TSP #89 - Teardown, Repair and Experiments with a Tektronix RSA 6114A Real-Time Spectrum Analyzer

[@AureliusR]

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!!!

[@sivalley]

Aurelius R to wit; It is the tiny flaws that truly make a masterpiece. And let us laugh at cat jokes.

[@peterkjellstrom3100]

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.

[@DextersTechLab]

Excellent video as always! Keep the repair videos detailed, it's great to see how you work through a problem.

[@smgvbest]

Totally agree, love the detail and seeing you go through your thought processes. keep it up please

[@sivalley]

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.

[@JJayzX]

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.

[@educatedmanholecoverbyrich8890]

@@sivalley noise spikes? No, the power rails will be super smoothed.

[@sivalley]

@@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.

[@daveblane6442]

WOW. GREAT job! NO schematics, minimal block diagram -- and you fixed it! SOOO impressive!

[@w2aew]

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.

[@braylenzeke4269]

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[@jasperarian1789]

@Braylen Zeke Instablaster :)

[@braylenzeke4269]

@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.

[@braylenzeke4269]

@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!

[@jasperarian1789]

@Braylen Zeke No problem xD

[@richsmith46]

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.

[@k1mgy]

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.

[@dufflepod]

I definately prefer these longer repair videos to the teardown ones.

[@AureliusR]

"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!

[@BruceNitroxpro]

Aurelius R , Yes! Truly awesome moment! Well taken!

[@jasonmilldrum]

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. :)

[@garybevis8691]

Shahriar, I very much like this type of teardown and repair video in which you explain and guess at what you are seeing and come to the logical steps of progression thru the trouble shooting and diagnosis. You are a very bright young man and I watch these videos because of this style of yours. I am a recent subscriber to your channel and I am working my way through the entire catalogue and have noticed your improvement over the years. Keep up the good work and you have a way of making sense of circuits and "signal paths".

[@rkstr9965]

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.

[@MoraFermi]

Frankly, I find your repairs -- and this one in particular -- much more interesting than the reviews. Keep them up, please!

[@ruhnet]

Unbelievable fix, WITHOUT a proper schematic or even decent block diagram! 👍

[@964tractorboy]

Re style: thumbs-up from me on keeping it like it is. The ad-hoc style is "user-friendly" and makes the videos more accessible, so to speak. Love them as-is. Thanks for every one!

[@DoRC]

please keep it the way it is. the reviews are nice but these repair videos are why I subscribed to your channel!

[@sebastianmaderner8727]

Thank you for the great video! Leave the repair videos as they are. I learn a lot from your videos!

[@jipihorn]

"It also fails the signal path, which I take offense to". I bet you do !

[@ikocheratcr]

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.

[@michaelkarr7558]

I like the mistakes and extra detail. Following along with your thought process is the most interesting part.

[@babybearkill1]

people cannot learn by quick overviews effectively, only the long and quite internment connection with the signal path proper will suffice. block then detailed circuit analysis is quite refreshing and in my opinion should never be overlooked. keep up the great work and we will keep watching

[@keithhearns3783]

I like the repair videos as you have been recording them. Your reasoning process is instructive. The repair techniques you use please continue to hint at those as well.

[@rcleveacp]

I love the detail in the repair videos. The detail really helps the rest of us. Thank you again for all your hard work.

[@nated1971]

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!

[@JackZimmermann]

I really like this format of following along. Don't change a thing.

[@Golem386]

I absolutely love the style of your repair videos, because it's much more interesting to watch someone make mistakes and figure it out later. Keep doing the good work ;-)

[@pa4tim]

Please keep the repairs as you do now, very educational and it makes me feel better because now I know I'm not the only one :-)

[@ZEROSTATIC72]

Great video, keep the whole style. One heck of a complex LO generation path. Thanks. :)

[@hyperplastic]

Great video! Keep the repair videos as they are - important to see the process!

[@Electrolab28Ag]

Wow! what a gamble. You really done a great job.... Hope the Cat scan work. I really enjoy your explanation and how things work and what should be expected to happen. It really show you skills and knowledge in this field. Keep them coming, we enjoy them. Thanks for taking the time to share.

[@michaelhawthorne8696]

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

[@frederikfrank5226]

Hi, I also really appreciate your repair videos. I think there's no problem of keeping different styles for different types of video. For a repair, I prefer to hear all the thoughts going into it. The procedure and so on. I can also learn from all mistakes maybe done. So for my point of view, keep it as it is. I love your channel and like the reviews as much as the repairs.

[@techtalkmike4968]

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!

[@EcProjects]

Thanks for the video! :) I would say keep doing it the way you do! Works very well in my opinion!

[@paulrautenbach]

I like both your repair and more structured videos.

[@youpattube1]

More like this. I like hearing you reason your way thru the problem.

[@RodrigoForrequi]

Wonderfull instrument but most impressive it's your goal! No schematics, basic block diagram and you fixed it! Great!

[@g1fsh]

i prefer the longer videos where u share everything including mistakes. making.mistakes is one of the best ways to learn. thanks for a great video as always

[@PeregrineBF]

I'd love to see a list of all the equipment you have in your lab. And do keep the full explanations going for the repair videos, watching someone step through the process is far more educational than just getting a final result.

[@PelDaddy]

Thanks for another great video. I like the mistakes... I like to hear your thought process as you go through things.

