Should I get a Keysight DSOX6004A ? - Page 1
Forum section: electronics / testgear

author: grg183
author_rank: Contributor
timestamp: August 20, 2021, 10:31:46 am
content: I'm exploring the options for a 1GHz+ bandwidth oscilloscope for professional use (I am an electronics engineer and run a small professional electronics design business). I'll probably not be buying this until next year but I'm starting to evaluate the options.Some main features that I am looking for are:- 1GHz bandwidth, preferably upgradable to 2.5Ghz or more.- 4 analog channels, digital channels a plus but not necessary- jitter analysis- eye diagramsThe main need for this oscilloscope is for high speed signal analysis. I have been working on high speed designs already but this is becoming increasingly common and demanding so I am looking to upgrade my equipment.I am a bit of a Keysight fan, I own a Keysight MSOX3024T oscilloscope and a Keysight FieldFox N9923A VNA and have always been happy with their quality and support.I also understand the value and importance of quality tools, I need my tools to be reliable and accurate, every time. I don't have time to waste troubleshooting problems with tools and or worse being misled by an inaccurate measurement.I also have a Keysight N2790A high voltage differential probe and a Keysight N2893A current probe, which have a Keysight specific active interface. These probes alone cost around $6k so I would ideally like to be able to used them with the new scope too.Having a 'brand name' oscilloscope is also beneficial for when I need to include it in reports or screenshots sent to clients, but it is not the deciding factor.Unfortunately being a small business puts me in a sort of gray zone between markets, since I have the needs for a high end scope for professional use but while I can afford some of the brand names, I don't have money to throw away like big companies do.By the way, I'm sure there are great deals to be made with used equipment but I am generally not interested in used equipment, no matter how good of a deal it is (well I'll take it if it is practically free :-) ), except perhaps for 'Keysight Premium Used' but even that only if I really cannot justify the price of new hardware.So naturally my first choice would be the Keysight DSOX6004A. I could get the 1GHz version and then upgrade it as needed over the next few years. That would be perfectly reasonable budget-wise.I was considering the RTA-COM4 offer from R&S too but it is not upgradable past 1GHz and afaik doesn't do jitter analysis or eye diagrams, so while I'm sure it is an excellent instrument I think it would be limiting me in future.In general I don't like Tektronix gear so much but if it makes sense I will consider it.The Lecroy WavePro 254HD would probably be the best choice from a technical and feature standpoint. Budget-wise I can afford it and probably even justify it but for the current size of my business it is still a lot of money. I am not very familiar with Lecroy gear but it seems to be a better bang per buck compared to the Keysight DSOX6004A.About the DSOX6004A, my concern, is that the DSOX6004A is based on a now fairly old MegaZoom IV asic and still only has 4Mpt memory (I know the benefits of segmented memory but still..). Meanwhile I am seeing that in these past years the 'cheap' brands have come a very long way. I'm looking at the Rigol MSO8204 for example and I cannot help but think whether I should really spend all that money on the DSOX6004A. On paper the Rigol MSO8204 seems to be a good fit, with loads of memory and at a fraction of the price. It could potentially make sense to get an MSO8204 now to cover my current needs and then look back into something better in a few years time. I didn't hesitate when I bought the Keysight MSOX3024T 5 years ago but it was a smaller investment and the cheaper alternatives were nowhere close to it's specs back then.So I guess my main questions for you are:- Do you think that in 2021/22 the Keysight DSOX6004A is still a good investment considering the old asic and limited memory?- What is your opinion on the Rigol MSO8204? Am I crazy to even consider this for professional use? I've looked around for reviews of the MSO8000 series but the only videos I found are from Rigol and even on this forum there are only a few sporadic comments about it. I'd be interested to hear from anyone using the MSO8000 in a professional lab setting.- Excluding Keysight, what oscilloscope would you suggest for my use case?For these questions I am more concerned about having quality equipment for professional use rather than saving money, but at the same time I'd like to spend the money wisely.Thanks

author: tv84
author_rank: Super Contributor
timestamp: August 20, 2021, 01:15:29 pm
content: https://www.eevblog.com/forum/testgear/recommendation-rs-rta-4kcom-or-siglent-sds-5102x-or-rygol-mso-8064/msg3613426/#msg3613426

author: nctnico
author_rank: Super Contributor
timestamp: August 20, 2021, 03:46:17 pm
content: Don't rule out Lecroy yet but they are different compared to other scopes. I have a Lecroy Wavepro 7k series -which is a much older model- myself and it does have some caveats:- no peak detect (I knew that before buying)- the post trigger delay is really short. On other oscilloscopes you can get to over 1 second but the Wavepro 7k is limited to the screen width. If you want to do some form of jitter analysis on a 1PPS signal then you are out of luck- record length is automatically shortened just enough to fill the screen- getting more advanced analysis functions going can be a bit finickyAll in all: check the datasheet very carefully if you want to buy a Lecroy scope. These scopes are great for signal analysis using math operations but for a daily driver I'd look somewhere else.Personally I'm very wary of Rigol. They release way ahead of schedule and then fix problems based on how many units they sell. So if you happen to stumble upon a bug that is in the way of what you want to accomplish you'll likely find yourself buying a different oscilloscope. Nowadays Rigol is a very small player in the test equipment market. Siglent is much bigger if you compare them revenue wise.I also don't quite understand why used is out of the question. Great deals can be found including units which still have a couple of years of manufacturer warranty left. The last 2 years I bought two pieces of Tektronix gear with nice discounts from reputable companies. One basically new in the box (screen protector still on) and the other in mint condition.

author: LaurentR
author_rank: Frequent Contributor
timestamp: August 20, 2021, 05:09:44 pm
content: Something to consider: Keysight has an EBay store where you can purchase a lot of their scopes (used for the most parts - demos, rented units or trade-ins) and save quite a bit, especially if you need the higher-end models and the app bundle. They do have a couple of 6004A right now like this one:https://www.ebay.com/itm/Keysight-Used-MSOX6004A-Oscilloscope-6-GHz-20GS-s-4-Channel-w-app-bundle-/174885860472?hash=item28b8027478Note that they do take offers and you can usually save at least another 10-15%, sometimes more depending on the model and how long it's been listed.

author: grg183
author_rank: Contributor
timestamp: August 20, 2021, 05:23:27 pm
content: Quote from: nctnico on August 20, 2021, 03:46:17 pmThanks for the tip, I am not familiar with Lecroy scopes and only now considering them for the first time. Their advertised specs and features are quite interesting but will definitely look into the details if I choose a brand I'm not familiar with.Quote from: nctnico on August 20, 2021, 03:46:17 pmI do have a Rigol DSA875-TG Spectrum Analyzer a Rigol DP832 power supply and a Rigol DL3031 electronic load, all of which have served me very well without trouble. I have no regrets in having bought Rigol for these. However for an oscilloscope I'm not very confident in buying Rigol or Siglent. You are right the Rigol gear that I have had already been released for a few years when I bought, probably explaining my trouble-free experience. The MSO8204 is probably too new for that.Quote from: nctnico on August 20, 2021, 03:46:17 pmThis is probably mostly a matter of personal choice, I find it very hard to accept a used item, not just test gear, but practically anything else. I am somewhat obsessed with proper equipment handling and not knowing what a used equipment has been through is a total deal breaker for me. I also don't want to deal with possible hidden damaged done by previous owners, even if minor and even if still under warranty. If it is factory refurbished along the lines of 'Keysight Premium Used' I might consider it, but even that I would have a hard time to accept it and only if I have no other option. 'Keysight Used' is totally out of the question. Probably it's some mental condition, I know

author: 2N3055
author_rank: Super Contributor
timestamp: August 20, 2021, 05:40:08 pm
content: MSOX6000 series is least capable of all the scopes in that class. Lecroy runs circles around it dollar for dollar.It has big screen, basic jitter package, color grading and faster A/D converters, but it is basically exactly the same scope like 3000T/4000 series.That doesn't mean it is bad, just that there are better choices for the money.As for Rigol, read posts of user Sighound36. He actually owns one (unlike many who still have opinion despite never tried it). Basically, you get similar capabilities to MSOX6000 series and 100x more memory.Quality is just fine, and it works quite well for what it is.And also, scope market is moving target. I you are going to purchase it next year, by that time there might be new players in the game, and pricing and choice might be better.I would suggest to look into current Lecroy midrange offer, just to educate yourself what is possible for your money. You will soon see how huge is the difference, compared to Keysight 6000 series.As for used, I don't like it either. But there are used certified scopes sometimes offered by manufacturers, where you can get used, fully qualified, freshly calibrated scope with full, as new, warranty.That is a good deal.As for your very nice active probes, keep them for use with your MSOX3024T. You'll want to keep that one for everyday tasks, midrange and high end scopes are not optimized for service type of work.But as I said, next year situation might be much different, and I suggest to make decision then.

author: grg183
author_rank: Contributor
timestamp: August 20, 2021, 07:37:25 pm
content: Quote from: 2N3055 on August 20, 2021, 05:40:08 pmThat's my impression too. The MSOX3024T that I have is great scope and despite it's limited memory I've never found this to be a problem. There were cases when I wished it had more memory but this never prevented me from getting the job done. However I'm finding it hard to justify buying the DSOX6004 as a higher end scope with the same memory limitation, same ASIC and for a much higher price. It feels like buying the same scope with a few extras. It is not so much about the price, it's more about making sure that I get the oscilloscope that will best fit my current and foreseeable future needs while to a lesser extent also make best use of my money.Compatibility with the active probes that I have is not a priority. It would just be convenient to be able to use those probes on either scope but definitely not a requirement.You're right, I need to check Lecroy's ranges in more detail, I never really looked into them much but now I'm really starting to like them.

author: tv84
author_rank: Super Contributor
timestamp: August 20, 2021, 07:58:23 pm
content: Quote from: 2N3055 on August 20, 2021, 05:40:08 pmSighound36 has the Rigol and experience in most others that are included in this discussion. I poked him to say something here.BTW, with such a budget, why not the new R&S RTO6?

author: grg183
author_rank: Contributor
timestamp: August 20, 2021, 09:06:01 pm
content: Quote from: tv84 on August 20, 2021, 07:58:23 pmThanks for the tip, definitely interesting!

author: tautech
author_rank: Super Contributor
timestamp: August 20, 2021, 09:15:08 pm
content: Another that can be thrown in the mix is SDS6000 that should not be too far from release.From what I've heard the beta testers have given it a good workout however we don't yet know what models and specs will be offered to western markets.https://www.eevblog.com/forum/testgear/siglent-sds6000-pro-10-and-12-bit-dso-coming/

author: Someone
author_rank: Super Contributor
timestamp: August 20, 2021, 11:33:04 pm
content: The answer is probably no, unless you have some need to sell the 3000T and have only a single scope. As the DSOX6000 is the "top" of their interactive/fast update rate models and doesn't really push much crossover into the deep memory and analysis (as mentioned above R&S have scopes better straddling this market or look at the newer EXR range from Keysight), way too much crossover between the 3000T and 6000.If probes are a significant push and you think you might invest in more into the future (not uncommon to spend as much as the scope(s) or more on probing) then consider the complementary scope to a 3000/4000/6000 being a 9000/80000/90000/MSOS.Quote from: grg183 on August 20, 2021, 10:31:46 amThis might be the most important specification to narrow down and decide on. You could also consider doing more in the frequency domain to higher harmonics and/or a spectrum analyser. Not much can be seen with scope bandwidth only 2x above the bitrate.Quote from: grg183 on August 20, 2021, 10:31:46 amDon't bother thinking ahead, only buy (or rent) what you need right now. Very rarely does the market for test equipment stagnate or see increasing prices.

author: Sighound36
author_rank: Frequent Contributor
timestamp: August 21, 2021, 01:52:44 am
content: Tough choices to make I can sympathise I am tied up until tomorrow afternoon but will offer some experience on most of the svopes you mention

author: grg183
author_rank: Contributor
timestamp: August 21, 2021, 09:06:45 am
content: Quote from: tautech on August 20, 2021, 09:15:08 pmDefinitely worth checking, thanks. The issue with this is my same concern about the Rigol, in that I'm not sure I should rely on a Rigol or a Siglent for professional use. If it were for hobby or occasional use it would be a no-brainer and I would probably prefer a Siglent over a Rigol for that. It would probably be also a no-brainer as a second/spare scope for professional use. There are two things at play here, first I absolutely need a scope that is reliable all the time and gives accurate and dependable readings all the time. If I even have a doubt on a measurement it's essentially unusable, and I cannot afford to waste hours here and there troubleshooting or working around scope bugs. I don't mind if the UI is weird or if I have to press 10 buttons instead of one, as long as it is functional. The second thing is that although my business is on the smaller end, I often compete or collaborate with much bigger companies so having quality 'brand name' tools can be an advantage in such cases. Still the prospective of saving some $10-20k and still having a tool that gets the job done for a business of my size is very inviting.Quote from: grg183 on August 20, 2021, 09:06:01 pmThe only disappointment about the RTO6 is it seems to only have an 8-bit hardware ADC, otherwise it seems a really good fit.

author: Sighound36
author_rank: Frequent Contributor
timestamp: August 21, 2021, 10:24:54 am
content: I have to say the R&S RTO6 is a vast improvement over the prvous RT models, GUI is hughly improved and much more intuitive BUT its still quite noisy and to obtain the apps you wish puts in a different price bracket.K/S 6000 series can be had for good prices now a couple of guys on here felt that it was not enough to change to the MXR, the newer EXR is possibly where to start looking.I run a Wavepro.MDA and 6000A lecroy, plus a Rigol MSO 8000 series which is suprising good, the new Siglent will not have eye and jitter I believe or will it be 12 bit licencing outside China.Back later customers today!

author: 2N3055
author_rank: Super Contributor
timestamp: August 21, 2021, 10:31:03 am
content: Quote from: grg183 on August 21, 2021, 09:06:45 amAs for "fit for professional use" we passed that point half a decade ago..At this point, quality or dependability is on par with A brands. They are still lagging a bit in depth of analysis options, but mostly at high end. In entry level and mid range, they are getting close, and quick.They are working tirelessly on it.Also why presume anything is weird in U/I? They are no better or worse than A brands. Problem with all new scopes is the they are COMPLICATED. They have so much measurements and analysis options that it takes time to learn what is there in a first place, much less where it is.For that problem, new touchscreen scopes are much better, and having tried most of the brands (Keysight, R&S, LeCroy, Rigol, Siglent) I would say it is more of a style difference than anything else. LeCroy, R&S and Siglent take more modern full touch screen interface approach, and Keysight and Rigol are more of standard scope with touch added approach. They all take a week or two to get used to, and then you simply use it and don't think about it anymore.Also, "brand name tools" as advantage to customer is a moot point. If customers trust you, they will not go into that. If they don't, fancy tools are waste of money. You won't get the job. Also, if I was your customer, I would rather you have Siglent or Rigol under maintenance interval and freshly calibrated, than 15 years old Big Brand that was never calibrated.I would pay more attention to quality and completeness of your documentation that what logo is on scope screenshots.I see more and more research papers that use Siglent and Rigol in it with no shame. Whatever prejudice is there will dissipate in next few years.I had only one encounter where customer made a comment "that he would like that i calibrated it with proper equipment" meaning Fluke or Keysight. On which I answered that my meter was in official calibration cycle, that it was order of magnitude better than was needed, and that I will gladly make an wager with him: I would take (or he can) somewhere and verify calibration on "propper gear", and if it was out of cal I would gladly pay for all expenses. But if I was right, he would pay for the pleasure out of his pocket. At which point it was suddenly fun and games "we were just joking" moment... Customers are always right, up to the point where they aren't. And they always have "special requests" until the point they have to pay for the pleasure. Then suddenly "standard service" is good enough.If you do stumble upon customer or job that simply require special equipment you don't have, include it in cost of project and rent it. You always say to your customers that you have fine very well equipped lab, but is need arises that you rent special equipment. So they can rest assured that you have best tools at your disposal, and pass the savings to them by managing the cost of equipment by prioritizing what you purchase. Sometimes project will buy you a whole instrument if it makes sense financially and you can integrate it in cost structure.As for 8-bit hardware, going over 2 GHz and more than 8 bit A/D is not very common, and gets expensive fast. Also, despite claimed resolution, ENOB will be different story.For looking at jitter and eyes, and fast protocols, 8 bit is more than enough for the most purposes. At such bandwidths noise is getting to be big part of what you see on the screen. As I said, take a look at the ENOB numbers , that is more important.There is a lot of merit for higher than 8 bit scopes at lower frequencies. For power electronics, having 12 bit is improvement. For lower frequencies, working on sensors and such, 16 bit is even better.But those are special tools for special jobs. If you work on those jobs, you will need to get those tools separately. There is no scope that will do everything best. They will usually shine in one area and be usable elsewhere. For instance 8ch, 20MHz, 12 bit scope will work great for switchers, power electronics (frequency converters, motor drives) etc. You could check 7+1 AV receiver outputs all at the same time on single correlated plot. You can measure and monitor 3 Phase systems, 3 phases, V&A and PE current, all at the same time.But it is only 20MHz. For you, something not useful at all. For power electronics guy, probably all the tool he will ever need.

