Thanks for the video. I think I might still have one or 2 of those that are similar in my classroom storage. I never knew what they were for since I have several 60-70 vintage scopes that have the dual trace on them. I likely have one or 2 that have a single trace that I can use it on if I decide to restore it. My department wants me to throw them and buy new scopes and I do have 2 new DSOs but I still like the old units as they are simpler for students to use at first to gain an understanding of function before letting them play with the fancy DSO that does everything for them and has enough buttons to make their eyes gloss over. I need to go through all the working scopes and replace caps before they fail. I did replace a few bad caps already on 2 that were not working and they sprang back to life.
Those older scopes are your best learning tools, don't discard them, use them to teach! The newer scopes are fine for the end result (solving a service/repair issue) but very poor for the understanding of the scope itself. Sounds like you're on the right track kuhrd!
I was looking at the TBS1000B-EDU line of scopes if I do have to buy a few replacements in the future but I will try and keep the old stuff going strong for as long as I can. I have 2x Rigol DS1054Z that I have not firmware unlocked yet (waiting for the warranty to run out) I snuck them on my new class budget when I resurrected the electronics class 2 years ago. Electronics had not been taught since I was in high school at the very same school. Kinda felt it was my duty to get the class going again. The Rigol DSO scopes work well enough for showing students waveforms and troubleshooting circuits but I always let them play on the old ones first. It is nice to have access to a scope with 4 inputs when doing things with Arduino and stepper motors. Some days it is hard enough convincing the trouble makers that the lab power supplies are not arc welders. On those days when I am working on my own stuff I wish I had even 25% the experience you have with electronics.
Very much enjoyed watching your channel for the first time. Seeing that Heathkit oscilloscope brought back great old memories. Around 58 years ago I was a teenager working the summer as a dogsbody in my father's marine electronics shop on Fort Myers Beach, FL. It happened that he needed an additional oscilloscope on the work bench for the technicians. So he purchased a Heathkit and put me to assembling the unit. Well, I was over then moon being given such a challenge and responsibility. I completed the assemble and when the time came, it didn't work. One of the technicians took to troubleshooting the unit and found that I had failed to put a ground insulator between one of the can capacitors and the frame. Easy fix and I was relieved.
Hello a general question related to use and restoration of older test gear in your projects have you worked on Fluke 8600A DMM's? I have one I am interested in getting back into working condition. TX Theo
This is so restful! I know just enough about the mechanical side of tube equipment restoration to feel like your apprentice. Watching your videos is like meditation to me. I wish I understood the electronics side of it better.
Your videos are not only stimulating for the brain, but they're a treat on the eyes too. That thing is ridiculously gorgeous. It really reminds me of the old equalisers they have in the Abbey Road studios.
Wonderful work upgrading this fine old switcher. I liked your very clear demonstration and explanation of how it works. Reminds me of what we did in EE lab work during my college fun years.
I'd have to say this instructional on older tube technology is probably the best I've found on TH-cam. Thanks for providing your knowledge and time to educate the rest of us. It's appreciated very much.
Now all you need is a type 132 Sylvania oscilloscope to go with it. I think that is the model that was being made in the early 40's. It should make a great addition to your bench. It turned out really nice. Thanks for sharing.
Hi Mike. Would you be surprised if I told you...... I have a 132... LOL :^) And.... It's little brother, the 131 as well :^) They will both be future restoration video's. Thanks for stopping by Mike, always good to hear from you.
Mr Carlson's Lab LOL, your as bad as me. If it's old and electronic we probably have at least one in our collections. Now you have even more reason to restore one of them. I have been searching for years for one of the rare Sylvania VTVM's. They are supposed to be a beast.
Great vid! My dad was an electronics tech for 60 years, graduating from Oaklands' Central Trade School, in 1937. Seeing these old units brings back countless memories. :-) It's great, knowing that there are young people keeping the old trade alive.
Thank you for showing this. I have a project that i wanted to get started on and you gave me the motivation to work on it. One thing i need to get is a tube tester. for the past 2 years I have been obtaining tube radios from clean outs, most are in bad condition. I save the parts from them to one day build something crazy. I was thinking of a 7.1 surround system. something that i can be proud of. I had a teacher long ago that took his time to show me how tubes worked. Build my first radio for high school. Thank you again for taking your time to show us the projects you work on!
Thank you Mr Carlson! I am a motor head/electronic hobbyist from way back who has always had a fascination for old tubed devices. I understand enough about them to stay alive while servicing them but have had a few things puzzle me about their operation, one being “bias”. Your comparison of bias being like a stall converter on a starting line is one I understand well. Now I understand some of the mechanics behind bias as well! My shop is almost finished and I hope to put all the old collected equipment back to work here soon. Thank you for the awesome video's.
Always amazed at the knowledge on tap, in your brain. I have experimented a little with small projects in the past. But, I could never retain your level of knowledge. Fascinating to watch. You have convinced me to get another soldering station and get back into it. I'm retired now, so I have the time. Just not a lot of money or brain capacity to do much. But, I really enjoyed it, back in the day.
This is awesome. As soon as the cover came off, the quality was evident. I sold my dad's O-11 scope before I saw your restoration video, and I hope the buyer enjoyed restoring it - his intention. He may have seen your video. Very enjoyable watching your restoration and explanation. Excellent work!
This is really long and very well done...... long is good..... Im going to add it to my watch it later since it is so late for me..... Im saying this to help you with your Analytic's so when you see someone clicking off the video early that its not a bad thing....... This video is awesome and I will be back to finish it. Thanks
Hell,Paul! My name is Jim Ashton and I was born in Birmingham in England in 1943, so you can understand that this video took me back in time to my early days in valve (tube) electronics.I was most impressed by your very clear explanation of an instrument which I had never encountered. At no point did I become bored and I picked up a lot of useful tips. I shall be following your videos avidly from now on. As a matter of interest (or not!) I am now a qualified Egyptologist and travel each winter to that country. There is no danger and I encourage all my friends to go there and see the miracles that these people wrought! Jim.