[@vincei4252]

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

[@m4dizzle]

Definitely keep the "mistakes" and learning process, it's very helpful :)

[@Mrjm5411]

Awesome Shahriar, thank you. Like the detail. Please, no need for less. Length of presentation not an issue. Once again thank you!

[@mikedillon729]

No. Don't change anything, this is Great info, and really neat to watch!

[@drulli1]

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 ...

[@tllong2]

Love your videos & seeing your troubleshooting process. Thanks!

[@konradmuller5312]

Thank's for this great video. I really like most of your content, I can't think of any other youtuber doing so detailed videos about testgear and repairing it.

[@zuccasnow]

Normally I don't bother commenting stuff on KZbin, but it this case... You are deserving this.. thinking to support you on Patreon now... God bless you! Amazing

[@stevedavies3985]

Awesome video. Really enjoyed the investigatory approach, including the dead ends. You made one comment about replacing the parts. It sure would have been interesting to see the part replacement mechanics including the who, the how and the equipment involved.

[@netman69]

I love your repair videos, more so than the reviews admittedly. By all means keep things as they are :).

[@jensmarkwart5316]

Keep it as is ;) I like the detail in the videos.

[@demesisx]

WOW. This is the first of your videos I have seen. Thank you for doing this. Amazing content.

[@raccoonnyc]

Definitely an Oscar winning repair!

[@MeiklesAndDimes]

Definitely like this style of repair videos

[@docpedersen7582]

Good repair... and your lab is absolutely awesome!

[@benrd9111]

Very nice repair wich seemed impossible without schematics ! Congratulations 👍👍👍💪💪💪 You have one more nice instrument in your lab now.

[@donreid358]

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.

[@prabhnoorkainth1520]

Dang uploading videos at 3AM. Keep up the good work! Should I watch this now or tomorrow? So tempting.

[@dentakuweb]

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.

[@alankellerhouse1249]

I like your repair videos You explain very well. I also like The detail information on your repairs

[@rysend]

Love the style. Excellent video as always. Thanks!

[@Newsparklabs]

Another great video, thanks Shahriar!

[@TheAlfieobanz]

From 47:35 - 53:36 my nose started bleeding. Awesome vid.

[@DrekRose]

Great format, more detailed = better. Keep up the good work!

[@robbowman8770]

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.

[@TheDefpom]

I prefer the live comments, rather than rehearsed

[@SirMo]

"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!

[@drdiesel1]

Exceptional video, very well done Sir.

[@tedvanmatje]

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 ;)

[@rogeronslow1498]

Jackpot. It works! Well done.

[@gbowne1]

"Signal Path" - "FAIL" lol.. that one was hunting for you Shahriar.

[@DaruoshAghajaney]

excellent troubleshooting and repair. thanks a lot dude.

[@phuang3]

The Signal Path fixed the signal path failure. Very interesting.

[@philippoMC]

I like the style how it is. Great video!

[@AF6LJSue]

I like your repair videos the way they are.. good Stuff

[@PetreRodan]

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?

[@Thesignalpath]

I did. It does run hot, some places up to 60C.

[@waverleyrocker]

Fantastic video. Thanks very much. Good job on the fix!

[@widecast]

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. 😊

[@widecast]

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.

[@tariqgorsi7505]

Brilliant work, thanks for sharing.

[@hpux735]

These videos are great! Please don't change the format :)

[@glenwoofit]

I like this style of video. Great Video!

[@MochaboyRC]

amazing job! watched the whole video! Format is fine...don't change a thing

[@grantfullen9559]

I like your repair vids just the way they are :)

[@PapasDino]

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?

[@RobertGallop]

Awesome repair!

[@kaigarrels]

Great video, thank you. Can you explain why they chose such a complex LO design?

[@hannonm]

oh wow...thats a lovely unit.

[@DoRC]

$2700 is a heck of a gamble. Is this the most expensive broken thing you've purchased?

[@Thesignalpath]

It is the most expensive broken one yes, definitely the biggest risk considering no information is available.

[@stevec5000]

There's one on Ebay for $18,500 so it's not too much of a gamble.

[@daveblane6442]

New they are about FIFTH FIVE THOUSAND DOLLARS! GREAT job! NO schematics, minimal block diagram -- and you fixed it! SOOO impressive!

[@BruceNitroxpro]

@@Thesignalpath, This shows that you are indefatigable. NOTHING stops you or fazes you IF you feel challenged. Superb engineering.

[@daverhodes382]

@@stevec5000 There's no logic in that statement.

[@fnordingers]

"I can do FM modulation, if i'm fast enough!" LOL

[@Urbanstrangler]

Really cool video. Keep it up, thanks!

[@breedj1]

Excellent video. Maybe it would be nice to use two cameras and split screen to show the scope screen and the probing?

[@MauroSedrani]

Excellent video!

[@ernestuz]

A superb video!

[@OnTheRocks71]

I feel like I'm getting spoiled with all these new videos.

[@nikmilosevic1696]

I really enjoyed that video, thanks.

[@andreykorenev1433]

Hi! Thanks again for your videos! And congratulations with a successful repair! Can you tell us something about probing microwave signals next time? I mean, which types of probes exist, tips and trick of using them. The video about the Agilent power probes was really useful.

[@ddlsmurf]

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

[@trickyrat483]

Keep the style as-is. We all make mistakes, so no worries. :)

[@fthorup]

I really enjoyed that!