Neat Electronic Device from 1939 Explained with Restoration

Follow along as Paul explains how an Electronic Switch works, from 1939! Detailed explanation with hand drawn schematic (reverse engineered) Let's restore it, and try it out! To join the ongoing Electronic Course, or just support this channel, Click this link: / mrcarlsonslab "See you there!"
Sylvania Electronic Switch Type 104

[@MrCarlsonsLab]

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

[@kuhrd]

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.

[@MrCarlsonsLab]

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!

[@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.

[@chadcastagana9181]

Mr Carlson's Lab Your mouth movements look animatronic

[@nathandean1687]

should show them king of random vids then. also show the troubler makers. the repair bills as well.

[@bjl1000]

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

[@mikesradiorepair]

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.

[@MrCarlsonsLab]

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.

[@mikesradiorepair]

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.

[@rot_studios]

Is there an oscilloscope you DON'T have hahaha

[@amber1862]

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.

[@MrCarlsonsLab]

Thanks Amberoot!

[@Omnihil777]

Amberoot Audio You took the words right off my keyboard. Love this channel.

[@indigogolf3051]

Absolutely agree Amber Root. That thing is handsome indeed, and I can't believe something I will never use or need is so fascinating.

[@petegaslondon]

@@indigogolf3051 I had the earlier model - used to put sound through it as a crude ring modulator thing - it was fun!

[@jamesconner8275]

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.

[@MrCarlsonsLab]

Great story James, thanks for sharing that!

[@TheTheo58]

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

[@zetacon4]

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.

[@charleslayton9463]

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.

[@bobbyvarnell9350]

What an amazing device, I love the fact that you are reviving this old equipment!!! Keep up the good work.

[@sa8die]

i love how detailed you are in your explanations !!

[@michaelbishop3701]

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.

[@MrCarlsonsLab]

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.

[@silverknight5880]

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

[@Richdudevids]

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

[@yereverluvinuncleber]

Always a good audio description, knowledgeable and articulate.

[@Tracks777]

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

[@Vintage_USA_Tech]

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

[@mellagarde7142]

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

[@josephmagedanz4070]

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!

[@H2R5GSXR]

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

[@BerlietGBC]

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

[@richcampoverde]

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

[@paulandrews171]

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.

[@gregorybraun6458]

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

[@mikedrz]

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.

[@notarookee778]

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

[@Cyruscosmo]

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.

[@MrCarlsonsLab]

Hey, that's great to read that the "stall converter" description resonated with you! I may be a bit of a motor head myself :^)

[@bobbyvarnell9350]

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

[@MrCarlsonsLab]

You're Welcome Bobby! I'm glad you're enjoying the video's.

[@talps128]

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

[@ae1tpa92gwtom2]

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.

[@fatwood8642]

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.

[@PurityVendetta]

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.

[@chrismosley409]

Lots of good tips in this video. Thanks Paul.

[@damianvieira]

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.

[@jeffminnick5209]

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

[@smenkharebsa]

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.

[@MrCarlsonsLab]

Thanks for taking the time to write Jim!

[@rubusroo68]

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

[@johnhowell4908]

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!

[@TheOneTrueKaliban]

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.

[@steelcity321pb6]

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

[@MegaBakerdude]

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!

[@waynecarlson3736]

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

[@samiam5557]

Mr. Carlson does it again! Great job Sir.

[@MrCarlsonsLab]

Thanks Sam!

[@bucyruserie1211]

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++

[@FarzadNL]

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.

[@DrTeddyMMM]

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

[@djhaloeight]

Fascinating video. Great job on the restoration!

[@paulkocyla1343]

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.

[@TarakuT]

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!

[@MrCarlsonsLab]

Glad you enjoyed Taraku!

[@dogmakarma]

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

[@MrCarlsonsLab]

Thanks!

[@uploadJ]

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

[@leppie]

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

[@JeffreyGroves]

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

[@fpvrcstuff]

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

[@Quark.Lepton]

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!

[@MrCarlsonsLab]

Glad to be there for you!

[@EdWatts]

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.

[@stephenroberts655]

hi ed enjoyed reading your comment do you have any interest in time travel machines

[@siyifu50]

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

[@laohantun7404]

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

[@billpotter9716]

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.

[@jackneff179]

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

[@TheRadioShop]

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.

[@MrCarlsonsLab]

Hi Buddy! Thanks for stopping by. Building that kit (with new caps of course :^) would make a great video.

[@alecjahn]

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

[@MrCarlsonsLab]

Thanks Alec!

[@marioxuereb5125]

NICE JOB AS ALWAYS !

[@aussieaeromodeler]

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

[@ajaxlepinski3285]

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

[@garywilkinson8197]

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.

[@MrCarlsonsLab]

Thanks Gary, glad you enjoyed!

[@otoniel780]

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

[@Echapm40]

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

[@AJMjazz]

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.

[@dallbrown2849]

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.

[@MrCarlsonsLab]

Glad you're enjoying Dall!

[@Pwaak]

Very nice piece of equipment, outstanding video!

[@robertconklin3322]

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

[@MrCarlsonsLab]

Thanks Robert!

[@Tomcat721]

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

[@mcdradus]

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

[@iskandertime747]

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

[@dryzoneau]

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]

Glad you like them!

[@dryzoneau]

@@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.

[@Tangobaldy]

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.

[@gregorythomas333]

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 :)

[@larrygall5831]

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

[@tpcdude]

Fantastic work, both electronic and video production. i learned something new about dust in pots, makes sense to mount them hole down.

[@I967]

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.

[@njphilwt]

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!

[@MrCarlsonsLab]

Thanks Phil!

[@stevedoubleu99B]

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

[@MrCarlsonsLab]

I agree Steve, this one behaved.

[@medhawk4885]

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

[@rebelba42]

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!

[@MrCarlsonsLab]

Thanks Reb!

[@jasontaranto6359]

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

[@sheep1ewe]

Another great video, as always!

[@budandbean1]

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!

[@MrCarlsonsLab]

Thanks Buddy, glad you enjoyed!

[@brunofonseca9686]

Ohh yeah, a new video from Mr Calson.

[@waltschannel7465]

Sheffield Lane I think he's already there!

[@JimTheZombieHunter]

Cathode ray porn star?

[@scottjohnson7774]

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!

[@MrCarlsonsLab]

Thanks Scott!

[@air54plane]

You make it look so easy!!! nice!

[@0drdefcon0]

i love listening to you explane tubes .... thankyou i actually get it

[@nelsonmedley4349]

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

[@jamespaterson7597]

very interesting mr carlson thank you

[@MrMoggyman]

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

[@michaelmurray3422]

Very Well Explained. Easy to follow!!! Enjoyed this very much!!! Looking forward for more!!! Thank You!!!!!

[@MrCarlsonsLab]

Thanks Michael, glad you enjoyed!

[@BruceNitroxpro]

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.

[@MrCarlsonsLab]

Thanks Bruce! I pronounce solder like this, click the link, then click "UK" dictionary.cambridge.org/pronunciation/english/solder

[@BruceNitroxpro]

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

[@winstonsmith478]

Very cool! Loved it.

[@kevinobrien8803]

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!!!

[@mrpedrodrodriguezsr7628]

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 !! :)

[@MrCarlsonsLab]

Thanks Pedro!

[@mrpedrodrodriguezsr7628]

Thanks to you for the memories !!

[@hofnerbass]

Great job as usual.

[@MrAllen-nc1rn]

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.

[@Spoif]

Thank you Mr Carlson... That was very interesting.

[@MrCarlsonsLab]

You're Welcome!