Aside from the education, I really love your passion for the history that the devices "tells" when you open it up. You show your anticipation and excitement of the preservation of history. That aspect is just as important as your videos.
I would like to be you next-door neighbor! I have a great deal of test equipment (everything from decade boxes to microwave spectrum analyzers -- maybe more than you!) which I have collected -- and repaired/calibrated -- over, well, more decades than I want to recount; and I, too, really enjoy bringing old devices back to life. My current "stereo" has surround capabilities combined with Grommes 260A amplifiers for the main (front) left and right channels, most of the equipment for which I bought in less-than-perfect condition. Anyway, I really enjoy your videos (You da MAN!), and I hope they continue to be available for many years to come. Thanks, Paul.
Wow! What a cool device! Simple yet sophisticated. I think you are spot on for the estimated date of the device - Loctal sockets (trademarked as Loktal, and developed by Sylvania) were released to OEM about 1938. With all of the interesting gear you have restored for your circa 1950's test lab, I can't wait to see the setup and see your projects in the "old lab". Great work, Paul. And, thank you for keeping the lovers of the vacuum state (a.k.a "us old geezers who think that it only works when it glows orange") well informed and entertained. Your theory and practice of reverse engineering - or "forensic engineering" - was great. Would love to see more of it in vacuum state and solid state as well. Your process is very close to the techniques I teach in harmonic and melodic analysis in music theory.
Fantastic job as always. It's admirable to see you not only reverse engineering the device, but find and fix a problem that problably the very manufacturers themselves couldn't find and repair. I hope in the future i can afford joining your electronics course on patreon. Thank you for all your perfectly produced videos.
Big thumbs up for Mr Carl son's lab. I must get my patreon account sorted out. I just love the calm and logical but warm and engaging delivery. Thanks again.
You find the neatest stuff! I especially liked the sleuth like detective work into the suspected low hours of use. Thanks for taking the time to draw up and explain the schematic.. I always learn something from your video's.. A++
I always enjoy yr videos, grateful someone such as yourself still takes the time. Soon all of the analogue electronics knowledge will become mystery and rare if not already.
As a retired EE, born in 1941, I can attest to the knowledge of Mr. Carlson. Other than a very minor pronunciation error (silent "l" in "solder,") this is a perfect video. Excellent in every respect.
I apologize, Paul, for the misunderstanding... I have since seen the outrageous lengths which you take to remain completely purist in every respect in all of your videos. In fact, I have to watch out that I don't start talking like a Brit and make people think I'm a transplant to the US! LOL You have set an extremely high bar for the rest of the electronics community. Bravo! de KQ2E
I’m drawing my own schematic of a Kenwood TS-120S just for the heck of it, and I’m really enjoying it. Mr. Carlson also has a few schematic drawing tips and tricks in his Patreon pages that are really helping me with the technique-gotta say thanks for that!
My head is going to pop. You have an incredible amount of knowledge and understanding for this gear. Thank you for the great videos and narration. Absolutely enjoy all your shows Dr. Carlson.
you polished up that front panel so well, it has a mirror finish. I also spend a lot of time polishing old stuff up. takes a lot of time but i enjoy it.
Another wonderful piece of equipment restored. Thank you for another interesting presentation Paul. But for those of you interested in restoring old vacuum equipment there are five things to know. First, you need a circuit diagram. Never go fiddling in an equipment unless you have one, because you do not know what the heck you are connecting to. This can lead to causing more issues in the equipment by destroying valves and components, not to mention your test gear. Second, don't plug it in direct to the power source and destroy it. You need an isolation transformer, a variac, and current limit just like Paul's, so that you can see whether it is going to behave or not. Remember, you do not know where the equipment has been, or what condition it is in. It could be faulty, and old components invariably fail. Third, you need to understand how the circuit works. If you do not then it is like coming off the street, climbing into an F15 fighter jet and expecting to fly it! Well it is the same here too. If you do not understand how the circuit works, seek advice. Fourth, large capacitors charge up. Yes it is turned off and unplugged, but if you have had voltage on it they can charge up and still give you a very nasty surprise. Fifth, and VERY IMPORTANT you have to understand that this is not solid state devices like bipolar transistors and FET's that you fiddle around with with your bare hands, and that there are REAL voltages in there that can KILL YOU. My mentor always told me, ground on chassis, one hand in your pocket, and the other on the probe. It was valuable advice when working on valve gear. If you get connected to those voltages, and many have, you will definitely know! High voltage is pretty unforgiving of incompetence, and can put you in the hospital or the ground for good, so always take great care when in live valve equipment. Watch Paul's videos. You can learn a lot. He has mastered valve gear and electronics, knows the hazards, and understands the circuits in detail. You can have no better teacher. My mentor? Derek Colins, in television repair for over 20 years, and when I met him a bench radio transceiver repair technician. The best. Paul even uses some of the terms Derek did.......badly repaired electronics.......butchered boards! LOL
As others have said, a brilliant & detailed video, would it be worth mentioning that the replacement potentiometers musst have a linear track? So many are logarithmic for audio use these days. However nothing can beat silck smooth "sizzle" of a 1940s wire wound pot!
Excellent information, great detail. Many of us old timers learned about circuit design (and mechanical design) by disassembling military surplus items. Helps to develop a way of thinking that is invaluable today.
I used to go to sea as a Merchant Navy Radio Electronics officer, but it's been a while since I did any hardware work (got into computers when I came ashore.) Very pleasant and informative video to watch. I first went to sea with valve (tube) equipment which moved to solid state in the course of my sea-time. Definite thumbs up. :-)
Wonderful switch...I really love seeing this older equipment getting brought back to life! It is funny that the problem was an un-soldered capacitor that kept getting missed. That is one of those "DOH!" moments Homer Simpson keeps talking about :)
Another excellent presentation, Mr Carlson. I am reading a 1956 book about oscilloscopes and there is a similar schematic of an electronic switch, but it only uses four pentodes, excluding the rectifier. And I must say, those big vintage Mallory capacitors are very pretty. If only the Czechoslovakian Tesla components I come across here in the Czech Republic were as colorful and with such nice writing as their American counterparts have. They would make for an interesting wall decor for the lab, framed in a flat glass box. Thank you for making this video.
