TSP

[@wadehsu2347]

Most likely there is a DBR laser inside the Agilent lightwave transmitter. If it's the modulation it will cause symmetric sideband on both sides, however to create sideband this far away you have to modulate the laser at hundreds of GHz frequency. The most likely cause of the two peaks, besides a broken laser, is that the laser hasn't worm up properly and the temperature of the DBR is not yet stabilized which cause the diode to mode hop.

[@topherteardowns4679]

Watched it all, loved it. Would like more of whatever you want to film. Always interesting and educational. May the universe bless you for your noble deeds

[@soiTasTic]

It always amazes me how Japanese engineers manage to use every bit of available space inside a case.

[@w2aew]

What LED backlight modules do you use to replace the CCFL?

[@Thesignalpath]

I usually just buy something like this one: www.ebay.com/itm/DC10-30V-540mm-Adjust-Backlight-Strip-Kit-Update-24-LED-CCFL-LCD-to-LED-Monitor/322590707639?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

[@food-roger.eijkhoudt7049]

Thanks for the great video’s. Gotta love them with great appreciation. I recall from spectroscopy classes at university that spectral lines such as laser light may be splitted by magnetism. I think it was called the zeeman effect. Hope this helps.

[@mikehorrod4367]

I just applied for a job at Anritsu today here in japan.

[@RaivisRengelis]

When it boots, it says MS9710B, not MS9710A.

[@Thesignalpath]

I didn't notice that! Interesting.

[@jtowich]

It would be interesting to know the source of the two peaks, even if it in fact is a problem and you are not able to fix it.

[@douro20]

I think the old LeCroy WaveStation had a built-in printer as well as some of their 9300 series oscilloscopes.

[@AF6LJSue]

That was great. :) Thanks for the video, a few THZ above what I am use to working on....

[@hausaffe100]

a bit late to the party, but might this be fine Struktur splitting due to stark or Zemann effect?

[@442bank]

Hi, I would like to ask during disassembly, did you find some small battery to run clock ? (Like cr2032 or cr2024) bcz mine is not record the present time anymore. Every turn on it always show initial date around year 1996. Thanks

[@BluefanNL]

Nice! I have the exact same OSA, if you want I can do the same test with the attenuator. I actually got a grating error once, freaked me out, I though my nice instrument was broken. Good to see it's probably just a cable issue. The laser you have can have 2 modes, actually laser diodes usually have more that one or skip between modes, having only 1 takes some effort. I also have an ANDO OSA which is a lot smaller but it has worse specifications and it's boken, it simply won't power up. So it can be made even smaller. I also have an HP wavelength meter, it occasionally gives a motor error. It has 1pm accuracy but not for peaks that close together probably, and the second peak is 12dB lower. I'd have to look up the specifications. you can actually acces the spectrum the wavelengthmeter measures, I though both graphically and via GPIB, then you can check if it cannot resolve it or that it's just the peak searching algorithm not separating the peaks.

[@brunopinheiro698]

hello, have you solve your problem? with grating error? Thanks.

[@KaveendraVithana]

It may be a second order intermodulation distortion, but changing the fiber is a first step. If fiber and laser source is hunky dory, then may be the issue is on the analyzer, may be modulators.

[@wadehsu2347]

Kaveendra Vithana in order to have intermodulation, you need two frequencies. If the laser is fine, then it should output single frequency. Unless there are some nonlinear process happening inside the fiber. Which is pretty unlikely judging by the low power output of the laser.

[@EvanZalys]

What fraction of equipment that you acquire are you able to fix?

[@Thesignalpath]

I have posted every instrument I have attempted so far with the exception of one scope where the custom ADCs where bad and one Keithley DMM.

[@EvanZalys]

Wow, that's really impressive.

[@vataie]

It is perhaps a side mode from laser source, looks like there is also a small peak at the left within a same distance. There is a wavelength tuning nub at your source that changes the laser temperature, it is interesting to see if changing the temperature has any effect on these modes. BTW, you will have a ~110GHz oscillator in your lab if you send this laser to a high speed photodiode!

[@wadehsu2347]

vahid ataie where is the 110GHz coming from?

[@PlasmaHH]

Result of mixing of both frequencies

[@wadehsu2347]

If it's the beat note frequency it should be ~190GHz not 110.

[@vataie]

Sure, to be accurate it is 138GHz. But the interesting fact is that having two locked emitting light sources is not something that can be easily generated at ~1nm apart, and it could be quite useful.

[@wadehsu2347]

I don't think those two frequency are actually locked to each other. And also locking two laser at 1nm apart it's actually quite easy. Use a transfer cavity and Pound-Drever-Hall lock you can lock a slave laser to any mode the cavity allows.

[@TheDefpom]

Those look more like sidebands, centered around the main frequency, but my experience is RF not optical,

[@brunopinheiro698]

hello my friend, i have one anritsu ms9710b but wont start. have one error optical unit initial error. Can help?

[@pa4tim]

Can you make a video about how to measure a wavelength and maybe in relation to mass spectrometery

[@DoRC]

You were right it's not always a bad cap. Sometimes it's a loose connection:) :) :) kidding, you do awesome work and I love your videos!

[@PapasDino]

Were there any other issues you found or was it simply reseating boards/connectors that brought it back to life?

[@Thesignalpath]

I re-built a lot of the connectors and re-set the boards. The grating mirror was giving an error and the LCD wasn't working. Both seemed to be fixed by-rebuilding.

[@taubrafi]

It was 12dB difference not 4.8dB.

[@Thesignalpath]

You are right, I was looking at the wrong place. Thank you.

[@DavidMG99]

👍👍

[@1st_ProCactus]

I had no idea lasers could be polychromatic. Makes me wonder if frequency modulated LEDs or lasers exist too. I must consult the Google edit: Seems there is some fancy things and concepts, But nothing as a single device like an LED. Maybe one day.

[@jaa93997]

Optical voodoo >> microwave voodoo

[@wim2874]

I have a MS9710C that I repeared. The unit was pretty beat up (I bought this one from Ebay: www.benl.ebay.be/itm/ANRITSU-MS9710C-OPTICAL-SPECTRUM-ANALYZER-ANALYZER-OPTICAL-opt-05-G410/311929746096?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649) To answer your question, when I enable the optical attenuator, I see exactly the same result as you do (increased noise floor). So, or this is a common fault with these units, or it is normal. It seems you have the internal calibration source with two ports (SLD output and reference output, see www.upc.edu/sct/documents_equipament/d_125_id-630.pdf) , which one did you use for the calibration? I only have the reference output (1-port), but I was expecting to see the acetylene dips in the spectrum, but this is not the case (also not on yours, hence my question). On mine I can execute the wavelengt calibration with succes, but when I try autoalign I get a level error. I used to think the acetelyne cell had lost is content, but now when seeing yours, this is maybe not the case. When I see your video, your peak reference output is around -32dbm, where mine is -36.8dbm, so this is maybe the reason.Anyway, thanks again in making this interesting videa, it always make my day when a new one appears!

[@gesteinsrad2409]

I appreciate that you take out the boring bits but this time around you really lost me. Somehow it went from ripping out the HV backlight to booting with correct date and time.

[@PeregrineBF]

He cleaned the contacts, put it back together, and it worked. Probably loose contact / corrosion was causing the issues. It's a boring fix, none of the active bits were bad (except the CCFL backlight).

[@totaldude155]

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