Keysight DSO4024 vs Tektronix MDO3 - 200 MHz bandwidth vs Teledyne lecroy 3024Z - Page 1
Forum section: electronics / testgear

author: whiskeyjack
author_rank: Contributor
timestamp: February 11, 2020, 08:29:46 am
content: My organization is getting into LED driver development business and we lack certain measurement and test equipment. One such equipment is a decent oscilloscope. Currently, we are considering Keysight DSO4024A, Tektronix MDO3 - 200 MHz bandwidth and Teledyne lecroy wavesurfer 3024Z. These are all 4 channel 200 MHz oscilloscopes. Keysight and Tek are giving some software enabled power measurement features which might come in handy. These features are not free.I am doing some online research to form an opinion which one to go for. I have seen the demo of Tek MDO3 but still waiting for the other two vendors to arrange a demo. Price wise, these are comparable. Keysight being the cheapest and rest two approximately 20 % higher than keysight when looking at scope + probe bundle price. I am also assuming that Tek and Teledyne will give similar discounts as what keysight is offering.Can you guys help me decide which one would be a better pick from technical and usage perspective? Since these tools are used on a frequent basis, I would like to have a tool which is very intuitive and pleasant to use. At the same time, I don't want to compromise R&D quality by buying a tool which is convenient to use but gives wrong measurement.During my research, I came across a video from Tek -This video compares keysight and tek and mentions the fact that keysight uses displayed data for math and measurement functions. Should I be concerned about this?

author: KE5FX
author_rank: Super Contributor
timestamp: February 11, 2020, 09:06:09 am
content: I predict this thread will remain calm and free of biased personal opinions, hurt feelings, and moderator intervention.That being said, don't buy the Tek without evaluating the Keysightin person. One of the two will drive like a dream. The other one may make you want to throw it off the top level of the company's parking garage, a la Bob Widlar.I don't know much about LeCroy, but at least one frequent poster can speak authoritatively on them.QuoteHere's the "opinion" part: you don't want your measurements to come from data that doesn't correspond to what's currently on the screen. That's a fairly fundamental aspect of what makes an oscilloscope an oscilloscope. By their nature, it's easy to get bad data from an oscilloscope, and measurements that reflect the entire acquisition record make itreallyeasy for that to happen.Thatdoesn'tmean that the data being measured should come from the actual screenspace output buffer, though. While measurement data should come from the part of the acquisition record that corresponds to what's on the screen, it ideally shouldn't have undergone downsampling, quantization, and clipping to conform to the LCD's resolution. Keysight's architecture is good in this respect, since a lot of their measurements are performed on an ASIC that has direct access to acquisition memory, rather than on a CPU that doesn't.The downside is that their ASIC imposes record size limits of its own. So if huge records are important to you, that will be something you have to consider. (Are they? Are you sure?)

author: RoadRunner
author_rank: Frequent Contributor
timestamp: February 11, 2020, 09:48:32 am
content: From where is see I would not touch Tektronix with a stick. MDO3000 is unuseably slow. Still have lots of bugs there is no active devlepment. I had gone through almost a year of sending and receiving emails.I would not buy any Tek scope in future as well because if you look at there new scopes they do not seems to make any progress internally on orther hand cosmetics they look nice, with nice big display and stuff.Tektronix support at liest in DE I contacted was pertty unsupportive and Blame everthing on customer type, Specially when customer is an individual rather than a company.I have not used any high end keysight scope ever but i have used highend lecroy at work place so i would incline towards lecroy for ease of usablity. With lecroy price may be more though.

author: Pinkus
author_rank: Frequent Contributor
timestamp: February 11, 2020, 10:45:01 am
content: I own a DSOX4024a and worked with a MDO3 for a few days. Indeed the Tektronix is slow as hell and I would not work with it, even if I got one for free. Though, the MDO4 might be better - I have no experience with it.I can highly recommend of getting a demo unit of the Keysight for a week. You will love it! It is so intuitive and responsive, working with it is always a sheer delight.You might save some bucks by purchasing a DSOX3000 T instead. It is almost the same unit and software. Basically what is different are: screen size, 1 vs. 2 channel AWG, optional/integrated VGA/LAN, input of external 10 Mhz clock reference possible with 4000 series.

author: nctnico
author_rank: Super Contributor
timestamp: February 11, 2020, 10:52:28 am
content: Another forum member is not fond of the Lecroy Wavesurfer 3000 models due to unfixed bugs. Also Lecroy oscilloscopes typically don't have peak-detect mode which I consider a must-have. I'd consider the R&S RTB2004 and RTM3004 as well. I think these have a lot of pros compared to the other models. Faster to operate compared to Tektronix and more memory compared to Keysight.You can have long debates about using acquisition memory versus screen memory for math. The first is always accurate but very slow. The latter is faster BUT it will typically only be accurate if you can see the waveforms on screen. If you zoom out to much where the waveform become a unform band you'll see that the calculations will fail. The Keysight oscilloscopes will indicate this. Another thing to look out for it whether an oscilloscope adheres to the memory depth setting or just captures enough data to fill the screen (Lecroy and modern Keysight scopes seem to only capture enough data to fill the screen). In the latter case you'll need to go back & forth between time/div settings in order to make long captures. There are several usage scenarios where this becomes really tedious. It is very nice to have more data on what happened before an event to see what happened leading up to it even if that data is off-screen at the time of capturing. It is not a given that an event is easy to reproduce so the more data you have the less time it will take to track down a intermittant bug.

