Electronic Circuitry Diagnosis And Fault Finding! [Repair]

[@wansolve289]

I went to a Vocational High School in 1969 and took Radio & TV Repair. It was a half-day class with academics the other half. Learned Electronics Theory and Tube operations. Semiconductors were introduced in our Junior year. The Instructor was a Ham Radio Extra Class and he encouraged us to learn code and pursue a License. I never opened a Radio/TV Repair Shop but it was great training for getting an Associates in Electronics Engineering in college. Since then I’ve repaired/restored hundreds of old tube radios. It was a breath of fresh air discovering Mr Carlson’s Lab and getting the urge to clear off the old workbench and fire up the soldering iron again.

[@terminalpsychosis8022]

Absolutely this old piece of art needs to be restored. This isn't even a question.

[@chinchan9]

He could get paid hundreds of dollars an hour but chooses to teach us, Thank You Mr Carlson!!!

[@MrCarlsonsLab]

You are very welcome!

[@hans429]

Mabey not a day but hundrets of dollars a year...anyways...yes!!!

[@tedmoss]

Or at least 200-300 thousand US a year. That's why I am a Patron.

[@vernonsmith5465]

Would love to see this radio restored!!

[@jessiecastille204]

I agree, Thank you Mr Carlson

[@Maadhawk]

This entire channel, and others like it, are why we need to preserve our right to repair the things we buy.

[@twicebittenthasme5545]

I remember going to the drugstore around the corner from my house to test the tubes for our Dumont tv. It was one of my favorite things to do as a little kid! That tv didn't last long between the foil on the eventually broken rabbit ears and the constant "give it a whack, son" so the family can watch The Jackie Gleason show or Sky King. It got to the point the little round screen would not stop fading away until it finally became a blank. Pop said the flyback's days are done. Asked how he knew and he said the Simpson told him so. It took a couple of years before I knew what he was talking about. Thanks for the memories! And yes, I believe that "box" should be given another go! They are vanishing from the world and that looks like it become a museum piece! Excellent video. Thank you for sharing!

[@engineguy54]

You know you're old if....

[@paullesho2693]

I have been buying and restoring these old radios for years. I have really learned a lot from your diagnostics. Thank you sir

[@peep39]

This is my favorite style of video that you do. Using diagnostic tools, along with educational explanation and application example, and an approach of looking from the outside in. I learn so much from watching these. I love it

[@kheangtang12]

Song Khmer,

[@michaelmerta8956]

Please bring it to new and replace everything to new it is worth it. The outside of the radio is an lovely display of an gone by area, love it. Please bring it back like new.

[@InvestigationsDepartment]

Me too

[@davidmckenzie1046]

Fantistic ,You are terrific for sharing your knowledge. I wish you had been around in my younger days. In my time people would not share their knowledge.It was always kept very secretive to make people think those in the know were geniuses.REAL BARSTEDRY.Thank you very kindly I will watching more of you.

[@sgit1]

The days of tube radios and televisions provided good jobs for repairmen - and many did not possess your knowledge. They accumulated so called tricks of the trade. I remember the ads in magazines - learn radio/TV repair at home. I attended RCA Institutes back in the day - wish you were one of the teachers.

[@Barracuda48082]

Rotc school..?

[@Barracuda48082]

I still have my tv, radio training books from 1954, prior to color tvs. The manuals and cyclopedia look fairly new, red hard bound and embossed..treasure of history and knowledge.

[@sgit1]

@@Barracuda48082 The RCA Tube Manual was the "bible" back then.

[@gurunatrajannatrajan9846]

Your videos are brining me to those days around 1972 to 1980.This is the period for all tube Radios of those early times. As a technical person of that period with roaring practice in Servicing of those tube radios, I feel happy to see your videos. THANK YOU.

[@genestatler2514]

Yes, please Mr. Carlson restore it. I'm from that era and I love those old tube type radios. Thanks in advance.

