Tektronix 576 Curve Tracer - Part 2

[@R.Daneel]

A thumbs-up isn't enough for this criminally under-subscribed channel. Only 3 minutes in and I know this is going to be yet another brilliant video. Thanks, Atkelar!

[@Spookieham]

Agreed 4300 is ridiculously low for this quality of content

[@graealex]

I see, or rather hear, we getting some new music... good selection.

[@malteibs6350]

New music? Like it!

[@arampak]

I am pressing the “like” button even before watching. That’s because I am waiting for the next episode eagerly.

[@inspired_alex9082]

9:45 These are simply resistors that have been trimmed with a laser so that they have very precise values. I think because ceramic was often used as an insulator in those days, it made sense to use this as a carrier material. I have heard that the 576 was only developed for internal purposes, which is why it was built in such an elaborate and complex way. Looking forward to the next video! I'm also in the process of finishing a 576 and it's a very nice project.

[@atkelar]

I found out about the resistors after I did the voice over part... it's became clear in the schematics, as soon as I found out which of the resistors map to them. ☺️ It's still interesting to see in such a device. I know that ceramic carrier from hybrids, as the company I worked for during my apprenticeship made some in house. I never got close to htat part of the factory though. But it did seem a rather "modern" technology back in 1993-ish. I would have never guesed that similar stuff was around since at least the late 1960s. Wikipedia doesn't really answer a precise timeframe either, at least at a glance. So I was wondering if anybody had more insights to that timeline. I have heard that "designed for internal use mostly" twice now... It would be interesting to know how many units were actually sold; the need to optimize such a speciality product would be low, if there's not many expected sales. And finally: I am already working on the next video! Quite a few things happening in the script, Let's see if it's going to be a four part series after all! At the very least, there's a little add-on project to be expected!

[@colinstu]

I wonder what the factory that produced these originally looked like... also stunning continued restoration work.

[@Pulverrostmannen]

They should give you the keys to the kingdom for all your effort and patience with all your projects. Mighty impressive as always. I have finished one of my own projects now making an old Heathkit IO-17 Scope working again, I am currently working on another scope too which desperately need calibration to say the least along some other stuff. I think of you when I feel stuff is against me with a project lol

[@brianbeasley7270]

I'm dizzy at the stunning level of detail of clean up and assembly! Wow!

[@t1d100]

Fabulous work! "Stage hand" and "fore" "shadowing" = grins.

[@TheDefpom]

@5:28 those first three caps you took out were wet Tantalum not electrolytic and rarely fail. and also the large one 2nd from the right is Tantalum, you replaced all with electrolytic, you should go back and replace those with more Tantalum ones instead. You can tell the difference as the Tantalum do not have the recessed band around the end of them. I do love the dedication to restoring the item though!

[@atkelar]

Thanks! It's a bit difficult to pinpoint the difference at times; the parts list just says "Electrolytic" for these caps; The DC rails measure within specs, including ripple though...

[@draggonhedd]

Another lovely video from Atkelar. at 19:05 I find for soldering leads to the bodies of those tin can components, it helps to fold a little L in the wire before soldering it down, they tend to stick better and are less likely to break off that way i think.

[@atkelar]

Good idea! I didn't think of that at the time, mostly because I tried to mimic the original form factor. But if the wire comes off, I'll do it that way!

[@YuriyKrivosheyev]

Great, thank you. Recently I remember your technics having to rejuvinate rare stereo (concentric shaft) potentiometer.. missing old Q-tips with plastic not paper stick..

[@atkelar]

Glad it worked! Around here, there's now q-tips with wooden sticks even... can't say if I like those yet. The plastic ones doubled as a straw sometimes, that's what I miss most about them...

[@StFrye]

@@atkelarI remember visiting a sewer plant and the stuff that went all through the end where these nasty plastic pins, without the cotton. I don't miss them. P.S.: Nice new music and 1080p! Love it.

[@SeanBZA]

@@atkelar The ones with plastic tip, and with the tip made from a felting, are available, they used to come as part of a maintenance kit for solid wax printers, to clean the print head nozzles. Really good, and leaves no fibres at all.

[@SeanBZA]

@@StFrye Yes sewage plants deal with all sorts of nasty, though the worst for the plant is plastic bags and pallet strapping, as that winds itself around pump shafts, and destroys the seals and shafts. Funny enough all the pumps have macerating blades, they will happily pump bricks and rocks, turning them into sand, but string and plastic bags destroy them. That is why all of them are designed to be easy to change, with valves inlet and outlet, and you do not have to disturb the piping to do so, plus also they normally are run with a spare pump in each bank, so as to still be able to do peak flow while doing this. Outlet non return valves are also designed to be self cleaning. But running a sewage pumping plant is messy work. My father designed a few, which were fully tiled inside, including the ceilings, so they were easy to wash, even after you had an oops moment.

[@SeanBZA]

The wet slug tantalums with a glass seal are almost never going to fail, they are going to last and carry on. Only replace is shorted. The ones with a rubber bung you replace on sight, they are all going to fail after 15 years.

