TSP

[@artiem5262]

I worked for HP/Agilent in Labs, and supported the Santa Rosa site for a while. Congratulations on fearless troubleshooting and repair! Not many are willing to crack open an OXCO to look for problems, but that part is easy after digging into one of the RF decks!

[@vincei4252]

Love the new logo with Pooch :-) Stay safe in these crazy times!

[@erikbertram6019]

Ah yes, the classic common source cat amplifier, I think I'm going to use my cat as a wifi extender as well.

[@yoksel99]

Those two power transistors inside the oven are actually the heater elements. They operate in linear mode, and are easy to control how much power they would dissipate. And the white wiring inside probably goes to a temperature sensor close to oscillator itself.

[@Thesignalpath]

Interesting. It could be! I should have measured it.

[@jorditribo94]

It makes sense

[@pitot1988]

Best RF/Microwave repair video series on KZbin of all time!

[@nesagljivic]

The beauty of the troubleshooting. With thousand and one parts , you single out one poor diode and two wires detached. I really like to watch the process. Stay safe!

[@Cyruscosmo]

For future reference on repairing that crystal. Those broken wires could be welded to new wires by a good jeweler with a laser welder. I had some work done on a set of diamond ear studs that had one missing mounting stud, they welded a new one on in a few minutes.

[@video99couk]

I'm mystified how you could get thumbs downs for a video of this quality. Just what could anyone find to complain about? Good luck with getting and using a wirebonder, I last got to play with one of those around 1988.

[@JimmyAlzen]

There is a simple explanation for this; the like and dislike buttons are very close together. That's not a very good UI decision and you'll always get some misclicks.

[@vidasvv]

@@JimmyAlzen I have accidentally clicked the dislike on some videos when using my laptop with my fat fingers but you can always correct it. But I agree why anyone with even no brains would ever leave dislike on his great videos !

[@amciaapple1654]

That make the quarantine a little more bearable. Thanks!

[@proweb7271]

all videos about " Repair of an Agilent ... " are very nice, thanks, please continue ...

[@marwinthedja5450]

I think Pooch wants to tell you that you should definitely get a wire-bonder ;)

[@guilhermetheis4902]

Hey Shahriar, your episodes are getting better and better (I didn't think it'd be possible). Love the repairs and explanations! Also I want to compliment your work at Nokia Bell Labs, I've been through some of your papers and they're amazing! Cheers

[@Thesignalpath]

Thank you.

[@bfrost999]

Brilliant video, so professional. Fascinating to debug it in my head along with you, regards, Brian.

[@rigorouselectronics8089]

I really appreciate your videos and how you outline your train of thought. Invaluable.

[@ZoomtronicBlogspot]

I enjoy to watching these repair videos

[@campbellmorrison8540]

Wow a real black art, I didnt even recognize the parts you were talking about, great to have this Hi Frequency stuff

[@vincei4252]

Excellent repair! Looking forward to you getting a wirebond machine!

[@seymanursumeyraa]

Hi, do you know which kind of wirebond is used at 27:05 on the output line?

[@davidv1289]

Another excellent video, thank you! I'm suprised there is no key/notch/pin/set screw to prevent the crystal mount from rotating when the screw is tightened.

[@trickyrat483]

Consider their idea of anti-tamper - touch it and we'll have to sell you a new one! :)

[@madtechie.]

Nice work Shahriar. Looking at the way the crystal pins were twisted suggests the damage was done during reassembly. Sooo close :-)

[@raymonddompfrank1789]

I was thinking the same. BTW, how about long time oscillator drift after the thermal shock of soldering the crystal's pins?

[@Gameboygenius]

I like cats as much as the next guy, but connecting a static generator directly to the gate if a FET...? :)

[@electronic7979]

A nice and useful repair video. I watched every second with pleasure.

[@emiralid513]

Great video, thanks!

[@fromeijn]

Cool stuff!! It so nice to see the debugging process!