[@1mJustCurious]

It's been a very long time, 48 years to be exact since I last troubleshot a vacuum tube radio receiver and your video brings back good memories in high school. I love how detailed you are in explaining the signal tracing process and it is very effective! Thanks for sharing your trade secrets! More power to you Mr. Carlson!!

[@MrCarlsonsLab]

You are welcome!

[@CandyGramForMongo_]

I’ve been lazy watching KZbin all day. By far, this channel has the best sound. Go figure!

[@pierremartel3552]

He has a radio voice. and very good mike. I am sure he cut some high just enough, something like 8k and up.. I also think that all the equipement he have is his lab kind of remove all the echoe as they are not even and wont reflext noise as much.

[@InXLsisDeo]

@@pierremartel3552 Also Paul Carlson is a perfectionist. The lighting is also pretty much perfect.

[@TinyMaths]

Agreed. I was thinking that although I have little knowledge about what Mr Carson is explaining, it's so soothing to listen to his voice, articulation, enunciation etc, but then it also occurred to me just how good the sound quality is.

[@TheLawrenceWade]

The Mister Rogers of Radios. Paul knows what he's doing. :) He's not out there with Go-Pro cameras and a million angles, he's just someone with a real natural talent for sound and lighting and videography - and editing - and a real natural talent for repairing electronics. I can name the tubes as he points them out with the slight error (50B5 versus 50C5) and I don't need the routine lecture about AA5 safety - but he has to do it so no one gets killed and no radios get destroyed. Yeah, I spent a Friday night watching the Mr Rogers of Radios repair an AA5 while there's an RCA 88-T, a Grundig, and a Nordmende on my service bench. (God forbid I should try dating...) I love what he's doing. Thank you, Paul, from a fellow Canadian.

[@qzr0jt]

I've viewed this one two years later. Just found you only recently. If you've repaired this old Fada already, I'll find and view it too. I'm grateful that you're doing these videos.

[@dennisisham1989]

I like the testers and the explanations. They make things understandable without any confusion. Thanks!

[@MrCarlsonsLab]

You are welcome!

[@philipburrows]

Hi Mr Carlson I think that the radio is a beautiful candidate for your magical touch of restoration.

[@jptucsonaz8503]

Yes! Let's RESTORE IT! nice looking unit with shortwave, sure; why not.

[@TheLawrenceWade]

Absolutely beautiful little radio from a great but long-lost American brand - Fada. They made lots of beautiful and high-quality Bakelite radios in the day. This one, an early AA5 prototype, a pre-WWII radio, you know someone saved up for a while to buy it, and in its service life it was playing news of World War II, and probably well into the 1960s given one of the capacitors we saw under the chassis. Its physical condition is about as good as you can get without finding it NOS in its original box. It has been both lucky and well-loved all its life. When I restore something like this, I save all the original parts and tuck them into a baggie somewhere in the chassis, just in case the thing ever ends up in a museum.

[@jlucasound]

@@TheLawrenceWade Good idea, Lawrence, and considerate. It will one day tell a "story" to a future generation. Nice.

[@jlucasound]

I Concur! Really! I mean, it is so Compact! It's a keeper. He is going to have to straighten out that grill cloth. :-0

[@MichiganPeatMoss]

Nary an enthusiastic viewer is in a position to say "No". :)

[@Geezer1955]

Textbook troubleshooting techniques, bravo! Just replace the shorted cap. Use the radio everyday, when the next component fails take us through the procedures again! I learned a lot from this repair.

[@bradleyleben7785]

The radio has survived in this good of quality for 80+ years I say yes go for a full restoration. Your channel is my go to channel to see how these old jewels of history are repaired. I often wonder was these radios listen to to get the news during WWII. I know my grandparents stayed glued to theirs at that time. My two uncles were in Germany.

[@frankpitochelli6786]

Reminds me of my early yrs 1978 .... When people repaired everything. I miss those days in the service business. Great job and thorough explanation.!!

[@rootvalue]

1:03:35 gave me goosebumps. Eureka moments like that are rare on a tech bench. I love these “live troubleshooting” videos. Thanks as well for the auto-generated captions. You’re the best.

