What Oscilloscope buy? - Page 1
Forum section: electronics / testgear

author: montcler
author_rank: Contributor
timestamp: September 23, 2015, 06:38:45 am
content: Hello all,After so many years with my old Hameg 1507-3 testing my hobbies, and repairing etc ...I decided to buy a digital one, have never had one in my hands, and really have very many things along these days have gone reading in the forumsand meaning, characteristics of everything in this new world of digital oscilloscope. (Memory depth, sampling rate, update rate waveforms / s) etc ...And I'm really saturated.I would like that professionals madness every day with these teams guiasesis me into buying these models that I think are good.I show you what I think (all of 200MHZ):1 - DSOX3024T Keysight2 - Yokogawa DLM20223 - 3024 LeCroy WaveSurfer4 - Tektronix MDO30245 - Rigol DS4024Thank you.

author: JackP
author_rank: Regular Contributor
timestamp: September 23, 2015, 06:48:26 am
content: May I ask your budget?

author: montcler
author_rank: Contributor
timestamp: September 23, 2015, 07:16:59 am
content: Hello,Yes, I would like to not exceed the 4K6€Thx.

author: kripton2035
author_rank: Super Contributor
timestamp: September 23, 2015, 07:30:18 am
content: I really like the Tek MDO3000 and you have huge deals actually until 30th septembre : the 3ghz SA and all decoders for free ...but sorry I don't have one, and don't have the budget to buy one so can't argue about it more than that !

author: tautech
author_rank: Super Contributor
timestamp: September 23, 2015, 07:39:33 am
content: Quote from: montcler on September 23, 2015, 07:16:59 amIf we knew your location we could make local for you recommendations.You can select a country flag for your profile.

author: montcler
author_rank: Contributor
timestamp: September 23, 2015, 08:06:56 am
content: Thanks Kripton2035, but it is very expensive formy budget.At the moment the Keysight offering evey all free licenses until end of October.I am from Spain.Thx.

author: hayatepilot
author_rank: Frequent Contributor
timestamp: September 23, 2015, 08:45:50 am
content: Dave did a Review of the Agilent 3000 X Series:I'm sure you can do a lot worse than this.Greetings

author: montcler
author_rank: Contributor
timestamp: September 23, 2015, 08:49:59 am
content: Dave also said that in one of the previews, I seemed to understand that there are many functions Tektronix working for software and Keysight for Hardware .Greetings

author: kripton2035
author_rank: Super Contributor
timestamp: September 23, 2015, 09:15:06 am
content: Quote from: montcler onTodayat 19:06:56the MDO3024 is 4250€+VAT at farnell so it's around your budget (but a little higher I assume...)the Keysight DSOX3024 is 4199€ +VAT at farnell so the two scopes are quite identicalwith the tek you get a 3ghz spectrum analyzer too !

author: Groucho2005
author_rank: Regular Contributor
timestamp: September 23, 2015, 09:36:44 am
content: Quote from: montcler on September 23, 2015, 07:16:59 amWith that budget I would go for the Hameg (Rohde & Schwarz) HMO3000 series.http://www.hameg.com/710.0.html?L=0

author: nctnico
author_rank: Super Contributor
timestamp: September 23, 2015, 09:46:14 am
content: Don't just check base prices but also include the cost of options. A few options can easely make a scope twice as expensive. Deals with free options or a bundle of options can be very sweet.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 23, 2015, 10:31:23 am
content: Quote from: montcler on September 23, 2015, 06:38:45 amThe DSOX3000T is a good scope but also very expensive for what you get. It's also a somewhat dated hardware design (based on the DSOX3kA which came out in 2012) which has a very fast update rate but lacks in terms of memory (only 4Mpts, which is pretty low these days) and has limited FFT (64kpts only). At the moment you can get all software options for free, and a few of these aren't available on other scopes, and if you need them then the DSOX3kT is your only choice. If not then it's still a decent scope for a lot of money.QuoteYokogawa has nice scopes, and the DLM2022 is an interesting piece of kit. However, Yokogawa is pretty expensive, even more so their support which outside Japan for scopes can be pretty spotty. Plus the DLM2022 has a pretty low sample rate (i.e. only 2.5GSa full channel), and is a quite old an old design (IIRC it came out in 2009). It shows that Yokogawa's main customers for their kit is power electronics. Plus the selection of available probes is very limited.I wouldn't buy the DLM2022.QuoteThis is a very nice scope, and would be my recommendation unless you need one of the options only available in the DSOX3024T. It has very good scpecs (4GSa/s, 10Mpts memory), a fast update rate, a large screen, and is the only scope in your list with an UI (LeCroy MAUI) that has actually been developed for touch interface. It also has some features found in LeCroy's high end scopes like WaveScan (an analysis tool for finding glitches, runts and other signal deviations), and pretty good FFT (up to 1Mpts). It's also cheaper than the DSOX3024T.QuoteWell, it's a somewhat interesting scope as it comes with a built-in spectrum analyzer (SA). However, the few times I have seen one in real life I found it was buggy and slow, and the built-in SA has pretty poor specs. I'd say if you need a all-in-one unit that does scoping and SA then this might be worth considering, but in any other case I'd give it a pass. Plus Tek's support isn't as good as it used to be 15 years ago.QuoteWell, what should I say? It's a pretty basic scope in terms of capabilities and performance (way below the other ones on the list). It has been plagued by a lot of firmware problems of which many (but not all) have been fixed, but there are still issues with it. It comes with large memory but that's more like a tick box exercise as it can't really use the memory sensibly (and FFT is limited to something rididculously low, i.e. 16kpoints or so). Plus Rigol's support is pretty much hit and miss (more miss it seems based on the reports in this forum) and generally questionable as with most other B-brands. I wouldn't go there.My recommendation would be the LeCroy WaveSurfer 3024, at the moment it's probably the best option in its price class unless you really need one of the few software options that at the moment are only available for the Keysight DSOX3000T. if you're in Europe then there's currently a promo where you get all software options for free as well (and even if you're outside the Europe then I'm sure LeCroy would throw them in for you).

author: montcler
author_rank: Contributor
timestamp: September 23, 2015, 10:55:05 am
content: Hey all,Thanks Groucho2005 but I see very little advanced, not as formerly only talked about was true Hameg and was one of the best marks before and also wanted to switch brands.Thanks very much Wuerstchenhund for your opinions of all oscilloscopes, I had in mind, very interesting.Well, I talked to Fernell Spain for the offer, and the dealer Keyseight Spain with all the free licenses in both oscilloscopes.The MDO3024 is € 5,087.37 (VAT + Shipping costs included, Tektronix).The DSOX3024T is € 4,580 (VAT + Shipping costs (free) included, Keysight).The Keysight licences all free are:DSOX3ADVMATH Advanced math measurement applicationDSOX3AERO A/D trigger and decode (MIL-STD 1553/ARINC 429)DSOX3AUDIO Audio serial trigger and analysis (I²S)DSOX3AUTO Automotive trigger and analysis (CAN/LIN)DSOX3COMP Computer trigger and analysis (RS232/UART)DSOX3EMBD Embedded trigger and analysis (I²C/SPI)DSOX3FLEX FlexRay trigger and analysisDSOX3MASK Mask limit testingDSOX3MEMUP Memory upgrade to 4 MptsDSOX3PWR Power measurementsDSOX3SGM Segmented memory acquisitionDSOX3VID Video trigger and analysisDSOX3WAVEGEN Integrated 20 MHz function/arbitrary waveform generatorDSOXDVM Integrated digital voltmeterDSOXEDK Educator’s training kitThe Tektronix licences all Free are:MDO3AFGMDO3AEROMDO3AUDIOMDO3AUTOMDO3COMPMDO3EMBDMDO3FLEXMDO3LMTMDO3PWRMDO3USBThx.