I've been loving your videos Mr Carlson, they're all very informative, educational and very interesting. This was a great device, excellent restoration and great to see this old equipment come to life.
@@MrCarlsonsLab very much so, to the point where is renewed my interest in vintage tech. I recently received a General Radio Company impedance bridge. Note I just need to understand how it works and restore. Your videos are awesome, I'll be a patreon as soon as lockdown is over in my neighborhood.
This is great. Had no idea what it is was for, until last part of video. But glad I stayed till end, as I just built an oscilloscope from a very old book written in 1979 by a chap named F.G Rayer. (one of the many brilliant Babani project books) Really simple circuit and covers 20hz to 20khz nicely. But of course its a single channel scope. So now you have shown me how I can turn it into a two channel scope. Brilliant!!!
really love your vids , they take me back to when I was 12 years old and started playing with old electrical equipment , old radios mainly , back then stuff like you show in your vids sold for pennies in disposal stores , oh how I wish I had some of that old stuff now
Paul... Awesome job! This was just a really enjoyable video. And what a cool find... Now looking and working like new at almost 80 years old. Wow. Thanks for all the effort!
Wow, what a great in detail explanation! I really like the reverse engineering part and I'm looking forward to see more like this in the future. Never thought, that reading schematics can be fun. You doing a great job, many thanks Paul!
My first job in 1982 was working with an older gentleman in a two way radio repair shop. He had a lot of equipment like this. Sorry to say it all went to the dump. Glad to see you save some of that kind of stuff.
my first oscilloscope was a sencore PS148 from the early 60's. I'm in the middle of restoring a vintage general radio audio frequency generator. love your vids!
This was very inspiring. Admiring your deep understanding of this technology and the way you bring it out to us. Thanx for bringing the zeitgeist of this era back to life.
When you switched on the switch box after it was connected to the oscilloscope and we could see the path of how the two lines are made @ 1:07:03, that was really neat. Thanks for sharing this all. I wonder how hard it would be to make an equivalent of this for that cheap single channel scope I have. oh and then you really show how it works later!
Really enjoyed this. I started smiling when the trace started on the scope and didn't stop until it was over, heck I'm still smiling. That was so much fun and so interesting! Thank you!
What a reminder of my old years as a Radio & TV engineer !!! I loved those Continental Transmitters with a built quality as that Sylvania switch. Keep posting videos !! :)
OUTSTANDING video Sir!!!! Even with my limited self taught knowledge I was able to follow along and understand most of what you explained due (I am sure) mostly to your Great Teaching and explanation of what was going on as well as what you are doing. Really good video Two Thumbs Up!!!!! btw - I have two Heathkit pieces of test equipment that belonged to my Uncle back when he was a young boy and wanted to learn electronics. One is a VOM and the other one is a Frequency or Signal Generator I think he told me he had to build these items as part of his class, he since has past away but I think these items are from the late 40s early 50s ? Idk for sure but I am sure glad I kept them AND found your channel because now I feel like I might be able to "Check" these items out and put them to use Thanks to you Mr Carlson!! You made my day Sir !!!
Omg this channel is so useful but i could never watch it until i found 1.25 play speed. Now i can remember the beginning of the sentence by the time he reached the end of the sentence. Before i was falling off the concentration. Now it awesome.
Great Video! A lot of good advice on how to approach a restore. A valuable take away for me was drawing the schematic, reverse engineering, since nothing was available. I am restoring a Hickok 209B VTVM, unlike other models in the series , no documentation appears to be available. I am going to stop searching and start drawing, a bit of work, but part of the restoration journey. Thank You!
I have not looked at your channel for a while and I am now wondering what I have missed. There is no doubt that whoever designed this unit took pride in what they did. It may look old fashioned but I think it looks bloody gorgeous. After 50 odd years I have gone back to electronics as a hobby so to me in a way it's not so old fashioned. I can remember 410 V across the end of my nose ( Mullard Amp). A small scar is still there after 50 years. Thank you so much for this video - it's perfect.
I've been consuming your videos for the past while now and I went from 0 to absolutely stoked on vacuum tube electronics. Thank you, it's a great feeling. I've still only ever laid my hands on transistor equipment thus far, though. I'm looking to pick up an early 60's 4 watt EAF42-EL41 kit amplifier (with AZ41) as my first foray into vacuum tubes. I intend to give some fresh capacitors, if I do indeed get a word back from the current owner that he hasn't recently attempted to power it up. Judging by its casing alone, the caps are not going to be all of its issues. Bodgewires and questionably fitted afterthought connectors adorn most of the device's backside, and, I'm honestly still accommodating to the idea of electronics that aren't anchored to a PCB in the first place. Beyond being careful not zapping myself, and being gentle with the device and not zapping it , do you have any advice on the tubes it comes with, or European kit amplifiers in general? Are there more quirks to them than meets the eye? Should I just go for it, and, do you've any other words of wisdom for the very transistory man I am?
If your a transistor guy, just be careful around the high Voltage, it's all over vacuum equipment. Glad to read you're interested in the tube stuff now, I admit, it's much nicer to work on than the new stuff.