[@vineethramaraghavan5856]

This man tells more than I learned in my college..

[@atthefarm3269]

Yeah vineethramaraghavan5856 I agree, my EE curriculum consisted of microprocessor programming and discrete linear transformations

[@kharakim]

This should give you a laugh. I learned electronics fundamentals in 1957 in radar maintenance school at Keesler A.F.B. Of course, I understood the theory of vacuum tubes, but their operation was always something of a magical mystery to me-how they actually do what they do. Well, you killed all the magic and mystery. Your clear explanations and actual illustrations of the working parts of tubes has brought it all down to earth. I now know the mundane reality of how they work. Where's the fun in that? Thanks, as always, for your fine teaching. It's a real public service.

[@tesmith47]

Yeah I was at keesler in1965 got a good education in electronics I was a 30545

[@erikdenhouter]

:) I had the same experience of disappearing magic when Paul explaned how a shop worked at 9:33.

[@timgregerson612]

Thanks for the accurate analysis of this old radio, Paul. I have a 1937 RCA 10” Kinoscope Model# TC-1. I assume that the tc stands for television chassis. It is in working condition, but after watching your videos on restoring old radios, I will definitely build a Carlson superprobe and go through it and replace all the old “waxies!” The TV was given to me by my dad who ran a radio repair shop in Milwaukee back in the 1930’s, so it has a great deal of sentimental value to our family. Thanks again!

[@GBS1043]

It's also worth a lot of money

[@scubadoc7100]

Hey Paul, this is another great video. I love the way you teach and fully explain what you’re thinking and why. You are a tremendous teacher. I vote that you do a full restoration on this radio. I always learn much watching you troubleshoot and restore equipment and radios.

[@matthewhall6288]

My favorite electronics KZbin channel.

[@bigmac965]

I would love to see you do the restoration on this old radio, Mr. C! There's a magic about these old pieces that the new stuff just doesn't have, including the beautiful cabinets they're in. Thanks for sharing your knowledge!

[@InvestigationsDepartment]

I agree

[@chrisnguyenDQ2012]

Yes. Let's go! Restoration! We're in the digital world now but you brought us back to the day that non of us was born. I guessed it's gonna cost you more money and time! Thank you very much

[@garybalanesi610]

I like this guy! He's quite a storehouse of knowledge.

[@thomashowe855]

He is *the* storehouse of all humans know about electrical repair and function. Incredible, really.

[@robertmandell526]

I've got BS/UCLA and MS/Caltech in EE. None of my Profs 50 years ago were as clear, concise, and instructive as this fellow. Cost to troubleshoot and maintain phased array radars would have been much less if Mr Carlson had written the TS manuals.

[@telwood15]

and more.

[@deathlywraith2282]

If I had a lab/shop like yours, that is where I would be almost all of the time. While in high school went to Vocational Technical school for Electronics 1971-1972 then Data Processing 1972-1973. Computer Programmer job paid the bills while electronics hobby kept me off the streets - most of the time. Now retired and keeping busy doing nothing all day - still have not finished. Please keep on making and posting these videos. Thanks again for sharing all the fun stuff. Always plan on a great day - just in case it happens!

[@InXLsisDeo]

M. Carlson is so astonishingly knowledgeable about old electronics that it's like he was already around in the 1920s.

[@superrodder2002]

I lived 1 block away from an electronics repair shop. As a teenager I would haul tubes from old tvs and radios in there and he had a tester right in the showroom where I would check all the tubes. He would always take time to answer my questions and teach me stuff.

[@pupdog7374]

My parents bought a brand new Zenith television (B&W of course) back in 1952.. As this TV aged, its vacuum tubes would fail. My dad would then pull all of the tubes, put them in a paper bag and give them to me. I would hop on my bike and head over to our local drug store where I would do exactly what you described and test the tubes one by one. Ah, the memories.

[@rabindranarayanchaudhury7313]

Thanks Mr.Carlson for imparting the knowledge of Radio repair.

[@MrCarlsonsLab]

You are very welcome!