author: commie
author_rank: Frequent Contributor
timestamp: September 23, 2015, 11:17:16 am
content: My question is, why do you need such an expensive scope?, is it for hobby,enthusiast use or are you going to be doing R&D?There are very good 200MHz scopes for around the 1500.00 euro mark.

author: Circuitous
author_rank: Unknown
timestamp: September 23, 2015, 01:09:49 pm
content: I have the Rigol 4024 and I am looking to upgrade to a Keysight MSO3000 soon.The Rigol is slow and buggy. The various serial decoders are crap.Sent from my SPH-L720 using Tapatalk

author: nctnico
author_rank: Super Contributor
timestamp: September 23, 2015, 01:24:06 pm
content: I'd also look at the Wavesurfer 3000 from Lecroy!

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 23, 2015, 03:27:41 pm
content: Quote from: hayatepilot on September 23, 2015, 08:45:50 amTrue, but you can still do a lot betterPlus in Europe it also comes with all options for free:http://teledynelecroy.com/europe/promotions/promotions.aspx

author: GlowingGhoul
author_rank: Regular Contributor
timestamp: September 23, 2015, 03:47:23 pm
content: Quote from: Wuerstchenhund on September 23, 2015, 10:31:23 amTo put this in perspective, keep in mind this poster recommends LeCroy scopes exclusively and only levels criticism at their competitors. So take the advice, like all advice, with a big grain of salt. There's a good reason why LeCroy lags far behind in sales in your price range and it's not because purchasers of test equipment are fools.

author: Karel
author_rank: Super Contributor
timestamp: September 23, 2015, 03:56:45 pm
content: Quote from: GlowingGhoul on September 23, 2015, 03:47:23 pmI fully agree with GlowingGhoul! I was about to write the same reply.

author: Howardlong
author_rank: Super Contributor
timestamp: September 23, 2015, 04:24:32 pm
content: I believe that the lower bandwidth MDO3000 series can have their bandwidth liberated to 500MHz (as well as other options) if that's what floats your boat. There's a thread on it herehttps://www.eevblog.com/forum/testgear/mdo3000-hacking/45/

author: nctnico
author_rank: Super Contributor
timestamp: September 23, 2015, 04:58:41 pm
content: Quote from: GlowingGhoul on September 23, 2015, 03:47:23 pmCan you elaborate on that? The way I see it LeCroy has focussed on the high end market for a long time and has entered the low end market in recent years. When I was looking for an oscilloscope earlier this year I have considered buying the Wavesurfer 3000 but the options where too expensive. If the options where free back then I might have got one to try and probably ended up keeping it.

author: drws
author_rank: Unknown
timestamp: September 23, 2015, 05:41:43 pm
content: I really like my DSO-X 3024T.I got all the free licences with it and found the educators pack to be useful in learning the different features that were available (there is an advanced guide, you download the pdf from their site and the scope generates different outputs which you try to trigger/decode etc)I'd only used an old analogue scope 20 years ago, so it gave me an intro into the digital scope features was as I try and get back into electronics.I quite like the touch screen, doesn't feel tacked on to me, the zone based triggering it much easier by just pressing on the screen where I want to trigger. Again this may be because I haven't spent years twiddling knobs (no dirty jokes please!).

author: aklimaj
author_rank: Newbie
timestamp: September 23, 2015, 08:48:49 pm
content: Hello everyone. I'm an Engineer in Keysight's Oscilloscope Division. I'd like to address some of these comments.Hopefully you end up going with a 3000T!Quote from: montcler on September 23, 2015, 08:49:59 amMost of the functions of our InfiniiVision scopes are performed in hardware. We have a custom ASIC designed and manufactured in house which runs all of the basic functions like acquiring the waveform, triggering, updating the screen, and measurements. All of the serial decoding is done using an FPGA.Quote from: hayatepilot on September 23, 2015, 08:45:50 amDave also reviewed the 3000T this year.And a teardown.Quote from: drws on September 23, 2015, 05:41:43 pmI'm glad you're enjoying it!Quote from: Wuerstchenhund on September 23, 2015, 10:31:23 amTo address your comment about the 3000T hardware, it is actually based on the 4000X and not the 3000A.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 23, 2015, 09:42:35 pm
content: Quote from: GlowingGhoul on September 23, 2015, 03:47:23 pmOh look,my personal troll is back!How cute!But yes, you're soo right, I mean,I'd certainly never ever recommended buying an Agilent scope, no way!And I really never ever said anything positive about any other brand than LeCroy, for exampleSiglentorR&S.And of courseI'd really never say something bad about a LeCroy scope, ever.In all seriousness, I'd say you really need to get your head examined, dude.QuoteMy recommendation for the OP or anyone who's interested in real facts to read the "Rigol DS4000 series VS Keysight 3000T Better Value?" thread from not too long ago and look at the verifyable facts presented there, and decide for yourself who's presenting supportable facts and who's spewing unsubstantiated crap:https://www.eevblog.com/forum/testgear/rigol-ds4000-series-vs-keysight-3000t-better-value/But yes, I do often mention LeCroy when I think its appropriate, for the simple reason that most other people don't, because they're either not aware of their scopes or don't really know them (and believe the made up BS some people are spreading in this forum). The fact is that if people search for big brand scopes its usually "Agilent/Keysight" or "Tektronix". So not knowing about other alternatives means you could well be missing out. I may be wrong but I think one purpose of this forum is to help people make decisions, well we won't do that if we suppress anything outside the mainstream.As to LeCroy, they're not just a minor player, it's in fact LeCroy who has pushed digital scope technology forward like no-one else, not Agilent/Keysight, and certainly not Tek. When it comes to the ultra high end LeCroy is simply the only game in town, period. Even Agilent/Keysight has nothing to offer there because they don't have the technology. Plus LeCroy is the only big name manufacturer that so far hasn't engaged in bashing its competitors like Keysight and Tek tend to do in their staged 'ours-vs-theirs' comparisons, which is a plus in my book.As to their scopes, well I wouldn't buy their entry level stuff (WaveAce which is crap, WaveJet which is poor, both scopes are just bought in rebadges anyways) but starting with the WaveSurfer they offer great scopes. And I'm speaking from experience as I'm working mostly with high end gear, including Keysight's.Don't get me wrong, the DSOX3kT is not a bad scope, it really isn't. And it definitely has its strengths (i.e. the available options, some of them you can't find anywhere else in this price class). However, in my opinion the WaveSurfer 3000 is a very attractive alternative because unlike the DSOX3000T it's not just a facelift of an old design, offers more memory and advanced toolsets like WaveScan, plus its cheaper (a few hundred dollars for the low bandwidth variant to literally several thousands of dollars for the high bandwidth versions). Again, for the OP, read the linked thread, which is very similar to what you're looking for. I posted all the facts there.QuoteYes, LeCroy lacks in sales, so what? The DSOX3k is out since 2012, the WaveSurfer 3000 came to market mid-2014 (and before then LeCroy didn't really have an attractive scope in the low end segment). And still LeCroy manages to offer a comparable scope at lower prices. How come?Oh, and I guess you think its completely co-incidental that that Keysight already offers all options free for the DSOX3kT, a scope that was only introduced a short while ago, and it has nothing to do with LeCroy pushing WaveSurfer 3000s in the market for a lower price?QuoteYou're right, we aren't fools. But you, sir, managed quite well to look like a fool yourself. Again. As usual.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 23, 2015, 09:45:28 pm
content: Quote from: aklimaj on September 23, 2015, 08:48:49 pmI see. That explains the increase in sample rate over the DSOX3000A.

