TNP #31 - HP 87421 & 83017A 26.5GHz Microwave System Amplifier Teardown, Repair & Experiments

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Жыл бұрын

In this episode Shahriar repairs an HP 87421 power supply in order to revive a HP 83017A 0.5-26.6GHz Microwave System Amplifier. The power supply has multiple bad capacitors which can be readily exchanged. An X-ray of a bad versus good capacitor is also shown. A custom cable must be made and the pinouts of each module should be revers engineered.
The amplifier successful powers on and various performance metrics are measured. S-parameters, noise figure, PSAT, OIP3 and detector are all measured and verified. The instrument used are the Keysight FieldFox, Junkosha RF cables, R&S NRP power sensor, R&S SMB RF Vector Generator and R&S ZNL20 real-time spectrum analyzer / network analyzer hybrid.
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Пікірлер: 63

@bengineer_the Жыл бұрын

"if you don't have an LCR meter, you can always x-ray the capacitors" - XD ..I love you.

@dasflugdasflug4201 Жыл бұрын

Sure, we always go to XRay if we don't have LCR meter

@tommihommi1 Жыл бұрын

Really the correct approach is to build a fixture and de-embed it so you can use your VNA as a LCR meter

@neonkev7866 Жыл бұрын

@tommihommi1 Well a VNA is impedance analysis of a different sort, but I don't think that electrolytic is going to be a capacitor above a few KHz.

@tommihommi1 Жыл бұрын

@@neonkev7866 VNAs made for lower frequency stuff often go down to 9kHz

@neonkev7866 Жыл бұрын

@tommihommi1 The lowest freq. VNA I know of is the E5061B with option xL5, which goes all the way down to 5 Hz. I'm not sure if there is there is any sort of limit on output capacitance however; a bulk electrolytic like this would have much more capacitance than any practical rf device.

@tommihommi1 Жыл бұрын

@@neonkev7866 LCR meters work at the range of 100Hz to a few kHz

@CezarVideoBlog Жыл бұрын

Hi nice work ! but it is "bugged" : ) - 11:09 ants will attack a scout was there :)

@Thesignalpath Жыл бұрын

Its a lab ant!

@jjoonathan7178 Жыл бұрын

@@Thesignalpath I feel like this is the second or third lab ant... one of these days you're going to open an especially tenured piece of equipment and find the nest, here's hoping you catch it on camera lol

@der.Schtefan Жыл бұрын

Your knowledge about each and every aspect of these devices, and your way to present it, rivals, nay, surpasses my old "high frequency and telco engineering" professor from my study years. And all these years he was the gold standard. "Oh yes, about the -12V bias voltage", "Oh, about this microwave technology", "and 123 we have made a simple radar...?

@rarelycomments Жыл бұрын

Who doesn't have an LCR meter, but does have an X-ray machine? lol

@fredflickinger643 Жыл бұрын

Deepening the divide by what is taught and what experience brings to the table especially in RF engineering.

@mikesradiorepair Жыл бұрын

I see you have moved on from cat scans to ant scans. Little guy was checking out your display at around 11:10 on the right side of the screen. 🙂

@RoGeorgeRoGeorge Жыл бұрын

Yes, but only after checking all was properly connected, at 7:40 :o)

@AndrewZonenberg Жыл бұрын

There's a bug in the FieldFox! Gotta let Keysight know.

@tfinmoraes Жыл бұрын

Hi Shahriar, thank you for sharing this content! Really good to see you are motivated to keep creating content for us. A suggestion here if I may. These experiments that involve technical measurements, particularly those that characterize some aspect of a DUT /equipment are fantastic, because it scratches a bit deeper on actual theory. I'd suggest, however, that you take a bit more of time to explain more thoroughly what these parameters are and what they physically represent. For instance, why will you get some ISI? Why would you want to go to DC for broadband applications? What is the OIP3 figure of merit and why is it important so that you are measuring it? What is the importance of the saturated output power measurement? Why will the intermodulation terms go down 3 times faster if they are dominated by the spectrum analyzer? You've mentioned you are working on a tutorial of NF, that is fantastic. Please mind you, I am bringing this up as a suggestion because the setups that you have here are so high class that engineers like me, that don’t deal professionally with RF, feel the need to know. Your channel is highly educational, and a great starting point for someone to do his/her own research. Just pointing out, at the beginning of the channel, there was more of those even more educational tutorials and explanations. I know, however, it does take more time and effort. Anyways, thank you again for all you share with us!

@purerhodium Жыл бұрын

Note that graphite has a very high thermal conductivity along the basal plane, but fairly low thermal conductivity in the perpendicular direction. This makes it an excellent heat spreader, but it must be kept thin to avoid excessive thermal resistance.