Paul, its good to see another video on YT again, That electronic switch unit is a beautiful instrument !!!! I have heard of these being used with oscilloscopes but NEVER seen it actually done !! Thanks for the video restoration and demo, a real treat as always !!!!!! John A Bellas KC2UVN
That was great!! Again, another high quality explained video by the master himself, Paul. I always enjoy your videos and always learn something, if not allot. Thank you for the effort you have put into these videos. I really wish I could afford to contribute to your efforts, as I do feel that what and how you go about it, is priceless. But, spare money right now, is just not in the cards, hopefully in a few moths, things will lighten up on me, as I have bit off more than I can chew, from 2 months ago.Until that time, I still believe, it would be an honor to donate to Mr. Carlson's Lab, due fact, that I appreciate what you do, and how well you explain everything. I love the feeling that I get half way into watching one of your videos, of being inspired to monkey around in my own shop, but, can't stop watching your video, as I do not to miss anything, in turn, have to fight myself to wait until the video is over, before monkeying around in the shop, LOL.. Thank you, for the ability to keep giving me the swift kick in the butt, to get motivated. Drew
That was super cool. Finding out why the unit was in such good shape was like solving a murder mystery from years past. Thanks for sharing another great piece of history with us. I need to sit down one day and put my unbuilt Eico switch together.
Mr. Carlson you forgot to measure the output voltage on the square wave on the output. Once again a great video that simplifies the explanation of circuit design theory.
That was great. What made it a joy to follow was everything is so clean and pristine. Are you sure you didn't go back in time and get this in a specialty shop? It's like brand new. Down to the leaves on the bakelite tube bases, and no tarnish on the goat shields. Please do more like this, what a great rebuild.
Mr. C I have really enjoyed your videos. If I would have had teachers like you I know I would have been a better student. So thank you for your efforts. I look forward to every video and am learning a lot on your patreon site as well.
Awesome restoration! What Sylvania named at that time as an Electronic Switch, is actually a chopper circuit which, once integrated into future o-scopes got shortened to "CHOP" mode and eventually "ALTERNATE" or ALT mode. Even my late-80's dual-trace Tek scope has ALT mode on it :)
Very enjoyable video of a great old piece of gear. I was amazed how well that switch worked. I'd love to know how much usable bandwidth that switch has. It goes to show there were some very capable engineers back in the thirties when electronics was in it's infancy.
Your attention to minute detail, like the up/down potentiometer facing, is so far above most electricians that it is like listening to Tesla himself compared to the Cable Guy. Wow.
Excellent video. I am from the UK, sadly no one in the UK produces Video's like you, Keith Rucker, etc. do from over the pond! I was an apprentice 1953/1959 at the D.S.I.R. Radio Research Station working for Dr Smith Rose, Wilkins, etc. making the all the type of equipment you are interested in! Your video,s are jogging my memories ,
Marvellous stuff... I grew up in the days of valves (sorry, tubes 😎 ) when things were simple, or seemed so to me. That certainly brought back memories
Very interesting. I have an EICO Model 488 Electronic Switch. It's shape is like yours, but shorter and wider, but the front panel components are laid out just about the same. This video makes me want to check it out and get it working. Will hooke it up to my old Devry tube Oscope. First I need to get my Eico 960B Cap tester going first. Thanks! My interests in electronics started out in the late 50's when I was about 9 years old so tube stuff is very familiar to me.
My father (age 67) watch this before me and after i mentioned loctal valve he then told me about the similar equipment he used to use. Because he has explained to me how these older valves work in detail i had figured out about half of it works but couldn't quite figure how it mixes the channels together so i just had a 10min explanation of the oscillator component.
![How A Turn Signal Flasher Blinker Works - Complete Redesign With Schematic [Tung-Sol P229D]](/img/n.gif)
To go to the Mr Carlson's Lab Patreon Page, click here: www.patreon.com/MrCarlsonsLab
Thanks for the video. I think I might still have one or 2 of those that are similar in my classroom storage. I never knew what they were for since I have several 60-70 vintage scopes that have the dual trace on them. I likely have one or 2 that have a single trace that I can use it on if I decide to restore it. My department wants me to throw them and buy new scopes and I do have 2 new DSOs but I still like the old units as they are simpler for students to use at first to gain an understanding of function before letting them play with the fancy DSO that does everything for them and has enough buttons to make their eyes gloss over. I need to go through all the working scopes and replace caps before they fail. I did replace a few bad caps already on 2 that were not working and they sprang back to life.
Those older scopes are your best learning tools, don't discard them, use them to teach! The newer scopes are fine for the end result (solving a service/repair issue) but very poor for the understanding of the scope itself. Sounds like you're on the right track kuhrd!
I was looking at the TBS1000B-EDU line of scopes if I do have to buy a few replacements in the future but I will try and keep the old stuff going strong for as long as I can. I have 2x Rigol DS1054Z that I have not firmware unlocked yet (waiting for the warranty to run out) I snuck them on my new class budget when I resurrected the electronics class 2 years ago. Electronics had not been taught since I was in high school at the very same school. Kinda felt it was my duty to get the class going again.
The Rigol DSO scopes work well enough for showing students waveforms and troubleshooting circuits but I always let them play on the old ones first. It is nice to have access to a scope with 4 inputs when doing things with Arduino and stepper motors.
Some days it is hard enough convincing the trouble makers that the lab power supplies are not arc welders. On those days when I am working on my own stuff I wish I had even 25% the experience you have with electronics.
Mr Carlson's Lab Your mouth movements look animatronic
should show them king of random vids then. also show the troubler makers. the repair bills as well.
Very much enjoyed watching your channel for the first time. Seeing that Heathkit oscilloscope brought back great old memories. Around 58 years ago I was a teenager working the summer as a dogsbody in my father's marine electronics shop on Fort Myers Beach, FL. It happened that he needed an additional oscilloscope on the work bench for the technicians. So he purchased a Heathkit and put me to assembling the unit. Well, I was over then moon being given such a challenge and responsibility. I completed the assemble and when the time came, it didn't work. One of the technicians took to troubleshooting the unit and found that I had failed to put a ground insulator between one of the can capacitors and the frame. Easy fix and I was relieved.
Great story James, thanks for sharing that!
Hello a general question related to use and restoration of older test gear in your projects have you worked on Fluke 8600A DMM's? I have one I am interested in getting back into working condition. TX Theo
This is so restful! I know just enough about the mechanical side of tube equipment restoration to feel like your apprentice. Watching your videos is like meditation to me. I wish I understood the electronics side of it better.
