I actually got something working on the TRS-80 Model II!
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- Опубліковано 28 сер 2024
- Part of me felt like the left-for-dead TRS-80 Model II was a lost cause -- but in this video I actually make a little progress and get one subsystem working.
Part 1: • Another left for dead ...
Part 2: This video!
Part 3a: • This is how to use an ... (using 8" drives on a PC)
Part 3b: • This is how floppy dri... (all about termination)
Part 4: • I'm really scared to t...
Part 5: • I fixed the TRS-80 Mod...
Part 6: • How to fix a Keytronic...
Part 7: • Using an $25 Gotek flo...
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When I initially found this channel a few weeks ago, I thought "hey neat". Now I am truly blown away by your diagnostic skills.
BLOWN.
AWAY.
that is indeed one of Adrians prime qualities. Once he bites himself into a problem he will not rest until he figured it out.
1 skill to rule them all = PATIENCE :-)
He's far better than you realize. He also debugged the Commander X16 computer. He found the problem that even the two guys that designed it could not. And, IIRC, Adrian said he had no formal training in electronics or electrical engineering. I was hoping he would share his method and journey from zero to hero in learning this stuff when he reached 100k subs, but we haven't gotten it yet. Adrian, maybe a good 2nd channel video would be going into detail your process of troubleshooting.
Strongly agreed. The commander X16 fix and Adrians casual modesty around it are absurd.
Are you a capacitor? (hehehe, pun intended)
Some years ago I came across one of these things for nearly free so I decided to take it, but I've never been confident in playing around with it due to the strangeness of the thing. It doesn't help that there isn't really much of a enthusiast circle surrounding these things. This video series is really helping to demystify the Model II for me. I may take a stab at getting mine working. Thank you Adrian!
Dead bugs, spiders, leaves.. this is a perfect fall project!
And perfect scene for a horror movie featuring spiders 😅
And perfect scene for a horror movie featuring spiders 😅
I replaced a Game Gear screen yesterday, first time trying that much soldering and wiring. And it worked. I channeled Adrian as I succeeded "It works!". I never thought I would get so engaged by someone else's success with electronics repair. But, I've binged dozens of videos the last week or so, and I can't wait for the next part of this series.
So nice the engineers are showing the expected graphs! Should be a standard thing almost.
It was, back then. I've got numerous service manuals for 70s and 80s TV/video equipment, and they all show the expected waveforms at all the test points.
Interesting new game: "The need for sync - Tandy drift"
It's a racing game designed to run on Trash80s
Nice song… Neela was drifting there...
Adrian, I am watching your channel for some time now. And I really think that if you say you are not good at something, it actually means you are not experienced in it. And important difference taht we as your viewers probably sometimes see clearer than you.
But it's good that way, because the overly cautious tend to blow up a lot less stuff than the overly confident. Especially when the stuff is old, valuable and getting rarer.
It ties it with your thourough, methodical, researched approach to things which satisfies the German that I am on a deep, heartfelt level.
I mean, yeah there are adventures and sometimes screwups (like when you broke the ROM for the ultrarare 4-drive-Floppy-controller), but really, in general, it's deeply satisfying to watch how you go about things.
For so long I had wondered about the Magic in genlock syncing, but when your subtitle about not having an external trigger on the function generator showed up, it made me realise it’s probably similar to signal-triggered waveforms on a synthesiser.
Love your syncing by hand by the way :D
I was thinking similarly - time to pull out the video toaster! :-)
GenLock is very similar to wordclock. There will be a master timekeeper somewhere. Instead of using an internal sync to work on its own, and perhaps play well with others whilst marching to the beat of its own drum, everything set as a GenLock (or wordclock) slave won’t do anything until it gets the clock from the master timekeeper. In video world, you don’t get any distortion of frames when live switching between cameras. In audio world, it has two different prospects but the same principle.
@@brentadams28 oh, so it’s just a regular old external clock trigger. This entire time I was thinking genlock first locked-on to the master sync from video1, to then apply across the rest of the board with the other sources. (Which is the part I said about reminding me of a signal-triggered function in a modular synth.)
@@kaitlyn__L basically, yes. People started using different names when basic standards per application (and connector) were established. What you’ve described sometimes happens in an ad-hoc type situation, but in a professional environment there is either an external generator or the switcher is master and cameras are always set as slaves. Same thing happens in audio world with digital consoles/amps/snakes.