author: tautech
author_rank: Super Contributor
timestamp: February 11, 2020, 12:08:22 pm
content: Quote from: whiskeyjack on February 11, 2020, 08:29:46 amIs a SDS3024X made by Siglent whom have a long standing arrangement with LeCroy whom have the western world marketing rights for them.Siglent's new SDS5000X series supersedes the 3000Z series with higher sampling rates, more memory and individual vertical controls just to name the obvious. There's a thread here on the SDS5054X if you want to check it out.Dave's done a couple of videos on the SDS5104X that he tore down and ran against similar class DSO's.However whiskeyjack, the lowest BW offering in the 5000X series is 350 MHz and the pricing might exceed the other models you're looking at.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: February 11, 2020, 01:48:58 pm
content: Don't go for the Tek. Seriously, don't. Tek is pretty much the bottom of the barrel when it comes to A-brands. We got all their models for evaluation and every one of them had serious issues. You pretty much pay for a name that meant something back when analog scopes were still a thing.The Keysight DSOX4024 is a good everyday scope, we have a bunch of the higher BW models. As KE5FX says they are easy to use, but because of their architecture (which was designed for max waveform rates at all costs) they have some limitations, like the small memory (which in reality, will end up even smaller because of how the MegaZoom ASIC uses it).Keysight support is top notch, which was necessary as we had several which suffered from excessive noise and the NAND failure. Also, Keysight artificially limits the probe interface of the InfiniVision Series scopes (of which the DSO-X4k is a part of) compared to the Infiniium Series (i.e. Windows based high end scopes) which makes some probes incompatible.The LeCroy WaveSurfer 3024z is the successor of the WaveSurfer 3000 (non-z), both which are manufactured by Siglent (the software is designed by LeCroy). They are good scopes, although a bit slow at times. They're not as zippy as the Keysight, but they have more memory and offer more math and analysis tools (and larger FFTs). In addition, they share the probe interface (ProBus) with other LeCroy scopes, which gives them access to a wide range of probes. Like all newer LeCroy scopes they lack Peak Detect, and without going into another discussion of the value of PD (a feature designed to compensate for the shortcomings of early DSOs which had tiny memory) with modern deep memory DSOs, it's down to you to decide if this feature is critical for you or not (I've last used it some 20 years or so ago, same for my colleagues).I know some member from Europe had some complaints about a WS3000 but I'm not sure if this is down to the specific unit (we have many of the higher BW variants and little complaint). Unfortunately LeCroy support in Europe has taken a nose dive since it was moved to Germany (U.S. support is still great, though) so this might have played a role in the complaints.My biggest complaint with the WS3000z is that LeCroy has used the success of the modestly priced WS3000 to squeeze more cash out of the WS3000z. Still, they are good scopes for what you get for the money.As others said, other potential candidates could be the R&S RTB2004, and there's a new Siglent scope (SDS2kX+) as well as the Rigol MSO5000. None of them have active probe interfaces like the Keysight and LeCroy do, and really are of a different (lower) class than those two.The RTB2004 is a 10bit scope, however it's limited in functionality, it has some memory limitations (the 160M memory is only available in segmented mode, in all other modes you're limited to 10M/20M) and even lacks 50 ohms inputs. Options are truly expensive unless you're lucky enough to get one of the rare bundle offers.The Siglent SDS2kX+ is pretty new, has 200M of memory, but it appears to have a lot of capabilities for its class, offers a (software) 10bit mode and I believe has switchable 1M/50ohms inputs.All came with a range of bugs, and I leave it to others to comment on what the current maturity state is of these scopes.Take your pick.In any case, I'd strongly recommend to get loaner units to try for yourself, and not buy based on reviews and opinions only.

author: HighVoltage
author_rank: Super Contributor
timestamp: February 11, 2020, 02:18:42 pm
content: I got rid of all Tektronix scopes a few years ago, that is how bad they are compared to others.And I do not think that I will ever have a Tek scope again.Now I use Keysight 2000, 3000 and 6000 Series scopes and can highly recomend them.Like others said, get a loaner for a week and play around with it.

author: dreamcat4
author_rank: Frequent Contributor
timestamp: February 11, 2020, 04:03:52 pm
content: Quote from: whiskeyjack on February 11, 2020, 08:29:46 amwithout question the keysightQuote from: whiskeyjack on February 11, 2020, 08:29:46 ammost oscilloscopes do this so that limitation is not specific to only keysight. getting an honest picture requires learning these limitations behaviour across different modes etc and understanding the limits of that accuracy. if you need more performance than what the 200mhz model can provide at its limit then getting a better scope will probably cost significantly more. it you are not certain then ask so sample multiple keysight scopes.other than keysight maybe a lecroy because its software user interface. but it would seem that there are more question marks over lecroy than keysight. who else to consider?

author: tautech
author_rank: Super Contributor
timestamp: February 11, 2020, 09:19:26 pm
content: Quote from: Wuerstchenhund on February 11, 2020, 01:48:58 pmOf course it does as should any scope in this class.https://www.siglenteu.com/wp-content/uploads/dlm_uploads/2019/12/SDS2000X-Plus_Datasheet_DS0102XP_E01A-1.pdf

author: jake111
author_rank: Regular Contributor
timestamp: February 12, 2020, 06:27:56 am
content: Make sure to consider probes during your purchase.I am back to school now but worked for a semiconductor company in the power electronics group. None of the senior guys would use Agilent due to probe selection. They all insisted on Tektronix DPO/MSO4000 series with those TDP series probes for their work. Amazing probes and I will admit the scopes were wonderful though out of the price range for someone comparing it to that cost reduced DPO/MDO3000 series or anything Agilent. The ability to capture at maximum sample depth (I recall 20Mpts per channel) at any horizontal setting on the Tek was extremely useful for some things (i.e. you can capture and then literally zoom to infinity and beyond with amazing clarity) and my Agilent DSO-X 3000 does not seem to support this at all which sucks. I see in the Agilent documentation that they seem to put down the Tek behavior by claiming that this huge capture depth slows the scope down, and therefore update rate down, which it certainly does, however you have complete control over it at least on the Tek 4000 series and when I worked there the guy who always had the Eureka! moment solving a huge ongoing problem was always using a Tek if it was power related. For high speed digital stuff, I saw lots of Agilent and they may dominate here, I really don't know but if you are doing constant current drivers for LED consider what probes you might want and take that into account. As an example Tek TDP1000 probes look to be under $1500 used and for a probe with 42V common mode range and 100V damage threshold, yet 1GHz BW and such small parasitics, I don't know what Agilent has to compete but I sure can't find it on eBay for a good price if it's there.