author: GlowingGhoul
author_rank: Regular Contributor
timestamp: September 23, 2015, 10:40:15 pm
content: Quote from: Wuerstchenhund on September 23, 2015, 09:42:35 pmSpare me the personal insults. It is blatantly obvious to the regulars in this forum that you're grossly biased towards Lecroy scopes, and warning those who may mistakenly believe you're offering objective advice is prudent.This is an area of expertise where objectivity and analysis are the stock and trade, and those same people, when making purchasing decisions in this price range overwhelmingly do not choose LeCroy.

author: nbritton
author_rank: Frequent Contributor
timestamp: September 24, 2015, 03:36:57 am
content: Without a doubt I would recommend the Rigol 2072A. It can be software hacked to 300 MHz. Cost $788.66 over at tequipment.net with the EEVblog discount. Even if you don't want to hack the bandwidth setting of the scope, Rigol is currently giving away all the extra options with the purchase of a new unit.If you don't want to hack the bandwidth go with the 200 MHz DS2202A for $1,682.6

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 24, 2015, 05:38:24 am
content: Post removed by moderator, can we calm this down please.

author: Karel
author_rank: Super Contributor
timestamp: September 24, 2015, 06:40:54 am
content: Quote from: Wuerstchenhund on September 24, 2015, 05:38:24 amCan't you talk a little bit more civilised? Why is it that when people disagree with your preference for lecroy that you start to get personal?

author: Simon
author_rank: Unknown
timestamp: September 24, 2015, 06:42:03 am
content: why don't we just go back to talking about scopes, in a civilized manner.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 24, 2015, 07:51:54 am
content: Quote from: Karel on September 24, 2015, 06:40:54 amIt's really getting silly now. I mean, seriously, I got attacked because I dared to give the OP my opinion on the scopes he selected? Because I said that I believe a particular LeCroy scope is the best choice? Really? Is that what is now considered acceptable around here?For the record (again):I have nothing against citicism, but from any grown-up discussion I'd expect some arguments, i.e. show me why you believe that X is inferior to Y, and support it with some evidence. Let's talk about the individual merits and drawbacks of each product. Fine. I'm all for that.I also have nothing against criticising LeCroy, which I myself did on many occasions(well, if they screw up they fully deserve the flag).However, I have to admit that my tolerance level is very low is when I'm talked off from the backside from someone who's clearly only interested in provoking and not in a healthy discussion, and who seems to be overly keen to exclude a certain manufacturer from ever being mentioned around here.This particlular member has stalked me in the past, he's not a first time offender and clearly comes with an agenda. I might have reacted a bit harsh, but the problem with trolls is that if you don't kick them where it really hurts they become a nasty virus that will just spread on. There are many forums that have gone down because they tolerated the trolls that in the end just took over.As for me mentioning LeCroy, I do it simply because (almost) no-one else does, and because I genuinely believe that some of their products are great (and I have exposure to a lot of T&M gear, probably more so than a lot of other people around here). I also regularly recommend gear from other manufacturers where I think its appropriate. But there aren't many people in this forum who access to newer LeCroy scopes, probably because until last year they didn't have anything worthwhile in the entry level class. You'd think mentioning another alternative would be a good thing, as it only increases the choice for those who are looking for a scope, don't you think?And it's not that there aren't many people here that recommend certain other brands almost constantly, but because of the sheer number it's obviously more difficult to pick on them.Now ask yourself what kind of environment you want this forum to be, something resembling 4Chan, or something we can have discussions about test gear on a mature level.Now, can we all get back on topic?

author: Berni
author_rank: Super Contributor
timestamp: September 24, 2015, 07:56:24 am
content: All of those are pretty good scopes. In terms of speed you cant go wrong with the Agilent, the others might have some features that it doesn't have like deep memory or some specialized signal analysis and such. But the 200MHz requirement will eat in to the budget quite a bit.Now if you have a decent budget and you want bandwith then used scopes from ebay can be a great deal. I recently picked up a 4GHz Agilent 9000 series scope for 6 grand from Keysights official ebay store. While that was a pretty lucky grab you still get 500MHz to 1GHz scopes to fit in your budget while still getting a pretty modern unit with the features we come to expect from todays scopes.

author: Karel
author_rank: Super Contributor
timestamp: September 24, 2015, 09:02:55 am
content: Quote from: Wuerstchenhund on September 24, 2015, 07:51:54 amGetting personal when people don't agree with you is not considered mature.QuoteIn this thread, the only person that gets personal/is insulting is you.

author: nctnico
author_rank: Super Contributor
timestamp: September 24, 2015, 09:19:54 am
content: Quote from: nbritton on September 24, 2015, 03:36:57 amYou have to ask yourself if you can live with a quirky scope when spending that kind of money. If protocol decoding is not a requirement I'd look at a used scope from an A brand or bite the bullet and spend a bit more.

author: montcler
author_rank: Contributor
timestamp: September 24, 2015, 09:30:23 am
content: Hello, Thank you all,I already decided to buy oscilloscope.Keysight DSOX3024T all free licenses, and also 12h free training for Keysight to learn this oscilloscope, as I said the first time will have one digital, the payment facilitiesthat normally no one gives, as most is cash payment.Sorry for the disappointment of some, but I like Tektronix € 1K more expensive and indeed the spectrum analyzer, will not use it.LeCroy seems to be fine, but as I have in my country as a representative of Keysight also gives you more confidence if scratched etc ...The Rigol have seen many videos of tests on YouTube and truth are a little slow to decode ports (I2C, UARTs ....) and some things, and I do not think good idea fanciest twice the money .Yokogawa have never answered or called me and that I have another representative in my country (not interest them !!).Ahhh Thanks Dave for all videos Keysight 3000 Series.Thank you all and your opinions.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 24, 2015, 10:34:02 am
content: Quote from: montcler on September 24, 2015, 09:30:23 amCongratulation, that's a good decision. I'm sure you won't regret it.QuoteI agree (and I hadn't considered that there might not be a LeCroy subsidiary in your country), that's a plus. You can find yourself lost if you have to depend on resellers.