@@brentadams28 I think I saw it happen “ad-hoc” in a Video Toaster demo and thus thought all genlock worked like that. The irony is I was thinking a master clock would be simpler, but having seen syncing from one VCR to another on the Amiga I thought there must be more behind it.
Good to know my instinct was actually correct then. Using the master mixing console as the clock source and setting all the cameras to an external trigger is definitely the kind of thing I’d had in mind years ago.
The wishy washy way they explained it in the Toaster demo gave me the wrong impression that you needed something more complex than that to keep everything working together, with clock drift and re-locking on and stuff like that given CRTs’ wider timing tolerances.
I’ve known about eg timecode syncing in video production for the longest time, and I’ve known about vsync and hsync in analogue video for the longest time too, but I just wasn’t sure how genlock fitted into it all. So thanks for clarifying!
When Adrian starts screaming "It's Alive! IT'S ALIVE!!!"
There really should have been a clap of thunder and a maniacle laugh at that point.
It freak'in works ! :D
That's what we watch for!
Sounds like a mad scientist
From my heart and from my hand why don't people understand my intentions? (Weird) :D
Great stuff! The Model II never gets much attention and so it's nice to see this series. When I was a kid I used to hang out at a local Tandy store playing with their machines and while I didn't use the Model II much, the follow-on machine, the Model 16, was one I used a lot -- running Xenix, Microsoft's version of UNIX, of all things.
I always enjoy your excitement when you get something working. Keep up the great work!
It works ! It frikin' works ! Yet another AWESOME repair ! Congratz Adrian 👍🏻
Adrian,
If you're interested in de-rusting fasteners, take a look at electrolysis baths. it's super easy and relatively safe - a cheap "dumb" 12 volt battery charger, a sacrificial anode (a chunk of carbon steel), some metal wire to loop all the parts you want to remove the rust from, and a plastic tub with washing soda (or even baking soda). Set it up, and let it cook for a day or two and every single piece of rust is stripped from your parts. Make sure you dry and give a protective coating as soon as they're out - they can flash rust quickly. There's quite a few videos and discussion about how to do this, I have done it a lot repairing vehicle parts and tools.
3:15 - depending on the overall condition after the jelly you could put masking tape over the text to protect it while spray painting it. But if the rust is so bad that it eats it's way under the text you can't really save it, all you can do is print new labels and hope they will stick. This reminds me, I really wanted to get a nice Brother label maker but the nicer models are a bit too expensive for my taste with all the label options.
17:15 - those pads on the upper-right quadrant don't look nice, around that circular arrangement there are 2x2 quare shaped soldering and one of them is really rust-looking, check that too, please if it has continuity.
Wow, that was really exciting! Can't wait for the next part, I hope the PSU is okay now that the flyback has no problem, you should be able to fix it if any fault comes up.
Someone like Colin Furze could probably cut out a back panel on his plasma cutter and put in the 90-degree bend, but the final product would likely also come with a jet engine, fireworks, or rotating knives to boot.
On the Brother printer, we have a PT-2730 where I work and it really is just kinda overkill for 99.9999% of use cases. I've been thinking of getting a PT-D600 for at home organization since it has the connect to PC functionality I'd want for printing labels at home, which the $50 to $70 models typically don't, and is $100 rather than the several hundred a 2730 goes for.
@@chiblast100x I was thinking about getting a PT-P750W or something similar, it's between $125 and $175 plus all the different type of tapes for it. I really like them but yeah, probably a white masking tape with a regular pen will do for now :D
One suggestion for you, and everyone else for rust removal.
Evaporust. It works MUCH better and much faster than vinegar, and it's re-usable many times. It also has the advantage of never removing metal because it makes the rust soluble in water.
It's a little expensive, but since you can re-use it, and just dump what's left back into the bottle it's quite affordable. I bought a gallon of the stuff in early 2021 and removed a lot of rust from old tools. I still have likely 3/4 of it left, and I expect that gallon to last many years.
Since the PSU is going to be one of the next steps:
If you want to power something mains powered up which you are not to sure about the condition, you can put a classical light bulb in series with the mains connection (60-100W or so, typically, depends a little on the power rating of the device).
If something shorts out, this often will prevent further damage, since it limitx the current and the bulb lights up brightly, alerting you to shut off the power. Normally it should only glow dimly. If you combine it with an isolating variac, that's the luxury variant (well no, the one you are technically supposed to use, from a safety standpoint).
Admittedly, it can be a little problematic with switched PSUs, and prevent them from starting up correctly, but it will still very likely prevent the big bangs.
It is awesome to see the amount if effort you are putting into something that as you say may never work again. Definitely shows respect for this old hardware.