[@atkelar]

Thanks! What makes it weird to me, is that the BOM didn't list the Tantalumns as such. I ordered replacements based on "Electrolytic" type there. I'll give the ones I removed a test, but rest assured: the blue ones I used are not "random cheapo versions" either. Unless digikey got duped that is... And axial tantalumn ones are more expensive than gold these days x.x - it does seem to work, I did check on the power supply ripple as per calibration guide and was within spec.

[@PapasDino]

Sorry I missed the live play...look forward to "...trace or smoke"! ;-)

[@JimmytheCow2000]

Thank you so much for the update! I love your content and am impressed by your amazing skills. (Stage hands is okay too I guess)

[@ZenwizardStudios]

Following the rebuild with interest. I have a few of these rebuilt my self. Was glad to see some of the parts that you had in yours. Also would you like to add your videos to the Tekwiki page for the 576? My personal opinion is they should be there given the extent of the rebuild and the wonderful information contained within. I can add them to the page, just did not want to post them without your blessing. Zen

[@atkelar]

I'd be honored to have my videos linked; To me it's just a hobby around electronics and technology... so I don't think it is the perfect reference material; But I let you be the judge of that. Just maybe wait for part three? (spoiler) I did have a slight oopsie on the way 😊 The good news is that it is almost completely done by now!

[@ZenwizardStudios]

@@atkelar Sure I can hold off till the series is finished. Looking forward to it! When you are ready let me know and I will links in a bock on the TekWiki page. Zen

[@atkelar]

Eeps! Almost forgot about this. Now that all three parts are done, I think it's OK to link it from "official sources". At least it's no cliffhanger anymore.

[@ZenwizardStudios]

@@atkelar Sure thing! I will get the links created and add all 3 to the tek wiki page this afternoon. I do hope you enjoy your 576 for a long time. Your is most likely the closest to new out there in the wild. The rebuild was extensive and quite impressive. I am curious if you still have it if you could do a more detailed video on the calibration box or send me some photos of it. I have one as well but mine looks totally different to yours especially on the front porch that plugs in to the unit. Mine has no knobs or lights on the front porch it is just smooth paneling. Just my curiosity in some of the engineering changes that were made over time. Also if you need to calibrate the unit again and don’t have access to the cal fixture there is an updates service manual that has the calibration routine in it that does not used the box but uses some power resisters as well as some individual capacitors. A little more time consuming but definitely serviceable if the need arises. Zen

[@atkelar]

Thanks! As to the calibration unit: the insides of the wired box seem to add up 1:1 to the circuit diagram that is on the Tek-Wiki. The plug in box has only minor additions that "look important". That is: the "DC supply on" light is just connected to the 15V camera connector. The "true/false" lights are connected to the left rotary switch and that passes them to the output control lines, one by one. So you can see if the "vertical 5X" line is set active or not. The right rotary control does the same as an input, and has a "true/false" switch on it for that reason. So lots or wiring, not all that exciting... since I don't own it, I don't really want to dig into it too deep.

[@TheDefpom]

@11:00 for gold contacts you should wet some paper with Deoxit or some other gold suitable contact cleaner and pass it through the contacts to give some mild abrasive action to remove any oxidisation, they may be gold but they still get issues from oxidation formation or airborne contaminants after so many years.

[@atkelar]

I did use a paper strip and the mild contact cleaner I have for the final "wipe" of the contacts; it just didn't film well at all 😿 Maybe there's a bit in the "misc bin" for part three but it seems the only clip I had left with that was very unclear.

[@No_Quarter]

WOW! Thank you

[@intell2OOO]

very impressive!

[@paulcarboneNY]

wow wow wow - that's dedication! I just re-caped mine a few days ago and it sprung to life. K102 threatened to start a melt-down, but I got to it in time (contacts fused together and shorted + & - base supplies!) What is the blue grease you used around 17:20 on the concentric mini-pots?

[@atkelar]

I also have a relay adventure for part 3, but a slightly different one. K102 was fine... but the meltdown seems to be similar to the second issue I had... Don't want to spoil too much from part 3 yet :) The grease is "Molykote BR2 Plus" - it works really good for metal against metal uses. A freind recommended it and so far it has not yet disappointed.

[@senilyDeluxe]

The ASIC files - the truth (table) is out there 😀 (and if not, they're easy to reverse-engineer)

[@atkelar]

I have found the design documents (at least the circuit diagrams) on the Tek-Wiki. Since they are mandatory open collector (to drive the 0-4.5V lamps) they might not be all that easy to replace anyhow. I don't know enough about programmable chips that are not the typical Arduino based ones... :)

[@senilyDeluxe]

@@atkelar I once reverse-engineered some PALs from a super rare pinball machine (out of thin air as all remaining specimen were fried) and then went and programmed new ones. By foot (couldn't find a free JEDEC compiler on the internet because I suck at Google). PALs/GALs however don't usually come in a DIP16 package. And you'd need an open collector driver on the outputs anyway so you'd got to replace each chip with more than one. Btw. my comment was more of an X-Files reference joke.

