great explanation for a guy like me who only learned about transistor electronics.
Such a great episode! Really well explained, you have cleared for me few things about tubes which I have struggled with. I would love to see an episode on solid state audio equipment, I'm sure I could learn something new!
+Aniol1349
Good idea for a future topic! Thanks for your comment.
Thanks for making these videos! Best site I’ve seen on tube amplifiers and understanding electrical engineering
Excellent video. I really enjoy the tube related information. It's always great to see a notification of a new video. Thanks.
+jim mcdowell
Thanks for the kind comment Jim!
Great presentation ! Q : Shouldn't we have a capacitor on the cathode down to ground ? Regards, Patricia,
Patricia, that is a good question. In Mr Carlsons experimental setup this cap is not needed, he is slowly changing the voltages in the circuit to demonstrate the amplifying of a triode. In an audio amp you need this cap to stabilize or smooth out the cathode potential because of the fluctuation due to the varying frequencies and volume of the signal to be amplified. Otherwise the signal would distort somewhat.
Very well done video! Thank you so much for taking the time to make this.
~Jason
Your Welcome Jason!
Can you do a detailed video on how to check for amplifier problems in the signal path without destroying your oscilloscope?
Strange one I ran across was on a particular guitar amp where half of a 12AX7 was biased with cathode direct coupled to the second section grid. The heater to this cathode had over 100 volts relative to the heater. Several tubes would not work due to heater cathode leakage at this voltage and biasing. Manufacturer had specially selected tubes that would work in the circuit tested for low leakage..
Let me guess, Hiwatt? A good mod to do in this case is to raise the filament supply on a DC bias of around 50V (voltage divider from B+, with a smoothing cap, connect to center of hum pot or filament winding CT)
Paul, very good explanation for the novice. People these days seem to have such a problem understanding the basic functions of a tube and how they work. Great practical application demonstration.
What is the equipment in your opening picture. Reminds me of my old HP 460BR broadband fast pulse amplifiers. Basically just 13 tubes running in distributed amplifier operation. Nothing quite like a couple rows of tubes to keep you warm on a cold day.
Mike
+MikesRadioRepair .CBRadio
Hi Mike, that's out of an old Cordovox amp. Thanks for your comment!
Very well explained! So, the phase inverter would be used to drive a push-pull output stage, while the triode pre-amplifier would be used to drive a single ended output stage, right? It is now surprisingly simple. Never though I would understand vacuum tubes.
Thank you for explaining exactly how amplification works, i indeed did not know the signal was recreated from the rail.
Glad you enjoyed, your welcome!
Thanks Mr Carlson I revisit often
Hi, I have watched quite a few of your videos, I am a novice to electronics, I love vacuum tube amplifiers, and build quite a few of them for me and my friends, but the one thing I can’t understand is how to troubleshoot and remove him from few of my amps ..
You explain things really well is there any way you can use a prop and show us novices how to find the hum and get rid of it…
Thanks in advance
What does it mean when there is a hissing/crackling sound when the amp is on standby but it goes away when you start playing?
I like this very much. Its like im starting to understand. I sit and just faze out in deep thought about this stuff.
I really love your videos! You have such a great way to explain electronics. Thx so much for doing these videos. As said by others, if you one day release a book on vacuum tube audio I'll buy it straight away!!
You provide an amazing electronics resource on youtube
Thank you for all of your hard work and I'm learning more at this point than I can really understand, I only wish that I would have learned more before watching your posts, I will be watching your videos over and over again.
Very informative.
Mr.Carlson I have one question ... I bought a two NOS tubes, one 12at7 Brimar and one 12at7 RFT, and both of them have the flash on the filament when I turn on the amp. They show a different kind of filament flash, the Brimar is smaller and kind of faster and the RFT is just like the one you made your video about filament flash (Rogers - mad in Holland). When I wanted to return them to be replaced by the vendor, they said: "Hallo, you are wrong. A flash is mostly seen with tubes from east Europe and is not a problem or failure. The quality of these tubes is high. "
I would be very grateful if you could please shed some light on this as I am confused as to how to resolve this and what to learn from this experience.
Excellent series of videos, Paul--so well spoken, planned out and clear! Thank you for posting them. But please share how you get >330V on the 6C4 plate in this circuit if the B+ is only 300VDC w.r.t. ground, if I'm reading your Agilent DVM correctly around 17:40?
+Dennis Carlson
Hi Dennis, I think you missed what I said shortly after 15:33
Glad your enjoying the video's!
+Mr Carlson's Lab. Yep. I missed your switch to 350VDC. Makes sense now. Thanks for taking time to point that out.
Paul - Great explanation! Thanks for sharing your knowledge. Best, Don
+RestoreOldRadios
Your welcome Don!
Excellent demonstration! I am learning so much from your channel! Thanks again!
Your Welcome! Glad your enjoying!