author: tautech
author_rank: Super Contributor
timestamp: February 12, 2020, 07:01:40 am
content: Quote from: jake111 on February 12, 2020, 06:27:56 amThere's more than one way to skin a cat !1) Pick the timebase setting that provides the largest mem depth or enough to suit your needs.Place the scope in Zoom (split screen mode) and have ALL the scopes memory depth to work with using the Horizontal pan be it Run mode or for a capture.2) Single trigger on an event then use History which for some scopes provides even greater memory than 'official' memory depth.3) Segmented acquisition (Sequence) mode which divides the maximum record length into multiple segments WRT to trigger conditions.

author: nctnico
author_rank: Super Contributor
timestamp: February 12, 2020, 09:01:18 am
content: Aaarghh the Siglent marketing campaign againNo, history and segmented recording are not an alternative. Jake111 is right: capturing data beyond the screen is a feature which is a major productivity boost. It is a real shame Keysight has dropped this from their more recent products. Personally I wouldn't buy a general purpose oscilloscope which can't sample beyond the screen.

author: 2N3055
author_rank: Super Contributor
timestamp: February 12, 2020, 10:20:13 am
content: Quote from: nctnico on February 12, 2020, 09:01:18 amYou are correct when saying segmented memory is not good for that job.But Jake111 is not saying ANYTHING about capturing data outside the screen. That's your thing. Actually capturing at long time-base and using your hated zoom function to look up the data is explicitly mentioned. On that Tek it is only method to accomplish this.He merely noted that MSO 4000 from Tek has long memory (20/40 MSPS as opposed to 1/2/4 MSPS on Keysight) so you can capture many milliseconds worth of data at full sample rate (and loosing no data due to antialising). For that job is much better than Keysight 3000/4000/6000.In which case new Siglents (2000X+ and 5000X) with 100/200 MSPS and new Rigols with 100/200/400 MSPS, and Picoscope (500MSPS/1GSMPS) are even better at that job, having another order of magnitude more sample memory.Regards,

author: nctnico
author_rank: Super Contributor
timestamp: February 12, 2020, 10:47:22 am
content: Quote from: 2N3055 on February 12, 2020, 10:20:13 amZoom can also mean using the time/div knob and the way Jake111 describes it the Tektronix is capturing beyond the screen:QuoteI have some hands-on experience with the Tektronix TBS2000 series and this does capture beyond the screen like a good DSO should.

author: 2N3055
author_rank: Super Contributor
timestamp: February 12, 2020, 11:28:19 am
content: Quote from: nctnico on February 12, 2020, 10:47:22 amI don't know about TBS2000. But zoom means zoom in Tek speak, and is widely used and taught in tek literature.It is Tek recomended way of doing this, and frankly, most logical one to most people excluding you.Other fact is that Tex did make it very nicely (inteligently), so it uses least amount of screen space..

author: nctnico
author_rank: Super Contributor
timestamp: February 12, 2020, 11:36:35 am
content: But jake111 isn't a Tektronix manual. Just a user. There is no need for a semantic discussion here. And using zoom mode to get most of the memory may be logical but it simply isn't the most productive way. You still need to do more steps to make a measurement. Just let the user drive the record length.

author: 2N3055
author_rank: Super Contributor
timestamp: February 12, 2020, 12:27:34 pm
content: Quote from: nctnico on February 12, 2020, 11:36:35 amI wholeheartedly disagree. Simplest way is to simply use time base to set length of time to be captured (like you would on analog scope), capture the single event, and then zoom in to area of interest to see details.I usually want to capture some known time interval (exact or approximate), which DIRECTLY corelates with time base. PeriodDoing it your way, I need to calculate in my head what length at which sample rate I need and at which time/div.My way is much simpler. Except for screen real estate, it is simpler and more logical to do. And Tek has really good implementation on MDO4000 series, for instance, with minimum screen wasted, and even a special shuttle buttons for really nice navigation trough zoom.And also, you're confusing capability with comfort. On a 200 MSPS Siglent in zoom mode, you CAN capture 40ms at full 5GS/s.On very expensive MSOX-3104T you can capture 800us worth of data at full 5GS/s, zoom or no zoom mode... You CANNOT capture 40ms however you use it...

author: nctnico
author_rank: Super Contributor
timestamp: February 12, 2020, 01:12:41 pm
content: Quote from: 2N3055 on February 12, 2020, 12:27:34 pmYou misunderstand. It is the other way around. What I do every now and then is look at the part of an I2C or SPI message to catch a specific piece of information. In some cases getting a measurement does take some time to wait so doing many captures gets expensive quickly. With the memory depth set to full (10MPts, 20Mpts, 80Mpts, whatever) this means I automatically capture a lot of information outside the screen. If I want to see a more of the signal the only thing I need to do is turn the time/div knob to zoom out. It doesn't get any simpler. No need to think about what precise setting to use. Forgot to put the trigger point back to the center? No problem, the info is there. Forgot to set the time/div exactly right? No problem, the info is there. You can work very lazy this way and not care so much about the exact settings. Just capture lots of data and analyse afterwards. It gets especially rewarding if something unexpected happens. Often the data leading up to the random event is also there.

author: jake111
author_rank: Regular Contributor
timestamp: February 12, 2020, 01:20:16 pm
content: Sorry I triggered you guys (HA GET IT, IT'S A SCOPE JOKE!) but I really think the capture depth is very important and this is why the senior guys I worked with used them. That and the probes, Tek's active probes seem to be second to none. Segmented memory and all that is great when you are looking at a repetitive waveform and want to observe some trend over time but when you have one shot to observe a failure, for instance in a case where you get catastrophic IC failure under a specific condition and want to capture everything in great detail for analysis later in that one shot, the Agilent (at least my DSO-X 3000) seems kinda useless for that. I assume this was a cost reduction feature and this is why the Tek 4000 series still cost 10 grand more than 10 years later while the Agilent can be had for two thousand. If you don't need this deep capture depth because all you look at are repetitive waveforms and never care to capture something in one shot in great detail then the cheaper scope is probably better for you unless you need good active probes. Don't discount the value of the probes. Those guys had Tek active probes that were approaching a decade old, i.e. the Tek TDP and TCP series and those probes still passed cal every year and to be able to observe a medium voltage switching power waveform at those voltage levels without damage and also while exposing the DUT to such miniscule parasitics from the probe front end was pretty damn cool.Anyway I have an Agilent DSO-X because I don't have the money for something better, for the price I paid I am not complaining at all. I have used the Rigol MSO5000 series and though those seem to pack a lot of claimed functionality in a small price, I would take the Agilent over it for the small price increase any day. You get what you pay for.And in all of this I never mentioned the LeCroy because I've never seen one before other than their SPARQ VNA and their USB 3.0 test/cert setup which was more of a holy grail than a scope... I know nothing about these...