I swear there needs to be a collab between Adrian's Digital Basement and HandToolRescue to clean up this chassis. At the very least that giant bucket of evaporust might be useful...
Two more options that might help out for rust are Evaporust and elecrto rust removal. The Evaporust is great for connectors, screws and other small things that would be difficult to do with electro removal, and is reusable. It is super safe and you can leave stuff in it for days plus to really get into tight stops.
Electro can be nice because you can go directly from one tub for removal into another tub to do plating to prevent new rust from forming without having to paint. Say nickel for example. You just need three tubs, removal (water and some salt), final rinsing (distilled water only, use tap first) and plating (vinegar and salt). Just don’t let the part dry or you will get flash rusting (very cool to watch, but no fun).
But in ether case, you would need to use a paint remover and a wire brush first to really do a nice job.
That information on the input board for the display is fascinating to me. I would have suspected something entirely proprietary, but I guess Tandy didn't wanna reinvent the wheel. Good on them!
"This is a win", and you are a master. One of your best videos. Thank you very much for sharing your discoveries so neatly.
It's weird, I've never wanted to own a Model II (or any TRS-80), but I really want to see this machine live again as it played an important part in my formative years.
We had this machine in my home-room at my school in 1st grade . It was the very first computer I ever got to use regularly (at least a year before I got a Vic20 for my birthday). While any chance to use a computer was exciting, the TRS-80 was on the low-rung of that excitement. The other classrooms had Apple II's, and those had more entertaining education software and had graphics capabilities. But I fondly remember those early days: we even had a textbook that described, in fairly comprehensive terms, how the machine worked (and it was oddly specific to the Model II - perhaps it was provided by Tandy).
I learned basic on that machine, keyed in my first program-listing from a magazine. I remember staying late, with our "computer teacher", to debug / port the program, as it had specific problems with the disk loaded "professional' basic interpreter, on the Model II, having a different cursor positioning scheme. I was very lucky, at just 7 years old, to have that opportunity, and my fascination with computers (of all kinds) hasn't waned in all these years. The Model II was there, at the beginning, so I hope you get this one back in working condition.
Adrian, great video. It is not surprising it works. That flyback is silicone dipped and is quite robust. You did a lot of work to see if it works. You could have just injected a horizontal and vertical pulse and cranked up the controls. It would have shown a blank raster. As for the graphics on the monitor, you could get a "High Resolution Graphics" card for the machine for more than B/W video. Some even swapped out the P4 phosphor CRT bulb for a P1 for a green display like the 16/6000 had. We did that to one of our later upgraded IIs.
As for the power supply, BE VERY AWARE of the expoxy potted Rifa caps. I'd replace every one before powering it on. They look good, mabye even test good at first but may have cracks in the epoxy and most likely have had moisture intrude. They POOF quite nicely. Exact replacments are available from Digikey or you can use another brand. As for running it without a load, you can repair and test it with no load without an issue. I've repaired a few without incident. On a side note, the power supply for the computer is the same on used in the disk expansion unit (should you ever find one). I look forward to your next installment. Happy Computing and restoring.
I'm a regular viewer of your channel. Love it! Regardless the fact that I'm not an Tandy man myself this series is SO VERY interesting to watch. It taps into every aspect of what retro computing is about. Thanks Adrian!!! Great serie and I can't wait to see part 3
Hardware on that TRS-80 is likely the standard SEA sizes. Having some pan-head machine screws and nuts assortments is always handy to have around in the following sizes: #4-40, #6-32, #8-32.
Less common are the larger ones: #10-24 & 1/4-20"
Nice work on jury-rigging another horizontal sync signal for testing. Understanding the needs of the system under test is a valuable skill and I am glad you see you demonstrating that. It's unlikely you will need much of it going forward but if so, you could try adding a pulse stretcher to the CGA card to extend that horizontal sync signal. Not ideal as that will introduce some small delay (ten's of nanoseconds) but then the testing PC can generate all of the signals. I think though that you would be getting the TRS-80 video generator up and running first anyways... I think.
Signal upside down... did you plug the yoke back in backwards? I did not see that, just wondering. Both H&V would be flipped...
HV Flyback damage - Maybe a good idea to goop some HV silicon compound on that broken area at the top anyways, just to isolate HV and prevent ingress of moisture in future. Running it a bit first should dry the transformer out first.
Cheers,
Incredible work! This is a really cool series. Thank you for all of your work on it. I can’t wait to see how everything turns out.
