Tektronix 314 storage oscilloscope repair

Fixing a vintage analog CRT storage oscilloscope - Tektronix 314 made in 1976. In the process, I'm exploring what's inside, how does it work and I'm trying to understand its schematic. A teardown and repair - problem in the blanking amplifier.
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[@DrHouse-zs9eb]

Incredible complex oscilloscope fixed by an incredible talented man! Great content!

[@brucepickess8097]

Agree, couldn't say more.

[@eurlmokrani2033]

@@brucepickess8097 Same here

[@WagTsX]

wow, what a video, what a repair! Such a high quality equipment getting it's deserved attention. Thanks for doing it for us. I was wondering why didn't you replace the visibly faulty capacitor even before checking for the transistors, but later you explained it.

[@gabracal]

This guy once again silently shows us one of his quotes a few years back. "If you know where to look for the problem, you can definitely fix it." - DanyK

[@r2daw158]

109D (the leaky one) - wet tantalum 150D (19:48) - solid tantalum Both made by Vishay and still produced today (and have very impressive price). P.S Nice troubleshooting and repair.

[@Alchemetica]

Wow. A very interesting video and diagnosis. It was great to see a piece of equipment from the 1970s, particularly, as I have never seen anything with sockets for the transistors.

[@rkan2]

CuriousMarc is 60s and 70s tech galore (some 40s and 50s tech too)

[@DoctorCalabria]

I learned so many things from such a short video. Very succinct and informative. Thanks again. Please do more Tektronix videos 😊

[@vaclavtrpisovsky]

Sadly, Tektronix scopes are very pricey, even broken ones I think... Perhaps somebody could donate it.

[@dogwalker666]

I am in the middle of restoring one of these, I love old CRT displays.

[@Torogol85]

Good luck! I hope a successful repair

[@rkan2]

What's wrong with yours?

[@ElektronixHS]

Guys take a look at those internals. What kind of engineering it was back then!! Without nowadays CAD softwares and so on... I was repairing similar Tektronix oscilloscope from that era, it has two time bases, crazy functions. Top notch!! I was literally touched by that drum-engaging gold plated switches scale selector. Well built crazy stuff ment to last and to be repaired quite easily in case of failure. Transistors in sockets and so on.. This will never happen again.

[@doktor6495]

And even without software! ONLY hardware - yippi! ;-)ware - yippi! ;-)

[@-yeme-]

doing the board layout for something like this with literally a pencil and paper must have been crazy

[@paolomonai9511]

And it will last other 50 years ore more! Exactly the same as a Chinese equipment...😂😂😂😂

[@AmitabhAnkur]

I am thinking that who and how they designed the manual so perfectly without modern day softwares in 1975.

[@jbuchana]

@@-yeme- Back in the mid '80s I used to design circuit board. Software was available, but my company was too cheap to buy the computers needed, so I did it all with black tape on mylar. It's really easier than it looks, once you've gotten some experience. In the '90s I wrote software to add locally written functionality to CAD systems at GM, by then, of course, everything was CAD.

[@Georgy-fg3bg]

Excellent, excellent excellent! Simply excellent: analysis, diagnostics, explanation. Thanks for the great work!

[@piconano]

"How can we make this unit more expensive?" "I know, let's build it like a tank, and let's socket everything, including the transistors, and let's gold plate everything else"! I was in grade 10 high school when this was made. It's freaking gonna outlive me :(

[@Broken_Yugo]

This stuff was all industrial grade back then, and a storage scope was an extra expensive specialty piece. I forget the exact figures but IIRC the Tek 465 launched with a price of around $10k USD, inflation adjusted.

[@ronniepirtlejr2606]

It would be great to have you as a neighbor & a friend! Great job fixing this!👍

[@westelaudio943]

11:49 older US schematics often didn't use nano, for some reason. They usually only list uF (also written as "MFD" or no unit abbreviation is written at all, like here) and pF values.

[@flapjack9495]

This is what I was used to, having grown up in the US in the 80's - everything was either µF or pF, never nF, unless I ended up with one of those British electronics magazines like Everyday Practical Electronics. 0.001 - 0.1 µF was how I'd expect capacitances in the nF range to be written. I found nF very confusing when I first encountered it.