author: nctnico
author_rank: Super Contributor
timestamp: August 21, 2021, 06:15:55 pm
content: Quote from: 2N3055 on August 21, 2021, 10:31:03 amThat depends on what you are doing. Siglent gear has been falling flat on it's face for the measurement tasks I'm facing so I have to buy A-brand instead to get the job done. The problem with Rigol and Siglent still is proper verification of their software functions. So things appear to be OK at the surface but once you dig deeper you start to uncover the skeletons. This is likely due to being relatively new to making test equipment compared to the more established brands which have decades of experience and pedigree that goes into their designs.

author: tv84
author_rank: Super Contributor
timestamp: August 21, 2021, 07:08:47 pm
content: Quote from: nctnico on August 21, 2021, 06:15:55 pmNico, you know perfectly well that companies are made of people. And people tend to have a finite number of years. The fact that a brand has decades of experience doesn't mean it can't do new errors bigger than a recent starter.I think what the B brands lack is a schedule of FW updates. If Siglent/Rigol just announced that they would release a FW update every 6 months and stick to it, you guys would be all happy! For example, Keysight does that and you all love their "bug free" releases (they must be bug free because of the decades long experience). So, it seems that if you just have a firm FW update schedule, that could very well place you in the A brand realm.

author: nctnico
author_rank: Super Contributor
timestamp: August 21, 2021, 07:22:51 pm
content: Quote from: tv84 on August 21, 2021, 07:08:47 pmSorry but that is wrong. If your statement where true then we'd get cars which look like and drive like a model-T Ford every 30 years. It doesn't work that way. Rest assured that new people who get to work on the core functions get thouroughly trained by the seasoned engineers and have access to a vast library of documentation (just look at the dozens of appnotes Tektronix and Keysight have published over the past decades).A good example is the Tektronix AFG31000 I bought recently. The UI has some rough edges because it is a new touchscreen based UI instead of the usual Tektronix interface but the signal generation part is rock solid. The latter has been engineered and perfected during the decades that Tektronix has been making these kind of function generators. According to the datasheet a Siglent SDG2000x generator would be better bang for buck but unfortunately it has a bug in the modulation part (probably accumulating rounding error) which makes it useless for my purposes.

author: tv84
author_rank: Super Contributor
timestamp: August 21, 2021, 08:20:32 pm
content: Quote from: nctnico on August 21, 2021, 07:22:51 pmI meant precisely the opposite. I hate to derail the thing but, then, let me add 2 small examples: 1. it was the same NASA that put Armstrong on the Moon that decided to launch the shuttle Challenger, 17 years later. 2. That same NASA (together with all the A brands of the aerospace world) with many decades experience (successes and failures) were unable (or, at least, unwilling) to do what SpaceX has accomplished in these last 2 decades.So, what I meant is, decades long experience indoctrination nowadays is not a guarantee or assurance that you will excel in any new technology that comes into your field. For sure it's a big advantage but it's not a lifetime guarantee.Also, back on topic, Sighound just said that RTO6 noise level is disappointing. That for me is a BIG disappointment!I've seen the RTO6 UI and I consider it, just from videos, the best UI I've ever seen in these type of scopes. So, given R&S decades long experience, that new technology (which is the touch UIs) should be their hardest part. But, unfortunately they exceled in the UI and underperformed in the noise part...Let's hope it was Sighound misjudgment. We need further opinions like yours.

author: bdunham7
author_rank: Super Contributor
timestamp: August 21, 2021, 08:22:23 pm
content: Quote from: 2N3055 on August 21, 2021, 10:31:03 amI wouldn't presume to speak for all customers, but some of them still care--perhaps because they don't know any better, but they still have opinions. And as far as whether or not they trust you, what is that based on? If they have no other information, perhaps they are looking at your equipment. Now as far as under maintenance and freshly calibrated, we had that discussion....https://www.eevblog.com/forum/testgear/siglent-sdm3065x-issues/QuoteI'm not sure I see the connection. My take is that these brands offer great value with the occasional, often unexpected, shortcoming. I ran into this with my SDS1104X-E when I found that it had an extraordinarily long overload recovery time that prevented me using an uncommon but not unheard of measuring technique. All of my decades-old A-brand scopes were able to perform this as expected. Now I still think the Siglent is a great value, it does many things very well and I use it all the time. However, this raises two issues.The first is what do you do when you only have one instrument capable of doing a difficult measurement and you have no way of cross-checking--so you need to have great confidence in that measurement? This isn't an 8 bit vs 10 bit or 4k vs 14M of memory question, it is a question of whether the manufacturer has carefully engineered out all of the various arcane issues that can lead to errors or unanticipated results in corner cases. On paper a Tek TPS2000 series would seem like a bad joke compared to the Siglent SDS1000X-E series, and at 10X the cost to boot. In real life doing actual work, one is better at some things and the other is better at others.The second is how these issues are perceived by buyers when you start to move up the ladder. As I said, at $500 Siglent provides a lot of value despite the shortcomings. I could even accept some of those issues in a $1300 hackable SDS2104X+. But when you start looking at $5000-10000+ scopes, one has to start to wonder if those aren't going to have some shortcomings of their own and what those might be. If you are doing some research and none of those issues apply to you, then there indeed is no shame in using whatever works--if you can verify that it actually does work. However, if you are doing something cutting edge, or at least well beyond the basics, and you only have one instrument fresh out of the box and you absolutely have to rely on it, what would you like it to be?It's going to be a lot more than a few years. Siglent and Rigol have made progress in the hobbyist and educational levels and are just starting to knock on the doors of the mid-level users. That and OEMing the lower end of A-brand offerings....

author: Sighound36
author_rank: Frequent Contributor
timestamp: August 21, 2021, 09:28:48 pm
content: I do have time for nctnico he has a lot of very practical experiance over a wide range of subjects, far more than my limited /PDN/green energy/Audio and psu designs. Athough he is not to fond of Rigol which would a fair assementHaving not been in the electronics game for for about 15 years until a couple of years ago I was starting from scratch, I looked at a few of the popular low priced brands to find they were really not to bad at all. I ended up going through Rigol's catolgue for various reasons, increased BW, more features etc.I have owned a fully specificed MSO 8000 with all options for 18 months now, and its really is very good indeed, it has always been reliable, and simple and easy to use, packed with USEABLE features and 500Mpts of memory, 10G/s and pretty decent digital decoding and a genuine 2.3Ghz BW. The FFT is very respectable and pretty much on the money. Intutive and nicely built imho. Also the HDMI is a nice feature as well.All the instruments in the lab are tied togther with an ultra low phase noise master 10Mhz ref (-122dbc@1Hz).It sports a nice basic jitter meas/histograms/track plus good basic eye diagram parameters. It also has some decent hardware processing. never noisy ir annoying!Would suggest that its' not at the top of your list for taking low noise measurment but its damn good at the rest of the day to day requirements. If you are looking to do this then only the Keysight EXR/MXR and Lecroy better again. The New R&S scope as good as it is, is really is quite noisy and again its only 8 bits of HW the rest is SW despite the ENOB of 9.4 I compared the older RTO and MSO8000 at various frequenices and being honest the Rigol was equal to or better at least 50% of the frequenices I tried them at. Now the new R&S is a different beast and the RF properties of this scope are top draw, BUT remember the starting point here in the UK is £15K GBP for a bear bones 600Mhz unit and if you add up the apps IT costs and remeber the probes that you are going to need as well. My probe cupboard is around £100K ontop of the scopes and apps theselves if you at looking at multi channel low noise psu work and board level meas.My suggestion would be to either grab a ex works KS6000 with greater BW and a few decent apps for around the £1%K mark via their disposal sites> or buy a Factory refub Lecroy Wave ruuner 9000 is has the full SDA package and upto 4Ghz, only 8 bit but a really good 8 bit scope. Lecroy had a couple not so along ago for around £16K with max memoery and BW, and the would be happy to negoatiate on the apps at a very favourable rate going on past experiances.https://teledynelecroy.com/wr9000/A wavepro 254 of HDO8000 strating point is £29K with none of the fancy apps, but the tie you factor in say foue desriable apps and the correct probes you can make that £50K plus yes they will haggle buut you are not going to cleeve £20K off the price. R&S in the UK are more ameniable to this practice I am lead to believe.The EXR could possibly tick the boxes you are looking for, starting @ £15K GBP again BUT everything is on scope upgradeable including the BW upto 2.5Ghz, app costs around the mid point from memeory about £4K for the jitter and about the same for the full eye package.You could if low noise meas were important to use, use a small form Lecroy upto 200/250Mhz and then have a big Rigol or maybe used KS6000 or similar for the bigger BW and eye requirements.For myself personally Lecroy is just some bloody good and intutitve plus its accuracte and I would not be without them, other may disagree we all have perferenices. We have four Lecroy scopes now. No I am not paid or sponsored by the Chestnut Ridge, I just really enjoy using their products which I feel are first rate.At your budget you have some good options open to you, take you time and look at all of those you are considering, BUT remeber to factor in the cost of the apps and probes, plus remember total system bandwidth as well, so many forget.If you have any questions please feel free to ask.

author: 2N3055
author_rank: Super Contributor
timestamp: August 21, 2021, 10:18:24 pm
content: Quote from: bdunham7 on August 21, 2021, 08:22:23 pmWell, thank you for this response because it clearly illustrates the core of the problem.People are extrapolating that manufacturer of simple inexpensive cars that are good value in its class is incapable of starting making upper class models.Because that is how they see the brand. Nobody seems to remember anymore where Japanese manufacturers were once...Product that are MADE for hoby and entry level market, where cheap but still as good as possible is priority, are made certain way. With all the engineering compromises that stem from that.It wasn't top of their abilities, but a deliberate choice to serve that market.Product that are made for other markets are designed differently, made differently, tested differently.. Made by different teams, with larger budgets for BOM and R&D.And are different products, despite carrying same logo.That is same in R&S, in Keysight , Tektronix, Rigol or Siglent.Except A brands think entry level money is 2000-3000 USD.And it WAS until our fellow Chinese EE decided that even people with much less money deserve to be able to afford oscilloscope.And now people think that is all they are. Take Siglent for instance. How many completely new products they developed in last few years?You guys think that can be accomplished by being a joke? If anything, it scary how fast they learn and improve..When R&S took almost 2 years to fix basic stuff on their new scope platform that was OK..Why don't you doubt R&S ability to make basic measurements? In beginning they had huge problems with skipping triggers, losing parts of capture, wrong plotting etc.How do you know THEY fixed it all? Did they put enough money into testing process? Be warned, EU or USA companies will be MORE prone to save money to control profits. Are you sure? On what basis?With B tier companies it also about improving reputation and opportunity to prove themselves. They have to work harder. To prove the point. They are willing to give up part of profit to build quality recognition. And they do.And then there are people that buy 15 years old LeCroy for 2000 USD, hack the licenses and then say how Siglent (or Rigol) scope for same amount of money is a toy.They don't say that scope was 150000 USD when new, and that new one with same features is still North of 60000 USD..There are many apples and oranges being mixed here...So my stance on this is like always: we dabble in electronics here. And are supposed to respect measuring, not guessing stuff and real data, not speculations.When new product is released, then we can all see what it is. Until then, it's just like bad reality TV. All smack talk, no naked people...

author: 2N3055
author_rank: Super Contributor
timestamp: August 21, 2021, 10:20:54 pm
content: Quote from: Sighound36 on August 21, 2021, 09:28:48 pmBullseye...Thanks for taking time to write this up.Best,Sinisa

author: bdunham7
author_rank: Super Contributor
timestamp: August 21, 2021, 11:50:27 pm
content: Quote from: 2N3055 on August 21, 2021, 10:18:24 pmUm, no. First, R&D budgets can be high for high-volume low-priced products if need be. Second, I remember exactly where the Japanese auto manufacturers were...and how long it took them to overtake the absolutely moribund and decrepit US automakers. And to this day nobody regards even the most successful of them to be superior to the better old brands like M-Benz, Porsche, etc., They are peers to the mainstream manufacturers like VW, Ford, etc. And they got there with attention to quality and reliability--those are just as important, if not more so--in the mid-lower segment than the luxury segment.QuoteOK, so look at the hackable $500 Siglent vs the Tektronix TBS2204B, which at first glance appears to fill the same slot, but costs $3000. If money is tight, the Siglent does a lot for $500. If you have a commercial operation and your bench is occupied by an engineer making $100K and his bench has room for one scope, then you need to compare a little more. When you do you'll find that the Tek is so vastly superior and more useful in a gazillion ways (even though it has less memory) that it isn't even a close call. This same scenario plays itself out over and over--and the makers of the much more expensive instruments somehow keep selling them for some reason. I don't think Siglent is a joke at all and yes I'm impressed by their progress. But I also know that they aren't 'there' yet and I predict it will be more than a few years before they are considered by the professional and industrial market to be a peer of Tektronix.QuoteYes, and the likes of R&S and LeCroy are the jackfruits and pomegranates in that comparison. First, if any manufacturer does a bad job they should be pilloried mercilessly no matter who they are, there I agree 100%. And when I refer to reliable A-brand bench oscilloscopes that I personally have confidence in, I mean Tek and HPAK, in that order and that's the end of the list. Other brands may be high-end--like Alfa and Maserati if we're using the auto industry for metaphors--but they are low-volume mid-to-high end specialty manufacturers whose customers typically will put up with a lot to get the special features and capabilities that they have. And like the auto industry, high-end or exotic companies trying to capitalize on their brand name by dipping down into the mainstream market is generally a disaster for everyone, much worse then a lower-end manufacturer trying to move up.I think the current arrangement, whatever it is, between Siglent and LeCroy is a good one. And the current ultra-competitive entry level scope market is good for the buyer as well. But there should be no confusion about what you are actually getting and what compromises have been made to get there.QuoteWell that's why I see no problem in comparing decades-old stuff to new. The original price is irrelevant, it is what you can get today for your money. And if a decades-old instrument has an advantage over a new one, I see no reason to not point it out. And we have much more information about those older models since they were better documented and we have a decade or two of experience with them. If a new model fails to do something properly that a 30-year old scope can handle, what's the excuse? "We didn't know about that" or "that's what you get at this price point" ?

author: 0culus
author_rank: Super Contributor
timestamp: August 22, 2021, 12:01:22 am
content: *takes off hobbyist hat*Nobody got fired for buyingIBMKeysight is the operative phrase for this thread. Time is money, so if you're using your bench to make money, you are going to invariably prefer to buy products that are proven and have a good support network. Even more so if you are going to have clients/sponsors visiting your premises. A bench equipped with top brands makes a statement....a bench filled with not so top brands can make another statement that may not be desirable.

author: bdunham7
author_rank: Super Contributor
timestamp: August 22, 2021, 03:10:08 am
content: Quote from: 0culus on August 22, 2021, 12:01:22 amYes, and it will take a lot for those attitudes to shift. Even seeing and using the other brands as a hobbyist or in an educational setting isn't going to do the trick. For those of you that don't get this, imagine you are a large company with a complex, expensive product (say aerospace or medical) and you are subbing out the design and manufacture of some non-critical ancillary product, like a power supply or test jig or whatever. You go to visit your prospective subcontractor and they show you their lab which has an Ikea workbench with an Aneng bench meter, an Owon scope and a Kaiweets power supply, along with bags of parts kits from Aliexpress. Maybe that stuff all works, but impressed you will not be.Tektronix took over the scope market because they invented a practical trigger circuit that could be integrated into a reasonably priced (a relative term...) oscilloscope. Perhaps Siglent will make some progress towards a market takeover when they come up with a revolutionary new useful feature unique to them instead of being the 'almost as good for a lot less money' brand.

author: bdunham7
author_rank: Super Contributor
timestamp: August 22, 2021, 05:33:44 am
content: Quote from: nctnico on August 21, 2021, 07:22:51 pmCould you verify the AFG31000 bug that Shahriar showed in his phase noise video? Apparently FM modulation causes the center frequency to shiftdownup, so if you are putting out a plain carrier on one channel and a modulated signal on the other and put both on a scope, the modulated signal will 'walk' to the left. It might be a simple math error in the FM algorithm.

author: nctnico
author_rank: Super Contributor
timestamp: August 22, 2021, 09:35:19 am
content: Quote from: Sighound36 on August 21, 2021, 09:28:48 pmThat assesment is not entirely accurate. The thing is that when I look at relatively new Rigol oscilloscopes and go through all the user experiences/reviews I never get the impression that the firmware is really rock solid. I know you are very happy with the Rigol MSO8000 but for my line of work I need to be sure of is whether things like all the combinations for protocol triggering work as advertised. I could need it for a next project. That is also why I do so much rigorous testing when I check out a new oscilloscope. It is hard for me to plan equipment purchases ahead of a problem because I get to work on so many different types of projects.