[@h2o1066]

Awesome as always. All your videos are very informative. Thanks a lot for sharing these.I learn a lot from your videos

[@GnilCH]

EXACTLY what I was waiting for! 😍

[@Dextermorga]

This is all interesting. I even understand (at least I think, I understand), I studied electronics at high school (I would not even think about repair without a Masters degree). But I can not imagine, I could do the repair. even if I had all year for repair. I would 100% made even more damage to the instrument. My respect for all people who can do these repairs. It's quite depressing for me. But at the same time, I am enjoying them all. Thank you for your time and effort.

[@TheRestorationClinic]

Your videos are absolutely amazing. Keep up the incredible work!

[@maxwang2537]

Wow, how can I just say it's amazing?!

[@anandarochisha]

Impressive. Good Job !

[@tommihommi1]

these YIG-Modules are a really common failure point in HP/Agilent/Keysight devices. Earlier instruments didn't have the option to switch to a different reference, I think they added that because the YIGs fail so often

[@octavmandru9219]

There was nothing wrong with the YiG. There is a faulty PIN diode and a broken 10MHz TCXO module

[@Thesignalpath]

Keep in mind that the YIG does not replace the OCXO. In fact, the YIG always needs to be in a closed loop (using a PLL) in order to have the desired frequency.

[@metasequoia12]

Great video. One vote for a wire bonder!

[@AllElectronicsGr]

Considering that the bias leakege was happening before the ALC detector, you could put an AC coupled path to the next module. Any signal loss would be compensated by the ALC. Would an AC coupled V thru solve the problem?

[@Thesignalpath]

I did consider that option. But remember that the broken diode is constantly stressing all other diodes in that module by forward biasing them. Removing the broken diode from the circuit completely is better in the long run.

[@aqib2000]

The Signal Path I would have etched my own pn junction into the pcb

[@srmeister1]

@@Thesignalpath couldnt you put an SMD Diode ontop of the dead diode(after disabling it) and wirebond or even solder it into the circuit?

[@dtiydr]

@@srmeister1 The diods are some very special very high frequency ones and only the chip it self which you can't buy but must be replaced with, and ordinary smd diod on top would toally whack everything way, way of its spec since among many other things cant handle the frequency. And you do that by hand with stuff that is less than 0.1 mm wide and bonding wires that are less than 0.05mm, won't happen even under a microscope. And the 32GHz impedance and everything has to be hold so just the fact that one thing is 0.1 mm higher then the others will make that change. And if you looked at the video he clearly say he don't have wirebonding machine.

[@zainaabdin]

Though it is not my field but I appreciate your job highly good luck

[@SalvagedCircuitry]

What is the best way to tell if an RF board is ceramic or Teflon, like at 24:43? I would have thought that board was some type of Teflon base material. Thanks!

[@jjoonathan7178]

If they can get away without flexing, like they can in a rigid metal enclosure, it's going to be ceramic, because the performance is better. If you have doubts, you can bang on it and see if it goes "click" (ceramic) or if it goes "thunk" (teflon).

[@SalvagedCircuitry]

@@jjoonathan7178 Thanks for the info. Yeah! I was thinking you could lightly tap it with a plastic spudger and judge by sound. Thanks!

[@johncox114]

at 25:15 where the trace jumps over the isolation it appears to be touching, could that cause the voltage you were seeing?

[@fredo514]

Love the new intro!

[@craigs5212]

Nice video! Yup, a wire bonding station would be a nice addition and produce some great content. Then you need as assortment of replacement chip diodes and transistors. Wonder if there is a supplier that sells chip components in less than 100K quantities.

[@tommy154451]

Amazing video. Thank you for it. What are those grid-like structures coming from the ICs in 24:09 ? Is that some kind of low-parasitic bonding technique ?

[@Thesignalpath]

Tomáš Thúróczy yes! :)

[@proweb7271]

VERY VERY NICE VIDEO, VERY THANKS ... WOW

[@nikmilosevic1696]

Another excellent video with a new error, another great learning experience.

[@saarike]

This was really interesting! Nice repair!