[@-yeme-]

some older US literature and schematics even used mmfd (micro-micro-farad) instead of picofarad

[@Broken_Yugo]

I've seen some old tube era schematics where every cap is in uF with no units specified, they'd write out a 22 pF cap as 0.000022.

[@airmann90]

Heck yeah. This should be great! And it is. Love the old tek equipment. Beautiful!

[@willrobbinson1]

me too part id,s metal work construction all with part numbers all hi end gear all best quality parts of time shame how things r now with lots of v cheap stuff with little life now poor quality ect how times have changed in this industry

[@FreeCircuitLab]

The every frame of this video helps me .❤️

[@LMB222]

Dude…respect. So few people understand analog electronics nowadays.

[@hullinstruments]

Holy shit would love to see you go through those chips and your transistor collection. All of those beautiful old chips would be amazing to see them dumped out. I have a collection similar... I love things like that and it takes years to amass a big collection But you never know when you'll need something I keep coming back to this video because of your awesome diagnostics and repair work... But every time I remember that I want to see your collection of transistors and chips also!

[@grins047]

I really enjoyed this video. Thanks for the technical explanation and explaining your thoughts on where to start and why. All around a good fix.

[@hermannschaefer4777]

Note to myself: Before seeing inside anything: Check capacitors, eletrolytic and tantalum ones. A slow ramping up signal cries for a dead cap

[@LMB222]

That makes a less interesting video ;)

[@geoffreykeane4072]

Great video! Also running it off DC means you can run it mains isolated 😃

[@crispy_otter]

Brilliant video - I've not seen a Sony Tektronix badged one before. Mr Carlsons Lab has restored some vintage Tek gear - it's so beautifully constructed and worth a view! Thanks lots for that one.

[@rhiantaylor3446]

When I transitioned from mainly valve stuff to transistors I tried to buy some transistor sockets but was warned off - a fault just waiting to happen I was advised. That would have been late @1960s. I see they used probably sil. grease to minimise poor contact risk on this premium product.

[@milantrcka121]

Gold flash on the sockets and the transistor leads makes perfect connections. However, when vibration is included, sockets are a problem.

[@brucepickess8097]

Congratulations on the repair. You diagnosed the fault by process of illimination, worked out the circuit functionality well, and honed in on the area of circuitry to fault find . I'm impressed.👍✅💯😏

[@pauldery7875]

WOW, what an incredibly smart man you are. I love your videos, so informative. Thanks so much for sharing.

[@wdavem]

This is great, I have to fix my Tektronix 466 which has this problem to a lesser degree. It's got other problems too though, good to know the cause of the problem you had. Thank you very much!

[@GadgetUK164]

Wonderful repair of a wonderful old scope!!!

[@blackarrow8683]

16:11 I translated the yellow card for you: Dear Customer, On the occasion of the repair or inspection of your Tektronix device, the primary power supply parts were checked for safety in accordance with VGB4. A test sticker has been attached to the device. The VGB4 demands a new check before the end of 6 months. Your Textronix Service Center

[@jakub3851]

Amazing device I would love to have one. The sockets are really cool If only new products were so serviceable

[@zx8401ztv]

Well done :-D That must have cost a fortune originally, what a well made oscilliscope. The sockets with a white seal was a smart idea, no dampness gets in to the connection. Ive seen sockets used on equipment but not that quality. Gold everywhere, no tarnish. Now did you diagnose the fault before the video was made ha ha :-D

[@tiborbogi7457]

To diagnose the fault before video, didn't make him less genius engineer.

[@zx8401ztv]

@@tiborbogi7457 Don't over react, i was pulling his leg, He has a good sense of humor you know :-D

[@willrobbinson1]

HI end gear at time very $$$ and long lasting

[@tedvanmatje]

Tek scopes are beautifully engineered. Good on you for saving this one, mate!

[@hosemarino]

One of the best videos on oscilloscopes I ever watched. Really amazing insight on electric circuit analysis.