You bet! I've been watching daily now; some videos I'm re-watching because as I'm learning I'm understanding better so the second time around I'm picking up on something(s) I missed the first time.
I just pledged some money at Patreon; I'm glad to see you're off to a good start there, you deserve it!
Hey Thanks! I'm looking forward to being here more often.
I've run across a few dual heater circuits with 6.3VAC CT 6.3VAC
I had my hands into old radios way back when I was young boy around 12 if remember right.And I guess had enough sense to know what to touch an what not to! Because i'm still here, and always seemed the manage to get them(tube radio's) working even if though trial and error.some of the funnest times in school was a electronics class I took in high school, it was just at the time of switch over from tube to transistor,so they taught both, the instructor was more of a tube guy! As to teacher to student, we got along great,so much some called me his pet! I could have cared less the man taught me allot.!And I'm grateful. For our class end of year project we had to build a super heterodyne am radio that would pick up 5 stations on a perfboard. Tune and make play.Mine picked up 7 some thought I cheated! Really the only cheating i did was helped others to get theres working that was against the rules! I think teacher knew but looked the other way!I love your videos keep them coming please! Dave wd8mbz
+David Grieb
Thanks for the story, and the kind words too!
thanks for your vídeos. my question is: when you puts the volume at max in your radio and can ear the noise is because is a static noise ok and no radio station is over your point of the dial. could be measured the static noise? your stick glass pointer could be used to check? thanks in advance.
Thanks for taking the time to do these Paul. This may sound odd but I knew how a tube worked but now, thanks to this video, I UNDERSTAND how it works :) 73 NE5U Mike
+Michael Lloyd
Great to read Mike! This sort of response make the video's worth doing.
I remember the days in electronics school (NRI) tube operation wasn't explained this well. We had to think hard where it made our brains hurt LOL. Great videos! Frank Ferraro--Audio Craft Electronics :)
+Frank Ferraro
Thanks Frank!
Good video education for the tube beginners. Many thanks. Do you have any further video plan to show more superb tube explanation?Again awesome good job.
+bee kay song
I will re-visit the tube explanation's in the near future. Glad you enjoyed the video!
awesome video. taught me a lot. I have a few tube radios and test equipment to fix and you explain the theory so well. very easy to understand. Thank youvery much
Glad you enjoyed Mike!
also, most Russian tubes use pins 4 and 5 for the heaters. and 7 pin tubes use pins 3 and 4 usually
Hi, I am working on a clone of a Vox guitar amp and wanted to use thermal flow simulation to assess the 60's cab design and orientation of the amp chassis. In the Vox amp the tubes face down (like many amps) inside the cabinet. I am not sure how to apply a value for the tubes in the chassis which for the simulation is input as Watts. Forgive my obvious lack of electronics knowledge but is there a relation ship between the Watts and external Temperature reached by a tube. The tube data sheets dont show a working temperature range. The flow simulation should show if the heat convection to the components in the chassis is better or worse depending on its orientation, which is the aim of the study. Some people have added fans to their old amps as they have a concern about heat, and some swear that the hotter an amp runs the better it sounds. However there must be an ideal temp range or at least max that a tube should run before its life span is dramatically reduced. I can also use the simulation to see if adding a fan will improve the air flow and therefore heat dissipation. There is also transfer of heat through the chassis from the tubes to other components on the turret board and I have often wondered if the amp is better off in an 'upright' config whereby the heat from the tube rises up and out of the cab, without passing over the rest of the components as apposed to the 'upside down' config.
Most of the heat in a tube is generated by the heater elements which operate at a specified voltage (in most audio equipment 6.3v) the current drawn by the tube heaters is always specified on the appropriate
data sheet. The bias voltage/current applied to the tube also adds to the operating temperature. The air temperature within the cabinet will not effect the operation of the tubes so adding a cooling fan will remove hot air but have no sonic impact. The heaters can be operated at a slightly lower voltage than specified. Some people believe that doing so will improve tube life although a more likely reason for tube failure is heat cycling, ie switching them on
and off. The reason that the data sheets do not give maximum operating temperatures is that as long as the tubes are operated within their electrical limits they will not become "too hot". There are exceptions such as high power radio transmission tubes some of which are water cooled. Some transmitter tubes dissipate as much as 10000 Watts so are in a different league to our humble domestic tubes.
Thanks, that helps a great deal with my understanding. I have noted that keeping capacitors to within there max temp range is important to their life, so I do intend to turn the clone chassis over so that heat from the tubes rises out of the cab and not through the chassis and onto the turret board. Intuitively I think it must be better to run the circuit resisters, caps and electrolytic caps as cool as possible by ideal orientation and layout of the chassis and avoid any unnecessary heat from the tubes whether by convection or conduction. I have post on the SW sight showing my work so far. forum.solidworks.com/message/666048?et=watches.email.thread#comment-666048