author: Berni
author_rank: Super Contributor
timestamp: September 24, 2015, 10:51:58 am
content: Quote from: montcler on September 24, 2015, 09:30:23 amCongrats on your first digital scope. Im sure you will love it.That scope should make you feel right at home if you come from a analog scope. All your classic analog-ish knobs are there, its as responsive as a analog scope pretty much and it pretty much hides all the new memory depth and sample rate stuff from you. It wont even allow you to adjust any of them as it constantly uses the max possible memory and sample rate. It will also never alias the signal or do something confusing like that. So its not required to know any of this modern digital scope stuff, but getting to know it later will help you get the most performance out of your scope(Dave did a good video about it)

author: nfmax
author_rank: Super Contributor
timestamp: September 24, 2015, 11:09:22 am
content: Quote from: Berni on September 24, 2015, 10:51:58 amThat's a good point! I went straight from using a DSO at work where you always wanted the maximum memory depth - because there were only 2,500 points - to an MSOX2024 of my own where the sample rate/depth selection stuff is fully automatic. That explains why I get confused with some of Dave's hands-on reviews.

author: Howardlong
author_rank: Super Contributor
timestamp: September 24, 2015, 05:32:55 pm
content: Quote from: butterfly on September 24, 2015, 05:16:54 pmTwo things.The screen on those 4000s is 12", it will inevitably seem noisier, I have the same on a 7000.Secondly, have you bandwidth-limited the scope channel(s)? 1GHz is a lot of spectrum.Also I'm not so sure that an (unaided) scope is really the best tool for that job particularly at the levels you're talking about.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 25, 2015, 05:08:11 am
content: Quote from: Howardlong on September 24, 2015, 05:32:55 pmButterfly has mentioned the noise in the DSOX4104 before, and since then I had the chance to look at two units at work and they showed the same noise levels.Bandwidth is no explanation for the issue:https://www.eevblog.com/forum/testgear/new-hmo-1002-economy-dso-from-rohde-schwarz-hameg/msg688309/#msg6883091Ghz isn't that much bandwidth, and you shouldn't have to bandwidth-limit a 1GHz scope to get better than 8mV.

author: montcler
author_rank: Contributor
timestamp: September 25, 2015, 09:57:40 am
content: Hello all,Hey Berni're absolutely right, the experience of analog oscilloscope will always be with us and all have had one, now is the great learning digital and what they can do.Thx.

author: aklimaj
author_rank: Newbie
timestamp: September 25, 2015, 03:33:29 pm
content: Quote from: Wuerstchenhund on September 25, 2015, 05:08:11 amTake a look at our recently updated App Note on Oscilloscope Vertical Noise.http://literature.cdn.keysight.com/litweb/pdf/5989-3020EN.pdf

author: Howardlong
author_rank: Super Contributor
timestamp: September 25, 2015, 04:19:15 pm
content: Quote from: Wuerstchenhund on September 25, 2015, 05:08:11 amMaybe not for you!

author: GlowingGhoul
author_rank: Regular Contributor
timestamp: September 25, 2015, 05:12:26 pm
content: Quote from: Wuerstchenhund on September 24, 2015, 10:34:02 amExcellent! Your first positive comment about a Keysight product ever!And we agree, it is a very good decision indeed, not just for today but for the long haul. Keysight's support is second to none. I speak from first hand knowledge.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 25, 2015, 05:43:08 pm
content: Quote from: Howardlong on September 25, 2015, 04:19:15 pmIt's on the upper end for a midrange scope but 1GHz isn't that much bandwidth for a scope in absolute terms (we're at 100GHz now, and even Tek manages 70GHz).And it's certainly not a justification for the high noise floor we've seen in the DSOX4kA. Much older scopes have maintained that bandwidth with less noise.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 25, 2015, 05:52:06 pm
content: Quote from: aklimaj on September 25, 2015, 03:33:29 pmYou mean "infomercial"? It has some interesting content but I wonder will we ever see any App Note from Keysight that doesn't include talking about your competition? Especially when you have to compare your current products with in some cases 8yr old competitor scopes.

author: Berni
author_rank: Super Contributor
timestamp: September 25, 2015, 05:59:48 pm
content: They are not the only ones comparing there products to the competitions carefully selected products. Its still a useful document since some of this stuff is not found in the datasheets.But if you are getting 8mVpp of noise then you surely must be doing something to it. But then again if you are looking at milivolt scale signals you should get a amplifier to boost it up some. I am planing to build a 1000x gain active scope probe for the smart probe interface on agilent scopes but i never got around to doing it yet. I don't see why Keysight wouldn't sell one of these things. They have a broad range of high bandwidth active probes but no low bandwidth microvolt probes.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 25, 2015, 06:15:09 pm
content: Quote from: Berni on September 25, 2015, 05:59:48 pmThat's true, but that doesn't make this practise less silly. Especially when they have to drag out old competitor's scopes that have already seen two successors.QuoteNo, that's with nothing connected and inputs switched to GND. It doesn't matter if the connectors are open, 50ohms terminated or even shorted. I didn't pay much attention as I usually don't use (yes, I know!) low-bandwidth scopes but after Butterfly mentioned in in the thread I referred to I just took two of them after they just arrived back from calibration at Keysight and gave it a try, and low and behold I did see the same boise.QuoteYes, depending on what you do, although signal amplifiers come with their own set of drawbacks (i.e. many have very limited bandwidth). However it doesn't change the fact that the noise level that Butterfly and I saw was pretty poor. I don't know if its a general problem with the DSOX4104A or just with some units (both of the scopes I tried were Agilent labelled), or if lower bandwidth variants are also affected, but no matter what it's pretty poor for a scope that costs approx $16k in the base config, especially when again older scopes could handle that bandwidth with much lower noise.It would really be interesting to see if the DSOX3054T suffers from the same problem (I guess not, if it's a general problem with the DSOX3kA then I'm sure they would have fixed it in the DSOX3kA). The referenced infomercial shows a pretty low noise floor (which is good), but then it does the same for the DSOX4kA.

author: aklimaj
author_rank: Newbie
timestamp: September 25, 2015, 06:35:33 pm
content: Quote from: Wuerstchenhund on September 25, 2015, 05:52:06 pmYes it is a marketing for our products. I agree with you, I don't like the attack based marketing. When I updated this app note, I actually took out much of the "our product is better than yours" content.I performed all the measurements myself and you can see that at certain V/div settings that Keysight is not always the lowest noise.The reason the scopes are so old is because those happened to be what we had lying around from the competition. When we get some newer scopes in the office, I will update the document again.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 25, 2015, 07:00:40 pm
content: Quote from: aklimaj on September 25, 2015, 06:35:33 pmI'm not blaming you personally of course (I know that these things are rarely decided at the engineering level) but as someone who buys a lot of test gear professionally let me just say that this isn't necessarily perceived as positive by your customers (in fact, sometimes "desperate" comes to mind).QuoteYes, I see, the R&S RTM is pretty good with noise, but that's what R&S traditionally focusses on. And their scopes are very expensive.Maybe you could also include some screenshots from your competitors? That could also help to maintain the impression that this is more about discussing noise in general and less so to make Keysight scopes look good.QuoteI understand, but frankly if you have to compare your current DSOX4000A against an roughly 8yr old scope like the LeCroy WaveRunner Xi (which has been replaced by a successor in 2008, and this successor has also been replaced by another successor in 2010, which again is now again due for replacement) then from my side of the desk it does look a bit desperate. You're really better off not including such old scopes at all.