author: jake111
author_rank: Regular Contributor
timestamp: February 12, 2020, 01:28:23 pm
content: Quote from: jake111 on February 12, 2020, 01:20:16 pmThanks this is kind of what I was trying to point out. If you are looking at repetitive waveforms with periodically repeating "glitches", sure you can get away with the poor capture depth of the Agilent. However if you are looking at a "once in a blue moon" failure that you spent 30 minutes carefully setting up triggering for, or a catastrophic failure that causes damage when it occurs, you only get one shot, and I think these two use cases encompass a lot of professional use. The repetitive stuff is for more run of the mill problems. The statement that you can just change your horizontal settings, or set up this bandaid segmented memory to capture something with more clarity just gives me the though "Oh, well that sounds nice, doesn't it... But in the real world..."... This waveform update rate thing is another annoyance - Yes Agilent that's great, you can update more waveforms per second and say "hey, that repeating glitch happened" - But what if it only happens once? Can I zoom in on that glitch with great clarity without reacquiring? And for lots of professional use, that really, really sucks.To each their own but if you are trying to bash Tek's deep capture depth and say that Agilent's segmented memory is an acceptable replacement you're either regretting your purchase or haven't had to do any troubleshooting of something that is a rare or single failure.

author: 2N3055
author_rank: Super Contributor
timestamp: February 12, 2020, 01:32:41 pm
content: Quote from: nctnico on February 12, 2020, 01:12:41 pmWell my way is exactly the same, except i turn time base in other direction ....Don't get me wrong, I respect you have way that works for you. I have a different way that works for me... They both do the job.But you are actually making important point. On my Keysight, I can capture at slow timebase, and then I can also change timebase and position, and traverse whole captured buffer (your way). Without using zoom. On little Rigol DS1074Z same thing.Can you do it on Siglent? Or new Rigols? Or does change of timebase erases the existing buffer? Can you change timebase to something shorter and traverse magnified portion on screen (as a sort of full screen zoom) ?

author: 2N3055
author_rank: Super Contributor
timestamp: February 12, 2020, 01:41:24 pm
content: Quote from: jake111 on February 12, 2020, 01:28:23 pmIt's okay that is happening all the time here.Seriously, there is no replacement for deep acquisition buffer when you need it. Period.I actually have a combination of Keysight MSOX-3000T and a Picoscope with 500 Msamples buffer, because Keysight sucks at longer captures.So, tool for the job...But Tektronix is not only one with more memory than Keysight. There is number of R&S, LeCroy, Siglent, Rigol, Picoscope(USB scopes) etc..And most of them are working better than Tek at most things.But.... If you have bunch of active probes for Tek ecosystem, then Tek might be the choice...Tool for the job.

author: jake111
author_rank: Regular Contributor
timestamp: February 12, 2020, 01:45:02 pm
content: I just have to say, I wouldn't consider anything that erases the captured memory when you change the timebase to be an oscilloscope... I would consider that to be a poor chinese copy, you have to understand these 9 year old kids are working 16 hour days to get this product to you and they can't do everything, give them a break...

author: nctnico
author_rank: Super Contributor
timestamp: February 12, 2020, 01:52:35 pm
content: Quote from: 2N3055 on February 12, 2020, 01:41:24 pmI have to agree. Going by the experience of others on this forum the Tek MDO3000 / MDO4000 scopes are not that good when it comes to actually using the deep memory for math and decoding. Makes me sad though because Tektronix has made so much nice equipment in the past. I really liked the elegant designs (the electronics) of the Tek 2230 and TDS500/TDS700 series oscilloscopes.

author: jake111
author_rank: Regular Contributor
timestamp: February 12, 2020, 02:03:25 pm
content: Quote from: nctnico on February 12, 2020, 01:52:35 pmYou need to use a 4000 series scope. For decoding, I don't get what the point is, if you need deep memory decoding you need a logic/protocol analyzer with that capability. It has always been a separate tool and I believe it always should be, connected to a PC. The decoding capabilities of the scope are for reference along side analog data and for triggering, IMO, not deep capture and analysis of bus data. The deep memory ability of the higher end scopes are for one shot failures in the time domain that are very difficult or very costly (your soldering time, or only one sample available, etc).And it's not about happening to have Tek active probes in the lab, its about availability of those probes. All of the agilent active probes I have used were unimpressive and hard to get, with the exception of very high frequency probes (like 4GHz for high speed bus cert and analysis) which is on a different class of machine and not really relevant to this discussion. I suspect Agilent dominates in that area but really don't have enough data points to say.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: February 12, 2020, 03:05:11 pm
content: Quote from: jake111 on February 12, 2020, 06:27:56 amInteresting. I have several large clients working with power electronics, and the majority of scopes there are LeCroy and Keysight, mostly Keysight Infiniium-S and LeCroy HDO600/8000 WavePro HD scopes, which all are HD scopes (10bit/12bit resolution) which is a big bonus. They wouldn't touch a 8bit scope with a slow architecture like the MDO4k with a barge pole.QuoteNot sure what your point is other than that you clearly bought the wrong scope with the DSO-X. If you'd done a minimum on research before buying then it should have been pretty clear right from the start that the DSO-X3k, like all InfiniVision scopes, has been designed with a very strong focus on very high waveform rates and therefore manages sample memory automatically only. This was by purpose as the InfiniVision (note the word "vision" in the name!) was always aimed at people coming from analog scopes and those that mostly work visually with a scope. And they value high update rates because it reduces the unavoidable blind time of your scope.The method to capture a certain period in time and then zoom in on the details is a common and effective strategy, and can be done with most (all?) newer scopes on the market down to the <$400 Rigol DS1054z.The funny thing that even your DSO-X3k can do that, either for the last acquisition in continuous mode (i.e. after pressing STOP) or in Single acquisition mode, where it uses the full available memory. So even if the DSO-X is somewhat limited due to its automatic memory handling (and the lack of user feedback on available memory), it could still used for your scenario when used properly, as long as the period you want to capture fits inside the 4M memory.Of course, part of being an engineer is knowing one's tools, so there's that element, too.Besides, and just to put this into context, Keysight wants some $5k for a 200MHz DSOX3024T and $15k for the 1GHz DSOX3104T. The 200Mhz MDO4024C starts at some $7.5k (i.e. roughly 1.5x as much as the DSOX3024T), and the 1GHz MDO4104C lists for >$18k (still some 17% more expensive). So there's quite a price difference here.QuoteI addressed this in more detail another thread but the short version is that there are plenty of inexpensive probes for other brand's scopes on the market, often even a lot cheaper than $1500.However, the 2nd hand value of more or less worn out probes should really not be used as a guideline for buying a new scope for professional use.Besides, cheap probes can't compensate for a lackluster scope.A chain is only as good as its weakest link.