[@maticz3923]

The insides look so beautiful

[@jbuchana]

Great job troubleshooting. That beautiful old equipment brings back a lot of memories. I was 14 years old and very interested in electronics when this was built. Ham radio and a lot of home-built projects. My father was an electronic technician with Tektronix from 1966 until 1997, and I learned a lot from him, and by studying old Tek equipment. Back in the '80s I used to buy old Tek 'scopes at swap meets, repair them and resell them. Such memories. Back then capacitors were specified in microfarads and picofarads, I don't remember nanofarads being a thing in the US until years later.

[@aleksandarvasilevski7410]

Big like for the laparascopy job. That cat simply reads my mind.

[@change_your_oil_regularly4287]

These older complex analog devices always blow my mind. Edit: well done on the repair 👍

[@SergeK]

Very good analysis, congrats! Always a pleasure to watch.

[@mcflapper7591]

Well done. Thank you. Another 40 years of service ahead!

[@SatyajitRoy2048]

Amazing repair. Thanks for all your hard work.

[@LawpickingLocksmith]

Heads up mate! Out of so many repair channels I must say your knowledge is superior and so is the presentation. Keep it up and a huge thanks from a retired repair technician.

[@michaelseitz8938]

Wow, this video was like porn! Proper detective work, good explanations, you showed off your assortment of transistors, you got the oscilloscope working again, and the cat was in it too 😁

[@cjay2]

Well-done repair and reasoning throughout.

[@Speeder84XL]

That was some impressive repair work! Really interesting to watch as well 👍

[@rilosvideos877]

Its always i big joy to watch your repair videos! Such a genius to analyse and understand such a complicated device from the 1970s with lots of tht-mounted components! I prefer these over modern SMD-parts which are hardly accessible. I have an old analog Hameg 60 Mhz 2 channel oscilloscope which i bought used and just made it work more smoothly mechanically. To find the defective transistors and adjust the right potentiometers is excellent job - hard to find such a genius today! Great respect!

[@hugoegon8148]

Thank you for this video. Great analysis and repair.

[@thomasbaumgart9209]

Superb Job, Daniel! I've got one of these scopes as well and worked on several such units (basically to make a good one out of a few "dogs"). One common problem is burnt-in CRTs. These vintage storage tubes are quite fragile and don't cope with high brightness too well, especially at no or very slow deflection. Yours looks almost pristine! Another peculiar detail in this instrument is that the PCB that accomodates the vertical attenuator cam switch assembly is made of a polyacrylic (plexiglass) substrate! I don't know why Tektronix chose this material here, the adhesion of the copper/gold traces is way less strong than on FR4 and soldering on this stuff is a nightmare due to its thermoplastic characteristic, maybe Tektronix even used a special low-temp alloy solder?? Could the choice have been made for better dielectric characteristics reasons? Otherwise, these "museum pieces" hold up surprisingly strong. But especially the "Tek-Sony" instruments of this compact (300) series are often a nightmare to work on, even upon disassembly it makes good sense to follow the service manual (which are fortunately available) since more often than not it isn't completely obvious in what sequence subassemblies are supposed to be removed for easy access to certain places. Internal de-bonding of the tiny bond wires of vintage metal can transistors happens once in a while. If the base bond came lose in your particular transistor, the observed behaviour gets obvious. To check for such a problem, you may try tapping the can (wit a small metal tool or the like) while the transistor is connected to a test circuit. Or just apply a high(er) voltage across the terminals with a current limiting resistor to see if the (tiny) gap may break down. Anyway, It was pure joy to watch your repair video and to see another one of these marvels being restored to working condition. Thanks so much for that!

[@pawelsawka6184]

Incredibly beautiful piece of engineering art.

[@qzorn4440]

it is a real pleasure watching the testing being done with hobby test equipment 😎 most anybody can fix stuff with expensive testers. i have used this type of Sony scope. nice!

[@paulpahl1607]

Great explantation - thank you for the video!

[@TheAllisonV12]

Great job! Well done!

[@kolinevans9127]

Awesome oscilloscope, great repair.

[@omniyambot9876]

I'm a student and bought a Tektronix 2430 oscilloscope for 20$. Believe me, I'm the happiest person on earth. But after I went back home, it doesn't work properly. The lines are chaotic. I've tried everything to understand it, read datasheets, research, asked people. But no, I couldn't fix it. The oscilloscope is such an astronomically complicated device. I thought I have a decent intellect. But now, I feel like an absolute idiot. I learnt many things tho. You are a very good engineer, I wish I will get better.