Your videos are not only stimulating for the brain, but they're a treat on the eyes too. That thing is ridiculously gorgeous. It really reminds me of the old equalisers they have in the Abbey Road studios.
Thanks Amberoot!
Amberoot Audio You took the words right off my keyboard. Love this channel.
Absolutely agree Amber Root. That thing is handsome indeed, and I can't believe something I will never use or need is so fascinating.
@@indigogolf3051 I had the earlier model - used to put sound through it as a crude ring modulator thing - it was fun!
Wonderful work upgrading this fine old switcher. I liked your very clear demonstration and explanation of how it works. Reminds me of what we did in EE lab work during my college fun years.
I'd have to say this instructional on older tube technology is probably the best I've found on TH-cam.
Thanks for providing your knowledge and time to educate the rest of us.
It's appreciated very much.
Now all you need is a type 132 Sylvania oscilloscope to go with it. I think that is the model that was being made in the early 40's.
It should make a great addition to your bench. It turned out really nice. Thanks for sharing.
Hi Mike. Would you be surprised if I told you...... I have a 132... LOL :^) And.... It's little brother, the 131 as well :^) They will both be future restoration video's. Thanks for stopping by Mike, always good to hear from you.
Mr Carlson's Lab
LOL, your as bad as me. If it's old and electronic we probably have at least one in our collections. Now you have even more reason to restore one of them.
I have been searching for years for one of the rare Sylvania VTVM's. They are supposed to be a beast.
Is there an oscilloscope you DON'T have hahaha
Great vid! My dad was an electronics tech for 60 years, graduating from Oaklands' Central Trade School, in 1937. Seeing these old units brings back countless memories. :-) It's great, knowing that there are young people keeping the old trade alive.
Thank you for showing this. I have a project that i wanted to get started on and you gave me the motivation to work on it. One thing i need to get is a tube tester. for the past 2 years I have been obtaining tube radios from clean outs, most are in bad condition. I save the parts from them to one day build something crazy. I was thinking of a 7.1 surround system. something that i can be proud of. I had a teacher long ago that took his time to show me how tubes worked. Build my first radio for high school. Thank you again for taking your time to show us the projects you work on!
Glad you enjoyed Taraku!
Thank you Mr Carlson! I am a motor head/electronic hobbyist from way back who has always had a fascination for old tubed devices. I understand enough about them to stay alive while servicing them but have had a few things puzzle me about their operation, one being “bias”. Your comparison of bias being like a stall converter on a starting line is one I understand well. Now I understand some of the mechanics behind bias as well! My shop is almost finished and I hope to put all the old collected equipment back to work here soon.
Thank you for the awesome video's.
Hey, that's great to read that the "stall converter" description resonated with you! I may be a bit of a motor head myself :^)
I used to use one of those switches ages ago. I'm in my 70's now.
Easy to see Mr Carlson's passion for electronics in every video he makes. Always amazing to see work and skill of his caliber.
Always amazed at the knowledge on tap, in your brain. I have experimented a little with small projects in the past. But, I could never retain your level of knowledge. Fascinating to watch. You have convinced me to get another soldering station and get back into it. I'm retired now, so I have the time. Just not a lot of money or brain capacity to do much. But, I really enjoyed it, back in the day.
Hi Michael. The only thing that's limiting you..... is you. You can achieve what ever you set you mind too.... No matter what others say.
This is awesome. As soon as the cover came off, the quality was evident. I sold my dad's O-11 scope before I saw your restoration video, and I hope the buyer enjoyed restoring it - his intention. He may have seen your video. Very enjoyable watching your restoration and explanation. Excellent work!
This is really long and very well done...... long is good..... Im going to add it to my watch it later since it is so late for me..... Im saying this to help you with your Analytic's so when you see someone clicking off the video early that its not a bad thing....... This video is awesome and I will be back to finish it. Thanks
Hell,Paul! My name is Jim Ashton and I was born in Birmingham in England in 1943, so you can understand that this video took me back in time to my early days in valve (tube) electronics.I was most impressed by your very clear explanation of an instrument which I had never encountered. At no point did I become bored and I picked up a lot of useful tips. I shall be following your videos avidly from now on. As a matter of interest (or not!) I am now a qualified Egyptologist and travel each winter to that country. There is no danger and I encourage all my friends to go there and see the miracles that these people wrought!
Jim.
Thanks for taking the time to write Jim!
Aside from the education, I really love your passion for the history that the devices "tells" when you open it up. You show your anticipation and excitement of the preservation of history. That aspect is just as important as your videos.
I would like to be you next-door neighbor! I have a great deal of test equipment (everything from decade boxes to microwave spectrum analyzers -- maybe more than you!) which I have collected -- and repaired/calibrated -- over, well, more decades than I want to recount; and I, too, really enjoy bringing old devices back to life. My current "stereo" has surround capabilities combined with Grommes 260A amplifiers for the main (front) left and right channels, most of the equipment for which I bought in less-than-perfect condition.
Anyway, I really enjoy your videos (You da MAN!), and I hope they continue to be available for many years to come.
Thanks, Paul.
hi ed enjoyed reading your comment do you have any interest in time travel machines
Wow! What a cool device! Simple yet sophisticated. I think you are spot on for the estimated date of the device - Loctal sockets (trademarked as Loktal, and developed by Sylvania) were released to OEM about 1938. With all of the interesting gear you have restored for your circa 1950's test lab, I can't wait to see the setup and see your projects in the "old lab". Great work, Paul. And, thank you for keeping the lovers of the vacuum state (a.k.a "us old geezers who think that it only works when it glows orange") well informed and entertained.
Your theory and practice of reverse engineering - or "forensic engineering" - was great. Would love to see more of it in vacuum state and solid state as well. Your process is very close to the techniques I teach in harmonic and melodic analysis in music theory.