[@johnt7502]

Our electronics teacher taught us to keep one hand in your pocket when field testing tube gear. By all means, restore. The case alone is worth it. Many period radios and TVs depended upon the cardboard back of the radio to protect you from shock. Maybe you can locate a photo and recreate one. Great video, looking forward to the future restoration. 👍

[@SteverRob]

John T in addition to the cardboard back, there were as few and inaccessible metal points as possible, usually 4 screws underneath. All knobs and switches are plastic/Bakelite.

[@josephrott1920]

Please restore it. I love your channel as it is the only electronics channel I have found that deals in pre transistor era tech. The engineering of such electronics is quite different than modern tech and is becoming a dieing art. The things you talk about and do are very important for historical documentary purposes. Thank you for your work.

[@a587g]

Definitely deserves to be restored. Very good, clear explanation of troubleshooting; narrowing the problem down to the section, and isolating it to a specific component with voltage measurements. Nicely done.

[@kenhammond3810]

I restored my dad's radio, an Automatic Radio 613-X, that he had when he was a kid in much the same way. I listen to it every day. I've restored a could of others since then. But you've shown me some new tricks. Well done! My latest project is my father-in-law's aviation band radio that we rescued from the basement of his childhood farmhouse in western Kansas, it was full of mouse nests, but will soon be working again.

[@lem1962]

Another great well spoken thoroughly explained video and I’d be glad to sit and watch you do a complete restoration. I watched this video rather than the Cowboys game. Keep up the good work.

[@Rev22-21]

I watched the game and later found this. Wonder if I just saw the last game Witten and Garrett are going to be w/the cowboys. Been a boys fan since 1965. Looks like i'll be pulling for N.O. & Brees(?) this time. Chances too, it may be Brady's last rodeo too. Oh well. The sugar bowl is my next watch.... Baylor wins I hope. Happy New Years!

[@lem1962]

That’s great news which I’ve not heard yet. Disappointing season to say the least. Glad their staying on as well.

[@timothysobina6777]

Good choice.. forgo the Cowboys game! Ha!

[@jungoogie]

This is really humbling to see some care shown to these pieces of electronic history.

[@alexkay1874]

Love the style and circuit of this radio a must for resto

[@jlucasound]

Agree!

[@deadfreightwest5956]

Indeed. This is a quality set.

[@coryheckler2354]

Paul, I haven't viewed all the comments...but yes, restore this radio! Love your tutorials. I'm a novice in electronics. It fascinates me how this equipment works and in how the circuit all work together in concert. Glad I found you on KZbin.

[@dadawoodslife]

When I studied electronics at college they said 'you'll never see valves anymore so we skip that from the course'. 20 years later I get presented with a valve circuit in a job interview. 44 years later, here I am, finally learning how to diagnose those circuits!

[@Ira06002]

I’m Fascinated by the AA5 and radio repair/restoration but new in my learning journey. I’m so amazed of your knowledge and pragmatic approach. Great video!

[@paolocanali3361]

Nice story about end users that find and replace the bad tube by themselves, and it is absolutely true. When I was a kid, the radio broke and the next day my father came home with a bag of tubes, borrowed from the local radio/tv shop. It unplugged the radio from the socket, opened the back of the radio, and exchanged the tubes with the spares one by one, until the radio worked again. It was a history professor, and far removed from any technical work. But repairing the tube radio by replacing a tube was something that was confident to do.

[@edwardallan197]

Pretty gripping troubleshoot! . He connects all the dots, I learn a lot!