[@r.kelectronics6164]

Nice job 👍

[@Carlitto314]

Cool, interesting episode, thanks!

[@xDevscom_EE]

PSG!!! I wanted one so bad , but even borked ones cost like my calibrator :(

[@Thesignalpath]

Me too. :( I'd love to have a good PSG (with vector modulation!)

[@ronniepirtlejr2606]

I had a ribbon cable with similar manufacturer design on a weight scale. It had an internal short down to .5 ohm. I looked around with a magnifying loupe but could not find it. I didn't want to continue poking holes in it trying to trace it down so, I replaced the ribbon with wires. I have a working scale again.

[@mysticmarble94]

Am I the only to think that curve 38:36 looks a little bit bent towards the right ?? Especially at peaks ?

[@fenugrec5697]

Neat ! Considering there was a high DC bias through much of the doubler too, how did it not get damaged ? Or can those usually handle the puny -13V bias ?

[@googacct]

It was interesting to see the little coils of wirebond wire in the module. Are those there for some kind of trimming? Adding those little coils in must have been pretty tricky. If you get a wire bonder, a few words of advice on shipping. Make sure the seller properly secures all moving parts. I had bought one a few years a go and the seller did not secure the arm. The head assembly and several switches got the living daylights beat out of them. Also if it is an older west bond, like I bought, make sure they secure or remove the PCBs from their slots. I had to replace a broken 40 pin edge connector because of that.

[@trickyrat483]

I thought the coiled wires were inductive elements..?

[@Thesignalpath]

Yes they are inductors designed to be attached using the same wire bonding techniques.

[@fatthar4804]

just amazing

[@PeterCut62]

It's a MacGyver surgery ! Very nice. Thank you.

[@zaprodk]

Love the new logo - Approved!

[@laurentthiol]

amaizing! that was a great discover 👍

[@YamenNazer]

Oh my god what just did i watch!!! this is absolutely amazing sir i appreciate your hard work you are legend absolutely!! How did you learn these things sir?

[@friedmule5403]

May I please ask you what cable you are using? I do need some thin pliable low Hz coaxial cables. :-)

[@KD0CAC]

I want to see the wire bounding unit on your bench ;) Thanks again

[@tomteiter7192]

oooo, looks like the mounting screw of one transistor (or both) is used a sa set screw to hold the crystal can in place... thats a bit.... sneaky...

[@ashrafhussain2326]

That is called a repair tutorial.. Awesome sir My question is what is the component connected between psg and Spectrum Analyzer to connect DMM.. Can we measure dc volt directly from PSG output port on DMM

[@BruceNitroxpro]

And here I was, wondering about the LAST schematic symbol you added to your logo.... the little pussy cat! I'm SURE she must add something to the logo!

[@MrJosiahCochran]

It looks like the V connectors go straight into the can and have a nice flat binding post that is wire bonded to the strip lines. Where can I find such a connector?

[@ashrafhussain2326]

Is UNLEVEL problem be solved with same troubleshooting..if not please guide.. And where can I find the block diagrams of keysight vector signal generator

[@IsettasRock]

I remember seeing a wire bond machine on ebay not long ago, it was for parts/repair

[@GeorgeGeorge-xj2bc]

Absolute specialized laboratory equipment and the repairings of these are not for common mortal technicians.Still happy even just take a look inside them.

[@joeseymour8504]

Is there a reason why you did not run self test to help diagnose the problem?

[@risfutile]

Did you pick up Electroboom's arc shenanigans in your lab or do you watch his videos anyway? 😁

[@mehdisediki5852]

Plz I need the RF output module schematic,and datasheet for M11 1005 SMD package

[@aaronlow1977]

I have to second the hp vs others service manuals. HP and successors have excellent service manuals but Rohde & Schwarz has a terrible service manual even when I got one from the vendor. I received a service manual from Rohde & Schwarz for an ESIB40 EMI Receiver and even that service manual did not have enough information to diagnose the problem. Additionally, HP and successors user manuals are fantastic vs many other companies.

