TSP #89 - Teardown, Repair and Experiments with a Tektronix RSA 6114A Real-Time Spectrum Analyzer
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- Опубліковано 29 вер 2024
- In this episode Shahriar attempts a difficult repair of a Tektronix RSA real-time spectrum analyzer. This well-equipped instrument reports several error messages during startup POST including LO Unlock as well as Signal Path failures. The service manual of the instrument does not provide any detailed block diagram and no schematics. Most failures require the instrument to be serviced by the Tektronix factory. The equipment has various advanced options including 110MHz analysis bandwidth, digital modulation analysis, wide-band IF output and deep memory.
The teardown of the instrument reveals a multi-board, multi-module design. The top of the instrument contains all digital blocks and boards while the bottom of the instrument houses the RF deck assembly. The RF deck is broken into various stages such as attenuator, RF switches, first converter, second converter, IF block, reference synthesizer and LO generator. For the purposes of addressing the YIG problems the LO board is examined. The problem is traced to two components, both dividers in the complex PLL system of the LO subsystem. The LO board is fully analyzed and described and the defective components re replaced.
The repaired instrument is tested for various functionality including DPX, de-modulation and measurement beyond 8GHz CW tones. The instrument passes all self-tests, alignments and detailed diagnostics.
The Signal Path
www.TheSignalPath.com
/ thesignalpath
www.Patreon.com/TheSignalPath
Shahriar -- KEEP THE MISTAKES! Keep EVERY little detail of the repair -- often you do things that you don't even realize are learning moments for us. PLEASE keep the repair videos long and rambly -- that's how I like them!!!
Aurelius R to wit; It is the tiny flaws that truly make a masterpiece. And let us laugh at cat jokes.
I love the detail in the repair videos. The detail really helps the rest of us. Thank you again for all your hard work.
Thanks for the video! :)
I would say keep doing it the way you do! Works very well in my opinion!
if I was to travel back in time and tried to explain Ohm's and Kirchhoff's laws to a caveman, the expression reflected on said caveman's face would most definitely be what mine looks like now. watching this has brought me right back down to earth - if I was to don an animal skin loin cloth, swing my club around a bit and utter gutteral one syllable words right now, i can honestly say that I'd be totally impressed if someone was to throw me a banana for me to gnaw into.
what I'm trying to say is Shah (and the above is the long-winded way of doing so), is that you are a veritable genius, man!
your video is almost as long as a feature film, yet it's far more entertaining and 'prods' those cerebral areas which rarely get reached by 'traditional' ways and means.
with humble respect, I'd like to thank you for dragging my prehistoric self into enlightenment!
....now, if only I can work out how to operate this complicated looking light switch, all will be gravy ;)
This was an adequate repair challenge for you! Serveral hours you needed to spend, aha, and you even had to read some datasheets! :D
It is very fascinating to follow your thoughts. And man, sometimes I found myself dreaming that I understood most of the lecture. But only for a view friendly seconds ...
I know someone else has made a similar comment about the cat but at the time the cat nearly walked on the board I thought that cat should be fitted with an anti static strap as well. As cat lovers will know. The fur on the cat can get very highly charged with static. 😊
Definitely an Oscar winning repair!
Great format, more detailed = better. Keep up the good work!
Love the format, if anything for my part they are even a bit short. As a patreon i'm wondering why you chose the per-video option instead of monthly ? I'd be happy to contribute monthly, its more predictable for me, and it means that if you don't have enough income we just have to wait longer
amazing job! watched the whole video! Format is fine...don't change a thing
I prefer the live comments, rather than rehearsed
Great job! Congratulations!!! It is fine the way you do. I wonder how many peolpe in the world could do what you just did...
Great video, and even though this is an enchant video I do like the format
The cat scan never lies
I was hoping that the YIG was defective. At least I can learn more of the outer space subject from you, like those chip devices, wire bonding, identification and your mantis etc.... I can tell you, it shamed me when I open one up, The slightest deflection of any of the bond wires, alter the circuit. Would like to see that in your future videos. thanks
Pooch the cat needs a grounding paw strap!
Keep stuff as is!
My opinion, leave the repair videos as they are, the mistakes, blind alleys etc. all make them more educational
Regarding the style difference between repair and review. Keep the explain-and-as-you-go style. it's one of the things that make your repairs so good.
Excellent video as always! Keep the repair videos detailed, it's great to see how you work through a problem.