author: nctnico
author_rank: Super Contributor
timestamp: August 22, 2021, 09:41:53 am
content: Quote from: bdunham7 on August 22, 2021, 05:33:44 amThis isn't a bug. In the end there is a limited amount of precission to generate the waveform and that is causing what Shahriar is showing in the video. Any AWG has this issue but it isn't always specified.From the AFG31000 datasheet:Frequency accuracy±10e-6 of setting (all except ARB), 0 °C to 50 °C (32 °F to 122 °F)±10e-6 of setting ± 1 μHz (ARB), 0 °C to 50 °C (32 °F to 122 °F)

author: 2N3055
author_rank: Super Contributor
timestamp: August 22, 2021, 09:45:05 am
content: Quote from: bdunham7 on August 22, 2021, 03:10:08 amYou wrote a lot in few responses and I'm not going to respond to all of it, but what you responded is just more of the same: in this case you still equate all Chinese brands to be equal while they're not, same as not EU or USA brands are equal. Equating Aneng and Brymen and Owon and Siglent and Rigol is pretty much not right, not to sayinsultingto some of these companies..In addition to that, of course itonlymatters to competeto currentproductswith currentproducts.Your comparison with TBS2204B is also very wrong. TBS2204B is quite unusual product that is a bog standard scope that has less capability than SDS1104X-E, and there is no scenario where it is superior and more usefull. It has one and only one quite unusual feature that it has TekVPI active probe interface, which is weird, because there is so little you can do with the scope and then you buy 15000€ of probes for it? Surely you would never have that one as a primary scope, butmaybeyou could get that one to supplement your primary big Tek so you could use same probes occasionally and would us that one for every day simple probing around not to fire up big expensive primary scope for little things.As a only and primary scope? Why would you want to do that? If you wanted brand name, you could get Keysight DSOX2014A or DSOX1204G for half the money and get a superb scope in comparison.But as I said your comparison is wrong. Because you should be comparingmoney for money: Is TBS2204B better and superior to Siglent SDS2354X+ or Rigol Rigol DSO/MSO7014 that are in thesame price bracket? I would like to see in what opposite universe is that true...So I do agree prejudice exists in people, I know it does,QED, but not in all people. And as you say, when they have a product that is different enough that it prompts attention, it will get attention.But times have changed from 20-30-40 years ago. Technical differences are not only differentiation factor you have today. You mentioned triggering: both mentioned alternatives to TBS2204B have zone triggering, that on Keysight you have to jump up to 3000T series and with Tek to new MSO4 series.Bringing advanced features to lower pricing ranges (like I said, for Tek 3000 USD isentry levelpricing) isinnovation. And one that is very much liked by those who have to make decisionshowto purchase equipment.Welcome to the brave new world where when you buy servers via contract with IBM you get Lenovo...Regards,Sinisa

author: nctnico
author_rank: Super Contributor
timestamp: August 22, 2021, 09:50:02 am
content: You are skipping over the part where the TBS2204B has better overdrive recovery compared to the Siglent bdunham7 mentioned. If that is what you need for a measurement then the TBS2204B is a better choice. For some of the measurements I do I need to get the steepest edge into the trigger so I like to use 100mV/div (or even lower) to do a measurement on a 5Vpp signal where I only care about the position of the edges. This measurement is only possible when the overdrive recovery is really good. Unfortunately overdrive recovery isn't always specified in the datasheet.

author: tautech
author_rank: Super Contributor
timestamp: August 22, 2021, 09:56:13 am
content: Quote from: 2N3055 on August 22, 2021, 09:45:05 amDualzone triggering.

author: 2N3055
author_rank: Super Contributor
timestamp: August 22, 2021, 10:54:38 am
content: Quote from: nctnico on August 22, 2021, 09:50:02 amNow THAT is avalidargument. You havesomething specific, aspecific technical requirementthat doesn't get fulfilled,unlessyou buyspecificpiece of equipment.But "there be dragons" (pun intended) fear mongering of unspecified troubles that lay ahead is not something I subscribe to. I don't like it in politics, and much less in engineering.As I said before, you, personally, usually have specific, documented reasons for your choices. You got your AFG31000 because it was capable of generating specific signal that other AWGs didn't (including Keysight AWG).That isgoodengineering. Youmade researchand found a piece of equipment thatdoes the job.I might go and solve the same problem differently and use different solution, but it doesn't take any merit from your decisions.That particular AWG works for your task, and all of these don't, for the reason of XYZ...You did research and made valid decisions based on the premise.On the same token, would I rather have Siglent SDS2354X+ on my desk (as a primary scope) instead TBS2204B ? Absolutely I would go with Siglent, because if you take into account ALL the things you do with scope, even if onesinglething is better on TBS2204B ,all other thingsare infavorof SDS2354X+ and that makes it that onaverageit would bemore useful. You could accomplishmore work donewith it. If that is not a good figure of merit, than I don't know what is..Unless you're have a technician that checks some sensor current all day long, and uses specific Tek current probe, because that is how characterization document was written. Then you get that probe, TBS2204B and teach technician the procedure. In that case,thatis good engineering. It's simple and works.For specific requirements specific tools. For general purpose, more versatile, the better.Versatileisnotcompatible withsimple and devoid of functions...

author: bdunham7
author_rank: Super Contributor
timestamp: August 22, 2021, 04:02:47 pm
content: Quote from: nctnico on August 22, 2021, 09:41:53 amPerhaps this should be discussed in another thread, but I'm still thinking it's a bug, one similar to the SDG2042X bug. The frequency accuracy refers to the TCXO stability AFIAK, but on a two-channel AWG I think FM causing a shift in the center frequency compared to the other channel is either a mistake or deliberate shortcut in how you calculate the waveform points. There shouldn't be a cumulative error even though you don't have infinite precision.

author: nctnico
author_rank: Super Contributor
timestamp: August 22, 2021, 04:25:55 pm
content: Quote from: bdunham7 on August 22, 2021, 04:02:47 pmNo. Frequency stability is a different thing.

author: mawyatt
author_rank: Super Contributor
timestamp: August 22, 2021, 05:30:48 pm
content: Long ago large companies didn't pay "list" price for HP and Tektronix products, they had massive discounts. At these companies the total cost of ownership must be considered, and the learning curve for unfamiliar equipment was expensive, so the use of HP and Tek equipment became a standard. Certification in-house and external also played into this. The USG had strict rules on test equipment and certification, they even had evidence of "cheating" on production equipment (know of one instance at a unethical company that modified an SMA attenuator to pass a power test).This cost of equipment ownership became the basis for the founding of the USF University WAMI program, which exposed students to quality, modern test and measurement equipment. I was able to get significant $ contributions to this program over a decade long participation by "selling" this to senior company executives that held the purse strings. The "sale" was simply, "it's way cheaper to have new grads learn how to use the latest equipment while in school rather than on your payroll"HP and Tektronix donated significant equipment to this program (we donated $), later followed by R&S and others. CAD tools spotted this and followed, later including Cadence. Early on we tried to get a program that allowed grad students to design their own chips, get them fabricated (IBM was a candidate fab), then get to test them. Unfortunately the lack of university management vision squandered this opportunityAnyway, I don't believe that Keysight and Tektronix are the same as in the past, which has opened the door for "others" to move up.

author: 0culus
author_rank: Super Contributor
timestamp: August 22, 2021, 05:50:23 pm
content: Quote from: mawyatt on August 22, 2021, 05:30:48 pmNevertheless, they (and Rohde) still have the best support networks and are able to meet all the procurement rules for .gov type customers. I don't think anyone else is going to muscle into that space anytime soon, at least in the west.It's plainly obvious that certain people in this thread are some combination of (1) never worked in a higher end professional lab or (2) have never done procurement for said environment or (3) are being willfully ignorant of the points I brought up in my post above. The shiny new models from Siglent are a great value for the hobbyist of some means (they are getting expensive but manageable for someone who has a good paying day job and has disposable income), but they (and others) are not "there yet" in many ways. Product support matters. If it breaks, the big name companies will get it fixed and in the meantime can often quickly get you a loaner to keep you moving. Optics matter, too. Visiting clients and sponsors are NOT going to be favorably impressed when they see you cheaped out on your equipment. Is it prejudiced? Maybe, but it's the way it is.

author: mawyatt
author_rank: Super Contributor
timestamp: August 22, 2021, 06:26:14 pm
content: With todays instruments relying so much on firmware, the hardware becomes almost a given (similar) with lower and mid range equipment. It seems to follow the same path as the personal computers with the PC and Mac, the hardware has merged and very similar, so the OS defines the computer.Also good point about the "after sale support", certainly KS, Tektronix/LeCroy, R&S have this already in place and have done so for decades. This also plays into the overall "cost of ownership" mentioned, if one has to jump thru all sorts of hoops to get after sale support, then how much is that worth? If you are a hobbyist, or retired (like myself), then time doesn't matter as much, however if you are working and time is valuable, then what is that worth??Think it's interesting that Siglent has made some inroads by supplying LeCroy with lower tier products, likely Rigol ( & others) have done so with other big name equipment OEMs.Best,

author: Sighound36
author_rank: Frequent Contributor
timestamp: August 22, 2021, 06:37:22 pm
content: Quote from: nctnico on August 22, 2021, 09:35:19 amI understand each situation is different and in a specific industrial or advanced R&D lab then yes unquestionably accuracy, repeatability and stability are key features no question.The Rigol 8000 has genuinelly been absolutely rock steady and no issues have I found when using it which is almost daily. Now when I am conducting our critcal measurments then yes I will use the Wavepro no question or one of the othe Lecroy's. Though on occasions; I have out of curiousity fired up the Rigol just to see how good in REAL terms it compares against a a quality reference. It does stand up very well indeed in a few areas no question. I would suggest this Rigol model is more than a hobbist scope, maybe a semi pro range but with some really nice features. Its also been robost and stable.The thing is were are arguing around minutiae I feel, all of the contibutors on this thread have make some valid points which the original O.P. should take into account when deciding to try out any of the suggestions.I love my Lecroys, but realise these are not small invetsiments these are LONG term instruments of quality and performance and should be treated as such to maintain their peak performance (as with any quality T&E equipment) I have a couple of companies so these are business purchases. Unless there are a few retired well heeled company director looking to reduce their pensions fund by £40k or so to play electronics in the extensive 3 double garage electronics man cave then the pooch is royally screwed!What I feel is that is easy to brand all Chinese equipment as second rate, well its not and hasn't been the case for quite a while, they have been at some of the level of the 'certified big four' in a few areas YES. It is easy to highlight, look at the Keysight new under £1k affordable hidious bench series (i understand their rationale, but both Rigol and Siglent are a beter bet here no question) or some of entry level R&S scopes sorry no have owned some of these. Tek's more expensive scopes are really not that clever at all, but yet demand premium prices in their applicable ranges.Sinsia made some quite pertinet points as well, given the short space of time these 'Far east upstarts' have been trading they have made some quite decent gains in a far shorter time that a big given their 40 or so year lead on these companies makes you think?Whether they will ever achieve the status of the big, who's know's? but they will keep improving and the time span will decrease with every spin of the board.I have a SNA 5104A stuck in UK customs currently so time will tell. Good discourse though chaps!

author: tv84
author_rank: Super Contributor
timestamp: August 22, 2021, 06:54:21 pm
content: Quote from: 0culus on August 22, 2021, 05:50:23 pm"willfully ignorant" of your points? Can't that category apply to you regarding other guy's comments?I think everybody here is big boy and understands perfectly well what is being said. There is absolutely no question that everybody should use the model/brand that provides him with the quality needed for doing his job. Period. What started all of this is that previous decade long experiences for older brands is not a guarantee, in itself, of eternal leadership in all fields, in all price ranges for these TE brands.Regarding the "buy IBM" moto, I findthisa good text. In the last decades, the telco world has seen much of it also regarding Cisco products. In both cases things have changed. Fortunately for all of us there are plenty of multi-billion systems in the world not IBM based and not Cisco based.Fortunately for all of us, there are companies like Siglent and Rigol doing the type of equipments they are trying to do with the prices they are presenting.

author: tv84
author_rank: Super Contributor
timestamp: August 22, 2021, 07:03:10 pm
content: Quote from: Sighound36 on August 22, 2021, 06:37:22 pmThis comment from this man makes me feel the MSO8000 is a great machine in its price range.Of course, no question about Sighound36 other toys.

author: bdunham7
author_rank: Super Contributor
timestamp: August 22, 2021, 07:25:43 pm
content: Quote from: 2N3055 on August 22, 2021, 09:45:05 amI'm not equating or even comparing the various brands--which would be pointless in the general--I'm just pointing out that to some, Siglent and Rigol are as far beneath their contempt as Aneng, Owon and Kaiweets are to you. And since Aneng meters are generally accurate, an Owon scope with a MicSig DP probe would probably suffice for looking at PSU concerns and Kaiweets power suppies put out, well, power, why do you regard them so?QuoteWhat I'm telling you is that well-heeled buyers of professional equipment often arenotcomparing "money for money" or obsessing over how many features can be crammed in at a price point. They want stuff that 'just works' and that they have a high confidence level in. The price of a TBS2204B is probably dwarfed by other concerns for most potential customers. And as far as capability--have you actually used both scopes? I have, and I wouldn't consider them at all comparable. The TekVPI is not 'weird' to have, it is incredibly useful in a large corporate or institutional setting.TekVPI aside, I can readily demonstrate perhaps 5 straightforward instances where the Tek is vastly superior to the SDS1104X-E, and probably the SDS2000+ series as well, except of course for hackable (or purchasable) bandwidth. And I mean real cases that I've run into trying to solve real problems where the Tek would 'get the job done' but the Siglent would not. That's OK at $500, but if those issues are due to a lack of institutional knowledge at Siglent, they aren't going to miraculously disappear in their more expensive products. If they cheaped out, well OK, it's a $500 scope, no problem.QuoteWell perhaps to the corporate or institutional buyer, but if the legacy products are available they are a viable choice for me--and many small businesses. But what is more interesting to me is to make those comparisons on a technical basis. Forget the TBS2204B, I can demonstrate real issues (failures to measure properly resulting in needing to use a different instrument) with the SDS1104X-E that an ancient, decrepit Tek TDS340A handles correctly.QuoteAnd when you buy LeCroy you get.....?? Perhaps Siglent will acquire them someday.

author: tautech
author_rank: Super Contributor
timestamp: August 22, 2021, 08:35:02 pm
content: Quote from: 0culus on August 22, 2021, 05:50:23 pmSo you might think.Our largest customer is .gov departments.

author: Sighound36
author_rank: Frequent Contributor
timestamp: August 22, 2021, 09:11:35 pm
content: Indeed a lot of eductaional facilities are accquiring Both Rigol and Siglent products here now, Tek along with R&S have always have the monoply on the red brick universities and larger conglomerates plus those Government departs we cannot discuss. These go back a long way in the UK.Although talking to more UK bodies it seems unless its ' 5G/6G/800G/Green Energy/Telecomunication or battery tech project then the bean counters are having a lot more of a say so both Rigol and Siglent will have more a stake in these foundation building business areas

author: 2N3055
author_rank: Super Contributor
timestamp: August 22, 2021, 09:14:43 pm
content: Quote from: 0culus on August 22, 2021, 05:50:23 pmLet me first start with the fact that I'm aware of your vast experience and consider you excellent engineer. I read your posts with utmost respect.But it this particular case you missed thewholepoint.Topic is not "How Boeing choses R&D" equipment.It was started by a person that has small consulting business. His business is similar in size to mine, Mike's , Sighound36, Nico's etc.I absolutely don't know how it is when USA manufacturer makes a deal with USAF. I'm not from USA and cannot know that.Also it is quite obvious that USAF can simply request that Chinese equipment cannot be used for a project for them, for security reasons. Perfectly valid argument for them.Heck, if a customer comes with a 150000 USD project to me, but insists that it should be done only with Keysight equipment worth 20000 USD, off I am ordering it right away.That is not the point. Point is is it necessary? For a small company?Not anymore for general purpose work, in my experience. Specialized tools and niche products are exception.But you are correct. I don't know how it is in USA, and what cultural prejudices are and how important they are.OP asked for experiences, to help him make a purchasing decision. And experiences came back that Rigol MSO8000, while not super high end equipment, does a decent job and is well worth the money and is comparable to A brands in how useful it is for the money. MSO8000 is NOT a hobby scope. It is not high end, but it is not amateur hour.Also it was hinted that Siglent might come out with something even better soon..When they release new products, all will see how well it does. But it also won't be hobby product.So answer to OP is that they should try to get test scopes in question and see if it works for them.As for support, if it breaks, Rigol and Siglent will replace it too. And give you loaners if you need. And support you.I agree the Tek or Keysight are not the same as they where ... I don't even think they are worse somehow, but different. They made a decision to be different type of companies.And I agree, that did open space for others. And they jumped in..Way I see it, A brands don't even care. They are only interested in super high profit T&M markets, and don't care for what used to be their bread and butter...In their own parlance they "evolved" and "repositioned" themselves.