On the positive side,at least you could make a "modern" (as in, something 80s-90s based) computer inside the thing driving the original monitor if the original hardware doesn't work... :P
If he does get it working I'd like to see CP/M running on it.
G'day Adrian enjoying the M2 vids. I've had the "pleasure" of repairing a couple of the M2s including painfully manufacturing the pads and restoring the keyboards one key at a time - aaaarrrgh.😣
One gotcha with Aztec supplies is the snubbers. Looks like you dodged the yellow Rifa "nades" but it would still be a good idea to replace them.
It might have been good luck but I've found the 8" floppies to be OK after a grease&oil change with one drive having a shorted tantalum which worked perfectly after replacement. The P/S took the short OK.
Happy to sit back with a hot cuppa and watch someone else go through it.☕
Adrian, what you just did to diagnose the missing signal, and then to generate it and test... I am truly in awe! Great work, and really nicely presented, thank you
My first computer was a Tandy Color Computer Model I. It was compact and easy to move. I never knew, that Tandy made a bloated Model II, until watching your videos. Nice job fixing up this computer!
This is really cool, I didn’t even realize this Tandy with the 8” floppy existed.
It was so cool watching you tap into the CRT drive board, power it externally and drive a signal from a CGA source.
This of course could be a controversial statement, but after watching you drive it with the signal generator, I couldn’t help but wonder if that could be done with a Raspberry pi.
Maybe some kind of A - B selector switch device could be used to toggle from a raspberry pi to the original Tandy. Then you could do all sorts of things with the Pi connected to that CRT.
I love the old CRT AIO computers, keep up the excellent work!
I just thought of suggesting that International Instruments gizmo to my dad...but then I realized that he already has everything, including a spectrum analyzer. Helps to have a lifetime of electronics experience.
After all that effort. Upside down and back to front. So excited. Rossman!
Congratulations! This is one heck of a restoration attempt. I dare say your magnum opus so far!
A PC BIOS screen being output on a TRS-80 video tube. Now I've seen everything!
Just another tip, use your DMM to do a resistance check on all electrolytic capacitors (mind the polarity) before powering up the machine. Electrolytics have to be formed to be capacitors, and that forming process reverts if not under charge for long periods of time. Anything more than a year, and you should be cautious. Putting voltage on them via a resistance check, helps to at least partially form the capacitor, so that when you actually power it on, the cap doesn't explode (small ones will just pop or hiss), thus necessitating a replacement and possibly damaging other components.
It works! It FREAKIN’ Works! Well done Adrian. I can’t wait to see how this ends.
You are freaking fantastic Adrian, you have so broad knowledge and and so good understand the nuts and bolts driving things, i got zero electronic skills and recognize your some sort of genius.
Keep fighting the good fight, Adrian. You'll get it working!
The level of probe jank on that analogue board testing was shocking and I fucking loved it
Never seen a monitor driven by horizontal from one source and vertical from another. Not sure it would have ever occurred to me to do that! Nice job!
I've run a TV CRT with the yoke and high voltage on one chassis and the neck on a completely separate chassis. I knew I had to be very careful or else I might end up burning a solid dot in the phosphor.
I'm 70 and the TRS modii was new when I played with it. Its really a simple machine. Sockets are most likely going to be a problem. They mostly didn't have gold plating.
The power supply may need a load to operate and if you test it without a load it may smoke. Test the caps before you turn it on, they are the most likely bad parts if its set for a few years...decades. It was a 4meg Z80. Some where in the barn I have a Z80 in circuit emulator with an rs232 port called a Nicolette. It had a memory test function and you could
read the bios and put data in ram. You have a manual so I"m sure you will prevail. Good luck man.
Nothing quite like knowing how something should works and having it work as expected.
At 19:01 You mention that huge capacitor at 2035 VOLTS!!! Imagine if that was true, no one would ever open any power supply with that kind of rating!! Lol! I know you meant uF and not voltage but, seems like I am the only one who noticed this??
BUT...
Great job Adrian as always! I can never wait until your next videos are released! I prefer the longer videos you create but shorter ones are also good too!
I have a BBC Master 128 computer in mint condition and working, but, upon opening the power supply, I broke a component off the power supply board when trying to remove the metal chassis. What a nightmare that was!
I don't know what the component was, but it looks like an old style inductor. It is small, round and has several colour bands on it and googling around, I cannot find either pictures of this PSU board or even the correct schematic for the PSU! All I can find are BBC Micro boards and schematics which are completely different to the Master 128!!
Do you own a BBC Master 128??