[@westelaudio943]

You definitely need a scope to fix another scope :)

[@omniyambot9876]

@@westelaudio943 absolutely!! I went to a repair shop they told me they could fix it. But charging me for 250$!!!!

[@cjay2]

Rewatch this video a couple of times and learn how he reasons out the repair. Then you will be able to think better about how to repair your 2430. Diagnose the problem on the schematic before dealing with the actual scope.

[@omniyambot9876]

@@cjay2 yeah I understand what he did. The interesting part is how he quickly finds the components in this complicated circuitry. That's my problem, I can't easily find the exact components. But I will try again later might just take a day. With his reasoning, I can now make theories on why my scope is malfunctioning. Thanks!!

[@eDoc2020]

That's a digital oscilloscope so there are many more places for something to go wrong. It could be the analog frontend, the ADCs, the digital system, or the CRT output. I would first see if the text overlays work properly and are stable. If that doesn't work then nothing will. If it was an analog oscilloscope I would say to make sure the range switches are cleaned.

[@faridsafazadeh1137]

you are just amazing. A grand master in Electronics!

[@Brian-yt8fu]

Beautiful diagrams easy to follow.

[@sortofsmarter]

This was great, I do a fair amount of high voltage work on marine systems and to have a oscilloscope that runs on low voltage is perfect. There are still models like this available in my are but I was always nervous about calibration and reparability. This helps a lot ....thanks

[@Betterstartnow]

Nice work, saved the scope. Love the cat!

[@greatmateworkshop9764]

Wow, well done! Keep making long and detailed video please!

[@rpbajb]

DGW is one helluva a good electrical engineer. Impressive work.

[@panzerkampfwagen161]

Wow beautifully explained. Thank you.

[@AlvaroGomes]

Excellent work

[@TheDefpom]

Nice repair.

[@pawelsawka6184]

And it is worth noting that the transistor that was used for the repair was manufactured by CEMI, in Poland. Me too.

[@florabee9283]

This is the only 314 I’ve ever seen besides mine that I use every day!

[@timohaavisto8491]

Super nicely done. You deserve much more attention than the youtube algorithms are giving you.

[@309electronics5]

nice video and what a beautifull scope only using a bunch of transistors and 2 ics IN SOCKET! wow never seen this but great scope and vid

[@ydonl]

Nice work! Nice oscilloscope, too.

[@AmitabhAnkur]

Marvel of electronics engineering.

[@lmwlmw4468]

Great work.

[@somewaresim]

Nice repair!

[@electronic7979]

Nice repair video 👍

[@gokerbg]

Amazing work. Thank you...

[@englishrupe01]

Fantastic video......thank you!

[@foto4chrepek315]

31:36 - old Poland transistors made by CEMI, not bad :)

[@andymouse]

Cracking video !...cheers.

[@campbellmorrison8540]

Well done. Ive never seen a Tektronix / Sony scope before

[@MsMarciax]

I would have replaced all the electrolytic capacitors as a precaution in this unit being they are all over 40 years old and wont be that far behind on leaking and failing themselves. Other than that a great job fixing it.

[@AllLoudNation365]

Oooo, an oscilloscope repair!

[@steffenk8955]

Only wow, that was e realy great Job, perfekt.👌👍

[@fernandocel2480]

I liked the asmr paper trace with a pen.

[@AmatorElektronik]

Nice repair :-)

[@cuf_]

Thats old scool. I love it.

[@AmerRimireZ]

Thank you it's great video

[@antraciet]

You are a genius!

[@ijapsdjhkahbefajldas]

Hello, nice that it works again! Did you also manage to repair the Trigger function? We couldn't made the thing trigger, at least it was the reason we threw it out. The cable was cut 100% because of a non-passed insulation test by the test company which made the test in our laboratory.

[@DiodeGoneWild]

I'm not famimiar with all the trigger settings, but I think it worked well in both AC and DC trigger modes. In both cases it was possible to find a position of the trigger knob where it synchonized.