author: 2N3055
author_rank: Super Contributor
timestamp: August 22, 2021, 09:22:07 pm
content: Quote from: bdunham7 on August 22, 2021, 07:25:43 pmI would genuinely like to know these cases, details etc.That would be great contribution by you and I would personally make sure those get presented to Siglent as an example what needs to be improved.Also it would be great service to Siglent users to learn.Would you be willing to quickly summarize your biggest showstoppers where Tek would be vastly superior to SDS2000X+, please?I'm sure Siglent would like to know, and maybe they can address it for the good of all current and future users.Thanks for the good discussion.Best,Sinisa

author: bdunham7
author_rank: Super Contributor
timestamp: August 22, 2021, 09:22:43 pm
content: Quote from: Sighound36 on August 22, 2021, 06:37:22 pmIt is a lot easier to make rapid progress when you are following the leaders. I have nothing against the newcomers, but I would prefer to be realistic about where they actually are. If a new product does not do well against a decades-old legacy product in any area or test of significance, they aren't there yet. And I'm not talking about tradeoffs due to deliberate design choices, or at least I think I'm not.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 22, 2021, 10:26:18 pm
content: Quote from: nctnico on August 21, 2021, 07:22:51 pmAnd yet, there's this:https://youtu.be/SOHjFtw0sgo?t=1248I see that's already been raised, but I thought I'd point directly at what was being referred to.You claim this is a precision issue, and perhaps it is. But, firstly, the comparison signal is being generated by the very same instrument and, secondly, the carrier frequency is an integer multiple of the modulating frequency. Now, admittedly, thisisFM modulation, so the instrument has to generate a range of frequencies, and the modulated carrier frequency will appear to match the fundamental carrier frequency only if the average is a direct match. I guess that might be a tall order for a digitally synthesized signal.In the video, Shahriar says that the carrier is at 1 MHz while the modulating signal is at 10 KHz. But what's shown on the screen is clearly a 100 MHz carrier modulated by a 1 MHz tone (EDIT: Correction -- Shahriar said that it's a 1 MHz modulating signal with a 10 kHz deviation. The carrier is 100 MHz). In the video, it takes about 13 seconds for the carrier waveform to shift by one cycle. That's a less than 0.1 Hz deviation between the modulated carrier and the unmodulated 100 MHz tone. This is well below the 10e-6 specification, but I'm not sure that said specification is what really applies to this. That specification is, I have to presume, with respect to a standard reference, whereas the issue here is with respect to another signal generated by this very same instrument using the very same clock. It should be noted that it isonlyFM that seems to yield this issue. AM doesn't.

author: nctnico
author_rank: Super Contributor
timestamp: August 22, 2021, 11:06:31 pm
content: Quote from: kcbrown on August 22, 2021, 10:26:18 pmYou should have skipped a few posts back. That isn't a bug but a limitation all AWGs have. In the end there is a limited number of point to form a waveform. Tektronix also specifies this in the datasheet. Shariar probably overlooked it in the heat of the moment.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 22, 2021, 11:34:20 pm
content: Quote from: nctnico on August 22, 2021, 11:06:31 pmYeah, I just now noticed that and corrected my message appropriately.But here, the carrier frequency is an integer multiple of the deviation. A fully upgraded instrument has 128 million points per channel. The frequency range that it needs to generate is from 99 MHz to 101 MHz. For special cases like this, it might be possible for a digital signal synthesizer to properly generate the needed waveforms, but the effort needed to do that might not be worth it.And even so, a modulated carrier frequency of 100 MHz that is less than 1/10 Hz off from its unmodulated form doesn't seem terrible at all.EDIT: By the way, this is the bug in the Siglent you're referring to, right?https://www.eevblog.com/forum/testgear/the-siglent-sdg2042x-thread/msg2893004/#msg2893004How does that differ from the carrier frequency drift issue we're talking about here?

author: bdunham7
author_rank: Super Contributor
timestamp: August 22, 2021, 11:45:43 pm
content: Quote from: 2N3055 on August 22, 2021, 09:22:07 pmI can quickly summarize a few and then when I have time I'll post more photos and detailed explanations if anyone wants. I don't want to do a hit job on Siglent either, and some of these things may merit further investigation, others are just known characteristics from design choices. I just compared the SDS1104X-E with an old TDS340A and the TDS340A is the worst performing Tek DSO I can get my hands on. It still wins, more or less, in these areas.1. My SDS1104X-E has a consistent issue with a spurious 2nd harmonic when using the FFT function. There's something with the input amp that I think causes this, and it can vary over time and whether or not I do a self-cal. This has actually caused me some issues recently trying to measure and adjust the THD of an AC voltage calibrator, since I do not have a THD analyzer nor an SA that goes to very low frequencies. Or, actually I do have an SA that goes to 10Hz, but it is a disassembled junker that is never going to work again. An 8-bit scope FFT isn't actually quite good enough, but I was hoping I could at least spot a gross error (and I guess I did...). The TDS340A, in addition to being way easier to set up the FFT, displayed it cleanly and without the second harmonic.2. When trying to look at a small signal immediately following a large falling edge, you may want to expand the vertical scale so that the part prior to the falling edge is many divisions off the screen, overdriving the input amplifier which is designed to survive such abuse, presumably clamped and well protected. Every scope has a recovery time from the overdriven condition, they're almost never explicitly specified. The actual signal I was trying to read when I ran into this would be too hard to reproduce, so I'm using a 0-5V 1kHz square wave with 10mV pulses riding on it. The TDS340A has about 100uS recovery time when overdrive 500 divisions, which is terrible compared to everything except the Siglent, which is over 40ms and is totally useless for this measurement.3. Aliasing. We all know about it, so no big deal, right? If I were a Tek salesman, I'd make it a big deal. Set up one channel with a 300MHz input and you get a nice clear signal with a readout of 300.000 MHz. Turn on the other channel and you get a very similar screen--about the same amplitude--but now it is 200.000 MHz with no other indication that something is wrong. This is simply a result of overselling the sample rate. It doesn't bother me too much, but it could easily cause a major error and it isn't pro.4. The whole memory management thing that has been discussed before. Even the ancient TDS340A will allow you to view a half of screens worth of extra signal from either end of a stopped acquisition. Again, a design choice, but not a good one IMO.Anyway, that's just 4 off the top of my head. Only the first two are worth discussing further, the last two have been beat to death already and I doubt anything is going to change.

author: nctnico
author_rank: Super Contributor
timestamp: August 22, 2021, 11:58:06 pm
content: Quote from: kcbrown on August 22, 2021, 11:34:20 pmMy assumption is that the Siglent generator accumulates a rounding error somewhere. For really slow modulations there is no reason for the carrier to drift.

author: bdunham7
author_rank: Super Contributor
timestamp: August 23, 2021, 12:30:57 am
content: Quote from: nctnico on August 22, 2021, 04:25:55 pmI'm going to think about the whole thing, but I'm not convinced an AWG must have this error even with limited math precision, at least not when every parameter is a power of 10. And if the spec you quote is due to intrinsic AWG design issues, why do they list the temperatures at which it applies?I'm thinking that if an AWG is asked to output the same frequency on two channels but modulate one of them, for the modulated one it could always start with the base signal and then calculate the deviation from there. There may well be limited precision issues (but in two dimensions) with regards to the placement of any one point, but I see no necessity for those errors to become cumulative. Perhaps I haven't thought it through far enough or there is some worse consequence for doing it that way.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 23, 2021, 01:24:50 am
content: Quote from: nctnico on August 22, 2021, 11:58:06 pmI'm not sure I follow. Was the carrier actually drifting, as in changing its apparent frequency over time (so if you were showing it alongside a wave of the base frequency, you'd see the relative movement change over time), or was it simply slightly incorrect, but otherwise consistent?And how were you measuring it?

author: jmw
author_rank: Frequent Contributor
timestamp: August 23, 2021, 02:22:28 am
content: If I had a year to wait, I wouldn't be buying any Keysight DSOX series scope (except maybe the 1000-X if that fit my needs). Reason: MegaZoom IV is getting very long in the tooth; notice how the 1000-X and most other Keysight equipment now comes with black furniture, while the 2000-6000 are still wearing white? That's a tell that they're likely getting a refresh soon. With a year to go, time is on your side to wait and see what's new later on. Worst case they dump WinCE for Linux and nothing else changes, best case some of that UXR/MXR tech walks its way down the value chain and shows up in lower end scopes.

author: 2N3055
author_rank: Super Contributor
timestamp: August 23, 2021, 06:39:43 am
content: Quote from: bdunham7 on August 23, 2021, 12:30:57 amThank you for the time and effort to write it up. I appreciate it.But you misunderstood me. I said compared to to SDS2350X+ scope that cost the same.Nevertheless since you did take time let me reply a bit.1. That second harmonic seems to be valid point, provided amplitude was correct. In cases like this playing with vertical sensitivity is recommended to see if there are changes that would point to distortions. But a valid question.2. Overdriving input amplifiers was discussed to death. You cannot do that, and it's not a guaranteed spec, not even on 150000 USD scope. On SDS2350X+ you could use vertical zoom. But not at factor of 1000x magnification. Great late Jim Williams had several application notes where he had to create custom circuitry for that type of measurement. Only scope that can do that is sampling type ( analog repetitive or random with sample bridge ).EDIT: went and tested, my MSOX3104T craps up at 100 mV/div, with a 5V P-P signal....3. I have been repetitively saying that SDS1104X-E is a great100Mhzscope. I advise against hacking it to 200 MHz, because people are not disciplined (or knowledgable) enough to be trusted to use it only with two channels. Or sometimes signal is tricky and there is a choice of : A. not seeing anything because front end simply cut it of with a lowpass filter. B: seeing aliasing. Pick your poison. I prefer A.But, also not important, because I said against SDS2350X+. Which has 2GS converters and has no aliasing problems.4. Spend too much time on that allread for the rest of my life. But NOT a SHOWSTOPPER. You have full right not to like it. Some people are vegan, I eat meat. Power to us all!!Please keep them coming...Regards,Sinisa

author: 2N3055
author_rank: Super Contributor
timestamp: August 23, 2021, 06:48:14 am
content: Quote from: jmw on August 23, 2021, 02:22:28 amAs I mentioned some time ago, I stumbled upon a model number MSOX-3104G mentioned...They are surely preparing new models, but don't expect earth shattering changes. They have to preserve the structure... It could be only a color change, or some minor upgrades.They could come out with MegaZoom V, but if they do, it will be carefully tailored not to be TOO powerful.. Pricing structure is the king...Maybe a bit more memory and that's it. Which might not be a bad thing, no changes. I keeps familiarity, and minimum changes on both their and customer side.But mind you, that means new 2000, 3000, 4000 and 6000... That is a lot of scopes at the same time...

author: nctnico
author_rank: Super Contributor
timestamp: August 23, 2021, 09:22:08 am
content: Quote from: kcbrown on August 23, 2021, 01:24:50 amThe drift rate was constant. I compared the 10MHz reference input to the output signal using an oscilloscope triggered to the 10MHz reference clock. On the oscilloscope you get a band which goes from left to right. Over time that band moved indicating that there is a phase drift. Note that phase drift and frequency drift go hand in hand. In hindsight it is possible that it is a limitation of the SDG2000X series. In that case the effect Shariar shows in his video on the AFG31000 should be much worse on the SDG2000X.Quote from: bdunham7 on August 23, 2021, 12:30:57 amAs soon as you start modulating the frequencies no longer have a relationship that is an integer number.QuoteThat is a good habbit when writing a specification.

author: bdunham7
author_rank: Super Contributor
timestamp: August 23, 2021, 02:22:09 pm
content: Quote from: 2N3055 on August 23, 2021, 06:39:43 amOh, well I don't have one and I don't have the TBS2204B here with me. Someday!QuoteWell, every Tek scope I have, DSO, hybrid or otherwise, will do this type of thing even though you're right in that it isn't a guaranteed spec. It is interesting that your MSOX3104T loses it at the same point as my Siglent. I suppose it is possible that modern input amplifiers have made design compromises that result in improvements in other areas at the cost of this ability. My newest Tek, a TPS series, also recovers quickly--although that is an old design that Tek sells for an exorbitant amount. So I can't even guarantee that the TBS won't fail the test--but I'll report in as soon as I try it out.QuoteI thought that was my line. But the SDS1104X-E uses a digital filter after the ADC for the 100MHz cutoff, so its ability to suppress a 300MHz signal is determined by that filter's attenuation at 200MHz. The aliasing is still happening.I would assume the SDS2000X+ works the same way, so you might call it a great 200Mhz scope. And Tek would agree, since the TBS2204B uses the same 2GSa/s per two channel setup. It would be interesting to see how either of them responds to mild overdriving with over bandwidth signals.

author: 2N3055
author_rank: Super Contributor
timestamp: August 23, 2021, 05:33:26 pm
content: Quote from: bdunham7 on August 23, 2021, 02:22:09 pmTPS2000B ? Well that one is a bit unusual, that one has floating insulated channels. I can see that those input channels might have a bit different design, that would (could?) make it recover better. Whether that is deliberate or just happenstance of the design , who knows .... But all single ended modern scopes will have low voltage amplifier design and they will all have pretty much same problems.

author: grg183
author_rank: Contributor
timestamp: August 23, 2021, 05:45:30 pm
content: Thanks for all the responses, I still need to go through the posts but I wanted to share my opinion on the discussion of A-brand vs B-brand tools...It is true that at the end of the day it is the end result that matters, an oscilloscope is just a tool to get a job done. It is like a car, you could buy the cheapest car or the most expensive one, as long as you get to destination it doesn't matter which car you drive. If you drive a lot you'll appreciate the comfort of the luxury one, if you have an accident you'll appreciate the better safety features, better infotainment might make your life in traffic a bit more pleasant but at the end of the ride no matter which car you drove you can get out and do the same great things. For many years I used a $40 Atten hot air station and an equally cheap Hakko knock-off soldering iron. I was able to solder virtually anything from 0201 parts to fairly big BGA parts and get the job done successfully. Did I like these tools? No. Did I waste more time than necessary de-soldering some parts? Yes definitely. Did I damage a couple of boards due to unintentional overheating? Yes. Did they sometimes fail on me? Yes. However these annoyances didn't stop me from starting and being successful in my business. In more recent years I bought professional JBC soldering iron and hot air station, in total costing at least 50 times more than the cheap stations I had earlier. Are these JBC units 50 times better? Absolutely not but I bless every dollar that I spent on them every time that I use them. They are easier to handle and control, quicker to reach temperature, the operate in a more predictable manner, I no longer have to worry about damaging boards, I de-solder parts in a breeze, etc... What I'm getting to is that the difference between an A-brand and a B-brand tool is not so much about the 'getting the job done' part as much as it about making life easier and also ensuring that you can get the job done every time in the most efficient and repeatable way possible. When you are building and growing a business there is a point reached where these 'annoyances' related to cheap tools become more important than the 'getting the job done' part.As to being able to 'show off' A-brand equipment to clients, this is not so much a matter of 'showing off' in an attempt to win clients (although it could get you the edge in certain cases). Clients that are not knowledgeable in test equipment can be impressed with the cheapest of brands, while big companies will probably have better equipment themselves anyway. Having A-brand equipment also doesn't imply that you know how to use them properly or that you are keeping them calibrated or well maintained. If I demonstrate a result using either the cheapest of oscilloscopes or the most expensive one it really doesn't matter so much, a research paper that demonstrates a result using the cheapest of scopes doesn't make it less reputable. The main difference with A-brands still has to do with those annoyances that I mentioned above. Going back to the cheap soldering station example, if I am expecting a client to pay abundantly for my service, do you think it is acceptable that I send them a discolored PCB just because my $40 hot air station is unable to control temperature correctly? or that I delay everything by 2 weeks just because my $60 soldering iron broke down? It is the same thing with all equipment including oscilloscopes. If I quote for a job that should take a few hours but I waste a day trying to figure out and searching online as to why something doesn't add up, I'd simply be making a loss. As you grow a business you eventually reach a point where neither you nor your clients will tolerate having to deal with annoyances like that, having tools that 'get the job done' is not enough anymore. Having A-brand tools also helps to build a sort of 'trust chain'. It is true that if a client trusts you they will also trust that you are able to choose your equipment wisely as someone said above. With bigger projects and bigger clients there are often multiple parties involved, clients will have their own clients, so there are a lot of people to convince and in my experience having A-brand equipment often gets you a long way at that. Whether having A-brand equipment ultimately translates to a better end result is a totally different matter, there will be always those who can do incredible things with a bunch of cheap rusty tools while others whom with an entire workshop of top quality tools wouldn't be able to screw a light bulb even if their life depended on it.

author: tv84
author_rank: Super Contributor
timestamp: August 23, 2021, 06:59:02 pm
content: Regarding KS position on customer service for hobbyists, I advise all to readthislatest post (and KS answer to the OP).

author: grg183
author_rank: Contributor
timestamp: August 23, 2021, 07:22:38 pm
content: Quote from: tv84 on August 23, 2021, 06:59:02 pmQuoteWow that is the lamest excuse I've ever seen, it would have been better had they not replied at all! I must say that whenever I needed support for my Keysight equipment I've never had any problem and support was prompt even though I am a small business.I have however seen this kind of attitude by parts manufacturers including big ones like Texas Instruments and Bosh that openly ignored my requests for basic support simply because in their view I'm not big enough of a business to be worth their attention, even though my client's volume production forecasts were rather high. Texas Instruments support (on the ticket system) even told me directly that they only forward requests from "serious customers" to their sales team, how they got the impression that I'm not serious I don't know. This is absolutely ridiculous, especially in this day and age when small businesses is where a lot of innovation is happening.

author: tautech
author_rank: Super Contributor
timestamp: August 23, 2021, 07:41:42 pm
content: Quote from: bdunham7 on August 23, 2021, 02:22:09 pmYou're forgetting another factor which is the analogue input design yet certainly the digital filter predominately determines max BW but that's only relevant to the model in a series whereas input design is the overriding factor.The 350 MHz SDS2354X+ with it's 500 MHz option is some example of this however its 500 MHz rating only applies to 2 channels (one on each ADC) so to comply with Nyquist and SW limits its total BW by reducing it if more than 2 channels are active back to 350 MHz and displaying such in each channel tab.

author: grg183
author_rank: Contributor
timestamp: August 23, 2021, 07:49:41 pm
content: Quote from: Sighound36 on August 22, 2021, 06:37:22 pm@Sighound36 thank you for your valuable input as someone who actually has a Rigol 8000.From your input and some other comments that I've seen around it appears that the Rigol 8000 is not to be underestimated and as a second high bandwidth scope it is definitely a good choice. However if you were to hypothetically have the Rigol 8000 as your only scope without any of your Lecroy scopes to cross-check with, would the Rigol give you enough confidence in your measurements? Would it limit you in any way and if so what would be the main limitations in your opinion?