author: tautech
author_rank: Super Contributor
timestamp: September 25, 2015, 07:08:52 pm
content: Quote from: aklimaj on September 25, 2015, 06:35:33 pmIf you don't like it, why keep fostering it?These scope manufacturers pissing competitions have been going on for decades, I don't like them much either.History shows these claims and counter-claims and the selected parameters used to discredit compeditors, like any statistics can be tailored to show the author in a more favourable light.Many experienced users can see past these novels, so why produce them?

author: Howardlong
author_rank: Super Contributor
timestamp: September 25, 2015, 07:30:06 pm
content: FWIW, these are the measurements on a couple of scopes, sample rate was 4GSa/s in both cases. Connections terminated directly at the scope's BNC. 8mV does seem very high, if that is the Vrms shorted at the scope's BNC. It would explainable if the short was made at the probe end.TB 100us/div2mV/divAgilent/Keysight MSO7104B1GHz/4GSa/s1M impedanceBW Lim offVrms Open/Short 338uV/354uV1M impedance20MHz BW Lim onVrms Open/Short 168uV/204uV50 ohm impedanceBW Lim offVrms Open/50/Short 310/310/318uV50 ohm impedance20MHz BW Lim onVrms Open/50/Short 104/109/123uVAgilent 54831D600MHz/4GSa/s1M impedanceBW Lim offVrms Open/Short 450uV/375uV1M impedance20MHz BW Lim onVrms Open/Short 361uV/199uV50 ohm impedanceBW Lim offVrms Open/50/Short 325/324/332uV50 ohm impedance20MHz BW Lim onVrms Open/50/Short 132/141/153uV

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 25, 2015, 08:02:51 pm
content: Quote from: Howardlong on September 25, 2015, 07:30:06 pmWhy would anyone do that? If you want to measure the noise level of a scope it would be silly introducing a probe.

author: Berni
author_rank: Super Contributor
timestamp: September 25, 2015, 08:05:58 pm
content: Quote from: tautech on September 25, 2015, 07:08:52 pmThat's just how it works in large companies. They have a whole groups of marketing "geniuses" that come to work every day to do nothing else than to try and make the companies products seam superior to everything else. Later on the bosses whip the engineers in to doing there bidding. Its the same thing with how the products are designed. I'm sure most engineers there would agree that they should just slap on a ethernet port on the X3000 scope rather than sell a box with a RJ45 jack and some magnetics. But someone had the idea that they would make more money selling these things so it had to become a module.Most of the time these fools with business PhDs don't do too much harm but here and there they do cause some facepalm moments to the customers while the engineers that had to execute there "genius plan" bang there heads against the desk.

author: Howardlong
author_rank: Super Contributor
timestamp: September 25, 2015, 08:15:40 pm
content: Quote from: Wuerstchenhund on September 25, 2015, 08:02:51 pmI don't know, I was trying to explain the apparent aberration.Relaaaaaax..... just a thought, you may not realise it but did you know that you do frequently come over rather abruptly and patronisingly? Just sayin'...

author: nctnico
author_rank: Super Contributor
timestamp: September 25, 2015, 08:19:08 pm
content: I guess the days are gettings shorter...

author: tautech
author_rank: Super Contributor
timestamp: September 25, 2015, 08:23:27 pm
content: Quote from: nctnico on September 25, 2015, 08:19:08 pmOurs are getting longer, daylight saving 1 hr timeshift soon.

author: tautech
author_rank: Super Contributor
timestamp: September 26, 2015, 09:24:58 am
content: Quote from: GlowingGhoul on September 25, 2015, 05:12:26 pmWell hunting for threads on a request about Siglents today I came across positive comments too.https://www.eevblog.com/forum/testgear/siglent-ds1102cnl-dso/Post #2

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 26, 2015, 09:59:23 am
content: Quote from: tautech on September 26, 2015, 09:24:58 amWell, it shows that at leastyouknow how to use this forum's search function, but then I guess the results wouldn't fit some people's "only bashed other brands" BS agenda.At the end of the day, the truth is out there (my recommendation for Siglent, Agilent/Keysight, R&S, even Tek, plus all the links and references), easy to find if you're truly interested in the truth and have some time to spare. Nothing is hidden. And the gullible that may be interested but can't be arsed to check some unsubstantiated claims fully deserve being spoon-fed crap. At the end of the day, it's them who are potentially missing out, not me.Now I suggest we return to the actual topic.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 26, 2015, 10:05:20 am
content: Quote from: Howardlong on September 25, 2015, 08:15:40 pmGeez, Seriously? What's patronizing on a simple question? Maybe spend a little less time being oversensitive and more time reading more carefully as I already stated that this noise was with open connectors, so it should have been clear that there wasn't a probe connected (and no cable, and no antenna, or anything else). Plus it should be very obvious why connecting a probe would be a pretty stupid thing to do if the aim is to measure the internal noise of a test instrument.

author: Howardlong
author_rank: Super Contributor
timestamp: September 26, 2015, 01:50:31 pm
content: Quote from: Wuerstchenhund on September 26, 2015, 10:05:20 amI was trying to point out in as reasonable way as I could that your responses are frequently abrupt and patronising, just like the one you've just given in fact. Maybe you should think about the way you're coming across a bit more? I'm sorry if you don't think you come over like that, I was trying to help you. There's just no need to bite peoples' heads off. A bit of consideration, humility and respect doesn't cost anything you know, just a bit of thought before you say things.It wasn't clear to me that the termination was at the scope by the way. I am sorry if I missed something where that was stated, or misinterpreted what was said. In your world that may be stupid, but I did actually look to see if the tests were done terminated at the scope and I couldn't see that explicitly stated when I looked across threads. I was trying to offer a suggestion.I am sure you have plenty of knowledge and experience to share, it would just be appreciated if it came over with a bit less arrogance and condescension please, you'll find people will accept and understand things when delivered that way. Again, I'm just sayin', I'm trying to help you here.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 26, 2015, 03:43:07 pm
content: Quote from: Howardlong on September 26, 2015, 01:50:31 pmMan, come down! All I did was asking why anyone would test scope noise with a probe. That's "biting your head off"?Seriously, if you're that sensitive then maybe a web forum isn't the right place for you.QuoteThat's fine, but again, all I asked is why anyone would do that. Because it doesn't make much sense. If you don't know why, no problem, but just say so. I don't have a cristal ball, and can't possibly see why this simple question was so troubling to you.I really feel like Adam Sandler inAnger Management:After all, this form of communcation is text-only, you can't see your commincation partner, and you therefore can't see any emotive expressions aside from a few ugly emoticons. That means just because its limitations its prone to misunderstandings, and probably the worst form of communication for oversensitive people. That's just how it is.QuoteThis has nothing to do with experience, it's simple common sense and basic engineering. If you want to test the properties of an object then the #1 rule is to minimize all external influences that skew the test results. Using a probe when measuring a scope's internal noise is the complete opposite, it's the equivalent of trying to test the acoustic noise of a low noise fan inmidst a horde of screaming kids. You'll never get reliable results. Again, common sense and basic engineering.Now, if you wanted to know the systemic noise (i.e. internal scope noise + noise caused by the probe) then that's a different story, and then you need to have a probe connected as its part of the UUT (Unit Under Test).Again, even if you didn't know all this, fine.But then just say so!