Fantastic job as always. It's admirable to see you not only reverse engineering the device, but find and fix a problem that problably the very manufacturers themselves couldn't find and repair. I hope in the future i can afford joining your electronics course on patreon. Thank you for all your perfectly produced videos.
Big thumbs up for Mr Carl son's lab. I must get my patreon account sorted out. I just love the calm and logical but warm and engaging delivery. Thanks again.
You find the neatest stuff! I especially liked the sleuth like detective work into the suspected low hours of use. Thanks for taking the time to draw up and explain the schematic.. I always learn something from your video's.. A++
I always enjoy yr videos, grateful someone such as yourself still takes the time. Soon all of the analogue electronics knowledge will become mystery and rare if not already.
Paul....you never cease to amaze, your knowledge is 2nd to none...cool find for sure....kudos and 2 big thumbs up
As a retired EE, born in 1941, I can attest to the knowledge of Mr. Carlson. Other than a very minor pronunciation error (silent "l" in "solder,") this is a perfect video. Excellent in every respect.
Thanks Bruce! I pronounce solder like this, click the link, then click "UK" dictionary.cambridge.org/pronunciation/english/solder
I apologize, Paul, for the misunderstanding... I have since seen the outrageous lengths which you take to remain completely purist in every respect in all of your videos. In fact, I have to watch out that I don't start talking like a Brit and make people think I'm a transplant to the US! LOL You have set an extremely high bar for the rest of the electronics community. Bravo! de KQ2E
Hi Paul, I want to thank you for sharing your knowledge and your love for these vintage devices.
You're Welcome Bobby! I'm glad you're enjoying the video's.
I'm glad to hear you tell people to beware going off willy nilly and plugging old crap in before looking inwide.
I’m drawing my own schematic of a Kenwood TS-120S just for the heck of it, and I’m really enjoying it. Mr. Carlson also has a few schematic drawing tips and tricks in his Patreon pages that are really helping me with the technique-gotta say thanks for that!
Glad to be there for you!
My head is going to pop. You have an incredible amount of knowledge and understanding for this gear. Thank you for the great videos and narration. Absolutely enjoy all your shows Dr. Carlson.
you polished up that front panel so well, it has a mirror finish. I also spend a lot of time polishing old stuff up. takes a lot of time but i enjoy it.
What an amazing device, I love the fact that you are reviving this old equipment!!! Keep up the good work.
Another wonderful piece of equipment restored. Thank you for another interesting presentation Paul. But for those of you interested in restoring old vacuum equipment there are five things to know. First, you need a circuit diagram. Never go fiddling in an equipment unless you have one, because you do not know what the heck you are connecting to. This can lead to causing more issues in the equipment by destroying valves and components, not to mention your test gear. Second, don't plug it in direct to the power source and destroy it. You need an isolation transformer, a variac, and current limit just like Paul's, so that you can see whether it is going to behave or not. Remember, you do not know where the equipment has been, or what condition it is in. It could be faulty, and old components invariably fail. Third, you need to understand how the circuit works. If you do not then it is like coming off the street, climbing into an F15 fighter jet and expecting to fly it! Well it is the same here too. If you do not understand how the circuit works, seek advice. Fourth, large capacitors charge up. Yes it is turned off and unplugged, but if you have had voltage on it they can charge up and still give you a very nasty surprise. Fifth, and VERY IMPORTANT you have to understand that this is not solid state devices like bipolar transistors and FET's that you fiddle around with with your bare hands, and that there are REAL voltages in there that can KILL YOU. My mentor always told me, ground on chassis, one hand in your pocket, and the other on the probe. It was valuable advice when working on valve gear. If you get connected to those voltages, and many have, you will definitely know! High voltage is pretty unforgiving of incompetence, and can put you in the hospital or the ground for good, so always take great care when in live valve equipment. Watch Paul's videos. You can learn a lot. He has mastered valve gear and electronics, knows the hazards, and understands the circuits in detail. You can have no better teacher. My mentor? Derek Colins, in television repair for over 20 years, and when I met him a bench radio transceiver repair technician. The best. Paul even uses some of the terms Derek did.......badly repaired electronics.......butchered boards! LOL
I wish my teachers were this good! Mr Carlson has taught me so much. i hope to buy him a beer someday.
Keep it up! Looking forward for more videos from you, don't stop!
Thank you Mr Carlson for another wonderful reverse engineering video. I am really learning a lot from watching you work.
the comments are the best , mr carlson i am ready to bust open a old tv or radio. thanks for sharing
Your knowledge of electronics is astonishing, I am sure it comes with many years of experience. Great video as always, keep up the good work.
Mr. Carlson does it again! Great job Sir.
Thanks Sam!
Ohh yeah, a new video from Mr Calson.
Sheffield Lane I think he's already there!
Cathode ray porn star?
Thank you Mr Carlson.....that is what I want to learn....you are so blessed man....
brilliant video with exceptional detailed explanations as always. Thank you Mr Carlson!
As others have said, a brilliant & detailed video, would it be worth mentioning that the replacement potentiometers musst have a linear track? So many are logarithmic for audio use these days. However nothing can beat silck smooth "sizzle" of a 1940s wire wound pot!
Excellent information, great detail. Many of us old timers learned about circuit design (and mechanical design) by disassembling military surplus items. Helps to develop a way of thinking that is invaluable today.
Glad you're enjoying Dall!
i love how detailed you are in your explanations !!
Fascinating and great to see the old equipment brought back to life and to see how well it works when in good condition.
Thanks for sharing!
Bravo with that restoration. Your videos take me back to my young working years. Thank You.
I used to go to sea as a Merchant Navy Radio Electronics officer, but it's been a while since I did any hardware work (got into computers when I came ashore.) Very pleasant and informative video to watch. I first went to sea with valve (tube) equipment which moved to solid state in the course of my sea-time.
Definite thumbs up. :-)
Thanks Bob!
That's why we don't "sea: tubes any more!
Another excellent video made entertaining and educational as always. I really enjoy when you have great vintage gear on your bench. Thank you.