[@JerryEricsson]

Years ago, back in the 70's I was in the US Army. I cross trained into Radio Teletype, after first cross training into land line teletype. One of the rigs I learned on was a huge old transmitter/Duel receiver set called the 26D rig. It was so large that it took a 2 1/2 ton truck to haul it around, and we towed two 10KW Generators to power her up in the field. Part of the shut down procedure of the transmitter was to take a large tool that resembled a rubber sword with a hook on one end, and a large clip on the other. You had to find a solid ground, then open a special door on the transmitter housing, that contained the huge vacuum tube you spoke of. With the grounded rubber sword, you hooked that top cap and discharged the tube, it had several thousand volts present, and could ark a bit when discharging. The old 26D was neat in that you could transmit on almost any frequency, including standard AM. In Vietnam, during the war, many communications soldiers would tune the transmitter to around 800 on the AM, hook their little Pioneer PL 50's or reel to reel sets to the radio and run pirate radio stations for the troops. Soldiers loved it, they used to have a saying, the only happy troops are bitching troops, and man those pirate's did a lot of bitching, but they played the cool rock of the anti-war crowd and that was very popular, especially with the draftee's.

[@hawkinscsa]

Yes Sir, please do a full restore. This is an excellent video. Thanks to You, this is getting much easier to understand! The way you followed the signal through the radio was great!

[@RANDALLOLOGY]

This video brought back so many memories from back in the day. When I was young, I remember going with my grandfather to the Recall drug store to a RCA tube tester. He would check his tubes and the ones that said bad or weak, he would get new ones. That intrigued me so much that I wanted to learn electronics. When I went to high school I took as many electronic classes as I could. I cut my teeth on vacuum tubes and moved up to what they called transistors. Later in life I got a bachelor's degree in electronic engineering. Nowadays it's IC chips ,5 volt supplies, and all Digital. But I miss the old days. Lol

[@chrisbridge3175]

Hi Paul, I'm also an experienced technician and ran across your video by chance. I have to say that you are by far one of the most technically accurate presenters, and you use a heavy dose of common sense. I can't tell you how much I support your efforts and how you are doing this. There is far too much mis-information and terrible examples of how not to do things. Please continue doing what you are doing, and on behalf of one tech who is sick of cleaning up after hacks - thank you!!! -Chris

[@MrCarlsonsLab]

Thank You for your kind feedback Chris.

[@dougrobison5342]

Well done Paul, you do a Great job explaining everything. Thanks much!

[@MrCarlsonsLab]

Glad it was helpful!

[@martinbjorses1958]

You must be a teacher. All makes sense because you take the time to explain. Good stuff.

[@samuellourenco1050]

Thanks, Mr. Carlson, for sharing your knowledge. Learned a lot with this video. Your probe works a treat and is great for troubleshooting.

[@davearmstrong1932]

THANK YOU Mr. C This is what I do Restore Radios from the 20s 30s 40s and 50s. I don't know much about electronic's (and I can prove it) so videos like this are very helpfull.

[@moshezaharia4666]

A very well built radio like this deserves a restoration.

[@tbriglia01]

Thank you Mr.Carlson . You are a God send explaining the process ! There are a lot of us out here who can make a repair but, very few can answer how and why. The how and why,in my opinion are very important. I am an extra class amateur radio enthusiast but struggle with some of the formulas . My technical journals are books from the 20’s and 30’s along with some old magazines from ARRL and some others. I love your lab !

[@billpowell5931]

Very nice presentation (as usual) to get this radio operating. I believe a complete restoration would be great. I love the vintage radios.

[@henrikkliebhan4874]

So relaxed, so professional. Stay alive with your channel🙏

[@nviduumde3497]

You know you'll get quality content and an extremly high grade of knowledge when Paul uploads a new video. All american 5s are always a great topic to learn something. Great work. keep it up!

[@BruceNitroxpro]

Nviduum DE , But this was before the all American 5 sets. Review the section about the choke placement.

[@marknash7113]

Another fine job of troubleshooting. This circuit is a great example to restore. Great job reminding us that you can bring even series filament radios with original caps up on the variac and dim bulb limiter and find the problem(s) before wasting time and money on shotgunning things. You may have to anyway, but if the iron is bad or coils open your in for way more work than its worth. Keep em glowing!