author: joeqsmith
author_rank: Super Contributor
timestamp: September 26, 2015, 04:25:29 pm
content: Hey Wuerstchenhund, you know the SSD in the old 64Xi has been in there since April 13th without a single issue, even without any changes to any of the OS settings? Just a mirror of the drive. That's not just sitting on a bench but using it. The one in the 8500A has been in there longer but it has seen much less use. Again, no problems (same for the 1G Ethernet card). Even channel 3 (which was the problem channel of the 64Xi) continues to work just fine. The only issue has been the button battery failed in the 8500A.I suspect that the older SSDs you were using had problems. You may want to try using a modern SSD and see if you run into any problems.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 26, 2015, 04:41:26 pm
content: Quote from: joeqsmith on September 26, 2015, 04:25:29 pmYes, I know. The Transcend SSD you used is a newer model than the one I used, to my surprise Transcend has actually fixed (or better, worked around through the drive's firmware) the UDMA issues in these newer drives which is great. However, they seem to be the only ones who fixed the issue of higher UDMA modes and the lack of 80 conductor cables for the high density (44pin) EIDE interface.I now got one of the newer SSDs myself for my WR64Xi, but at first I have to have the connectors on the acquisition board replaced, which isn't easy (don't have the tools myself, nor a source for the connectors, and can't take it to work, so I have to outsource). Probably have to send the boards to LeCroy.My WavePro 7300A still has the intel SSD 320 I gave it after I bought it, and its still going strong, too, but that's not surprising given that this is connected via SATA.Now that you had your WRXi for a while, how do you like it?

author: Howardlong
author_rank: Super Contributor
timestamp: September 26, 2015, 04:59:36 pm
content: Wuerstchenhund: That's a bit better.The reason I mention your way of responding is to help you, so you can avoid some of those negative responses you've been getting. If this is the way you want to behave on an internet forum the so be it, but please don't be surprised when you get the responses you do. I somehow doubt you behave in this way with your colleagues at work or with family or friends, or even someone face to face at a check out for example, so why would you do it here?You might think that something's obvious, when in fact, it might not be to someone else. Stating something is simply good or bad engineering practice, or common sense or basic engineering, as a justification and leaving it at that adds little if any value, that is like learning by rote instead of by understanding. There's really no need to say something's stupid or silly, that is just condescending. Instead you could suggest why something might or might not be a good idea, and how better it might be done and why, now that would be constructive and helpful.I am sure at some point in your life things weren't all so obvious. Try to think back to those days and how you'd feel if someone called your lack of understanding silly or stupid. Again, I think you have much to offer, but it's just lost sometimes I'm afraid. I'm trying to help you here.The positive aspect of this is that the test with the probe in and out is a good test for someone to do if they want to see how much difference it makes to the scope's noise floor. All part of learning about the limitations of their equipment and how to use it.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 26, 2015, 05:46:34 pm
content: Quote from: Wuerstchenhund on September 26, 2015, 04:41:26 pmYou may remember I was using an adapter on my 8500A to use a SATA drive with it. I actually figured this one would have a problem but it was a newer drive as well.After using that 64Xi for almost 6 months now as basically my main scope I have to admit, I like it! Really, for a general purpose scope I like it a lot! I am glad I took the time to up the RAM and add the SSD. The new knobs they sent for it stay put. Sure it's old, not the fastest thing out there, throws out a fair bit of heat, fairly loud but this is all stuff I am used to and it covers 99.9% of my home projects.The only thing that I don't care for is their calibration routine. If you turn them on from a cold start and use them (fully expecting them to cal often) and select normal trigger. The DSO will sit there and not run an auto cal. Minutes go by, no auto cal. Then you put in a signal, bang the auto cal starts and you may loose your signal. Of course, you can turn off the cal or just let the thing warm up. Maybe there is a work around so the thing will cal no matter if there is a trigger or not. I have not asked.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 26, 2015, 06:34:15 pm
content: Quote from: joeqsmith on September 26, 2015, 05:46:34 pmThis data corruption issue only affects 44pin UDMA interfaces, not the 40-pin variant for which there is an 80-conductor cable suitable for the higher UDMA modes.QuoteYes, it'a good scope, although the build quality could really have been a bit be better, and LeCroy could have put in a bit more memory and a faster processor right from the start. But the scope performance is still very good, after all this is the first scope with a max update rate of 1.25M waveforms/s, long before Agilent made waveform rates their key argument for selling their scopes.QuoteThat's a bit strange, mine does a calibration run after the scope app starts and the channels become active, and if its cold and the auto-cal setting is enabled it does re-cals pretty often. Once it has temperature stabilized the auto-cals come up less often.The annoying thing is that on some older LeCroy X-Stream scopes (i.e. WP7kA and WM8kA before production of late 2008) auto-cal can only be reduced but not disabled completely (even though the setting suggests that it does disable it). I can't remember if the WRXi is one of them (mine is currently disassembled because of the connectors) but I'm pretty sure it is (it's better with the successor WRXi-A). Funny enough, on the older non-Windows scopes, auto-cal could be disabled completely.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 26, 2015, 07:14:59 pm
content: Quote from: Howardlong on September 26, 2015, 04:59:36 pmI'm the same person at work, or in any other way of life.QuoteThat's appreciated, but you really should develop a thicker skin. This is an international forum, which means there are many people from different cultures around, so what you might consider condescending isn't necessarily seen the same by others.I guess it's cultural, I see you, too, have listed UK as country, so I guess you're a Brit. I occasionally see similar sensitivities here in real-life (and they don't necessarily involve me, but it often involves American colleagues), something that for me as a German (as well as my European and especially my American colleagues) pretty much comes across as hypersensitivity. Sometimes it drives my American colleagues crazyQuoteThat's true but the difference is that if I don't know or understand something I ask for clarification and don't feel embarrassed or humiliated. Life's a path of constant learning so why not make the most of it?For example, at the moment I'm in the process of buying a soldering station, something which I don't have much experience in (I use the Pace rework stations at work but I don't buy hand tools or have much experience with other brands), which turned out to be much more complex than I initially thought. So I just opened up a question thread in another section of this forum and asked, which gave me a lot of valuable information. Had I not asked then I would have missed out. So if you don't know anything, just ask. Simples.(btw, Dave, we need a Meerkat emoticon!)QuoteBelieve me, I've done my fair share of stupid things in my life, even in the lab, and have been called out for that many times. So what, I suck it up, learn and move on. What would be the point of victimizing? After all, I wouldn't have been called "stupid" if I hadn't done something stupid, so it was well deserved. What's the point making it into a drama? Learn and move on.QuoteThat's appreciated of course. But again, relax, and don't take everything here so personal. If you think I'm rough then you haven't seen some of the other people I met here. I really don't care if some of them swear like a sailor (I'm not a saint, either), what's important for me is the information and knowledge that's exchanged. Which I believe is the main point of this forum.QuoteThe problem with the probe is that amongst other things it also acts as a kind of antenna, so how much it impacts the noise level on the scop's display very much depends on where you are and what the RF environment is.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 26, 2015, 10:15:39 pm
content: You are going to have your 64Xi repaired then? I am surprised mine had not had any more problems after I had it apart.The whole setup is the same as my original post when you suggested there would be problems using the SSDs. These were the 3.5" drives and am pretty sure they were using mode 2.The 64Xi's plastic case has a few chips in the corners and the internal chassis does flex a bit. On the bright side, at least the knobs don't fall off anymore! The CPU speed has not been a problem for me but adding the RAM helped it out a lot.I have never seen the auto calibration problem in auto mode, only normal. It doesn't always do it. I made a short video using the 64Xi to better help explain. It works the same with the 8500A. I bring it up from a cold start. You can see it triggers and displays just fine the first few times. Then after a while it gets into this mode. I show this part in actual time so you can see how long I am letting it sit for. As soon as it gets that last transient at the end of the video, it starts the cal and losses the next transient. All that dead time with nothing to do but autocal but instead it waits for the signal, then runs the cal.I assume it was done this way for a reason. For me, loosing the data I want to see is more important than any gains they think they gained by making it work this1.27 if you want to skip to where it all starts.....https://www.youtube.com/watch?v=EK3I55MHiGg