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 23, 2021, 08:16:39 pm
content: Quote from: nctnico on August 23, 2021, 09:22:08 amOK, so it sounds like you were viewing themodulated10 MHz carrier signal against a 10 MHz reference signal. With an FM signal, you'd expect to see the modulated waveform change its drift rate over time as it is modulated back and forth around the carrier frequency, with the drift rate boundaries being defined by the frequency deviation value you selected. For your test to work, you'd have to use a pretty small frequency deviation value (1 Hz would get you a maximum drift rate of 1 peak to peak change per second).What was the frequency deviation value you used for your test?Now, in your case you were using atinymodulation frequency, 10 millihertz, i.e. one complete modulation cycle every 100 seconds. So you wouldn't see a band on your scope, but rather a waveform that drifts back and forth around the carrier frequency, with the maximum rate of drift depending on the frequency deviation you selected.What was the actual average drift rate that you noticed from that? Which is to say, how long did it take,on average, for a peak of your modulated waveform to move from one peak of the reference waveform to the next peak (it has to be an average because the actual drift rate of the modulated waveform relative to the reference changes over time due to modulation)? That'll tell you the amount of error in the generator's carrier frequency.In the case of Shahriar's Tektronix, the error was less than 0.1 Hz for a carrier of 100 MHz, which is rather good.QuoteThat's possible. When you had yours, did you compare the average drift rate of the 10 mHz modulated carrier against the drift rate of the same carrier modulated by a much higher frequency signal (like, say, 1 kHz)? If so, what was the end result?

author: nctnico
author_rank: Super Contributor
timestamp: August 23, 2021, 09:18:04 pm
content: QuoteI have not done any further tests; using the SDG2000X is no longer relevant. Maybe someone with an SDG2000X generator can chime in and do some tests. There is a thread about this issue but I don't know if anyone has bothered to test various function generators.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 23, 2021, 11:16:18 pm
content: Quote from: nctnico on August 23, 2021, 09:18:04 pmWhich generator do you use now, and how does it perform with respect to something that's reasonably close to what Shahriar was doing?

author: Sighound36
author_rank: Frequent Contributor
timestamp: August 23, 2021, 11:57:47 pm
content: Quote from: grg183 on August 23, 2021, 07:49:41 pmHello grg183Sorry but the pc swallowed the last reply:Th reason I use Lecroys is for the work we do I require really tight accuracy that the 12 bit scopes really do give, the app toolbox is just amazing and they really do work very well and have many decent features but at a cost.We have a narrow focus of products, audio digital, high speed data transfer, PDN, ultra quiet linear power supplies, fpga coding and green energy projects. The Rigol 8000 is a very capable scope is far and away any toy. It has features that a lot of the big four scopes will not be able to access until you reach a basic scope price of £18Kish. the apps from R&S and KS are not in the 'its only a bit more category' IMHO if you spend £20K on a scope then with the basic quality robes current/HVDP and qaulity 1Ghz active probe then that can be up to half the cost of the scope again, this is without any toolbox apps, Tek jitter app is £6K alone.To have the Wavepro HD to have the same features as the Rigol 8000 this is going to be £54K plus the logic probe is quite a bit and the 500Mpts of memory they have another of you buy model 'x' then you will receive either a BW upgrade or Mem upgrade to 1GPTs to 2, but that’s costly.The HDO8000 is not far behind and limited to 2Ghz bw. but again its a class act only with 10G/s instead of 20G/s compared to the wavepro HDthe EXR & RTO6 are the same money as basic 600mhz units, add in the basic eye and jitter apps plus probes and you are well over £30+KThe 8000 has a great long memory which is useful for diagnosing serial data faults, clock lane noise, signal glitches that are infrequent, serial data glitches etc.Its noise floor the lowest I managed with an open port 50 ohms, High rez on and bw to 20 Mhz with precision mode engaged on a 2.3Ghz model was around 85uv (after warm up) which is not bad for a 2.3Ghz scope, the Lecroy (8Ghz) manages around 1/3of that. Buts its more than four times the cost!The eye app is a good basic starting point that will help you with signal integrity and data lane noise and checking board connectors and for looking at ISI by way of eye-opening patterns and widths. Te persistence is rather good to plus it has big waveform rates as ell.The jitter app is also very nice and well thought out with C2C/TI/ -W2<>-W/ +W<> +W, plus you can change the cornerstone frequencies as well as a couple of PLL as well. plus three clock recovery options. Standard measurement parameters are all there and work well you can move the whole meas panel around the screen no probs either.With jitter you can add a track & trend graphs as well are a histogram and throw in a spectrum analyser plot as well, It is all on the same screen though so do not expect multiple windows on this scope.It is pretty accurate when you get into the large VTB numbers but it is very stable and never locked up on me at all, the digital ports and harness is pretty fair as well (this came with the scope as part of the bundle).This is like a third generation Rigol product at this level and I feel they are really getting the acts together. Would it be my primary scope if we didn't need the fancy low noise and speed plus monster apps. It may well be.This is just about using your tools to work for you in the best way possible imho.If you went down this route you could also purchase a great Keithley 6.5 or 7.5 digit DMM as well plus a a couple of misig new current probes as well.Each has it place on my bench, for different reasons.Here some images of the 8000 and the Wavepro going head to head last year and you can see the 8000 is not bad at all.Its still on my bench 18 months down the line and sitting with some big hitters but it feels safe and secureSighound36

author: bdunham7
author_rank: Super Contributor
timestamp: August 24, 2021, 02:22:44 am
content: Quote from: tautech on August 23, 2021, 07:41:42 pmEven in 350MHz mode, a 600MHz signal will alias back down to 400MHz, which will not be efficiently suppressed, or at least I'm guessing it won't since I don't have one to try. Give it a whirl if you have the stuff handy--I'd be interested to see how it does. If you had a fixed hardware single-pole input filter at 200MHz followed by digital anti-aliasing, that would be suppressed pretty far down. If you take the 2GSa/s - 1GSa/s split channel architecture as a given, it then boils down to a design and marketing choice, includingupgradeabilityhackability.

author: tautech
author_rank: Super Contributor
timestamp: August 24, 2021, 02:53:36 am
content: Quote from: bdunham7 on August 24, 2021, 02:22:44 amDon't overlook this is also a manufacturing choice in which one HW design covers models from 100-500 MHz.Only have SDS2104X Plus in stock ATM so no playing today however I do know the top models have Full,350, 200, and 20 MHz filter settings and experienced operators can immediately identify if they're entering aliasing territory from the OSD indicators of frequency, sampling rate, timebase setting and mem depth.As an advanced novice I overlooked such visible things until posting some screenshots pushing SDS2202X-E way way above rated BW where it still triggered perfectly and waveforms looked perfect but the HW frequency counter was miles off ! rf-loop rightly picked me up on that and such a simple lesson is not forgotten.

author: 2N3055
author_rank: Super Contributor
timestamp: August 24, 2021, 06:50:10 am
content: Quote from: bdunham7 on August 24, 2021, 02:22:44 amWould please, you , and everybody else, please,stop repeating this nonsense. License unlocking of bandwidth is not there "because of hackability".. All manufacturers do it because they want to physically produce only one motherboard, and to give option of field upgrades. Nobody wants to send scope back to factory to install other motherboard to get new options. All the scopes on today's market are done this same way.As for "hackability", it is also same as different manufacturers of software take piracy protection differently. Some software will have hardware dongle, computer locked licenses etc, and some have only a string you type in and it unlocks it.Very strong security is a burden to manufacturer. It makes many steps in production more complicated. So if you take R&S effort to make their scopes less prone to "hacking", that practice not only resulted in not many of those hacked, but also, and you believe this, it is one of the reasons that contribute to higher prices. It makes it more expensive without benefit to customers.So Siglent is simply pragmatic here, i believe. You cannot unlock just like that, and if you do take effort to unlock it, at any moment it can be proven it is not legal license, if need be. Fact that they are not being harsh and cracking down on people is because they want to be friendly to their customers. Hacking is hurting them financially, don't doubt that. But not as much as a mad customer.It is just they don't want to behave like Keysight is doing right now, as evidenced in few new topics that appeared on the forum last few days.Also, SDS2000X+ HAS analog anti aliasing filters (software switchable ones). It is only when you unlock it to 500MHz that what you're saying is true. That is why I said: If you're are so concerned with aliasing, you get 2204X+ (200 MHz is max on that Tek we spoke about) and you will not have aliasing problem. In which case you made deliberate, conscious tradeoff between maximum bandwidth and minimum aliasing because that is your priority. Somebody else that wants to look at 400MHz sine signal might want to buy 500MHz version because that is their priority. And they will have to make sure to keep it in 2 ch mode.Of course, none of that will save you from what some people are doing to "prove something is wrong" : You cannot input 5V RMS 600 MHZ signal at input set at 500uV/div and expect some of that signal NOT to shoot through all the way to the A/D and alias.. Filter will suppress it 30-40-50 dB but some of it will still go through if you shoot bolt of lightning in the input BNC...But in that case if you switch to 2 Ch mode, you will still get even nice 800MHz sine signal without aliasing...

author: bdunham7
author_rank: Super Contributor
timestamp: August 24, 2021, 06:15:40 pm
content: Quote from: 2N3055 on August 24, 2021, 06:50:10 amI'm not convinced that is true, anymore than I think piracy hurt Microsoft in its early days. The incremental cost to them of a hack is zero if they wouldn't have been able to sell the upgrade to that customer in any case. Any rational analysis would not count losses from sales that would not have happened in the alternative. And I'm guessing they have done that analysis and sold a lot of equipment in the process.QuoteI wasn't aware of that. Are you sure? And at what BW are they? Is it just at the 350MHz point?

author: armandine2
author_rank: Frequent Contributor
timestamp: August 24, 2021, 08:46:30 pm
content: Quote from: grg183 on August 20, 2021, 10:31:46 amBe sure to make a youtube video if you do plum for it - It seems the others are too embarrassed to show theirs.

author: Caliaxy
author_rank: Frequent Contributor
timestamp: August 24, 2021, 08:48:03 pm
content: Quote from: 2N3055 on August 24, 2021, 06:50:10 amThat’s one way of looking at things.Another way is that Siglent (or Rigol, for what it matters) are deliberately selling their equipment at dumping prices in an effort to take over the market. In theory, they are not selling dirt-cheap equipmentper se(that would be too obvious and could trigger legal procedures in many markets). They are only selling reasonably priced equipment that can be hacked (i.e. upgraded) at no cost.Hard to prove, but the hackings (which appeared out of nowhere and don’t seem to bother them) might have “leaked” from their own marketing departments. In practice, this would allow them to effectively sell at dumping prices while keeping the dumping pricing policy under the radar.I’m not complaining (I recently cheerfully “upgraded” some of my ownRiglentequipment), I’m just noticing.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 26, 2021, 04:26:45 am
content: Quote from: Caliaxy on August 24, 2021, 08:48:03 pmIt's pretty easy to show that these companies want their devices to be "hackable". How do we know? Because it would be trivial to design them so that the feature activation mechanism is hack-proof. To wit:Use a strong cryptographic private key to sign a message containing the serial number and feature identifier. Encrypt this signed message with the device's private key. The result will be the magic file that you put onto a USB stick and tell the device's UI to import for activating the feature in question.The device will first decrypt the file with its own public key, and then check the signature with the company's public key. If the signature verification works then the device will enable the feature specified by the message, as long as the serial number matches. You could keep the file itself stored on the device and have the device check its file store upon boot to activate the features it finds therein.Keep the firmware upgrader in ROM, and cryptographically sign all firmware updates with the company's private key. The firmware upgrader would fail the firmware update if the bundle fails signature verification with the company's public key.The security of this mechanism is near-absolute as long as the company's private key, or the encryption algorithm it depends on, is not compromised. And even if it is, the mechanism is reasonably safe as long as the device's private key remains hidden (the only way to hack it would be to use the company's compromised private key to sign a modified firmware bundle that contains a different public key for the device, one for which you'd have the private key).

author: nctnico
author_rank: Super Contributor
timestamp: August 26, 2021, 05:55:29 am
content: Quote from: kcbrown on August 26, 2021, 04:26:45 amIt is pretty simple to find the place in software where the key is checked and simply turn the answer in 'yes' regardless of the option is present or not. Obscuring that is a whole other ballgame.

author: Bassman59
author_rank: Super Contributor
timestamp: August 26, 2021, 04:36:27 pm
content: Quote from: Caliaxy on August 24, 2021, 08:48:03 pmSo what I don't understand is this.Rigol and Siglent know that most of their customers buy the base products and "upgrade" them. How many of their customers are actually buying the "upgrades"? Surely even the Big Company customers are always looking to save money, so if the end user engineer with a hard budget cap is looking at oscilloscopes and sees that a Rigol can be bought for $X and "upgraded" at no cost to the same "level of performance" as a Top Brand product that blows the budget, they'll buy the base Rigol.I don't think R&D groups worry too much about traceability and regular ongoing calibration. They (we, I'm in this category) need performance and features. The Tek DPO3054 on my bench has seen almost daily use since we got it some number of years ago, and it just does its job without much fuss. If it needed service, it would get fixed.So the point: why do Rigol and Siglent continue the charade of offering "lower-cost" versions of their products knowing that the customers will immediately get a free license key and upgrade it? If they just said, "we are streamlining our product offerings, and no longer offering the license-limited lower tiers," the cash registers would ring ring ring.After all, this wouldn't seem to cost them much money.And then the handful of Big Customers that might balk at the notion of buying the base product and letting the users "upgrade" them would be more likely to buy the products.What am I missing?

author: nctnico
author_rank: Super Contributor
timestamp: August 26, 2021, 04:42:11 pm
content: QuoteActual numbers to back your assumption.Before saying that offering upgrades on any piece of test equipment makes no sense because people hack them, you have to gather numbers from a large group of users / test equipment buyers and figure out whether they hacked their equipment or not. And then apply some statistics so get a number that tells you what percentage of test equipment gets hacked. It wouldn't surprise me if that percentage is in the single digits even when it comes to equipment from Rigol & Siglent. Be aware that albeit hacking is very well known on this forum, there still is a massive amount of EEs out there that have never heard of EEVblog and let alone that test equipment is hackable.

author: bdunham7
author_rank: Super Contributor
timestamp: August 26, 2021, 04:52:28 pm
content: Quote from: nctnico on August 26, 2021, 04:42:11 pmThe same issue played out decades ago with Microsoft. Their products were easy enough to pirate for the hobby-level or developing world user, but western corporations couldn't get away with that. For Microsoft, every pirated version used did not represent a monetary loss for them, rather it represented a lost salefor their competitors. Eventually everyone got hooked on Windows and Office and the rest is history. What we don't know is what proportion of Siglent customers are willing and able to simply hack cheaper versions vs. those that have to do things 'properly'. And we don't know what sort of deals Siglent is offering their government, educational and corporate customers.As far as why they play the game the way they do, they didn't invent it--they're just copying the A-brands in that regard. But it is possible that they noticed a huge surge in sales after the hacks were published...

author: Bud
author_rank: Super Contributor
timestamp: August 26, 2021, 04:57:15 pm
content: Quote from: Bassman59 on August 26, 2021, 04:36:27 pmThat in general companies have support contracts with their vendors and are not interested in this acrobatics.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 26, 2021, 05:45:20 pm
content: Quote from: nctnico on August 26, 2021, 05:55:29 amYou don't have to obscure it. You have to make it difficult or impossible to change it. I did forget to add one item to my list: have the basic bootstrap in ROM, which will load the firmware image from flash and check its signature using the company's public key.Even without that, the device is hackable in software only if you flash the firmware directly. You won't be able to upgrade the firmware without first having compromised the company's private key because the updater will perform a signature check of the firmware update with the public side of that key.You can't prevent people from hacking the device via hardware changes, of course, so changing the ROM would obviously accomplish that. That can be mitigated if the ROM contents are in the CPU/SOC directly. While you can't entirely prevent people from bypassing your code through hardware changes, you can make it expensive enough for them that it isn't worth it.The point of my message wasn't to illustrate how to make it impossible to hack your way towards enabling features. It was to illustrate that weknowthat these companies want their devices to be easily hacked, because they're not taking the rather trivial steps needed to make it difficult enough to do that most wouldn't try (there's a world of difference between a device being "hackable" by way of a simple key generator, a la a number of the Siglent devices, and it being "hackable" by directly flashing the firmware via JTAG or something).