[@bobvines00]

Paul, here's my vote for a restoration, with your detailed explanations as you perform it. Like many other commenters, I remember walking into drugstores with tube testers close to the front door. As a kid, I remember looking down into our TV through the grill at the lit-up tubes and feeling the heat rising from them. ;)

[@youtubeaccount8048]

I am right about to start my career in maritime electrics/electronics, but my interest started when a Sansui fm tuner broke down when I was a kid, I remember tracing the board in absolute aww, made it much worse, and swore to understand it one day XD. There is something very sad to me about electronics looking so good but being dead, I can follow perfectly what goes on in your videos now, and watching them is truly inspiring, and educational. Your reasoning is great, and you are quick, calm, careful, experienced, and equipped awesomely. I think alike, but have much to see still, and equipment to buy. Mr. Carlson thank you very much for making these videos in such heroic precise detail, one can actually learn the practice from. My school should freaking put them in the curriculum, would be 300% more educational. How much stuff did you burn to get this good? Its not a measure but still :)

[@MrCarlsonsLab]

Thanks for your feedback, and kind comment!

[@XRoadie1]

Welcome back, Paul! I was afraid you had called it quits. I always enjoy your thoughtful approach to troubleshooting. Best regards!

[@McTroyd]

Of course it should be restored! FIX ALL THE THINGS. I could use a refresher on peaking up the receiver sensitivity... just bought my first one to try fixing up, based on years of watching this channel. It's so weird to have a manual say something like "the newly-allocated FM band" and find out the radio is the same age as my father. LOL

[@quicktastic]

Yes on the restore it question. Always like seeing that.

[@springwoodcottage4248]

Fabulous how with a single snip it jumped back into life, makes one appreciate how components have improved & everything become so much smaller in the eighty three years since this was made & also how nearly everyone is now decoupled from the slightest understanding of how things work & how to resolve faults. Thanks for sharing!

[@jamespfp]

The worst thing about long-form videos is how long it takes to make them; I can say from experience that every minute of video footage takes about an hour's worth of post-processing effort, if I include the render times at the end, and so forth. *BUT* the best thing about them is how excellent they can be, and how interesting. Thank you for your dedication to sharing information with others.

[@allthegearnoidea6752]

jamespfp I make videos your right and the quality requirement and time is ever increasing

[@jamespfp]

@@allthegearnoidea6752 I certainly wasn't joking or exaggerating about the ratio I stated. 120 minutes of video takes 5 days to properly edit, depending on the number of cameras, cuts, audio tracks, and the rendering happening while sleeping. 120 hours is 5 days.

[@allthegearnoidea6752]

jamespfp I’m definitely agreeing. Just spent a week making a not particularly good video myself

[@spudhut2246]

Enjoyed the video and the detailed troubleshooting. You are a master of all things electrical. Thank you for making these videos.

[@markphilpot4981]

It would be both educational and fun to see this radio receive a full restoration. Much like others you have done, this radio is in grave need due to how dirty it is and the state of some components. Your other restorations have been great fun to watch and I think others and myself would like to see this one done also. I look forward to seeing you do this and I am sure the other viewers would to. Happy Christmas Mr. Carlson! Blessings come to you in the new year!

[@dugwthree]

i remember going with my dad to check for bad tubes. I'm 69 so that was a long time ago . Much of this is over my head. i hope it was restored . I and will be following you

[@fredfeldmeier8228]

Of course Mr. Carlson.. we all enjoy the superb quality & knowledge of expertise.. keep up the good work.. Thanx for the video.. happy new year 2020.. God bless..👍👌

[@johne6081]

Thank you for taking me back to my undergrad days, when I earned my tuition working in the audio service department of a ham radio and hi-fi shop ca. 1970.

[@anno250]

When I did my Advanced certificate in Electronics ,nearly 40 years ago one of the students just couldn't leave thing alone tried testing a radio with the Oscilloscope and didn't listen to the bit about live chassis and cause an almighty bang that blacked out one wing of the Tafe building and blew a hole in the front of the oscilloscope . So thats stuck in my head about using a isolation transformer. Funny thing was up till then the teacher was sticking things up on the board that we destroyed ,bit hard to stick an oscilloscope to the board .

[@MrCarlsonsLab]

Thanks for sharing your story!