Mel
Wonderful switch...I really love seeing this older equipment getting brought back to life!
It is funny that the problem was an un-soldered capacitor that kept getting missed.
That is one of those "DOH!" moments Homer Simpson keeps talking about :)
Another excellent presentation, Mr Carlson. I am reading a 1956 book about oscilloscopes and there is a similar schematic of an electronic switch, but it only uses four pentodes, excluding the rectifier.
And I must say, those big vintage Mallory capacitors are very pretty. If only the Czechoslovakian Tesla components I come across here in the Czech Republic were as colorful and with such nice writing as their American counterparts have. They would make for an interesting wall decor for the lab, framed in a flat glass box. Thank you for making this video.
i enjoyed every second of this vid. the fqct you took over an hour of your time to go into detail shows that you have a passion keep it up my friend
I've been loving your videos Mr Carlson, they're all very informative, educational and very interesting. This was a great device, excellent restoration and great to see this old equipment come to life.
Glad you like them!
@@MrCarlsonsLab very much so, to the point where is renewed my interest in vintage tech. I recently received a General Radio Company impedance bridge. Note I just need to understand how it works and restore. Your videos are awesome, I'll be a patreon as soon as lockdown is over in my neighborhood.
This is great. Had no idea what it is was for, until last part of video.
But glad I stayed till end, as I just built an oscilloscope from a very old book
written in 1979 by a chap named F.G Rayer. (one of the many brilliant Babani project books) Really simple circuit and
covers 20hz to 20khz nicely. But of course its a single channel scope. So
now you have shown me how I can turn it into a two channel scope.
Brilliant!!!
really love your vids , they take me back to when I was 12 years old and started playing with old electrical equipment , old radios mainly , back then stuff like you show in your vids sold for pennies in disposal stores , oh how I wish I had some of that old stuff now
I have used that type of device in the past with older single trace scopes. Very interesting that you found one still around. Thanks for the share.
Thanks Gary, glad you enjoyed!
Your instruction is very thorough and easy to follow...the best!!!
Paul... Awesome job! This was just a really enjoyable video. And what a cool find... Now looking and working like new at almost 80 years old. Wow. Thanks for all the effort!
Thanks Phil!
Wow, what a great in detail explanation! I really like the reverse engineering part and I'm looking forward to see more like this in the future. Never thought, that reading schematics can be fun. You doing a great job, many thanks Paul!
Thanks Reb!
My first job in 1982 was working with an older gentleman in a two way radio repair shop. He had a lot of equipment like this. Sorry to say it all went to the dump. Glad to see you save some of that kind of stuff.
my first oscilloscope was a sencore PS148 from the early 60's.
I'm in the middle of restoring a vintage general radio audio frequency generator. love your vids!
Thanks Scott!
This was very inspiring. Admiring your deep understanding of this technology and the way you bring it out to us. Thanx for bringing the zeitgeist of this era back to life.
Very nice Paul. Not only the electronics details but the cleaning / restoration process shows your attention to detail. Thanks Jim
Thanks Jim!
When you switched on the switch box after it was connected to the oscilloscope and we could see the path of how the two lines are made @ 1:07:03, that was really neat. Thanks for sharing this all. I wonder how hard it would be to make an equivalent of this for that cheap single channel scope I have.
oh and then you really show how it works later!
Always a good audio description, knowledgeable and articulate.
interesting video , your a true electronics engineer. i used to work on valve amps may years ago but your in a totally different league :)
Really enjoyed this. I started smiling when the trace started on the scope and didn't stop until it was over, heck I'm still smiling. That was so much fun and so interesting! Thank you!
Thanks Buddy, glad you enjoyed!
Mr Carlson Great troubleshooting as always. Always good to learn something new Thank You
What a reminder of my old years as a Radio & TV engineer !!! I loved those Continental Transmitters with a built quality as that Sylvania switch. Keep posting videos !! :)
Thanks Pedro!
Thanks to you for the memories !!
"Chicken Head Knobs"! So that's what they've called. Thanks.
OUTSTANDING video Sir!!!! Even with my limited self taught knowledge I was able to follow along and understand most of what you explained due (I am sure) mostly to your Great Teaching and explanation of what was going on as well as what you are doing. Really good video Two Thumbs Up!!!!! btw - I have two Heathkit pieces of test equipment that belonged to my Uncle back when he was a young boy and wanted to learn electronics. One is a VOM and the other one is a Frequency or Signal Generator I think he told me he had to build these items as part of his class, he since has past away but I think these items are from the late 40s early 50s ? Idk for sure but I am sure glad I kept them AND found your channel because now I feel like I might be able to "Check" these items out and put them to use Thanks to you Mr Carlson!! You made my day Sir !!!
You're very welcome Rosario!
You really had passion with electronics. Your really make simple what is really complex. Congratulations.
Omg this channel is so useful but i could never watch it until i found 1.25 play speed. Now i can remember the beginning of the sentence by the time he reached the end of the sentence. Before i was falling off the concentration. Now it awesome.
Wonderful, I have been watching one of you videos every day this last week, can’t leave the alone , thank you
Great Video! A lot of good advice on how to approach a restore. A valuable take away for me was drawing the schematic, reverse engineering, since nothing was available.
I am restoring a Hickok 209B VTVM, unlike other models in the series , no documentation appears to be available. I am going to stop searching and start drawing, a bit of work, but part of the restoration journey. Thank You!
Great Bill! Thats a nice VTVM you have!
Very Well Explained.
Easy to follow!!!
Enjoyed this very much!!!
Looking forward for more!!!
Thank You!!!!!
Thanks Michael, glad you enjoyed!
Am hugely enjoying your videos, delightfully detailed, informative and entertaining too!
Thanks Robert!
Thank you Paul: your explanation about the mechanics of this switch device made perfect sense.
Phil.