author: jake111
author_rank: Regular Contributor
timestamp: February 12, 2020, 03:14:19 pm
content: See you are still basking the Tek without really providing any real reasons why they are "inferior". Do you work for Keysight?I bought the DSO-X because it was really cheap at the time. And while I know that the agilent probes suffer wear (with all the removing and reinstalling of attenuator hats, etc), most of the Tek probes at my previous employer were approaching 10 years old and still what I would consider "good as new" and passing cal every year.I really think it comes down to preference, everyone cares about different things, but in the end one doesn't really outperform the other unless we are talking about cheap econoscopes like my DSO-X 3000 or anything that companies put a "3000" on. For that matter, even these china brand (Rigol, Siglent) in the "5000" range still look like econoscopes, I think this must be marketing.I'll take a 20 year old RS6 over a brand new S6 any day and the RS6 is way cheaper due to its age. The 20 year old RS6 may have less "features" and take a little more education to use effectively but the quality and longevity is superior in every way. They don't make them like they used to. I strongly suspect this translates to scopes too. Everything is cost reduced nowadays, the investors want their money no matter what the market looks like and engineer's aren't allowed to obsess over making a truly excellent design anymore. The project schedule is predetermined and the product is released on time and on budget whether it's ready or not.

author: nctnico
author_rank: Super Contributor
timestamp: February 12, 2020, 05:43:35 pm
content: Quote from: jake111 on February 12, 2020, 02:03:25 pmThis is very bad (deadly) advice. Decoding is typically used when you also need to look at the signals in the analog domain. In most cases a problem with a protocol is happening in the analog world. Two examples:1) A third party was developing a gadget for one of my customers but he got stuck with getting the interface going. After 2 or 3 weeks and some finger pointing I went over to see what the problem was. It turned out the engineer was using digital inputs to check the protocol on his oscilloscope. After I hooked up the signals to the analog channels the problem was clearly on the screen in 30s.2) I had to hunt down a problem which occured about once every hour. For this I used segmented recording to record the interaction between a microcontroller and I2C device. I just let the system run with the oscilloscope on circular segmented recording and stop it when the problem had occured. After some analysis on the PC (save decoded messages to CSV format) I could figure out which segment to look at and lo & behold there was an I2C problem. Finding the cause of the problem using a logic analyser would have taken way more time.In both cases having decoding on the oscilloscope was a major time saver. Also protocol decoding can show values in realtime which is very handy for a quick check of an ADC or DAC. Sure you can make-do with other tools but you end up wasting a lot of time especially when hunting down an intermittant problem. The key to solving problems quickly is to get as much detail (=deepest memory) as you can in one go. I don't want to peel an onion layer by layer; I want to cut it in half and see what is inside.Beyond that you typically can do protocol analysis/debugging much easier at a higher level (let the devices output a log with the messages they receive in readable form) compared to using a logic analyser. If I had to choose between protocol decoding on an oscilloscope or a logic analyser I definitely choose protocol decoding on an oscilloscope.

author: jake111
author_rank: Regular Contributor
timestamp: February 12, 2020, 07:11:01 pm
content: Quote from: nctnico on February 12, 2020, 05:43:35 pmNo - Nothing deadly here, you misunderstand. What you are saying here is just reiterating/restating my point, maybe it's not clear to you. If you want deep memory capture/decoding because you are analyzing or reverse engineering some communication, i.e. "looking at bus data" as I said, you really should be using the separate logic analyzer, IMHO the scope is totally useless for this due to very limited capture memory - You won't be grabbing some bitstream to an FPGA for analysis with this. As I said, the scope protocol decodes are for triggering and looking at the data when you need it in parallel with analog to find problems with the bus, in this case you aren't concerned with capturing the specific data you are interested in troubleshooting a problem that lies in the analog domain. Now consider that with the advent of analyzers like the saleae which do digital and analog in parallel at very high sample rates, and eliminate the need for this middle step of importing to PC in some format and viewing that way, it really starts to make a lot less sense to use the scope and more sense to use the dedicated analyzer in many cases, especially given the many options for automatic recording and triggering, and massive (or even infinite within reason!) storage capabilities of the PC based analyzer.The scope is optimized for short, high precision captures with respect to almost any legitimate logic analyzer (not talking about toys like the bus pirate here). I have seen guys try to capture large amounts of bus data with a scope based logic analyzer - It can be entertaining to watch as they either try to capture it in segments and assemble these later on the PC side, or try to creatively reduce sample rate to minimum and carefully trigger to try and grab "most" of it, etc.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: February 12, 2020, 07:12:26 pm
content: Quote from: jake111 on February 12, 2020, 03:14:19 pmWhere should I start? Painfully slow, outdated architecture, horrible UI, locks up when doing demanding stuff, overpriced for what it is, one of the worst support departments in the T&M industry, shall I go on?QuoteNo, I just happen to see more test equipment than most people. A lot more.QuoteAll probes suffer wear. Some less some more, also dependent on how careful individual users are. Tek is no better or worse in this regard than any other manufacturer.QuoteYou may call it preference, but a lot is down understanding the facts and properties of individual pieces of equipment, and how that applies to your specific requirements. And yes, if all you do to use a scope for is looking at the screen and counting graticules then the difference between the various offerings may indeed not be relevant to you.Once you start using a scope as a serious debugging tool then even small differences become pretty pronounced.QuoteLike in most other cases, car analogies are misplaced, too (and it's the wrong place talking about the sins in the design of older Audis, of which there are many).I can't confirm that the quality has gone down. Technology has progressed dramatically, which has made costs come down. There never was a time where we had better scopes than today, going up all the way to 110GHz bandwidth, with powerful analysis tools and tons of memory. Gone are mechanical switches which eventually fail, or the need for regular manual re-adjustment.Chances are good that even a cheap Rigol DS1054z will have a much longer service life than most of the scopes of yesteryear.