author: rsjsouza
author_rank: Super Contributor
timestamp: August 26, 2021, 10:14:42 pm
content: Quote from: Bassman59 on August 26, 2021, 04:36:27 pmIndeed a daily driver for testing and diagnosing might not need to be accurate but, if you are putting a product out of the door or validating a customer's design, it needs to meet a solid standard so the published specifications/parameters can be reproduced at a customer's lab.

author: Bassman59
author_rank: Super Contributor
timestamp: August 27, 2021, 01:54:31 am
content: Quote from: rsjsouza on August 26, 2021, 10:14:42 pmSure, for those uses traceable/supported equipment is bought and put into service. It would be interesting to see how many oscilloscopes, for example, are used for product validation and how many are used for R&D/debug/repair.

author: rsjsouza
author_rank: Super Contributor
timestamp: August 27, 2021, 02:06:11 am
content: Quote from: Bassman59 on August 27, 2021, 01:54:31 amI personally have no idea. Just like with DMMs, I imagine the ration between cal/uncal is absurdly slanted towards the latter.

author: tv84
author_rank: Super Contributor
timestamp: August 27, 2021, 08:04:19 am
content: Quote from: kcbrown on August 26, 2021, 05:45:20 pmThis is not correct. KS has done a lot of work in trying to make if hard to hack the enablement of features. They have had one of the best methods around.First, all the points in your first message are currently implemented by KS.Secondly, the secure boot process that you describe in the 2nd message is the most important thing and you missed that one in the 1st msg.The "impossible to change it" is almost impossible as you have access to the device HW but, that, would be definitely a new ballgame .But, this go against the nature of the very own feature we're trying to protect: enhancement on the field. A secure boot process could introduce problems in the servicing of these units making them harder to service.It's not like PS/XBOX quantities where, if you have a problem, they replace with a new and get on with it.

author: 2N3055
author_rank: Super Contributor
timestamp: August 27, 2021, 08:53:17 am
content: Quote from: tv84 on August 27, 2021, 08:04:19 amThis...People who are not in security industry at all (no knowledge at all) and people who are professionally in security industry have same problem in common: they disregard how expensive security is.First one think it's cheap so it should be done to the fullest, because they think it's free and have no negatives, so why not.People in security industry OTOH, have no regards or even perception of limits where security is getting to expensive, and too damn taxing to people and and how it interferes with actual work trying to be done here. They are aware of the price but don't care. Somebody else is paying. As long as they follow the latest trends that don't have connection to reality anymore..One company I consult for, just introduced 15 CHARACTER passwords (at least one number, capital letter, letter and special character) for login to Windows Domain.They think they are more secure now. There cannot be any hacker attacks on this, right? From my real life experience, they just plummeted security to efin zero.First thing people did was to write the passwords down on PostIT note papers and stick it to the monitor.Because , 95% of people working in their offices cannot be expected to remember that shit.Not to mention they had like 1000% increase in locked accounts, because when people want to log in to windows in a hurry, then typing 15 characters blindly (yeah no peeking, that is insecure, someone could read it from the screen. If your PostIT note has bad handwriting).Support is overwhelmed.People are livid. And security is zero. Passwords are all over the place, stuck to the monitors.Security "Experts" don't care. They read it in some magazine that is a modern thing to do nowadays or whatever.It is not that they designed retarded, unrealistic security solution.No, problem is them people are not following rules.WTF happened to risk analysis? What is the cost/benefit here, security wise? How is that good security?Same thing with scopes. Creating a secure WORKFLOW for the whole scope company, costs a LOT of money and drops productivity. It is not as if: you zip it and it's secure.It has to be secured from beginning to the end. You can have everything secured, if someone leaks keys, bye bye.. So suddenly, you're not scope company anymore. You're running a military facility, with pat downs to see if someone tries to bring in forbidden surveillance equipment. No phones or communication devices on the premises. Partitioned offices with security clearances. Regulated paths to bathrooms and cafeteria. Security staff that supervises implementation. SIGINT monitors for 24/7 monitoring of illicit communications equipment. Human resources doing background checks.... Down the rabbit hole.And customer pays for it...Not doing same type of security like Keysight or R&S , by Siglent and Rigol, is also part of savings passed on to customers.So yeah, they made the right decision... If few hobby users hack the scope, that is not important.Also hackability has dick squat influence to purchasing decisions of professional users. Companies perform regular inventories and actively monitor all IT equipment to make sure nobody installed illegal software and licenses to any equipment. They think the same about this too..And why would you even consider that: Keysight Full Bundle for 3000T series is like 2500€ +VAT. Siglent SDS2350X+ can be had for that money. With most protocols included.Companies think like that. Even when you pay full price, Siglent equipment is good deal compared...

author: rsjsouza
author_rank: Super Contributor
timestamp: August 27, 2021, 01:21:07 pm
content: Quote from: 2N3055 on August 27, 2021, 08:53:17 amIndeed. there is always a balance of insecurity between the blatantly insecurity (free text passwords that give in to "1234" combinations) and the übersecure systems you describe.(such statements could easily be adapted to the entire government decision making process throughout 2020/2021...)

author: grg183
author_rank: Contributor
timestamp: August 27, 2021, 03:09:00 pm
content: Quote from: Sighound36 on August 23, 2021, 11:57:47 pmThat pricing is very much in line with the WaveProHD quote that I have, and of course I need to factor in the price of any possible future licenses/ probes, etc. It is certianly not an insignificant amount, expecially also because this year I have already spent a good deal in a major refurbishing of my lab - reason for which I had to postpone this scope purchase to next year. However I know that the WaveProHD would be a tool that would satify my requirements for the forseeable future without any compromises. On the other hand, there is currently an offer on the Rigol MSO8204 for Eur8990 with full options bundle which I am highly tempted to grab. Realistically and judging also from your valuable feedback and other sources I am now more confident that the Rigol would satify my immediate needs. At that price (practically equivalent to a good WaveProHD probe), I am seriously considering getting the Rigol, use it as far as it can take me and then reconsider the purchase of a higher-end scope in the future.I looked at the R&S RTO6 too, it is very interesting and more affordable but the 8-bit ADC, apparently higher noise floor, etc... are not convincing me.I still need to look into the HDO8000Quote from: Sighound36 on August 23, 2021, 11:57:47 pmThese comments sound very encouraging, if after 18 months you have not found anything worth complaining about I guess it is mature enough for a professional environment.Quote from: Sighound36 on August 23, 2021, 11:57:47 pmActually I already have a Keithley DMM6500 and also a few nice Keysight current probes.

author: Sighound36
author_rank: Frequent Contributor
timestamp: August 27, 2021, 04:04:26 pm
content: Some good thoughts there grg183I also have an MDA8000 HD, you can run SDA III apps on this on this one as well and they do have a BW limit of 2Ghz.We are involved in a lot of 3 phase work, hence why we have oe of this scopes as well plu 8 channels @10G/s all the time unlike TekDo also tae in to consideration, if you purchase moe of the apps @ time of scope purchase leCroy tened to look favorably on this, after the inital purchase then you may find its little or zero discount, so buy all of the 'prefered and esstenail more costiliers apps then.The Wavepro has aroud 20 apps. the MDA8000HD has around four, the HDO6000 has 22 apps which are used almost daily.According to our Lecoy rep my nickname is probe-miesterwe have seventeen of the genuine Lecroy probes, especially the RP-4030 rail probes four of these, three HVDP, five current probes, three passive probes and three active probesThe Rigol 8000 has All of the options available, I do take it out in the field as well, have five probes for this unit including nice pcio connect 4Ghz passive unit and the neat TPA189 30 amp 1m/a resolution current probe.We also have a DMM650 & 7510 units.Good luck with your decision, if you wish to know anything specific just pm me.Sighound36

author: NEDM64
author_rank: Contributor
timestamp: August 27, 2021, 04:56:45 pm
content: Quote from: grg183 on August 20, 2021, 10:31:46 amNo, they will give you the middle finger if it breaks outside the warranty and tell you to pay for their "keysight care" BS.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 27, 2021, 06:07:33 pm
content: Quote from: tv84 on August 27, 2021, 08:04:19 amYes. And have you noticed that nobody is able to enable features on KS equipment without going to substantial effort, including hardware modification of the device?My argument isn't that full prevention of feature enablement is possible. My argument is thatthe fact that manufacturers such as Siglent don't go to the rather minimal effort to attempt such prevention is proof that they want their devices to be, or at least don't care if their devices are, easily "hackable".QuoteYes, well, it took me all of about 30 seconds to come up with the items in the first message (a bit longer to actually type them in), so that what I showed wasn't entirely comprehensive is perhaps forgivable.And in any case, the secure boot process is necessary only if you're trying to prevent someone from being able to flash the firmwaredirectly on the board. The first set of items is still sufficient to prevent modification by way of a "key generator" or something, presuming that the company's private signing key remains uncompromised.QuoteCertainly.QuoteAll it means is that the firmware image you supply has to be properly signed and free of corruption. Interestingly, the signature also gets you integrity checking for free, which for these instruments is highly desirable. If your firmware upgrader is also in ROM, which it clearly should be, then the only way the device would be harder to service would be if the ROM itself were bad, in which case you're now looking at a hardware repair. But that's no different than any other hardware malfunction, and if you're looking at a hardware repair then as a practical matter you're looking at board replacement or unit replacement anyway.QuoteUm, well, with many of these instruments, particularly the low-end hobbyist models, that'sexactlywhat they do. And, honestly, that shouldn't be much of a surprise. Replacing the unit means that the customer is back on his feet faster, and gives the company as much time as it wants to repair the original unit, should it decide that it's worth the trouble.And we're really talking about the low-end hobbyist models in the first place (seeing how the question is about whether or not the manufacturers want their devices to be "hackable", and the people most inclined to do thatarehobbyists).Ironically, the upper-end models are the ones that need the least protection. They're so expensive that few hobbyists would buy them, which leaves companies and other professional-level entities that have to keep everything above board because for them, the after-sales service is even more important.

author: hpw
author_rank: Frequent Contributor
timestamp: August 27, 2021, 06:12:37 pm
content: So would one man now trust and gets into heaviest trouble as getting this nice used 6004 for $22,233.00https://www.ebay.com/itm/Keysight-Used-MSOX6004A-Oscilloscope-4-GHz-20GS-s-4-Channel-w-app-bundle-/194282706085?hash=item2d3c26d4a5#shpCntIdjust for 30 days warrantyincluded many SW options and without any probesHp

author: nctnico
author_rank: Super Contributor
timestamp: August 27, 2021, 06:17:30 pm
content: Quote from: hpw on August 27, 2021, 06:12:37 pmThe idea is that you buy extra service so it gets fixed if it breaks. Probably you can negotiate a bit to have it included in the price or a discount.

author: 2N3055
author_rank: Super Contributor
timestamp: August 27, 2021, 09:24:36 pm
content: Quote from: kcbrown on August 27, 2021, 06:07:33 pmSingle hardware revision simplifies complete process immensely. You basically make a batch of 1000 all the same scopes and then you can dynamically decide which ones are which. Let market decide. Big plus. Same for spare parts... Same for fixes, upgrades..Your argument is wrong.Keysight made 3 separate oscilloscopes for 3000T series because they are asses, because the cost of "protection from customers" is paid by those very customers by charging them higher prices.What you extol as a virtue is asshollery... If they had to pay for it from their already small profits, they would switch to single motherboard per model like everybody else..There is nothing positive or virtuous in their practice, only disregard for anything but their interest and yet Siglents and Rigols are somehow villains..Few years ago I bought a fully loaded brand new MSOX3104T for a fraction of price, because they make it in batches, and if they don't sell (and they don't as well as lesser models because they cost too much) at some point they are selling them off at ridiculous prices to get rid of the stock. It they were all the same model, they could have had reconfigured them.And yes, the new Keysight EXR and MXR is completely software configurable. Even if you buy 500MHz 4 ch scope, you get full 8 channels 2.5 GHz (6GHz on MXR) scope, signal gen, MSO, everything, software locked to less channels and bandwidth.So on old models with cheaper components they were doing 3 hardware variants. Now on new expensive scopes (I would think that saving 4 16GS/s and 4 6GHz analog front ends would save a lot of money.)only one hardware variant per model. Go figure.. Maybe it still make some kind of sense for them to do it that way for all the benefits they get.

author: grg183
author_rank: Contributor
timestamp: August 27, 2021, 09:46:56 pm
content: Quote from: kcbrown on August 27, 2021, 06:07:33 pmI don't think it is so much that they don't care or want them to be hackable, it is more likely a simple matter that they are not willing to spend more than they need to in development costs on something that is not a marketable feature. When you sell a product with soft-license enabled hardware features like this, the amount of savings in R&D, prototyping, testing, validation, part sourcing, production, production testing, product stocking, distribution, warranty replacements, etc... are huge. Just think of the simplified logistics of having to only build and ship one version instead of 4/5. The price that they sell the lower-end model at needs to cover the cost of the higher-end hardware that they are giving you plus a good profit margin. Especially for someone like Siglent/Rigol who is targeting the budget conscious market, they know that their biggest sales will be on lower-end models, so the profit margin is already adjusted for that. If they have to spend more money in development, testing, debugging, support, and possibly higher cost parts just to secure the license further they would just be eating away from their own profit margin and most of their sales would still be on the lower-end model. Keysight and the others target the less budget-conscious users and their profit margins are high enough to justify the extra costs for license protection, they also know that many of their sales will be on the higher-end models so the effort is justified. In product design everything is done based on a target cost (both in terms of BOM and also development costs), if the development effort to add the security does not fit in that cost it is simply not done. That development time is better justified on marketable features for new products.

author: nctnico
author_rank: Super Contributor
timestamp: August 27, 2021, 10:40:35 pm
content: Quote from: Sighound36 on August 23, 2021, 11:57:47 pmWhat I don't like in this picture is the focal point around the trigger level. On a good scope the (inevitable) trigger jitter should result in the edge of the signal being smeared out equally to the left and right. With a focal point you get a much thicker trace below and above the trigger point (and any rising/falling edges) than it is in reality so using a mask test is not going to give good results.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 28, 2021, 01:24:01 am
content: Quote from: 2N3055 on August 27, 2021, 09:24:36 pmSorry, I apparently wasn't entirely clear when I said "nobody is able to enable features on KS equipment without going to substantial effort". I was referring to people enabling features that they weren't authorized to enable. I thought the overall context made that clear, but apparently not. No worries.I'm not arguing that thehardwareneeds to be different across models. I'm arguing that if the company wants to prevent people from "hacking" the firmware, the company can do so throughthe firmware itself(which, of course, includes a moderate amount of ROM).Hackableis not the same assoftware configurable. The former means that someone who isnot authorizedto change the configuration on the device, or not entitled to enable a given feature of it, is capable of doing so anyway without going to the trouble to make any hardware changes.What I spoke of are firmware-level operations. The upgrader is a piece of firmware. The boot loader is a piece of firmware. Those two pieces should be in read-only memory (i.e., fixed at manufacture time) and should enforce signature verification of the firmware stored in flash (i.e., the firmware that actually provides the functionality of the device) if the company wants to ensure that hacking cannot occur except through hardware changes (here, at a minimum, it would mean replacing the ROM, and if the ROM is embedded in the processor then it would require a processor change).