@Thesignalpath Жыл бұрын

Yes, I should have mentioned that too.

@keithlambell1970 Жыл бұрын

A tutorial on Noise Figure measurements would be very useful, thank you

@PixelSchnitzel Жыл бұрын

Very interesting! I can't wait to see the project this amp will be used in. I would totally love a video on noise figure!

@rolfdieterklein Жыл бұрын

excellent video again. x-ray of the capacitors is really a great idea never saw this doing from someone.

@Bianchi77 11 ай бұрын

Cool video, well done, thanks for sharing it :)

@logmeindog Жыл бұрын

Excellent!

@muhammedtunbak1385 Жыл бұрын

New to the channel, i don't know if it is common practice and i didn't know to put attenuator after amplifier while testing OIP3 to verify it but i loved it its so smart. Thanks for the video

@tommihommi1 Жыл бұрын

nice that The Noise Path is appropriate, you're talking about noise figures in the video after all

@sinager Жыл бұрын

+1 for the noise figure tutorial

@OneBiOzZ Жыл бұрын

i will never as long as i live get used to the sight of the remote display flukes

@neonkev7866 Жыл бұрын

Nice repair work! Old capacitors never 'fail to disappoint'. Or do they? Hmm... Looking at this older unit really shows how far amplifiers have come. If you can get your hands on a Fairview USB preamp, those seem like interesting units. They are about the size of a large thumb drive, use USB for power, and are fairly broadband from 50M-18G/40G. The 40G part # is SBUA-400-12-010-K.

@joshmyer9 Жыл бұрын

17:50 Off-topic, but: does anyone else find the Fluke 233 deeply unsettling? My brain kept trying to find the bottom half of the multimeter, with a "body horror dread" thing going on.

@Thesignalpath Жыл бұрын

It does look strange...

@cashewmilkfan Жыл бұрын

at 11:08 an ant climbs up the side of the fieldfox microwave analyzer

@neonkev7866 Жыл бұрын

It's ruined. I'll take that e-waste off your hands now...

@tomteiter7192 Жыл бұрын

ooo I'd love to have a Fluke 233. The remote display feature is so cool :D

@xDevscom_EE Жыл бұрын

Still room to get capacitor CT or MRI 😅.

@neonkev7866 Жыл бұрын

Would you like your capacitors shaken or stirred? 😂

@R2AUK Жыл бұрын

🔥 👍

@user-lq7mo9oy7q 7 ай бұрын

Thanks a lot Shariar for this tutorial on the HP microwave amplifier... two-tone test: Did you test it with 10 dB down on the input of the amplifier ? The 3rd overtone values would be interesting to see on a lower RF level.

@unrealillusion87 Жыл бұрын

Now I want an X-Ray machine :D

@leoroberts2708 Жыл бұрын

Lol, Ant 🐜 in the lab at 11.55

@Thesignalpath Жыл бұрын

Its a lab ant!

@LordPrecision Жыл бұрын

13:00 looks like the power sensor is hanging on the output of the amplifier. Not good: it puts stress on RF connectors.... Wouldn't it be a good idea to put something under the sensor?

@kcmichaelm Жыл бұрын

I caught the same thing - I’m assuming there’s something underneath. I know Shair knows better than to stress connectors after years of talking about how delicate they are.

@Thesignalpath Жыл бұрын

There is a small plate under the part which you cannot easily see. But certainly nothing should ever ben resting on the connectors.

@paulpaulzadeh6172 Жыл бұрын

Just wonder how is THD in such amplifier, anyway to measure it? But very nice way to find out IMD .😮

@Thesignalpath Жыл бұрын

I could have measured that too, actually easier to measure than TOI.

@tamaseduard5145 Жыл бұрын

👍🙏❤

@LyleHouk55 Жыл бұрын

Did any body see the ant?

@w6by Жыл бұрын

Yeah, funny.

@neonkev7866 Жыл бұрын

11:10

@kariputtonen Жыл бұрын

Pooch must be sleeping. :)

@Thesignalpath Жыл бұрын

Lazy lab cat!

@w6by Жыл бұрын

Maybe the amplifier needs an ant-tenna.

@ThatEngineerGuy_ Жыл бұрын

Real ones let the ads roll. Excited for this one. Why’s the video only 720P :(

@Thesignalpath Жыл бұрын

All videos are in 1080p 60FPS. Please check your settings.

@dtiydr Жыл бұрын

If the video has very recently started to be uploaded then the initial video resolution from KZfaq is very low (just to get something out even if the whole file is not uploaded yet) and will slowly go up to full intended resolution when the whole file has been uploaded.