author: jake111
author_rank: Regular Contributor
timestamp: February 12, 2020, 07:26:17 pm
content: Quote from: Wuerstchenhund on February 12, 2020, 07:12:26 pm

author: KE5FX
author_rank: Super Contributor
timestamp: February 12, 2020, 07:53:54 pm
content: You could both be right. The MDO4000 might be a really nice scope. I don't know, I haven't used one. But I do know that Tek has shipped some good scopes as well as some really terrible ones in the not-too-distant past. There are downsides to doing that. Over time, poor user experiences turn into prejudice, and prejudice turns into conventional wisdom.Tektronixbenefitedfrom that phenomenon for decades, after HP tried to sell some clunkers back in the 1970s. So they can't be too surprised if customers are reluctant to jump back on board after they start selling good hardware again.

author: james_s
author_rank: Super Contributor
timestamp: February 12, 2020, 08:08:23 pm
content: Tek was at one time way, way ahead, but I think they have a hard time really standing out these days.I still love the Tek user interface though, probably largely because it's what I'm familiar and proficient with. If they sold an updated TDS3000 series with similar performance but deeper memory and some modern features like serial protocol decoding at a price competitive with other lower-mid range instruments I'd be interested. They've been milking that design for what, 25 years now? A brand new TDS3054C can still be purchased, for something like $22k. No way I could justify paying that.

author: tautech
author_rank: Super Contributor
timestamp: February 12, 2020, 08:44:42 pm
content: Quote from: jake111 on February 12, 2020, 07:26:17 pmYou greatly underestimate the vast experience of whom you're dealing with here !Quote from: jake111 on February 12, 2020, 07:26:17 pmCertainly a larger universe than yours.Threads like these get passionate depending on experiences and POV however the specs of a piece of equipment and a users ability to use it to its capability always wins the day. We can go round and round about certain ways things should be done but the truth is modern equipment is very capable (even a $500 DSO) yet not all brands do the same thing the same way nor they need to.I grew up in a time when Tek ruled the roost and have owned a few of their Asian manufactured models over the years that now pale in comparison to models made by other Asian brands of today.To fully understand the capabilities of the modern DSO we need study the architecture of their designs to see what use case they're optimized for, be it to mimic a CRO's capabilities or maximise the capabilities or a DSO. Each has their advantages and each offer tools to allow crossover and mimic what the other is better at.Understanding the tool set of your instrument is paramount to getting the best from it. One users use case will be for the least amount of button pressing while another the flexibility to get the best overall capability yet not suffer from too much dead time.ymmv

author: tmbinc
author_rank: Frequent Contributor
timestamp: February 12, 2020, 09:51:48 pm
content: I've used a Tek DPO4034 for a long time, eventually switched to a Tek DPO5034 ~7 years ago for which I paid ~$5000 back then. I'd consider it as a mid-end scope. I've also used a number of low-end scopes (the usual sub-$500 Siglent, Rigol scopes, and years ago even a TDS2xx etc.). Unfortunately I don't have a lot of experience on Agilent scopes.Of course what you need strongly depends on what you're doing with it. I love long sample depth for automated captures (I've been doing DPA - differential power analysis - which requires sometimes million of captures, and segmented capture with 120M sample depth, a fast CPU that can write data at almost Gigabit speed to a network drive is super helpful in improving the acquisition time by an order of magnitude over what other scopes give you). I love "complex" measurements with statistics ("what's the latency standard deviation from this input signal to that output signal" etc. type). I use protocol triggers, protocol decoders for interactive debugging. I've used a scope to trigger on, and capture, a wide bandwidth RF signal (using a mixer) to debug a wideband artifact of a Wifi radio that happened every x thousand packets, and was hard to catch with a standard spectrum analyzer.I don't do much analog stuff, but occasionally I need to check if a power supply rail is noisy or not.In theory, the "cheap scopes" can do all of this as well. They are useful for interactive debugging (probe this testpoint, display some I2C transfers...), but you relatively quickly run into limitations of their protocol decoders or trigger logic (even though they do digital triggers, which in theory should be way more flexible). You can use them for automatic captures, but very quickly curse at them because they either crash every 10k transfers, or are just veeeery slow, or a combination of both. They can do measurements, but then miss exactly that type of measurements you just need. But of course they are a fraction of the cost.I know people here hate Tek instruments - and yes, there are a few stupidities, especially around the UI of the DPO5xxx-series - but:- They are rock solid stable, at least in my experience. They don't randomly crash, or worse: display wrong results.- They have pretty decent analog frontends.- They have protocols decoders that are solid (and work better than, for example, Saleae Logic decoders)- They can easily be scripted (via SCPI) to do what I want them to do, _and_ they are stable when doing that.- Their UI performance is okay, except for really long waveforms. This is actually my biggest issue - using the UI with 120M waveforms is borderline painful.- Active probes are available on eBay- I can use the Scope remotely over the network without limitations.But the reason why I keep going back to this instrument is that it's versatile enough that it can do _all_ of this, and quickly switch between usage cases. For example, after finding test points for an I2C bus I can check the analog voltages, then quickly setup a long capture, and decode into a CSV file. I don't need to re-wire my setup to use a logic analyzer. I don't need to buy a different scope if I want an "analog-like experience" (instead I just press the DPX button).On the negative side, I've never been a big fan of the integrated MSO port, some of the trigger limitations are annoying, and they seriously miss a few more physical keys (like the DPO7xxx have for trigger setup). But aside from that, I'm very happy with this instrument and haven't felt a need to upgrade in the past 7 years (which, combined with my TEA, means a lot).(For the record I was also pretty happy with the DPO4034, but going back to it now I miss some of the flexibility that I've learned to love.)