[@atkelar]

I thought that looked familiar 😸 but still, it would be possible to replace the readout lamps with a more modern version quite easily. But I love the charme of the old school solution...

[@senilyDeluxe]

@@atkelar There's nothing much above light pipes. Maybe Special signage Nixies or plasma displays.

[@oblioi]

:o)❤

[@gammarayflash1170]

What a journey! Just a quick question: have you replaced all of those tiny incandescent lamps?

[@atkelar]

I found some with the same voltage/current rating. So I only replaced the broken ones. I'm pretty sure they won't be the exact same brightness, but according to the schematic of the ICs, it shouldn't matter if the current is slightly different.

[@gammarayflash1170]

@@atkelar That might be true, but incandescent lamps tend to fail over time. If one lamp is failing at my car (Abblendlicht), then I replace both lamps. And since those incandescent lamps in the 576 are much older, I think they might fail as well in the near future. Similiar principle to the electrolytics. I keep my fingers crossed this won't happen to your 576 but I'd have change all of them for sure.

[@t1d100]

So, I am watching you clean all those tiny parts and I'm thinking that surely you have an ultra-sonic cleaner. Then, my mind wondered... Not to consider why you were not using it... But, to how you would individually contain the myriad of multiple assembly parts, without losing any in the bath, and still allow the solvent to reach the parts... That is a question that I am asking of you. I do not have an USC, but I had this container idea... Stainless steel tea ball strainers... Maybe you would have to wrap some self-sealing tape around the mating circumference... These strainers come in a great many sizes and shapes. They are not cheap, so maybe DIY some of your own design. Just daydreaming and spit-balling... Cheers!

[@atkelar]

I got myself a strainer for small parts in the parts washer ^^ - My issue with the US cleaner is that it so far has not yielded any recognizable results... So far, anything I put in came out the same way again, only wet. And thus I don't want to invest in any larger/more powerful ones...

[@t1d100]

@@atkelar The US cleaner not working well for you is interesting, because most folks find them useful. Particularly for mechanical parts. Also, some folks put a whole PCB board in them. I am not sure what I think of that, though. Do you have a video on your experience? If not, maybe make one, so that we can help you find a solution. I am sort of wondering if you have a defective cleaner, instead of just needing more power. A poorly mounted piezo would be a sneaky hard-to-find fault. I also am aware that the cleaning procedure does make a difference... Type of solvent, heat, time, etc. I am sure that you have investigated everything thoroughly, but, if we can help you, we would want to. No need for frustrations in our lives.

[@atkelar]

Thanks for the offer... I'll keep that in mind when I have the next possible candidate for a try. Indeed I don't have the most expensive one, and maybe there is something wrong with it, but so far I didn't have enough small parts to be worried too much; An "Oh, well, le't tackle this by hand" was always a possible solution so far.

[@bobbauvian7700]

please list the large lone capacitors behind the boards in the back,.

[@atkelar]

These are the power rail filter caps - their numbers are printed on the chassis, and values are listed in the schematic. I had to flip around a few for clearance reasons (the CRT cover interfered with one) - do you need the values or just which ones I shuffled around? There's multiple answers to your question :)

[@bobbauvian7700]

@@atkelar thank you for the reply, the problem with mine was trace jumping around all over the place. so I cleaned the switches and trace is kind of stable but not sharp and really there yet. I measured the 75 v (not sure +or-) it's been a while since I messed with it. trying to collect all info and parts needed. otherwise, I will take it apart and it'll never be put together. the 75 V measured around 58 and could not go over 65. so I figured it's the cap everyone is pointing out, the bottom cap. I would like to change a few more while I am in there. which ones do you recommend changing.?

[@atkelar]

The -75V cap is the C707 one, a 200µF one. The number should be printed next to it. There's a potentiometer on the power regulator board to adjust that one. But: I'd double check if there's any ripple on the 75V rail; i.e. attach a scope to it in AC mode and see how "even" the trace is. If the cap is bad, it should have quite a bit of ripple on the -75V one. Mind you, it's -75, so the scope ground goes to any of the black wires on the DC supply board, the probe to the negative pin of the cap, which should be Pin "K" on the regulator board. Now, the signals for the CRT and all the high voltages related to it are created in the silver box on the left side of the unit; There is a capacitor on the rear of that too which I'd double check. A "fuzzy" dot on the CRT can have multiple sources; it might be the focus voltage, it might be the brightness...

[@bobbauvian7700]

@@atkelar thank you for taking the time. I may start on it within the next month to two. thank you for the video and the information. that should be enough to get rolling.

[@rallymax2]

That electric guitar is gonna make me unsubscribe much to my fury because I love what you do. Please stop using that music.

[@atkelar]

Awww... sorry to hear that. Could you point to what song exactly? A timecode would help, as there are more than one "new" songs in here. I try to mix things up a bit, cause many viewers mentioned that the same song loop is getting on their nerves...

[@uthor707]

Can't please everyone, I like the music choices.

[@bziemko1066]

First

[@MothKeeper]

🙄😴😴😴😴