I know you mentioned something about it in a previous video and maybe know what the component is and its value???
Oh my, I love these videos. I can't say why as you are way beyond me in most of what you say but still, there's just something compelling about these. Please keep more coming.
"It freaking works!!" - Definitely needs to be on a merch tshirt. :D Awesome stuff as always!!
The VirtualBench sure is nice, no doubt about it but also very expensive. Prices start(!) at 2000+ Dollars and used it isn't cheap either.
That's an extremely generous donation! I hope we see more of it in the future.
There are cheaper solutions, though. The Analog Discovery 2 Pro from Digilent costs "only" about as much as the oscilloscope that Adrian uses (Rigol DS1054Z).
Great video. Perfect drama. Love it and well done.
I'm loving the Model II series so far! I also spied a climate sensor (I am assuming Zigbee) stuck over your laundry machines. I guess I shouldn't be surprised that the Basement is also smart. Maybe do a Second Channel video about what you are running for home automation? Nothing fancy, just a down and dirty tour?
Amazing you turned the yoke without wearing gloves.
When you were describing all the wire connections for the video signal, I just had a big 'ol grin. That was great. That's the sort of thing I like watching your channel for!
Wow. It looks like you were hand wiring a Colossus Mark I at Bletchley Park! So many wires! Great job!
The second channel should have been called “Adrian’s Analog Basement.”
"Adrian's Analog Attic"
ok on the cap readings, keep in mind all those caps have a tolerance of +/- 10%, so that first one you checked that was supposed to be 470 has a upper limit of 517. you might not think its off by that much but older power supplies very much utilized an RC time constant for regenerative feedback. and of the cap gets too far out of spec it throws off the timing of the pulse and the supply wont work. so to be sure I'd take it out and measure it out of circuit.
Bloody fantastic job - well done Adrian, I salute you !!
Really impressive work!
Hey man I just want to say I love all the hard work you put into these videos and the stuff that you do thank you for making content on UA-cam for us to watch I and I'm sure many other people appreciate and enjoy it
Good as always! Thanks Adrian and greetings from Bosnia.
I have washed a ton of monitor chassis and the flybacks were fine. I don't know if that particular flyback is ok to get wet. Also, use cleaner wax on that paint before you use a clay bar.
meguiars paint cleaner is good
@@TotoGuy-Original yeah that's exactly what I meant. LOL
Can't wait to see the next component test video.
Thanks! I love this machine, good job getting that crt going :)) Can't wait to see the rest, keep it going!
Very fun video. Got a buzz when you got the picture up. You’re a wizard Adrian.
You needed an insert of your new t-shirt "It freaking works!". Loved this one. Super interesting.
Apple cider vinegar overnight is very effective in removing rust. Of course you must remove all connectors before and sink just the rusted metal part in a basin with vinegar.
EvapoRust is your friend where rusty metal parts are found. Once wiped or rinsed off. Brush with wire wheel, remove any oils and then paint with Rustoleum-type product. On screws, after EvapoRust, brush with wire wheel, heat to red hot and drop into food-grade oil. It will darken the screws and prevent further rusting. Don’t wash them in vinegar as it erodes the metal. Vinegar is good for Brass or Copper as it removes p patina. You could further polish the brass/copper fasteners if need be.
2:45 I'd get a (preferably battery powered) mini-dremel with wire brush attachment(s), that will allow you to clean the rust mechanically off stuff without damaging in-tact metal parts, but still gently and with a decent speed (you don't have to wait days or weeks like with most rust dissolver fluids)
Virtual Bench seems very useful. I'm surprised I've never seen something like that sooner for people who can't afford oscilloscopes, although all the comments here are saying its much more expensive than one.
Dang, Adrian! You are quite knowledgeable.
Supreme resurrection! Nice work Adrian. :)
This was fascinating. You are a genius. Happy that you're making progress!
Nice flashback for me, my dads workplace had one of these (with an extra floppy drive), and I was allowed to play with it and write basic programs at age 10 :-)
That was a heck of a stunt to pull off. Well played.
Since the CRT is in great shape, you could at the very least make a convincing knock-off of a TRS-80 Model II such that someone would have to look under the hood to know it's a Raspberry Pi or whatever you'd use. So we know this isn't a total loss. If that doesn't appeal to you, maybe make the weirdest looking Mac ever. :)
Very cool series, must be a ton of work doing this while making a UA-cam video of the process. Thanks for the effort!