author: GlowingGhoul
author_rank: Regular Contributor
timestamp: September 26, 2015, 10:25:35 pm
content: Quote from: Howardlong on September 26, 2015, 04:59:36 pmPlease don't bother. It doesn't matter how many people tell this guy he's abrasive and rude. His arrogance has him convinced everyone else is wrong. He clearly thinks very, very highly of himself and not so much of the rest of us. In my experience, this kind of behavior is compensation for an otherwise disappointing life.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 27, 2015, 01:19:46 pm
content: Quote from: joeqsmith on September 26, 2015, 10:15:39 pmYes, because aside from it being a great scope it's still pretty valuable (used ones still sell somewhere between $3500 and $4000, and the ones with the MSO option for even more). And even if I have it repaired by LeCroy this shouldn't cost me more than say $1200 or so (just a guess, wouldn't be surprised if its a lot lower).QuoteI vaguely remember you mentioned that yours had been in repair before, so maybe that makes a difference. The connector problem is mostly an manufacturing/assembly issue (the tight bolts leave no room for the PCB to expand when warming up), and when a scope is sent in for repair this should be mitigated by using nylon spacers and less torque. The upgraded fans also help to keep temperatures low (although this makes the scope a bit louder).How's the touchscreen of your scope doing? The protective sheet on it tends to delaminate after a few years, but that's not too difficult to fix.QuoteHey, that's a LeCroy trademark! It ain't no LeCroy if you don't leave behind a trail of knobs when moving it!You're right with the chassis, but on mine (which is one of the early models, don't know if they changed it on later models) the press-in nuts that are pressed into the alloy chassis are pressed in from the outside, which means that the bolts pull the nut out of the chassisThankfully that's easy to fix as the nuts can just be taken out and pressed in from the other side, but still that's pretty stupid.QuoteYes, RAM makes some difference, but when I upgraded mine from the standard 1.3GHz Celeron-M (400MHz FSB, 512k cache) to a Pentium-M 1.8GHz with 533MHz(?) FSB and 2M cache the scope became noticably faster. Not that it was slow before, but the slighly sluggish feel when changing settings is gone, plus FFT and math are noticably faster (it also increases the performance of WaveScan). The main benefit will be the bigger L2 cache (LeCroy X-Stream does all calculations in the CPU's L2 cache due to its speed). It now feels as snappy as most embedded scopes.Considering that these CPUs now go for a few bucks it's an upgrade worth doing. The other benefit is that unlike the Celeron-M the Pentium-M supports SpeedStep powermanagement, which keeps CPU temps lower than for the Celeron.QuoteWhat auto mode do you mean? There's a setting that allows you to disable automatic calibration, is it this one?QuoteI see. Do you have Automatic Calibration enabled or disabled? It shouldn't do that if its disabled unless there's a larger temperature change.QuoteThe reason for this auto cal functionality is to make sure the scope maintains its specs in the whole operating range and not just at the temperature it was calibrated at (as it is the case with scopes from other manufacturers). Unfortunately on the older X-Stream scopes auto-cal got a bit overzealous, but if you disable it then it should stop calibrating unless the temperature changes significantly.Also, make sure you have the latest firmware installed, as there were some improvements re. calibration as well.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 27, 2015, 11:06:10 pm
content: I have not seen any delamination problems with my two touch screens and these are fairly old scopes. Maybe its a climate problem. Do you see air pockets in it?Quote from: Wuerstchenhund on September 27, 2015, 01:19:46 pmAuto vs Normal trigger mode. Surely you have heard of them?I have the autocal enabled and let it do its thing. I understand why they autocal and can't see why I would want to disable it but I also don't understand why if the trigger is set to normal that they would wait for a trigger event to start the cal instead of just running it.

author: Muxr
author_rank: Super Contributor
timestamp: September 28, 2015, 02:22:33 am
content: Quote from: Wuerstchenhund on September 26, 2015, 03:43:07 pmI sometimes feel like this, when I am involved in online discussions:

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 28, 2015, 05:04:19 am
content: Quote from: Muxr on September 28, 2015, 02:22:33 am

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 28, 2015, 05:23:37 am
content: Quote from: joeqsmith on September 27, 2015, 11:06:10 pmNo air pockets, the protective sheet just becomes comes loose and eventually falls off. It's a common problem with the particular touch panel used in the WRXi (it does not affect the WM or other LeCroy scopes, or the successor WRXi-A).It may well be that yours has been fixed in the past and no longer suffers from the problem.Quote from: Wuerstchenhund on September 27, 2015, 01:19:46 pmAh, OK. Yes, I think I heard of themBut the trigger mode shouldn't affect the calibration cycle.QuoteAuto-cal can be disabled to avoid the problem in your video - to avoid the scope calibrating when you need it to capture a signal. If you disable auto-cal then the WRXi performs the same as any other non-LeCroy scope that doesn't have a similar auto-cal feature, and unless the temperature variations in your place are extreme (i.e. your lab was a garden shed in Alaska) then disabling it won't give you any problems (plus it will still occasionally calibrate i.e. if the temperature changes a lot, just less often). I'd give it a try.

author: tautech
author_rank: Super Contributor
timestamp: September 28, 2015, 06:23:12 am
content: Quote from: Wuerstchenhund on September 28, 2015, 05:23:37 amHmmThis implies when auto-cal is disabled the OS can stiil sense large temp changes and stiil auto-cal despite being disabled. Is that correct?Is there a way auto-cal can be permanently disabled and self-cal performed manually at the users discretion ?