Totally agree, love the detail and seeing you go through your thought processes. keep it up please
pahom he speculated it was likely due to thermal stresses through the board from the power supply sections on the opposite side. Considering how tight the module envelope is with likely poor airflow (essentially a closed smooth bright aluminum block) I would agree that over time those GaAs devices would fail. Failing that, power supply noise spikes.
The way he flows through repairs is comfortable to watch too, they don't feel long. Some people will have videos a fraction of the size but feel like they drag for eternity.
@@sivalley noise spikes? No, the power rails will be super smoothed.
@@educatedmanholecoverbyrich8890 I was referring to incoming line voltage noise that would make it across the suppression capacitor across the transformer. Those capacitors are designed to couple secondary side switching noise but can also allow noise to feed back to the ground side of the secondary. Those spikes would raise the ground potential and possibly invert the voltage (ground side momentarily higher potential than V+) causing damage to voltage sensitive components without polarity protection.
Shahriar - great job with the reverse engineering and repair. As you said, always a bit of a risk, especially when the fault could have been in a custom (unobtainable) device. The "A" series used a 32 bit PC running XP. Unfortunately, the firmware development/enhancement for this series is now frozen. The B models run 64 bit win7, and firmware is still current, so all the latest software options are available. Of course you could always export a TIQ and analyze with newer options on SignalVu-PC. Congratulations again on a successful resurrection of a fine instrument.
you all prolly dont give a shit but does anybody know a way to log back into an Instagram account..?
I somehow forgot my password. I would love any tips you can offer me!
@Braylen Zeke Instablaster :)
@Jasper Arian thanks so much for your reply. I found the site thru google and im trying it out atm.
Takes a while so I will get back to you later with my results.
@Jasper Arian It worked and I now got access to my account again. Im so happy:D
Thank you so much you saved my account!
@Braylen Zeke No problem xD
"It also fails the signal path, which I take offense to". I bet you do !
"I can in fact do FM modulation if I'm fast enough" I was laughing so hard I was almost in tears... that's just awesome!
Aurelius R , Yes! Truly awesome moment! Well taken!
I definately prefer these longer repair videos to the teardown ones.
$2700 is a heck of a gamble. Is this the most expensive broken thing you've purchased?
It is the most expensive broken one yes, definitely the biggest risk considering no information is available.
There's one on Ebay for $18,500 so it's not too much of a gamble.
New they are about FIFTH FIVE THOUSAND DOLLARS!
GREAT job! NO schematics, minimal block diagram -- and you fixed it! SOOO impressive!
@@Thesignalpath, This shows that you are indefatigable. NOTHING stops you or fazes you IF you feel challenged. Superb engineering.
@@stevec5000
There's no logic in that statement.
I really appreciate your style of presentation, please keep it the same - I always learn something new in watching you work. You're very courageous fixing such complex instruments that's for sure.
I really like the free flowing narrative as "how" you go about working thru a troubleshooting exercise is very instructive and one to emulate although everyone does it a little differently. Is it possible to donate without going thru the Patreon route?
very nicely done, as always!
just out of curiosity, did you look at the board with a thermal camera? and if yes, was that voltage regulator from the other side the most prominent hotspot?
I did. It does run hot, some places up to 60C.
WOW. GREAT job! NO schematics, minimal block diagram -- and you fixed it! SOOO impressive!
Always glad to see a new t-shooting video. One part threw me for a loop...
While probing the suspect HMC363S8 (@ 44:17) it looked like it was in backwards!
As it turns out the datasheet used (@ 39:57) has the wrong pin configuration pin 1/3 IN and 7/5 OUT.
Luckly you use a different datasheet (@ 46:40) which shows the correct pin out.
please keep it the way it is. the reviews are nice but these repair videos are why I subscribed to your channel!
Before you removed that div. 8 chip, i wondered why you didn't just check that it had Vcc first. Did you rely on the outputs being pulled High to indicate there was at least come Vcc supply.
Keep it as is ;) I like the detail in the videos.
Unbelievable fix, WITHOUT a proper schematic or even decent block diagram! 👍
the signal path repairing the signal path 🤔 😂
A. R. Jasso , You just couldn't resist that... LOL I was thinking it but you said it. ROFL
Nice result and a nice instrument too.
I prefer this video style where you work on the fly and this reveals your thought processes more, 'warts an all' to quote a phrase.
I like all your videos and I'm pleased you're back doing them. What a lab you have there too.
I wonder if the cat of knowledge has any input sometimes. She's watched you enough times. lol
Absolutely brilliant repair. As you walk us through your thinking and experience, analyzing and repairing these magnificent instruments, we are learning. There is tremendous value in the journey to a solution! So please, please don't change anything in your overall presentation.