[@companymen42]

Nice new intro!

[@AKAtheA]

how does one replace the diode? (as in how do you get it off without destroing things around it) Those coils made of bonding wire look like they've been tuned by hand...

[@artiem5262]

The bonding wires in some situations can and are used as adjustments! As an example, positioning the bonding wires in the Hp/Agilent 848x RF power sensors is an important part of calibration.

[@mikewillis1592]

I was assuming a copling capacitor had gone short circuit. Perhaps a DC block would have been a quicker temporary fix?

[@Thesignalpath]

The DC voltage constantly forward biases other diodes in the same module. DC block would have solved the issue for the next stage, but no the same stage.

[@witeshade]

considering the fact that the unit is now functional, but missing a diode and thus technically not up to spec, is there anything they can do with the instrument? Can they rent it, or will they just have to sell it as an as-is kind of thing? Or just wait until they get the correct parts anyway.

[@Thesignalpath]

It depends on where it is used and for what purpose. If you want 100% factory performance in all conditions and corners, probably a new module is required.

[@redalaaraj8464]

I can make a generator of 50 ghz with 12v ? Thank you

[@notamage9956]

Here is a sincere question: How do you afford all of those equipment? Honestly I can financially manage myself - amen for that - but the thought of buying an entry level VNA, or even a simple Spectrum Analyzer overwhelms me. Are these equipment simply not available for hobbyists? If so, then how do we measure stuff at GHz frequencies?

[@spacenomad5484]

"Keysight classic design" - That's one way to spell HP

[@simonstergaard]

Triple keyboard...wooo hooo

[@Thesignalpath]

Simon Østergaard There are 14 of them actually. ;)

[@MatthewSuffidy]

Creative thumbnail had me thinking it was a flow oven.

[@DavidMG99]

👍👍

[@Iceteavanill]

What could have happened if the -13V would have reached your spectrum analyser?

[@stargazer7644]

He would have had two instruments to fix. As he says at the beginning, spectrum analyzers often can't tolerate any DC voltage at their inputs. It can destroy the input circuit.

[@lmamakos]

I think it lets the magic smoke out!

[@philliplopez8745]

Does your head ever hurt ?

[@ve2zzz]

A few years ago, going upto 31,8 GHz was some of exotic.... But today with 5G phones (25 - 39 GHz in Canada, 27,5 - 28,5 GHz and 37 - 40 GHz in USA), such frequencies wil become banal... ...but good luck for coverage, believe me !!!!

[@HelmutTschemernjak]

Great video, great repair. Don't forget to add a PayPal Link that we can sponsor your Lab. Regards from Germany

[@Thesignalpath]

Thank you. I will.

[@derkeksinator17]

3Gig isn't that bad, you could probably replace the diode.

[@ptronix]

Putting up to 13v dc into the attenuator surely is bad thing? But obviously it survived

[@Thesignalpath]

There is a biasing resistor in series with the diode and 13V source. That’s what has saved everything.

[@ВиталийСадовников-ж1п]

Hi guys! Help me upgrade the firmware E8251A 20ghz

[@tanzimhaque6219]

Pooch says "give an oscilloscope to this poor guy"

[@drdiesel1]

Isn't Alltest the company that threatened to sue EEVblog members a few years back?

[@NSAwatchesME]

don't you have spare components??? at least diodes jeeeez

[@bfx8185]

I love corona :D That's what I was looking forward will happen on this channel :D I'm so happy :D (yes I'm, but guys take care) thank you!!! Now you are ready for my donation;) 5min later: I'm your patreon allready ... keep going , I love those videos ;)

[@thevoidedwarranty]

Hi, are u persian ?

[@Thesignalpath]

hamedtheunforgiven Yes.

[@thevoidedwarranty]

@@Thesignalpath we are very proud of u man , keep learning .

[@Thesignalpath]

@@thevoidedwarranty Thanks!

[@GeorgeGraves]

Weird thumbnail.