To go to the Mr Carlson's Lab Patreon Page, click here: www.patreon.com/MrCarlsonsLab

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.

I used to use one of those switches ages ago. I'm in my 70's now.

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.

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.

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.

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.

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.

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.

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.

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.

I'd have to say this instructional on older tube technology is probably the best I've found on KZfaq. Thanks for providing your knowledge and time to educate the rest of us. It's appreciated very much.

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.

Always nice to see an old piece of kit responding well to copious amounts of T.L.C., very rewarding.

Fascinating! I have some crusty gear from 1970, but had no idea it went back another 30 years.

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.

Keep it up! Looking forward for more videos from you, don't stop!

the comments are the best , mr carlson i am ready to bust open a old tv or radio. thanks for sharing

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

Easy to see Mr Carlson's passion for electronics in every video he makes. Always amazing to see work and skill of his caliber.

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.

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 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 love how detailed you are in your explanations !!

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

Wonderful, I have been watching one of you videos every day this last week, can’t leave the alone , thank you

Another excellent video made entertaining and educational as always. I really enjoy when you have great vintage gear on your bench. Thank you. Mel

Paul....you never cease to amaze, your knowledge is 2nd to none...cool find for sure....kudos and 2 big thumbs up

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 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.

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!

Bravo with that restoration. Your videos take me back to my young working years. Thank You.

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!

Your instruction is very thorough and easy to follow...the best!!!

Mr Carlson Great troubleshooting as always. Always good to learn something new Thank You

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.

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++

brilliant video with exceptional detailed explanations as always. Thank you Mr Carlson!

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.

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.

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.

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

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!

I wish my teachers were this good! Mr Carlson has taught me so much. i hope to buy him a beer someday.

Hi Paul, I want to thank you for sharing your knowledge and your love for these vintage devices.

Always a good audio description, knowledgeable and articulate.

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!

I'm glad to hear you tell people to beware going off willy nilly and plugging old crap in before looking inwide.

Lots of good tips in this video. Thanks Paul.

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.

That was a great restore and is an awesome device! Thank you for sharing!

THOROUGHLY enjoyed this. Thank you for posting it, and PLEASE do more!!

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!

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 :)

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.

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.

Enjoyed the new video! thanks for putting it up. That is a cool device.

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.

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 !! :)

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.

Thank you Paul: your explanation about the mechanics of this switch device made perfect sense. Phil.

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.

Learned more about oscilloscopes in a video that isn't even about oscilloscopes than I did in a class about them.

Thank you Mr Carlson for another wonderful reverse engineering video. I am really learning a lot from watching you work.

Mr. Carlson does it again! Great job Sir.

What a beautiful little box; thanks for sharing and for your usual presentation/explanation. Cheers!

Totally awesome results with this -- as usual. Great work!

Fascinating ,such attention to detail in the old equipment. Very documented , you really know your stuff ! Cheers

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!

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!

How cool is that....great video Paul!

Fascinating video. Great job on the restoration!

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.

nice lab 100% and thanks for the videos Mr Carlson's

Ohh yeah, a new video from Mr Calson.

NICE JOB AS ALWAYS !

Am hugely enjoying your videos, delightfully detailed, informative and entertaining too!

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

Awesome vid!!! Mr. Carlson ROCKS!!!!

Thank you Mr Carlson.....that is what I want to learn....you are so blessed man....

Yet another great video. I enjoyed this one. Thanks.

Very nice piece of equipment, outstanding video!

That's a neat device indeed. Now I'm thinking about making a solid-state version for my scope :)

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.

VERY cool. Well done! Loved it when the two traces came alive on the O-11 scope!

If all of the "teacher" explained like Mr. Carlson, there will be a lot more brilliant students.

Quite an interesting video! Thanks a million for sharing and demonstrating these specimens and the fundamentals of their very being!!

Another great video, as always!

I love these videos! Keep 'em coming, and never lose your accent.

Fantastic video......Enjoyed it very much as I do all of your videos.

Made back in the day when construction was a work of art, when people really cared about what they built.

You really had passion with electronics. Your really make simple what is really complex. Congratulations.

Oh my! A Mr Carlson video I haven't seen yet. Sooo00 I must watch :-)

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!

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 presentation.. I had one of these Oscilloscope switchers about 45 years ago..

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 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. :-)