Thanks Shahriar for this blast from my past. I used to work as a technician on the RSA line when the 6k series was introduced, so it was fun to see an old familiar bit of gear again. I distinctly recall LO1 being a real trouble module. :)
Going to do a review of the Cat-Scan too? I would prefer no teardown...
41:27
Nearly a cat-tastrophe.
Justin Bell get-out.gif :P
Great video, keep the whole style. One heck of a complex LO generation path.
Thanks. :)
Thank you for the great video! Leave the repair videos as they are. I learn a lot from your videos!
Great repair, congrats you get it done.
As for the style, I love to see all of the mistakes. The analysis you made to determine the second chip, that is a video on its own.
Keep up the excellent work you do here.
I bought a rsa6114a tektronix spectrum analyzer.
But I needs repair .
I tried to fix it but I won't able to do it.
Have any suggestions!
"I can do FM modulation, if i'm fast enough!" LOL
Hi Shahriar, may I ask you, if you know some tutorials or handbook for PCB microwave design ? or some guidelines. I am involved in designing a PCB for a 3.2 Gbps data pattern signal generator (programmable by using a FPGA). Thank you in advance!
Just curious: how do you end up having all that expensive equipment in your home lab? How much use does it actually see? I'm always thinking about getting stuff for myself but investing that much money for a lab I baerly do any projects in doesn't seem right.... I mean, a rigol 100Mhz scope is one thing, a 8GHz agilent is the other..
I wish u do some repair on advantest r3465 too... Mine was intermittent faulting till it failed definitely.... All signals including Lo leakage downed by about 10dB... Step attenuator good... And i bet first mixer crashed or yig lo aged...
Normally I don't bother commenting stuff on UA-cam, but it this case... You are deserving this.. thinking to support you on Patreon now... God bless you! Amazing
What a noisy piece of crap. Tektronix could have simply made a PC card for less money, and a whole lot less noise.
Yes, keep the detailed debugging. I was a bit disappointed that we didn't see more of it, but of course that would have been many hours of video.
No totally keep the long explanations. Even if they end up being dead ends I think I learn more than from seeing/hearing the summary. Only (slight) criticism is it would be nice occasionally if you got lucky and found a non-trivial fix for a piece of gear that didn't require multi $$$ equipment.
I've learned more about RF circuit design and tradeoffs with components from you video than I did from my ECE department....and I'm an RF concentration EE major!
Frankly, I find your repairs -- and this one in particular -- much more interesting than the reviews. Keep them up, please!
Great video, thank you. Can you explain why they chose such a complex LO design?
I'd rather have the current format of the videos. It's interestig to see the thought process behind these kinds of repairs. Mistakes and all
Please do not change the format of your repair videos. Presenting the repair as a fait accompli would cut out the best part of your repair videos: Following your thinking process as you work through a problem. Thanks!
Hi, Shahriar,
can ask I if you have the oportunity to upload high resolution photo of the modules that you go through. That would be very nice. Thanks in advance, I learn many things from your videos
Signal PAth Test fails in my RSA5106A. Anyone who encountered such problem?
I have been dreaming of that exact model and I have purchased bigger broken items before. This would certainly intimidate me though.
"and it also fails the Signal Path.. which I take the offence to" hahaha that one had me laughing out loud! Nice video again Shahriar!
Hi mr' signal path can u please slow down you'r speech velocity i really dont want to loose 100% of untherstanding your theorry . Thank u very much
the mistakes and depth set you apart form every other EE channels. That said you wont be a bad channel if you stop but I feel you are a better channel with it. I never got why you tubers change there format for some that complain when the silent majority must like the way it is.
I am super impressed with your diagnostic ability with no schematic and a poor block diagram. The hittite company needs to hire you as an advisor with their equipment then you would have access to the schematics.
Your videos are great please don't abbreviate the fault finding process.
Very nice repair wich seemed impossible without schematics !
Congratulations 👍👍👍💪💪💪
You have one more nice instrument in your lab now.
Love your videos & seeing your troubleshooting process. Thanks!
You kind of lost me after replacing the first divider around 1:05:00. I newer could understand why two different dividers stopped working.
"Signal Path" - "FAIL" lol.. that one was hunting for you Shahriar.
hi pooch!
Nice repair ! Need much experience and proper instrumentation. Regards
It would be great to see you do a review video of the electronic watch you have on your wrist. It looks like it might be an Apple?
Excellent video. Maybe it would be nice to use two cameras and split screen to show the scope screen and the probing?
It's not equipment I'm ever going to use but to see your process of how you trace down the problem is useful for anyone interested in electronics.