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 28, 2015, 10:59:25 am
content: Quote from: tautech on September 28, 2015, 06:23:12 amAuto-cal is mostly hardware/firmware driven (Windows itself isn't aware of it), but yes, on those older X-Stream scopes there will still be auto-cal if there's a large temperature change.QuoteThat depends on the scope. On the non-Windows scopes (i.e. the old 9300 Series, the LC, the WaveRunner LT, the WavePro 900) if you disable auto-cal then it stays disabled, aside from a single calibration cycle after power-up.On older X-Stream scopes (Windows scopes) like all WaveRunner 6k(A) and WavePro 7k(A)/WaveMaster 8k(A) produced before late 2008 auto-cal can't be fully disabled, and when set to disabled the scope will still do an occasional cal cycle if there's a large temperature change. Starting late 2008, due to user requests LeCroy made some changes to their acquisition system on WavePro 7kA and WM 8kA so that auto-cal could again be fully disabled. Since these were hardware changes they can't be retrofitted to older scopes unless you replace the acquisition modules, though, but for these older scopes they still offered the slight improvements that could be done through firmware updates.There's not much use for having the user to start a self-calibration manually because he can't know when it's really required because he doesn't know the current status of the many parameters that go into that process. Don't forget that even the smallest/slowest scope variant (WR6k) comes with a 5GSps/10GSps acquisition system and up to 2GHz bandwidth, and WavePro and WaveMaster with a 10GSps/20GSps acquisition system and up to 5GHz bandwidth. It's oonly manual on low-end scopes because the acquisition system is simpler, the bandwidth lower and having a manual button is cheaper than implementing the sensors and processing the data necessary for proper auto-calibration.As to when to switch auto-cal on or off, my recommendation would be that for a scope that is used stationary in a lab with somewhat stable temperatures auto-cal could easily be disabled. However, if the scope was moved a lot and used in different locations then I'd leave it enabled.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 28, 2015, 12:24:14 pm
content: Quote from: Wuerstchenhund on September 28, 2015, 05:23:37 amWow!! That would be real bad but expected after the knobs fell off.I mention cold start for a reason. Until it warms up, seems you really want that auto cal on, and after it warms up, it's not a problem as it does not autocal very often.If I disable autocal under preferences, turn the DSO off, the next time it is turned on, autocal is enabled. If the DSO is in auto trigger at the time it was turned off, it will run an autocal as soon as it boots. If you then disable autocal, it will cal for each of the input range selections and or after several minutes after it has warmed up. Expected.If it was in normal trigger when turned off, it will not run an auto cal on the next power up (assuming no input signal). If normal trigger selected and it is powered up from cold, and then the autocal is turned off (so it has not yet ran a calibration), then let the system sit for 20 minutes. So the units exhaust on right fan, center measures 43.3 with an ambient temperature (also starting temp) of 24.7. At this time, no calibrations have been performed. That is what I would consider a big temperature swing.More interesting, I then apply a signal for the first time from power up. I would fully expect the system to run it's first cal. But it does not! It just runs along fine with no cal!! Do you think the results are within spec with a 20 deg change in temp??Now enable auto cal. Again, still no calibration is performed. DSO has been on now for almost 35 minutes! The exhaust temp is now 48.4 degrees!Now let's trigger it. Bang, there's the cal. Very strange. Give it a try on your WP.

author: Mark_O
author_rank: Frequent Contributor
timestamp: October 09, 2015, 09:49:31 am
content: Quote from: joeqsmith on September 26, 2015, 04:25:29 pmWait! What?I thought this thing was a piece of crap, that you hated with a passion?I remember you going on and on about how pathetically poor it was.Sounds like you've had a change of heart.QuoteWhen you first turn them on, they dooneauto-cal cycle. Then, if there is no trigger, they will sit there indefinitely, andneverauto-cal again. No matter how much the temp shifts.And the Channel sensitivity 'buttons' also sit there with question marks, saying "No data available". Even though it knows damn well what the amplitude & offset settings are, because they pop up instantly the moment the first trigger is seen.Basically, I'd consider these to be "initialization bugs", that skipped through the cracks.The only "work around" I'm aware of is to hit the Auto-Trigger button just before powering down. Then when you power back up later, it will run auto-Cal continuously as it warms up (because auto-trigger keeps firing). And then, when you're ready to get busy, you can shift it back to Normal-Trigger mode, and be on your way.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 09, 2015, 10:45:27 am
content: Quote from: Mark_O on October 09, 2015, 09:49:31 amIn my defence, it was used and damaged when I received it. The quote for repairs from the mfg was more than the DSO was worth. Pulling it apart and seeing the connector for the damaged channel had already been replaced once (I posted a few pictures) and then hearing from Wuerstchenhund how it is a known problem. The case construction is nothing near the quality I would expect from them and the case was already cracked in the corners. Not to mention it was slow and would hang.Then there was the whole knobs falling off of it... The quality was poor at best and I NEVER would have guessed that 6 months later this DSO would still be running with the amount I have used it.So yes, added RAM, all new knobs and for some reason, re-seating the connector has solved the major problems. Mind you NONE of these are anything I would EVER expect a LeCroy customer to have to deal with!That said, it's been solid (including the SSD swapout that was not supposed to work) and with those six long months of i not just sitting on a bench but being used and flawless operation, yes I have had a change of heart about what I originally called the "whore-o-scope"(... at least for home hobby use)Interesting. You state it will do an autocal on power up which is not what I wrote.QuoteI ran this test again just to be sure and sure enough, it ran a single autocal with it powered up in normal and no input signal. I must have missed it.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: October 09, 2015, 12:34:03 pm
content: Quote from: Mark_O on October 09, 2015, 09:49:31 amTo Joe's defense the WR(M)Xiisa particular bad scope, at least in terms of the overall build quality (the actual performance/specs is top-notch, though). Mine didn't lose knobs but when I opened it for the first time I was pretty shocked how poor the overall build quality was, especially considering that this was a pretty expensive (lower) high end scope. I've never seen anything so shoddy from Agilent or any other big brand.The thing with LeCroy is that they generally out-source the simpler parts of the design (i.e. chassis) to a manufacturing partner and focus on their core strength (the scope stuff, i.e. acquisition, front end and software), and unfortunately this particular Malaysian manufacturing partner (I couldn't find out its name yet) did a pretty poor job designing the chassis, and did an even worse job manufacturing it. Later WR(M)Xi models (IIRC end of 2007) where produced in the US and as far as I know resulted in a better build quality, although even those suffered from design flaws like delaminating screen protectors and broken carrying handles, or cracks in the plastics shell.Having said that (and I guess it won't be long until the trolls arrive to call me names), it's a great scope if the particular scope had its connector problem and screen delamination fixed and is mostly sitting on a bench, as it's really a very advanced and capable instrument, even when compared with current high end scopes. There are tons of options available for it including serial decode for a large range of common and obscure protocols as well as a Spectrum Analyzer option (which turns it into a VSA), and all WRXi can be upgraded to MSO (WRMXi). Plus there are lots of probes available often at cheap prices.Quote from: joeqsmith on September 28, 2015, 12:24:14 pmIndeed, but it was fixed pretty quickly (you mentioned your scope has been repaired before, maybe they also replaced the screen), and not every unit was affected anyways.QuoteI'll do as soon as I get a chance (which considering current workloads might take a while).BTW: my WRXi is now going to LeCroy for repair (I'm just sending in the Front End module and the acquisition board). We'll see how it goes.

author: Mark_O
author_rank: Frequent Contributor
timestamp: October 09, 2015, 12:50:41 pm
content: Quote from: joeqsmith on October 09, 2015, 10:45:27 amYes, I know. I enjoyed following your tear-down and voyages along the way.I was just pulling your leg.Someonehad to do it.

author: tautech
author_rank: Super Contributor
timestamp: October 09, 2015, 06:18:21 pm
content: Quote from: Mark_O on October 09, 2015, 12:50:41 pmNice one Mark, you got 2 fish with one bait.