author: jake111
author_rank: Regular Contributor
timestamp: February 12, 2020, 11:15:49 pm
content: Quote from: tmbinc on February 12, 2020, 09:51:48 pmMy experience: Any design *started* after Tek joined the Danaher group and killed off the older experienced engineers (or made them rage quit?) had issues. I believe the DPO5000 series was started before this happened but completed after, and the first production runs had so many problems that the DPO5204 were popping up on ebay, bricked, for under 3 grand for a couple seasons.I believe DPO/MSO/MDO4000B redesign of the original series was done post-Danaher but still retained the original OS and therefore very, very stable and just an all around great scope, but IMHO the MDO was a bad idea because that platform did not have the horsepower to do so much at once, and the latency of the mixed domain functions demonstrated this to some extent. However one attractive feature of the -B series and after was the ability to use the 1GHz passive probes, TPP series. I don't think they were over 4pF so if you didn't need diff, you had something very nice for catching high frequency harmonics and the like with minimal parasitic intrusion of your DUT.I only used the -C series briefly but they had that same "cheap" feeling as the DPO/MSO/MDO3000 series that they introduced at the same time as the 4000B series and it will be interesting to see what pops up on ebay needing repair. This is one of the reasons that the original DPO/MSO4000 seem to retain their value so much, they are workhorses, I saw ridiculous hour counts on many of them and never saw a failure and I believe they had at least 15 of them in the lab. I know there are some small issues with one or two power supply circuits that can manifest but I suspect that is due to thermal abuse, not taking care to keep the vents clear. Not sure.For me, the DPO/MSO4000 first gen set the standard that I judge other scopes by and this is probably one of the reasons that I find many Agilents to be so disappointing. Now also keep in mind, I am the guy that likes to buy the best tool in order to save as much time as possible, so that there is a little left for my wife. Time is money. And therefore woman(i.e. wife) = time x money. Therefore woman = money^2. And since money is the root of all evil, money = sqrt(evil), therefore woman = (sqrt(evil))^2 = evil. QED

author: jake111
author_rank: Regular Contributor
timestamp: February 12, 2020, 11:24:30 pm
content: Quote from: tautech on February 12, 2020, 08:44:42 pmI'm not letting on to who I am, what I've done, and what my experience is. This is the internet where a 12 year old can be a nuclear physicist on a forum. All I can do is claim I have the experience and state my opinion like you guys are, except hopefully with the cocky "my opinion is supreme" attitude that discredits everything you say.FYI my first scope was a Tek 485, that's as far back as I know and as far back as I care to know, servicing that thing was a real pain. I can't even give it away nowadays.

author: james_s
author_rank: Super Contributor
timestamp: February 13, 2020, 02:11:33 am
content: I'd be shocked if you really couldn't give away a Tek 485. That's a classic and one of the highest bandwidth analog scopes available, it was a real exotic piece of gear when new and it's still impressive today. If you need 350MHz bandwidth there are no new scopes on the market that offer that at a price most hobbyists can afford.

author: tautech
author_rank: Super Contributor
timestamp: February 13, 2020, 02:15:36 am
content: Quote from: james_s on February 13, 2020, 02:11:33 amSDS2352X-E and more capable than a 485 ever was.

author: tautech
author_rank: Super Contributor
timestamp: February 13, 2020, 02:32:51 am
content: Quote from: blueskull on February 13, 2020, 02:18:23 amhttps://siglentna.com/product/active-probe/

author: jake111
author_rank: Regular Contributor
timestamp: February 13, 2020, 02:41:33 am
content: I wish I knew what people were talking about with Tek's being slow! Do people always use them with the capture depth at max settings or something? The fastest Rigol I've used was as laggy as a Tek 3000 with FFT and averaging enabled at max capture rate

author: jake111
author_rank: Regular Contributor
timestamp: February 13, 2020, 03:19:46 am
content: Quote from: blueskull on February 13, 2020, 02:46:58 amNot to be impolite but that's a very broad and very incorrect statement... Unless the Tek you were using was actually a rock? Or maybe some sort of shrubbage

author: jake111
author_rank: Regular Contributor
timestamp: February 13, 2020, 03:33:35 am
content: Are you sure they weren't rigols with tektronix labels glued to them?

author: james_s
author_rank: Super Contributor
timestamp: February 13, 2020, 03:47:58 am
content: Quote from: tautech on February 13, 2020, 02:15:36 amI was not aware of that, looks like a lot of bang for the buck for a new instrument, although at almost 900 bucks it's considerably more than I've ever paid for a scope, and I would say well beyond what all but the most serious hobbyists are going to spend. There's a shrinking but still quite large gap between that and the say <$250 used scope hobbyist market.

author: tautech
author_rank: Super Contributor
timestamp: February 13, 2020, 04:01:08 am
content: Quote from: james_s on February 13, 2020, 03:47:58 amYep, it's more of a serious hobbyist DSO or for a small company that just needs some cheap BW however as the hobbyist buyer is generally not adverse to hack a DSO it's smaller bro SDS2202X-E for just $619 is a lot more attractive.QuoteYes the gap is getting much smaller as ppls get to understand and accept the power of a DSO plus less are bothered now with keeping the older gear functional because as their time becomes more precious they just wanna have something they can use and not have to fix.That's where I was once and while I enjoyed fixing CRO's it was time lost when you could be doing something else.

author: Sparky Faraday
author_rank: Regular Contributor
timestamp: February 13, 2020, 07:15:00 am
content: QuoteBingo! The older you get the more valuable your time .

author: nctnico
author_rank: Super Contributor
timestamp: February 13, 2020, 08:16:52 am
content: Quote from: jake111 on February 13, 2020, 02:41:33 amWell, what is the purpose of of long memory if you can't really use it? I have an R&S RTM3004 on my bench as well and this really is a nice all-round scope which doesn't slow down at all. Try it if you have a chance. Rigol is not a good benchmark to compare against.