Longer is better. I'd even like to see more of your thought process and first impressions, rather than the prepared reveals.
Live repair thoughts are best - if you tell us it might be three possible things, we learn three things. Wheras if you just tell us what it is, then we only learn about one thing.
I like your repair videos
You explain very well. I also like
The detail information on your repairs
ua-cam.com/video/30VxmTnhvfQ/v-deo.html How many times has your cat tipped over an instrument?
Schematics are often not provided because of intellectual property theft.
Super video!
Your repair vids are among the best in the electronic vlogs -- I would not touch your existing presentation format (wrt length, style, editing, Pooch!!)
Only suggestion for all your vids: please provide date of manuf . when possible. A close-up of the rear- or bottom-panel "boiler plate" would help. Thx!
No. Don't change anything, this is Great info, and really neat to watch!
Keep the mistakes! We need the occasional confirmation that you are human.
The Signal Path fixed the signal path failure. Very interesting.
Considering the R&D that goes into an instrument like this, putting a pc in it seems lazy
I really like this format of following along. Don't change a thing.
Exceptional video, very well done Sir.
Hey Shahriar, if you come any broken across units that you think are great deals but have no need to purchase (i.e. I'm sure you have tons of 500 and a few 1ghz scopes, so you don't need another), do you want to share the links with Patreon donors of a certain level? (Say > 10 mo?). We'd have to work out a system to make it somewhat 'equal' (theres always one jerk who wants to "slickdeals" it up; he'll pounce on everything and resell for major profit, rather than letting the rest of the community benefit). Maybe some sort of set of wait-lists where ("Cat IV dmms; Portable scopes < 50mhz Cat III up to ...;" etc) where the good deal gets sent to the top member of the list. If he decides he wants it/can fix it, he claims it and he gets moved to the back of the line. If he passes, it goes to the next in line, etc etc. Since you're already going through ebay looking for deals, you are in a unique position where you have an excess of knowledge ('this unit is a darn good deal, but don't need it!') that isn't being capitalized on. I'd definitely throw 25 bucks your way a month assuming it was a fair community setup (i.e., everyone gets to benefit from it, not just one guy).
Also, definitely keep the repair videos the way it is. Your thought process is what makes the videos so valuable. Even if you have an entirely failed repair, the meta analysis is what makes this channel great. Don't cut out a single bit.
excellent troubleshooting and repair. thanks a lot dude.
Will You upgrade your camera to 4k?
It is one of my Patreon goals!
Having 2 cameras (or screen capture of Scope/spec screens) splitscreen/pip would be nice. A lot of more work with editing , would wold make less hassle with camera movement.
From 47:35 - 53:36 my nose started bleeding. Awesome vid.
Good repair... and your lab is absolutely awesome!
That was very interesting. I wonder why those 2 parts died in the first place. When I look at the datasheets they both dissipate a fair amount of power and I wonder if the cooling through their PCB thermal pads might be insufficient. Edit: The /8 divider takes almost 0.5W and the programmable divider takes about 1W.
Keep the style as-is. We all make mistakes, so no worries. :)
When you label your video "repair and experiments" then it doesn't work well to say in the beginning "if its fixable" ;)
Oh and what about using some patreon money for a second camera?
I have not gotten any money from Patreon yet... As soon as I do, it will go towards a new camera.
LOL @ Signal Path Fail
I feel like I'm getting spoiled with all these new videos.
All of the optics I use are Nikon / Leica
A fantastic and informative hour. I can't fault anything here. Keep doing what you do so well.
Two takeaways:
1) In advanced repairs just skip everything and replace all the Hitite dividers (programmable or not) :-)
2) I just discovered after your Mantis segway that Vision Engineering is just over the hill from me in New Milford, CT. I think I'll take a wander over there one day during the week and see what's going on. I'd seen the Mantis in several of Dave's videos and really want one!
FWIW, regarding Hitite, I seem to recall you replacing a hitite divider in another advanced repair.
Cheers, Vince
I enjoy your 'train of thought' style videos ... takes me back to my days (and nights!) in the lab :) My favourites though, are the lower level ones, like when you made a DAC. Would be great to see some in depth stuff on PLLs as they're so important in the areas you work in? Anyway, thanks for the great vids.
Regarding your question about teardown & repair video format. I think you should absolutely not change your current format. Watching you go through the troubleshooting process, mistakes and all, is by far the most educational and propitious. I'm new to RF and your videos are invaluable resources -- so much so Shahriar, that I've signed up to your patreon. Keep'em coming!