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 28, 2021, 02:18:15 am
content: Quote from: grg183 on August 27, 2021, 09:46:56 pmAnd that would be the case even if the manufacturers implemented firmware signature verification and feature descriptor signature verification.It seems clear that there's confusion about what I'm saying. It looks like a primer on public key cryptography as relates to signatures is in order.In public key cryptography, keys are actually key pairs. When you generate a key pair, you generate a public key and a private key. The intent is that the public key can be published while the private key is a closely guarded secret. As a general rule, the public key is used for signature verification and to encrypt data that can only be decrypted by the private key. The private key is used to sign data and to decrypt data that was encrypted using the public key. Data which is encrypted and/or signed can be anything.When you sign a piece of data, you generate a cryptographic hash of the data and then encrypt that hash using the private key. That is the signature. Signature verification happens by hashing the same data using the same algorithm and then comparing what you get against the value you get when you decrypt the encrypted hash with the public key. When the two match, you have verification.So if you're the manufacturer and you want to prevent someone from enabling features on their device unless authorized by you to do so, then you can accomplish that by ensuring that the only way they can enable a feature on their device is through execution of firmware code that you wrote that checks for the presence of the appropriately-signed magic token (said magic token can be as simple as a single line of text that has the feature identifier and the device's serial number) that you would supply to them, and refuses to enable the feature unless both the signature verification of the token and the validation of the token (in particular, verification that the serial number in the token matches the serial number of the device) succeeds. Since the signature on the token was generated by your private key, i.e. averyclosely guarded secret, and because the signature and hashing algorithms used are cryptographically strong, the difficulty of fooling the feature checking mechanism would be astronomically high.That leaves only protection of the checking mechanism itself. And the same techniques can be used for that as well. To wit, you cryptographically sign the firmware, and embed in ROM a bootstrapper that checks the firmware's signature and refuses to load it if the signature check fails. Because the signature check involves cryptographically hashing the firmware image, this signature check is also an integrity check. Of course, because you have to account for the possibility of corrupt firmware, you'd need to supply a firmware upgrader in ROM as well.So the ROM would need to have four things in it:The first stage of the bootstrap loader (enough to check the signature on the firmware in flash and then begin execution of it if the check passes)The firmware upgraderThe device's serial numberThe company's public keyThat's it. Everything else can be in flash-held firmware.The thing here is thatyou only need to do the development of this systemonce. Once you've developed it, you can use it universally across your entire product range andguaranteethat if someone attempts to hack their device to enable a feature that you didn't authorize them to have, they can succeed only by replacing the ROM on their device. Which is ahardware change.So, to summarize, we know that companies like Siglent at a minimum don't care about their devices being feature-upgradeable by people who they didn't sell the feature to because they didn't go to what amounts to atinyamount of R&D (most certainly when amortized overalldevices) to implement a system like the above to prevent it. This stuff isn't hard, all of the heavy lifting was done long ago, so it just requires someone who knows what he's doing -- which is true of every properly functioning feature in every device.

author: Bud
author_rank: Super Contributor
timestamp: August 28, 2021, 03:03:14 am
content: This sounds exciting but the answer is always "it depends". In some cases such cryptographic protection can be circumvented. Example: Flir E4 thermal cameras (this forum has a couple threads on it).Secondly, hard coding the encryption keys is a poor practice. Keys can be compromised and require replacement, or may be other factors that may dictate key rotation.Thirdly, different encryption keys may need to be used for different firmware types for devices that utilize the same hardware platform. Example: Keysight 1000x series Linux-based oscilloscopes.And once the public keys are in the flash memory, they can be found and substituted with the attacker's own public key, then the attacker can upload the altered firmware signed with the corresponding private key, Job done.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 28, 2021, 03:45:57 am
content: Quote from: Bud on August 28, 2021, 03:03:14 amI'll have to examine those threads. Sounds interesting.QuoteWhile that's true in some cases, in this case you have to choose between hardcoding the keys (and suffering through the problems that might arise in the event your private key is compromised -- this is why you treat them like crown jewels) versus putting the keys in a writable medium and thus compromising the entire point of using them in the first place. Since private key compromise isextremely rarewhen the private key is properly taken care of (how often have you heard of a major signing authority's signing key being compromised? It's happened but it'srare-- the internet's entire security infrastructure would be worthless otherwise), and since the entirepointof the exercise is to prevent people from being able to circumvent the signature verification mechanism, it's obvious that in this case, hardcoding the public keys in ROM is the way to go.One other thing: when you hear of a CA certificate being renewed, it's thesignaturethat's renewed. The public and private key bits remain the same.QuoteThis doesn't make any sense to me at all. A cryptographic signature is a cryptographic signature. It's the same irrespective of the platform it's generated on or verified on, or the operating system it's using, or anything else. It's even independent of word length, endianness, and every other attribute of a processor. And that goes for the keys, too. They're just blobs of data in well-understood encapsulating formats. The algorithms in use today are public and widely used, and the methods for using the keys are widely known and exactly specified. This is so because they are intended to be universally used.Now, you'd obviously have to write your bootstrap loader to target the CPU you're using, and the same is true of the firmware upgrader, but that's a very different problem from the keys themselves.Remember, too, that there is a huge difference between the key material itself and its representation. The latter can change while the former remains the same. Whatwouldchange the key material is a change to a new encryption algorithm. But this, too, is an old and well-understood problem with well-understood solutions. And see below. For this use case, the company probably doesn't have to worry itself too much about it.QuoteWhich isexactlywhy you hardcode them in ROM.Engineering is all about compromises. Here, the proper compromise is obvious.These devices have a limited period of time during which the company's going to care about this problem anyway. After that, it doesn't matter if the device ends up being "hackable" or not. This means the company can change up their key material from time to time without any real consequence, and if an old key gets compromised the company doesn't have to care, as long as its usedonlyfor this particular type of purpose.The company could even use a different key for each device model line, thus greatly limiting the damage that a key compromise would do. There are lots of possibilities here as to how the company could manage its keys. And none of them require that the keys be stored in rewritable form.

author: Bud
author_rank: Super Contributor
timestamp: August 28, 2021, 04:23:17 am
content: Quote from: kcbrown on August 28, 2021, 03:45:57 amThis is not necessarily true. Nothing technically prevents a CA to generate a new key pair. It is a business decision whether to retain the old pair or go with a new one.QuoteI invite you to examine the Keysight 1200x scope firmware packages. They have if i remember correctly 4 individual firmwares in a single package, each firmware destined for a specific scope model, and each one has a different public key inside.Moreover, the fact that they ship public keys with the firmware means they have the possibility to rotate keys if they need to! So to me this was done on purpose.

author: Sighound36
author_rank: Frequent Contributor
timestamp: August 28, 2021, 09:13:26 am
content: All I did there was use infinate persistance to highlight the trace.

author: 2N3055
author_rank: Super Contributor
timestamp: August 28, 2021, 11:15:16 am
content: Quote from: nctnico on August 27, 2021, 10:40:35 pmIt is not trigger jitter. Trigger jitter with a rock solid signal can be completely compensated out, and all parts of waveform will overlap. You don't get this effect.That is being used on absolutely every jitter measurement application out there.We spoke about this before: if signal has a variation in rise time, and you overlay many captures over each other , you will get exactly this.Trigger point will go through exactly the same point and up and down of trigger point you get hourglass kind of shape. Changes (modulation) in edge speed can be caused by many things..That is basically same you get when you feed the scope white noise, or sinewave FM modulated with sinewave , just less pronounced. See attachments.What would be interesting is to go to upper part of that shape and calculate horizontal histogram to see if that rise time modulation is deterministic or stochastic...And mind you, that histogram doesn't have to be same as plotting histogram of risetime measurements. Parts of the edge below and above trigger point don't have to change at the same time...Risetime measurement will look at whole edge, so if you start slow and then speed up, and if you start fast and slow down, risetime will be the same, signal won't.It can also be an artefact of sinc interpolation. On scopes that support dot mode, you enable that and you know it's not interpolation artifact.

author: nctnico
author_rank: Super Contributor
timestamp: August 28, 2021, 11:37:15 am
content: Quote from: 2N3055 on August 28, 2021, 11:15:16 amNo. The signal in the picture can be considered to be close to perfect; likely it has a risetime over or close to the abilities of the oscilloscope. Think about it in terms of noise that is always present on a signal; that needs to show as an even distribution on screen. With the 'hour glass' effect occuring you can tell the noise of the trigger point has been smeared out the wrong way and thus is showing a signal which does not represent the actual signal. The hour glass effect also has a negative impact on the ability to measure the next edge at the tens of picoseconds level because that edge will also be smeared out further.You can try this yourself on a DSO which has an adjustable trigger threshold.

author: 2N3055
author_rank: Super Contributor
timestamp: August 28, 2021, 12:55:56 pm
content: Quote from: nctnico on August 28, 2021, 11:37:15 amIt is not TRIGGER NOISE. It is SIGNAL NOISE, that creates random changes to the shape of the signal in vicinity of trigger point.If it where only trigger noise, as you say, it would look exactly like this, with a thick uniform line.Like this:But it doesn't. Because noise contributes with it's harmonic content to slow up and speed up parts of the edge, making it nonuniform. Hence hourglas shape.To demonstrate, clean pulse:Same pulse with added noise:It can be clearly seen that there are faster and slower edges in there... If you overlap them you get hourglass shape.

author: nctnico
author_rank: Super Contributor
timestamp: August 28, 2021, 01:45:02 pm
content: Just try it with a DSO which has an adjustable trigger threshold (or a DSO which has a real trigger circuit and not one that is done in the digital domain resulting in an infinitely small threshold). The problem I'm describing is that the actual trigger point is being moved!

author: 3isenhorn
author_rank: Contributor
timestamp: August 28, 2021, 02:38:32 pm
content: Hello all,Somehow I got lost in the interesting discussion, but I wonder if anyone has mentioned that it is important to test the unit yourself.If I were buying something new in this price range, I would ask for a demo. The best device is the one I enjoy working with, nothing is more demotivating than regularly using a device that doesn't fit your workflow.On the technical side, I firmly believe that A or B brands cannot afford to sell unreliable equipment.

author: 2N3055
author_rank: Super Contributor
timestamp: August 28, 2021, 02:41:07 pm
content: Quote from: 3isenhorn on August 28, 2021, 02:38:32 pmGood point, but was said at the very begining. But good to mention, because it all went sidevays...Partially my fault, I will tr to stay on topic. Thank you!Best,

author: Caliaxy
author_rank: Frequent Contributor
timestamp: August 28, 2021, 02:53:26 pm
content: Quote from: nctnico on August 28, 2021, 01:45:02 pmThat’s really hard to understand. No matter how you move the trigger point from capture to capture, the result is the same: the waveform translates horizontally on the screen. Thus, the edges of the pulses would be parallel. It’s hard to imagine how you would get a “hourglass” pattern centered at the trigger point without varying the rise time or adding noise.

author: Caliaxy
author_rank: Frequent Contributor
timestamp: August 28, 2021, 03:11:39 pm
content: Oh, I can see it now: you trigger each capture at a different threshold and you plot it centered at the trigger point (so you also shift the waveform vertically). That would also create a hourglass pattern on the rising edge, with thicker horizontal traces. Is this what you are saying?

author: 2N3055
author_rank: Super Contributor
timestamp: August 28, 2021, 06:32:48 pm
content: Quote from: Caliaxy on August 28, 2021, 03:11:39 pmThreshold is fixed. It is what you set your scope at the moment. If edge is linear, monotonic, and well autocorrelated (meaning it will repeat to be exactly the same), and there is no scope jitter, you will get one single thin waveform, no matter how many million waveforms you overlap on top.If superimpose noise on top of that signal you will start to have distortions to edge linearity, i.e. it will change the shape. From straight line it will change to parts of sine/cosine shape being added to it. That will mean that such distorted edge will reachsame voltage threshold at different timethan linear edge. As the scope aligns all trigger events on top of each other (that is by design, trigger point is scope's zero of U/t coordinate system) they will have trigger point exactly on top of each other (there is no other way, really). The rest of the curve will kinda hang in the air left and right, becauseit isn't the same as previous one. Every single one will havedifferentslope, but will have to pass troughsametrigger point.So you get hourglass shape.Even with trigger jitter = 0.Fact is Nico ispartiallyright: because of noise in signal,there will be sometrigger jitter in that waveformtoo. But it isnot sourceof hourglass shape.Waveform itself is..When youhavetrigger jitter, yourwholewaveform "jiggles" left and right, because trigger is wobbling left and right. It is not doing good job and it's timing is random.This can happen if you have higher frequency signal superimposed on top of signal.This can happen on a analog scope with a noisy trigger level pot.Signal is smeared left and right.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 28, 2021, 09:20:42 pm
content: Quote from: Bud on August 28, 2021, 04:23:17 amIt's not just a business decision. It's a practical one.If you "renew" a CA certificate by generating a new key pair, then you get a discontinuity in signature verification by anything that needs to perform such verification against that CA. In particular, you would not be able to use the new CA certificate to verify signatures generated prior to the "renewal", whereas with a proper renewal you would. Since the entire point of a CA (in the internet infrastructure, at least) is to sign other certificates so that endpoints can validate those certificates when they're presented, such a discontinuity would cause a lot of disruption in the operation of endpoints that have to verify certificates that are presented to them.Now, if your CA is special-purpose, like what we're talking about here, then most definitely you could generate a new key pair. What I was referring to was public CAs like Verisign's, and I guess I should have said that explicitly.Generally, "renew" means to use the same key material whilst updating the signature, while "regenerate" means to generate new key material. Some customers where I work don't understand the difference, and sometimes regenerate their keys when "renewing" their CAs, with the end result being that their ability to manage their devices (which depends on their management node being able to verify the presentation certificates of their devices) stops cold. Hilarity naturally ensues. The pain of that experience quickly teaches them the folly of confusing "renew" with "regenerate".QuoteInteresting. But note that they do that by choice, not out of necessity (presumably -- if there's a use case where doing that is a necessity, I don't know what it is).QuoteSounds like it.But shipping the keys themselves in the firmware itself? If you do that, then you could just surgically replace those keys with your own and bypass the entire signature verification mechanism, no? Keysight has probably thought of that and may have a chaining mechanism of some kind to prevent that. If the keys are actually certificates then they'll be signed by something that presumably traces back to something that, hopefully, is immutable. In any case, I suppose much depends on what those keys are used for.Having multiple signing keys in the device does have some advantages. Nothing says you can't sign the same firmware bundle with multiple keys. That has the advantage that, presuming that signature verification is done by code in ROM, all of those keys would have to be compromised for someone to be able to overcome the signature verification.You know, I wonder if Keysight is using a TPM, or something with that kind of capability ...

author: Someone
author_rank: Super Contributor
timestamp: August 28, 2021, 10:38:51 pm
content: Quote from: 2N3055 on August 28, 2021, 06:32:48 pm.. and has been a common pattern with nctnico, making an "issue" out of normal behaviour, where they want different behaviour for some niche use. All the while completely avoiding explaining the obscure niche use case.The underlying behaviour is trigger interpolation, as in US patent US6753677Very few cases where people wouldn't want that. Why use only the analog trigger (with its jitter) when the surrounding acquisition data can reduce the total jitter?

author: Bud
author_rank: Super Contributor
timestamp: August 28, 2021, 10:48:52 pm
content: Quote from: kcbrown on August 28, 2021, 09:20:42 pmThis is a matter of semantic. We are talking same thing. We can call it "operational decision".QuoteNot until you first replace the current public key in the existing firmware in the scope, in order for the scope to accept the update. This is where practicality of such solution comes into consideration. Yes a few geeks can do it by doing some sophisticated manipulations but this will not be a mainstream type of hack that an average Joe Blow can replicate easily.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 28, 2021, 11:41:10 pm
content: Quote from: Bud on August 28, 2021, 10:48:52 pmFair enough.QuoteWell, this gets back to the claim that someone could hack their scope by directly flashing firmware to the chip, which is essentially what Nico was talking abouthere. The only reason for putting bootstrap code in ROM that uses a public signing key that's also in ROM is to prevent that from working.Keysight apparently does something very similar to what I described in my first message on this subject (here). Since they don't seem to be using a TPM and (we presume) don't have a signing key in immutable storage, the scope is vulnerable to compromise through a direct firmware flash operation. But absent compromise of the signing key, or an implementation error, it's vulnerableonlyto that kind of alteration (or, of course, replacement of the flash chip itself).In any case, the entire point of all this is to show that manufacturers like Siglent thatdon'tuse public key cryptography to prevent modification of their firmware and to prevent unauthorized activation of features arenotconcerned about their devices being "hacked" (i.e., having people enable features that they didn't pay for or are otherwise not authorized to enable), and this is so because implementation of these measures is straightforward, well-understood, and something the company would have to do only once,andthey areveryeffective, as Keysight's own devices prove (despite the fact that they have made some serious errors in their implementation on some scopes, such as, apparently, allowing boot from an external USB drive without a signature check of the boot image on the drive). Nobody has a "key generator" or something equivalent for reasonably recent Keysight instruments that I've ever heard of (examples to the contrary welcome).Yes, you have to implement it correctly and yes, you have to be rigorous about ensuring that there are no ways to bypass the signature checks. But this is no different from any other mission-critical feature.

author: Bud
author_rank: Super Contributor
timestamp: August 29, 2021, 01:19:15 am
content: Quote from: kcbrown link=topic=287131.msg3652684#msg3652684Often times things are much more prosaic. It very well may be that these manufacturers simply do not have the required expertise in that specific field.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 29, 2021, 01:48:53 am
content: Quote from: Bud on August 29, 2021, 01:19:15 amI thought of that. Buteverycompany has a web site these days andeverycompany has to deal with getting a signed presentation key for it, properly manage that key so that it is not compromised, etc., so every company at least has awareness of public key cryptography to some degree.Moreover, we're talking about companies with engineering groups that have some amount of operating system expertise, among other things. The likelihood thatnobodyin the engineering group knows enough about public key cryptography to at least understand that it's capable of doing what we're talking about here, much less be able to do the research necessary to find out such things, is vanishingly small these days, I'd wager, and I'd wager it's been that way for at least the last 10 years.And finally, all of these T&M manufacturers study each other's approaches to things. Weknowthis because we've seen that in the various implementations that are in use. All a company needs to do is understand that a proper cryptographic approach to the issue would make their feature activation mechanism nearly bulletproof, or see that some other company has implemented something like it and thattheirimplementation is nearly bulletproof.Once you understand the problem you're trying to solve and have some vague idea of what solutions are at least possible, you can hire an engineer with the requisite knowledge to implement the best solution. So while an inability to perform this kind of implementation might have been understandable as a showstopper 20 years ago or so, that's no longer the case unless the company in question has been living under a rock or something.

author: Bud
author_rank: Super Contributor
timestamp: August 29, 2021, 04:42:35 am
content: Big Clive, a prominent Youtuber, once said - "The Chinese are very good in copying but not very good in understanding how things work". I will leave it at that.