I have not looked at your channel for a while and I am now wondering what I have missed. There is no doubt that whoever designed this unit took pride in what they did. It may look old fashioned but I think it looks bloody gorgeous. After 50 odd years I have gone back to electronics as a hobby so to me in a way it's not so old fashioned. I can remember 410 V across the end of my nose ( Mullard Amp). A small scar is still there after 50 years. Thank you so much for this video - it's perfect.
Thanks jp! I'm glad you stopped by.
I've been consuming your videos for the past while now and I went from 0 to absolutely stoked on vacuum tube electronics. Thank you, it's a great feeling. I've still only ever laid my hands on transistor equipment thus far, though.
I'm looking to pick up an early 60's 4 watt EAF42-EL41 kit amplifier (with AZ41) as my first foray into vacuum tubes. I intend to give some fresh capacitors, if I do indeed get a word back from the current owner that he hasn't recently attempted to power it up. Judging by its casing alone, the caps are not going to be all of its issues. Bodgewires and questionably fitted afterthought connectors adorn most of the device's backside, and, I'm honestly still accommodating to the idea of electronics that aren't anchored to a PCB in the first place.
Beyond being careful not zapping myself, and being gentle with the device and not zapping it , do you have any advice on the tubes it comes with, or European kit amplifiers in general? Are there more quirks to them than meets the eye? Should I just go for it, and, do you've any other words of wisdom for the very transistory man I am?
If your a transistor guy, just be careful around the high Voltage, it's all over vacuum equipment. Glad to read you're interested in the tube stuff now, I admit, it's much nicer to work on than the new stuff.
Paul, its good to see another video on YT again, That electronic switch unit is a beautiful instrument !!!! I have heard of these being used with oscilloscopes but NEVER seen it actually done !! Thanks for the video restoration and demo, a real treat as always !!!!!! John A Bellas KC2UVN
That was great!! Again, another high quality explained video by the master himself, Paul. I always enjoy your videos and always learn something, if not allot. Thank you for the effort you have put into these videos. I really wish I could afford to contribute to your efforts, as I do feel that what and how you go about it, is priceless. But, spare money right now, is just not in the cards, hopefully in a few moths, things will lighten up on me, as I have bit off more than I can chew, from 2 months ago.Until that time, I still believe, it would be an honor to donate to Mr. Carlson's Lab, due fact, that I appreciate what you do, and how well you explain everything. I love the feeling that I get half way into watching one of your videos, of being inspired to monkey around in my own shop, but, can't stop watching your video, as I do not to miss anything, in turn, have to fight myself to wait until the video is over, before monkeying around in the shop, LOL.. Thank you, for the ability to keep giving me the swift kick in the butt, to get motivated. Drew
That was super cool. Finding out why the unit was in such good shape was like solving a murder mystery from years past. Thanks for sharing another great piece of history with us. I need to sit down one day and put my unbuilt Eico switch together.
Hi Buddy! Thanks for stopping by. Building that kit (with new caps of course :^) would make a great video.
Lots of good tips in this video. Thanks Paul.
Mr. Carlson you forgot to measure the output voltage on the square wave on the output. Once again a great video that simplifies the explanation of circuit design theory.
Oh my! A Mr Carlson video I haven't seen yet. Sooo00 I must watch :-)
Fascinating! I have some crusty gear from 1970, but had no idea it went back another 30 years.
That was great. What made it a joy to follow was everything is so clean and pristine. Are you sure you didn't go back in time and get this in a specialty shop? It's like brand new. Down to the leaves on the bakelite tube bases, and no tarnish on the goat shields. Please do more like this, what a great rebuild.
Mr. C I have really enjoyed your videos. If I would have had teachers like you I know I would have been a better student. So thank you for your efforts. I look forward to every video and am learning a lot on your patreon site as well.
Thanks for your kind words, and feedback Steve!
Fascinating ,such attention to detail in the old equipment. Very documented , you really know your stuff ! Cheers
Awesome restoration! What Sylvania named at that time as an Electronic Switch, is actually a chopper circuit which, once integrated into future o-scopes got shortened to "CHOP" mode and eventually "ALTERNATE" or ALT mode. Even my late-80's dual-trace Tek scope has ALT mode on it :)
Very enjoyable video of a great old piece of gear. I was amazed how well that switch worked. I'd love to know how much usable bandwidth that switch has. It goes to show there were some very capable engineers back in the thirties when electronics was in it's infancy.
Your attention to minute detail, like the up/down potentiometer facing, is so far above most electricians that it is like listening to Tesla himself compared to the Cable Guy. Wow.
THOROUGHLY enjoyed this. Thank you for posting it, and PLEASE do more!!
Thanks!
Excellent video. I am from the UK, sadly no one in the UK produces Video's like you, Keith Rucker, etc. do from over the pond! I was an apprentice 1953/1959 at the D.S.I.R. Radio Research Station working for Dr Smith Rose, Wilkins, etc. making the all the type of equipment you are interested in! Your video,s are jogging my memories ,
Excellent presentation.. I had one of these Oscilloscope switchers about 45 years ago..
Marvellous stuff... I grew up in the days of valves (sorry, tubes 😎 ) when things were simple, or seemed so to me. That certainly brought back memories
VERY cool. Well done! Loved it when the two traces came alive on the O-11 scope!
Very interesting. I have an EICO Model 488 Electronic Switch. It's shape is like yours, but shorter and wider, but the front panel components are laid out just about the same. This video makes me want to check it out and get it working. Will hooke it up to my old Devry tube Oscope. First I need to get my Eico 960B Cap tester going first. Thanks!
My interests in electronics started out in the late 50's when I was about 9 years old so tube stuff is very familiar to me.
What a beautiful little box; thanks for sharing and for your usual presentation/explanation. Cheers!
Thanks Alec!
My father (age 67) watch this before me and after i mentioned loctal valve he then told me about the similar equipment he used to use.
Because he has explained to me how these older valves work in detail i had figured out about half of it works but couldn't quite figure how it mixes the channels together so i just had a 10min explanation of the oscillator component.
That was a great restore and is an awesome device! Thank you for sharing!