[@SteverRob]

We had a “tree” about a foot tall made up of soldered together failed components from repairs and fubars over the years. We called it the “burning bush”

[@theduckisok]

Happy New Year! I enjoy these old school videos. I'm not much on surface mount, but anything from 1915-1965 is my forte. Tom

[@andrewjones6693]

Great troubleshooting, Mr. Carlson! I would like to see the complete restore. There's nothing better than well-cleaned and well-lit old radio dial! 💡 I also enjoyed the Realistic external speaker! As a former employee of Radio Shack, it caught my eye immediately! 😁

[@225rip]

Brought back a lot of repair memories, enjoyed this video.

[@johnopalko5223]

I'm _always_ in favor of a good restoration video. Nice to see a good old pentagrid converter tube.

[@s.sradon9782]

I love vintage/retro board-level repair it's a skill that can make you lots of money, especially as an engie student!

[@michaelbarg5582]

Thank you for yet another highly instructive, professional video, Paul! Yes, please restore this vintage radio. There is still much we can learn by following your thorough troubleshooting and practical restoration process. I wish you and yours' a very safe and Happy New Year!

[@d3w4yn3]

This is mad genius!!! Just discovered this channel, and this is exactly the kind of thought process that I can learn from!

[@dgretlein]

You are absolutely correct about the tube testers being in the drug store (my memory is a grocery store). I remember, being 10-12 years old in the late sixties, opening the back of our family tv, pulling the tubes, riding my bicycle to the grocery store and testing the tubes. I don’t recall whether I found the the replacement tube. “Thanks for the memories ...”.

[@MultiJennifer54]

i did too with my dad, he took by the hand to make sure i wouldn't touch electrical equipment, then later i started going on my own, push lightly and turn tube till it would drop down into it place, beautiful technology for days gone by. i then learned not to push tube but to align the notches and wham in she went, great days of a people that were at the beginning of radio tech.

[@aos3971]

I was servicing this type AC DC Operation radio on 1985. When the polarity of AC input changes it use to give current shock if we touch the chase or even control knobs.. I Enjoyed the audio quality on those days. As up to now i never heard such beautiful audio. This is from India. EL84 and ECH 81 vacuum tubes i used to replace on those days.

[@volvo09]

Looking forward to this! I love following fault tracing.

[@algratz760]

Enjoyed this way of re-learning this type and method of troubleshooting. Thanks much!

[@MrCarlsonsLab]

You're welcome!

[@algratz760]

@MrCarlsonsLab I would love to see you fully restore this old radio. I too used to work with technology such as this when I was in Tech school years ago and then got into 2 way radio troublshooting later in a factory in Minnesota. . I still love the process of analysis and trouble shooting. It just intrigues me so much.

[@rickkennard8027]

Glad to see a new video. Always waiting for a new one! Love the shirt

[@dkaloupis75]

I am not an electrician at all but I do really love audio amplifiers. Thanks to Mr. Carlson my 04 00 mornings have a new meaning to me and cannot wait to repeat a video or watch a new one and "have a play around" in my wannabee private lab. Next move-target is to become a patreon...Thanks Mr. Carlson for being so educational.

[@chrisnorton1245]

Mr Carlson. Great video sir. Again thank you for explaining the safety aspects of working on vacuum tube equipment with a possibly live (hot) chassis. looking at the circuit of the audio output stage and the failed wax capacitor, assuming that it was in a dead short condition, (which the scope-meter indicated) I would be very suspicious of the 240R cathode bias resistor. In the fault condition I reckon that resistor would be dissipating around 1/2W (based in the 10.6V fault voltage between the 25L6G tube cathode and the chassis). I bet that if you unwound that failed cap you would find that the dielectric had failed internally causing the burn mark on the side. If you are inviting votes for restoration, I vote do it. I have worked on vacuum tubed equipment before but I have not come across anything as early as the 1930s. Personally I have never seen a "Ballest tube".