author: tv84
author_rank: Super Contributor
timestamp: August 29, 2021, 08:35:35 am
content: Quote from: kcbrown on August 28, 2021, 11:41:10 pmTek, LeCroy and R&S have been using symmetric crypto for many years...Regarding keygens: You should know that the sharing of that kind of information is inversely proportional to the price of the equipment.

author: grg183
author_rank: Contributor
timestamp: August 29, 2021, 10:42:54 am
content: Quote from: 3isenhorn on August 28, 2021, 02:38:32 pmDefinitely a good point and I have no intention of forking out $40k+ on any equipment without a demo, just as much as I wouldn't buy a new car without a test-drive.I guess at this stage I am at a slightly earlier point in the buying process where I am trying to understand what makes most sense.Since my original post, reading feedback here and thinking further about it I have now answered one of my main questions "should I get a Keysight DSOX6000?" I think that is a definite no at this point. I think there are much better options for a not so much higher price or alternatively the seemingly comparable Rigol 8000 at a much lower price.

author: kcbrown
author_rank: Frequent Contributor
timestamp: August 29, 2021, 07:53:34 pm
content: Quote from: tv84 on August 29, 2021, 08:35:35 amJust to be clear,symmetric cryptographyis secret-key cryptography, wherein one uses a single key for both encryption and decryption operations.So I presume you meant public key cryptography, wherein one generates a key pair, where each key in the pair can decrypt the encryption of the other.In any case, that only reinforces my point. T&M manufacturers have experience with this. It's not new to them. So there's no reason to believe that Siglent and Rigolcan'timplement such a system if they want. Ergo, that they haven't is near-proof that they don't want to, which means that they don't care about their equipment being "hackable", and likelypreferit precisely because it gives them an advantage in the hobbyist market.QuoteOf course. And that shouldn't be a surprise. The adoption of a piece of equipment by hobbyists is also inversely proportional to its price, and hobbyists are the ones who are most interested in such keygens. As I noted previously, the most expensive equipment will tend to need the kind of protection I'm talking about the least.

author: grg183
author_rank: Contributor
timestamp: September 14, 2021, 08:53:22 am
content: Thought I'd give a follow up on my decision process...I've decided not to take the offer on the Rigol 8000, I've searched a lot on this scope and cannot find any bad comments about it, everything about it looks great, price is unbeatable and at least on paper it ticks most of my requirements. However I just cannot see this as giving me the confidence that I need in a primary scope, I simply cannot get myself to accept a Rigol for this. If it were a secondary scope I'd definitely go for it though.Meanwhile I came across the PicoScope 9400 series. I'm not a fan of PC based oscilloscopes for the general use case but this could make a lot of sense for my use case. The PicoScope 9400 can do eye diagram and jitter measurements at very high bandwidths using the SXRTO sampling technique (effectively this bandwidth would future-proof it for my requirements). I do realize that the SXRTO cannot be used for more general oscilloscope uses however I could then cover that requirement by getting a lower-end 1GHz normal sampling oscilloscope such as a WaveSurfer 4000HD, R&S, RTK4A, etc... Budget-wise this would be better since the overall cost would be lower and I can split the purchase of the two scopes over time. At the same time I'd have a 1GHz scope for general purpose use (which I require) and I'd also be able to do eye diagrams on high speed lines with the 9400 with a much higher bandwidth.Do you think this makes sense?Any opinions on the 9400?

author: 2N3055
author_rank: Super Contributor
timestamp: September 14, 2021, 10:09:42 am
content: Quote from: grg183 on September 14, 2021, 08:53:22 amIf you can afford that (and it seems that it might be even easier to purchase since you spread the cost over time) a "sampling" scope and one general purpose scope is a best option. That way you can optimize each for the job.Picoscope 9400 series is a superb piece of kit and Picotech has good support engineers.. One interesting thing on 9400 is also optional clock recovery outputs.. If you are really interested, you can always contact their pre sales support and explain your use case.

author: hpw
author_rank: Frequent Contributor
timestamp: September 14, 2021, 12:23:56 pm
content: Quote from: grg183 on September 14, 2021, 08:53:22 amMy opinion:12-bit 500 MS/s ADCs: how to go into fs??±800 mV full-scale input range into 50 Ω: This means no 3.3V digital logic10 mV/div to 0.25 V/div digital gain ranges: This means no 3.3V digital logicwhile was looking at them to, as some figures missingor I am wrong

author: 2N3055
author_rank: Super Contributor
timestamp: September 14, 2021, 02:23:29 pm
content: Quote from: hpw on September 14, 2021, 12:23:56 pmThese are quite specialized instruments. Usually used with 10x or 20x probes.. Or with attenuators. They are not general purpose scopes.Input connectors are SMA. It has 1 T(era)SMPS/sec equivalent sampling. 500 MSPS/sec is real time sampling rate of ADC.They work only on repetitive signals, or signals where you want to accumulate samples on top of each other for eye diagrams...Slower one has 0% to 90%: ≤ 70 ps and faster one has 10% to 90%: ≤ 21.9 ps..

author: Sighound36
author_rank: Frequent Contributor
timestamp: September 14, 2021, 02:56:48 pm
content: Yes the Picoscope equipment is very good I have two of them, the staff are very helpful and always will try and find a solution if possible, I visited the factory last year and found ALL of the staff I met (Including the boss!) to be genuinelly enthusiatic and techincally excellent. The software is also very good.If I didn't have the Lecroy's the Picoscope would be my next choice for accurate meas.

author: grg183
author_rank: Contributor
timestamp: September 15, 2021, 12:51:11 am
content: Quote from: 2N3055 on September 14, 2021, 10:09:42 amBudget-wise this comes down to: $12k (assuming a WaveSurfer 4104HD) + $20k (assuming a Picoscope 9404-16), this gives me a capable 1GHz, 12bit, 4 channel general purpose scope and a dedicated 16GHz sampling scope for high speed signal analysis. Two instruments that I can use independently and together should cover all my requirements for general purpose capture as well as high speed analysis with a high enough bandwidth to cover all foreseeable future needs. I could also get the 5GHz model for $5k less and it would still be enough. On the other hand I could get a WaveProHD 2.5GHz which with the extra licenses is at least $50k and as far as high speed analysis goes I'd be "limited" to a 2.5GHz bandwidth. Don't get me wrong, I know that the WaveProHD has a ton of extra measurement tools in the app toolbox but I think with the WaveSurfer + Picoscope combo I'd be putting the money specifically where I need it while also spending less overall. I'm liking this idea a lot but still reviewing the pros and cons.Quote from: hpw on September 14, 2021, 12:23:56 pmAs 2N3055 pointed out the 9400 is a highly specialized scope, the input range that it has is more than enough for it's intended use. You'd anyway need to use a x10 probe or attenuator. If you were to, for example, probe a DDR signal directly with the 50 ohm input it would anyway not be suitable as it loads the signal. The 9400 is not a scope you'd use for any "high voltage" applications really. It is also only suitable for repetitive signals.Quote from: Sighound36 on September 14, 2021, 02:56:48 pmI don't have any Picoscopes (the only PicoTech device that I have is a TC-08 thermocouple data logger, which is great) but I have used a Picoscope 3000 (if I remember correctly) in the past and I remember it was really good. I'm not a fan of PC based oscilloscopes and definitely for a scope that would be used daily I want a box with screen and knobs, but the 9400 is something that has a very specific use so I don't mind that being PC based. The software also looks really refined.

author: 2N3055
author_rank: Super Contributor
timestamp: September 15, 2021, 07:41:32 am
content: Quote from: grg183 on September 15, 2021, 12:51:11 amI think that is good thinking.I have Keysight MSOX3104T and 3 Picoscopes: MSO 3406D (500 MSPS), 4262 (16bit 5MHz low noise), and since few weeks 4824A (12bit, 20MHz 8ch beast).All those functions in a single scope don't even exist. Maybe WaveRunner 8000HD would come close (not to 8uV of noise though), but I chose to buy new apartment instead...As for being a fan (or not) of PC based instruments, it is a matter of habit and nothing more. I combined mine with a 23" touch screen monitor. If anything, it might be better than all in one scope for many things, depending on what you do.Screen is bigger than whole 3000T, see below. As a side note, I'm monitoring 230V AC power in my lab. It's been up for a week, 24/7... Rock solid.There is a new version 7 software in making, but that will take some time. They are taking testing very seriously, and will release only when they think is rock solid. Talking about high professional standards. Many other manufacturers could make a note of that...9400 software is actually different than standard Pico software, and it looks and feels even more refined. And as SI work is not button twiddling type of work, PC interface with everything nicely laid out on a large screen in a plain sight is an advantage in my view.One more thing: ease of documentation. On a PC based scope it is simpler and faster. It is already on your PC...

author: nctnico
author_rank: Super Contributor
timestamp: September 15, 2021, 09:31:20 am
content: But still you have to keep in mind what kind of workflow you need. Some measurements require probing one point after the other and changing settings all the time while other measurements require taking one of two acquisitions and spend time to analyse/dissect the signal.

author: Sighound36
author_rank: Frequent Contributor
timestamp: September 15, 2021, 09:40:10 am
content: Just to keep things even more anal, with my Picoscope 4262 I built a isolated ultra quiet linear (round 4uA of ripple @ 5Vdc) supply for the scope via a usb break out box arrangement for those like me that loathe usb power especially on test instruments.Yes I know 101 people will tell me I wasted my time, however it does seem to work

author: 2N3055
author_rank: Super Contributor
timestamp: September 15, 2021, 09:53:19 am
content: Quote from: Sighound36 on September 15, 2021, 09:40:10 am

author: 2N3055
author_rank: Super Contributor
timestamp: September 15, 2021, 09:54:12 am
content: Quote from: nctnico on September 15, 2021, 09:31:20 amSignal integrityisa separate workflow..

author: grg183
author_rank: Contributor
timestamp: September 15, 2021, 12:03:23 pm
content: Quote from: 2N3055 on September 15, 2021, 07:41:32 amWell yes it is primarily a matter of personal preference I guess. Both have their advantages and disadvantages. Personally if it is something that I have to use very often I very much prefer it to be completely standalone, ideally with an alternative PC interface for when data needs to be transferred to the PC. If post-processing of data on the PC is essential then I'd agree a PC based device is generally better.Quote from: 2N3055 on September 15, 2021, 09:54:12 amI agree with 2N3055, signal integrity is very much an independent measurement and I see no limitation with this being done with a dedicated instrument.

author: nctnico
author_rank: Super Contributor
timestamp: September 15, 2021, 12:16:09 pm
content: Quote from: grg183 on September 15, 2021, 12:03:23 pmThat is good. I triggered on an earlier post of you where you are mentioning that you where also considering getting a scope for general purpose use. Unfortunately the perfect oscilloscope that fits all needs has not been created yet. Would save quite a bit of space if it existed

author: egonotto
author_rank: Super Contributor
timestamp: September 15, 2021, 03:15:21 pm
content: Hello,the WaveSurfer 4104HD is sure a great scope. But perhaps you should reflect, whether a R&S® RTA4K-COM4 give you more potential.Drawback of the RTA4K it has the worser noise in lower sensitivities.Example31.4mV against 4.7mV in 1V/div range4.6mV against 0.465mV in 100mV/div rangebut:0.11mV against 0.125mV in 1mV/div range.But WaveSurfer 4104HD has 8 div and RTA4K has 10 div.Best regardsegonotto

author: Sighound36
author_rank: Frequent Contributor
timestamp: September 15, 2021, 03:28:25 pm
content: If you are looking for purely noise @ lower freqencices and you do not need to look above 200Mhz then the 4024 is the way to go, around 28uV of noise @ full bandwith open ports and no filters.Much as I love R&S equipment and they do make some of the best RF gear on the planet without question, their scopes for me are as our lab miester from down under would say Meh! sorry its just way I feel about them for me no.Then the Picoscope of your choice.

author: grg183
author_rank: Contributor
timestamp: September 15, 2021, 04:11:44 pm
content: Interestingly some months ago (before I started researching for this purchase) I was almost about to grab the RTA4K-COM4 offer when I came across it...The RTA4K is good scope, but compared to the 4104HD:- higher noise- 10 bit vs 12 bit- 64k vs 175k waveforms/s- 10 inch vs 12.1 inch screenIt wins on memory depth 100M/200M vs 12.5M/25M but it seems to me that with everything else the WaveSurfer is superior.Currently I could get either one at the exact same price, so I think the WaveSurfer would be the obvious choice for me.

author: bdunham7
author_rank: Super Contributor
timestamp: September 15, 2021, 04:21:27 pm
content: Quote from: grg183 on September 14, 2021, 08:53:22 amI don't have an opinion on the 9400 series, but Picoscopes in general are excellent if you don't need or want a 'conventional' setup, meaning form factor, PC-based vs one box and input characteristics.I would be very curious to know what the noise floor is on the various ranges and what sort of input probes/attenuators/etc work for you in various circumstances. For example, is it possible to use the 10mV/div range and 100X passive attenuation so as to get the input impedance up. I hope you can report back when you get it.

author: Caliaxy
author_rank: Frequent Contributor
timestamp: September 15, 2021, 05:10:01 pm
content: Quote from: Sighound36 on September 15, 2021, 09:40:10 amHave you noticed any improvement? It seems awkward that such a nice, low-noise piece of equipment is expected to rely on a computer USB port for power.I'm not telling, I'm asking

author: egonotto
author_rank: Super Contributor
timestamp: September 15, 2021, 05:33:58 pm
content: Hello,Quote from: Sighound36 on September 15, 2021, 03:28:25 pmThis is far far .... far better than the 65 uV in the datasheet?Best regardsegonotto

author: Sighound36
author_rank: Frequent Contributor
timestamp: September 15, 2021, 07:00:23 pm
content: Hi EgonottoI have found that every lecroy scope I own exceeds the quoted specs by a decent margin.Though I have a confession the Wavesurfer is actually 48uv (42uv and BW to 20Mhz), my apologies I was confusing them with the 6054-MS that is 72uv ( so apologies for the mis information), my badScopes are in calibration, been on for hour, open ports 50Ohm no filters at all 1mv setting max sample rateHowever it is still exceeds its quoted spec by a respectable margin.

author: Sighound36
author_rank: Frequent Contributor
timestamp: September 15, 2021, 07:04:49 pm
content: Quote from: Caliaxy on September 15, 2021, 05:10:01 pmI would suggest 100% yes the whole scope is just more stable, especially with FFT's and low noise meas I feel it delivers a small but useful improvment for the jobs I use it for, its plus from me.

author: Sighound36
author_rank: Frequent Contributor
timestamp: September 16, 2021, 10:12:19 am
content: I took some noise figures from the Lecroy last night (6054-MS) with an open port 50Ohm and fukk BW and one with a 20Mhz BW, the scope had only been running for a 15 minutes so not quite the usual readings, however you can see they are none to shabby!

author: 2N3055
author_rank: Super Contributor
timestamp: September 16, 2021, 12:49:43 pm
content: Quote from: Sighound36 on September 16, 2021, 10:12:19 amThat is very short timebase. How would it look at 1mV/div, 10us/div?Do you get around 25uV Stdev at 20MHz and 55 uV Stdev at 200MHz BW ?

author: bdunham7
author_rank: Super Contributor
timestamp: September 16, 2021, 02:20:08 pm
content: Quote from: Sighound36 on September 16, 2021, 10:12:19 amAm I seeing two samples per screen??

author: 2N3055
author_rank: Super Contributor
timestamp: September 16, 2021, 02:25:26 pm
content: Quote from: bdunham7 on September 16, 2021, 02:20:08 pmAre you saying you're seeing things ??Just joking..Yes you see right. What do you expect with 20ps/div. Yes, 20ps..That is why I asked for a timebase that will take at least some 1E6 samples , but still staying fast enough not to pick up low frequency noise.Also I have some notes written down from some previous testing, with those parameters, so I can directly compare..

author: grg183
author_rank: Contributor
timestamp: September 16, 2021, 02:34:58 pm
content: You've probably all seen this already but just to add to the discussion here is a video comparing the noise figures for the WaveSurfer 4000HD with the RTA4K:This video is made by Lecroy so it's not exactly what you'd call an unbiased review, but still...

author: Sighound36
author_rank: Frequent Contributor
timestamp: September 16, 2021, 03:03:43 pm
content: Hi SinisaSome good calcultaions there first one is 1m/v @ 10us 20Mhz BW Std/d around 29uvThe BW on this cope is 500Mhz, no problem to produce one @ 200Mhz for you bang on 55uv

author: 2N3055
author_rank: Super Contributor
timestamp: September 16, 2021, 05:08:41 pm
content: Quote from: Sighound36 on September 16, 2021, 03:03:43 pmThanks!!

author: egonotto
author_rank: Super Contributor
timestamp: September 17, 2021, 02:44:17 pm
content: Hello,enclosed a few measures with the RTA4004.50 Ohm and 20 MHz or 200 MHz with 1mV/div or 100mV/div.But RTA4004 has 10 div so it is 1.25mV/div or 125mV/div in comparison.With 1.25mV/div the RTA4004 is similar. But with 125mV RTA4004 is far worse.Best regardsegonotto