author: james_s
author_rank: Super Contributor
timestamp: February 13, 2020, 06:50:26 pm
content: IMHO Windows has no business being on an oscilloscope.The older TDS series work great, I have very few complaints. Why they started using Windows is beyond me. A scope shouldn't need to boot a fullblown operating system off a hard drive.

author: Mr. Scram
author_rank: Super Contributor
timestamp: February 13, 2020, 07:27:28 pm
content: Quote from: jake111 on February 13, 2020, 03:19:46 amIt depends on your definition of "faster" but the Keygilent ASICs do seem to make a noticeable difference.

author: KE5FX
author_rank: Super Contributor
timestamp: February 13, 2020, 08:39:22 pm
content: Quote from: james_s on February 13, 2020, 06:50:26 pmThat's like arguing that a cell phone doesn't need a full-fledged operating system. The market has spoken, the horse has left the barn, and the ship has sailed.Like a phone, an oscilloscope is just another device for gathering data, processing it, and communicating with other devices. It needs an OS, and Windows is OK, I guess.

author: 2N3055
author_rank: Super Contributor
timestamp: February 13, 2020, 08:59:28 pm
content: Quote from: KE5FX on February 13, 2020, 08:39:22 pmThis is 100% correct.Also, all those scopes has extremely complicated signal analysis software. At one point, it get really complicated writing that if you don't have full blown developer tools, high performance libraries and platform on which you don't have to write every single thing from the scratch.And contrary to all the haters, windows is the only one with very high performance graphics with plethora of support for writing graphical applications...

author: james_s
author_rank: Super Contributor
timestamp: February 13, 2020, 09:05:51 pm
content: Well I can tell you that I will never buy a scope that runs Windows, not unless it's a dead one for pennies on the dollar to play with. I have to do enough support of PCs without having to tinker with it on my tools too. I'm not even sure why but at least XP and earlier which are common on scopes tend to deteriorate with age of the install.

author: Mr. Scram
author_rank: Super Contributor
timestamp: February 13, 2020, 09:18:16 pm
content: Quote from: james_s on February 13, 2020, 09:05:51 pmUntil quite recently most of the Keysight kit came with Windows CE and that seems to work out well enough, boot times possibility excepted.

author: KE5FX
author_rank: Super Contributor
timestamp: February 13, 2020, 09:39:50 pm
content: Quote from: Mr. Scram on February 13, 2020, 09:18:16 pmSome people cling to guns and religion, I cling to VxWorks. Unfortunately, Keysight didn't.

author: nctnico
author_rank: Super Contributor
timestamp: February 13, 2020, 09:53:20 pm
content: Quote from: KE5FX on February 13, 2020, 08:39:22 pmNot just that but about every oscilloscope (and every other piece of test equipment) released nowadays runs on Linux which is a full blown OS too.

author: james_s
author_rank: Super Contributor
timestamp: February 13, 2020, 11:38:05 pm
content: Actually I don't even really care what's happening under the hood, but I don't want it to feel like software running on a pc with an underlying OS that I have to maintain.When I power up my TDS scopes they come up to their user interface and whatever underlying operating system makes them tick is completely hidden. I have embedded Linux based devices that are similar, the firmware is a packaged deal, not an application that runs on top of a standalone OS with its own desktop. I wouldn't care if a scope had the windows kernel underneath but I don't want it to feel like a piece of crusty old software running on windows with all the baggage that comes with it.

author: e0ne199
author_rank: Regular Contributor
timestamp: February 14, 2020, 12:29:21 am
content: people in this forum keep saying that 200MHz bandwidth is a bandwidth for entry level oscilloscope and yet i see this thread in which someone is asking for a recommendation about which 200MHz oscilloscope is the best for his professional use... why don't you recommend an oscilloscope whose bandwith is more than 200MHz? i am pretty sure it packs more features than 200MHz one.. just an opinion 😁

author: tautech
author_rank: Super Contributor
timestamp: February 14, 2020, 01:16:31 am
content: Quote from: e0ne199 on February 14, 2020, 12:29:21 amAnd a valid one.The scopes in question all have sampling rates of 4GSa/s or more and 200 MHz models are near the bottom of each of their ranges however such is pricing there are big jumps in $ when jumping to the next BW step.Maybe the OP considers these are outside his budget.Equally valid is why would one select a 4 or 5 GSa/s DSO for 200 MHz work when a 2 GSa/s DSO would be sufficient ? In this class there are certainly more options to consider and at considerably better prices.

author: nctnico
author_rank: Super Contributor
timestamp: February 14, 2020, 01:18:55 am
content: Quote from: e0ne199 on February 14, 2020, 12:29:21 amNot necessarily. There are oscilloscope models which have several bandwidth options including going over 200MHz. It is not like a high featured oscilloscope isn't available as a 100MHz or a 200MHz model. In some cases you may want the higher end features but don't need the bandwidth. There is much more to a DSO besides bandwidth.

author: Mr. Scram
author_rank: Super Contributor
timestamp: February 14, 2020, 01:20:47 am
content: Quote from: james_s on February 13, 2020, 11:38:05 pmBoth Linux and Windows based oscilloscopes do what you ask. Except the big boys maybe but you tend to very deliberately get into those.

author: james_s
author_rank: Super Contributor
timestamp: February 14, 2020, 01:42:57 am
content: Quote from: nctnico on February 14, 2020, 01:18:55 amYou can also often get away with rather little bandwidth. For many years I used a 100MHz scope and it was fine. After getting a 1GHz scope it has made me a bit of a snob and I have trouble getting excited about anything less than about 500MHz. Still for 95% of what I do 100MHz would be fine.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: February 14, 2020, 10:44:24 am
content: Quote from: jake111 on February 12, 2020, 07:26:17 pmYes, because I had the displeasure to use it. As had with pretty much every Tek starting from the MDO3k and going up to the DPO-X.QuoteMy experience comes from being on the buying end of the T&M industry to equip a number of labs around the world with equipment they need to do high tech stuff. That's pretty much the short version.But thanks for remining me of that profile list, and you're absolutely right, the list *is* dire (and no longer correct anyways). But hey, I'm living in a depressingly small and poorly built excuse of a house with literally no real space and that will only change once I have wound down all our UK operations, so there's little use to buy better gear. Even more so when I have all the great toys at work