[@mikekarpaty3871]

Use say this video was one of the best if not the best video I have ever seen. Professional, consice and well presented. Thank you for sharing. I have a few old pre transformer type radios that will need repairing so this will be an invaluable source of information. Once again thank you and all the best from sunny West Wales 🌞🌞

[@MrCarlsonsLab]

Glad you enjoyed it!

[@LakeNipissing]

*_HAPPY NEW YEAR, PAUL_* Thanks for sharing so much knowledge with us!

[@kamius1]

Amazing tutorial. Reminds me of my childhood and my own hobby as an electronic fan.

[@DanCalloway]

I remember checking vacuum tubes at the local drug store. Hard to believe that we had to do that. I would like to see this radio fully restored to factory condition. Thank you for a great video and wonderful learning experience.

[@JerryEricsson]

Indeed, when stationed at Fort Myer in the HQ Communications section officers and senior NCO'S with radio or tV decided that should be in communications, so they would bring them in and ask (read order) us to repair. They would cover the parts and most would slip us an extra ten spot for our trouble, way cheaper then taking them to a tv repair shop and paying 50 bucks to have the device opened up, plus parts and a rather high labor. We would pull the tubes out, walk across the street to a drug store and use their testers or some times just dig out our Government tube tester and check them, then buy the needed replacements keeping the receipt and fix the sets. We did have a trained radio mechanic in the Section and he would take care of the bottom problems after calling the owner and telling them that they would have to cough up another 20 bucks for his service. Most acquiesced. It was a fair sideline for some of us.

[@MatthewAE4JC]

That's a really nicely done schematic. Strange comment? Maybe. Context: I'm a former draftsman. Love your videos. God bless you!

[@wireworks616]

Great video. I could actually hear the radio saying restore me. Yes.

[@wilfredswinkels]

The mirror like coating inside the tubes is Barium. Barium is a strong getter material which catches residual molecules in the vacuum of the tube. If the molecules are stuck in the getter material they cannot move around hence there will no pressure generated, keeping the vacuum optimal. Barium oxide is a white powdery substance. So If you see that, the seal is broken and all the electrons fall out. Thanks professor for another wonderful video.

[@paulkocyla1343]

Even I am not a native English speaker, I can understand your well sounding, clean pronounced and perfectly structured articulation/explanation, even with 10 beers inside. If someone googles "Oxford English", your name should be shown beside the corresponding Wikipedia article. You are the rallye racer of tube tech, seriously! BTW: No jokes now, excellent channel! I´d like to see that radio restored, especially after having a kind of detailed overview about it now. Would be a pity to let all that information drown the drain. It would be a great to see a follow up.

[@ricoma6037]

Thank you! I really enjoyed going through this with you!!!

[@Counselor77]

I remember the good ol days when I went with my Dad to the store with a sack full of tubes for the TV and using the tube tester.

[@silenthill4]

/s

[@Counselor77]

@Robert Slackware That tube tester is worth its weight in gold, my friend.

[@Watchyn_Yarwood]

My mom and dad owned and ran the country store/post office in our tiny little town. We sold everything from pencils to horseshoes AND radio tubes! I learned at about the age of 10 (mid 1950s) how to test and replace tubes. Folks would bring their radios in, I would test the tubes and sell them new ones when needed.

[@gbennett58]

My Dad sent me to the drug store to test tubes. In addition to testing the tubes, I discovered you could get a thrilling electrical shock by hooking up the probes to your fingers. Wouldn't do that now, of course.

[@davidlegault9745]

@Robert Slackware Check out Glasslinger - he makes tubes.

[@andygarello4426]

I vote for restoration. I have several old radios, sig-gens, and other gear. I'm learning a lot from you. Thanks for your hard work.!

[@greengrayradio1394]

Nice, thorough explanations as always! I heard the "LU" beacon, seems it is in Abbotsford, BC. In some of my own radios I have left some caps, but the paper ones seem always bad and leak. I vote for a restoration!

[@robertborchert932]

Hehe, that beacon is close, very clear. Remembering my Morse code as a Cub Scout.

[@donrichards514]

Thank You for me this video is the next best thing to actually fixing an old tube type again .