You sounded almost despondent at the start of the video but be rest assured that myself, and probably everyone else watching this, was hanging onto every word and enjoying every minute :-D
My! That was quite exhilarating! Like my first motorbike ride!
Wow, that's so lucky that the analogue board was working fine! There's so many things that could've gone wrong with it, I would've thought for sure it would be bad after so long in such poor conditions. Especially with the flyback transformer looking as bad as it is.
Hopefully this bodes well for the power supply too, although those early switching units can be pretty petulant.
Food for thought: Try an impact screwdriver on those rusted screws.
It doesn't appear he's having an issue getting them out, he just needs to clean the rust off and make sure they don't rust so easily in the future.
Just carefully tape over the labels. When you are done, give everything a matte clear coat of Rusto. Painter's Choice 2x Clear Matte. It will look fine!
perfect Australian picture Adrian! Before you changed the yoke!
Very nice! I'm so ignorant about which are the high voltage parts of a CRT, I always cringe when I see someone in a video moving the yoke around, LOL. But, now that I've seen the flyback pointed out, I think that's the big, rusty part in my old Amdek monochrome CRT... which still works... so far... 😬 No idea how it was stored before I got it.
Halleluja! Congrats on this hack! More of this is highly appreciated :-)
As usual you demonstrate your amazing trouble shooting skills. Even for viewers like me that are not into TRS-80 this video was informative. Thanks!.
That was an AWESOME video. I really like that virtual bench device. Very handy! Can't wait to see more of the TRS-80 Model II saga :D (Go Newdos/80!)
Okay, that was really cool. Great idea to use the function generator and I think you showed a phenomenal amount of patience test as much of the board as possible before powering it up.
if you get the crt board functioning, i would use some electronics grade (NOT building supply grade) silicone to fill the cracked rubber on the flyback. builder grade silicone generates ascetic acid (vinegar) as it cures which is corrosive. electronics grade uses platinum group metal catalyst in it to cure without creating acid in the process.
For that rear panel with the connectors...you mentioned you have compressed air, head down to Harbor Freight and pick up one of their little handheld sandblasters, and then go grab a big ol box of baking soda. Blast the part with baking soda, it'll get all the rust and crud off and leave most of the paint.
To be honest, that power supply looks like an off the shelf part. It seems Astec is still in business, so maybe they have something that’s fit / form / function compatible if this one conks out. I remembered something else. There are two slightly different sets of frequencies for NTSC TVs. Monochrome is supposed to be 15750 Hz horizontal and 60 Hz vertical, and color is approximately 15734 Hz horizontal and 59.94 Hz vertical, the difference being due to the latter dividing into the 3.58 MHz color frequency.
“Are we gonna get a spot like the old Pet?” is a very scary question.... lol
It sounds like he buried Spot in PET sematary.
I never ever thought I would see you be a DJ. and yet there you were. mixing syncs. next up mate. fire up the records ;)
What a great troubleshooting video - Adrian you really are great at this, both the troubleshooting itself and making it into an engaging video!
I loved this video so much, I am giving a up vote and letting the ads play out even though I have already watched it as a patron.
I do retro computer restoration as a side business and I use a small sand blasting cabinet and I have a small paint booth. Along with a silk screen to reproduce the text and some graphics.
I learn new stuff from Adrian almost every video.
Especially the last one where he used Oxyclaen to do retro brighting. Good stuff!
This is awesome! Well done :D
A combination of CuriousMarc and bandersentv, love it! Also, for that flyback, I think bandersentv uses a high voltage dope like mg chemicals 4226.
Thanks so much for sharing your skills and knowledge. I actually have a Model II to revive and you are a great help. Merci beaucoup / Djiekuje !
Navel jelly is phosphoric acid. It is used to prep steel for painting. Use it on the screws and steel panel parts.
Awesome video !! I don't understand 99.9% of it , and the .1% I do is enough for Me to LOVE this..... Just Incredible !
Yes, this is a linear type of power supply and they do work in a different manner to switch mode supplies.
With this supply you have, there shouldn't be a need to attach a load for it to power up. I think, this will power up whatever the load is at the terminals. Switch mode supplies have current and voltage sense circuitry whereas this linear type does not.
So, if this is powered up and tested, should output the voltages listed for the output terminals.
Again, switch mode supplies will limit the voltage on the output if no load is applied.
When a load is attached to the output, the voltage will power up accordingly.
That was one of the best it freaking works ever!
it's interesting that the TO-3 transistor on the psu has a sil-pad.. i thought those were relatively modern, and expected something from the late 70s to use mica + paste. You learn something new all the time :)