[@sarathai2876]

That was fun 😊

[@MeriaDuck]

Very cool video, and very cool scope from my birth year 1975 🤣. Looks like it must've cost a fortune when new.

[@gacherumburu9958]

👍👍👍👍👏👏 Good job!

[@ayyadew]

Only legends can fix those

[@Emre-Sunay-Gebes]

its like repairporn. so satisfied.

[@doktor6495]

WORKING COMPLETELY WITHOUT SOFTWARE - G R E A T! ;-) Greetings, Doc64 - healing broken Commodore 64s

[@t1d100]

Tektronix equipment is considered to be high quality/excellent engineering. You should look up their history. Their vintage equipment is highly desirable. There are lots of DIY repair/collector forums. The forums are a good source for advice and documentation. Some USA companies have a policy of removing the power cord from any electrical equipment that is being disposed of. My guess is that the unit was taken out of service, because of the fault that you found. Meaning, there a good possibility that the power supply is okay. IMO, you should finish the repair, by servicing the power supply and doing general maintenance... Replace bad e-caps, Rifa caps, DIY calibration, etc... And, make a video of it. If you are not familiar with Rifa caps, you should research them. They are really bad news! It is recommended that they be replaced immediately upon discovery, whether they test good, or not. I did not see any, but you should look closely for them. They are in some Tektronix equipment of this era. Even though the scope is only 10MHz, it is a desirable piece. Plus, an analog scope is better at some things than the digital ones... Such as looking at curve tracer traces to diagnose bad components, or match transistors, etc.

[@petermikus2363]

Man i would love to find something like this one day but thats probably not happening i would have the beggist chance at some radioamaters gathering i assume. Anyways the video was really interesting and it is great that you saved this piece of old tech.

[@electrixhusky2379]

Mě se líbí tyhle staré osciloskopy s CRT obrazovkou. Hlavně ty od TESLA :D

[@mcflapper7591]

I'd be on the lookout for tantalum capacitors, besides electrolyte ones.

[@magnusterminus4728]

Ha I have the exact same model! Thanks!

[@althuelectronics5158]

Hello my brother amazing your all video waw good job

[@sebastian19745]

Great video, I like your explanations even if I mostly know, there were few things new to me in this video. Make a video about the component tester. What model it is? Also, can you compare it with other models or a dmm?

[@stalkerfromvoronezh4493]

10:26 - Yes it's simplest synchronous rectifier. Transistors driving by transformer itself.

[@ovalwingnut]

Yeah "Baby". Dats wat Im talkin bout. Very COoL and downright skillful. You are a "Diode of Many Trades", My GF says she loves you :O\

[@anissoulhaci2653]

I have the same one in my lab bench!

[@InssiAjaton]

The "unknown" capacitor looks like a hermetic wet slug tantalum. The hints are the tantalum lead spot weld to extender wire, and the glass frit hermetic seal.. There seemed to be several other similar types at other locations.

[@DiodeGoneWild]

The good ones have a very low ESR for such a low capacitance (just 1 ohm or less for 3uF). This would suggest tantalum capacitors. But the voltage rating (150V) seems a bit high for typical tantalum. But a normal modern 3.3uF electrolytic capacitor tends to have like 3 - 10 ohm ESR. It never goes as low as 1 ohm.

[@InssiAjaton]

@@DiodeGoneWild When you are talking about "typical", are you talking about the solid tantalum, the "drops"? Indeed they are not regularly available beyond maybe 63 V. I am not sure if you can find the Wet Slug types any more. Or if you do, they probably floor you regarding their price. They were used by military and NASA and some others to whom the cost was a secondary concern. I see that TEK was in a position to use them. I once tried if a plasma welder could be used for closing the tantalum cap (with its glass frit seal in place) to the tantalum cylinder housing. Turned out to be more than a usual challenge due to the very high melting point of tantalum and relatively low melting point of the glass frit. A usual way for narrowing the plasma arc is to use a few % hydrogen in argon shielding gas. But molten tantalum dissolves the hydrogen, causing porosity during the solidification. Then your weld does not pass the X-ray test.

[@JohnUsp]

Awesome.