Lecroy - HDO4034A vs Tektronix - MDO3104 - Page 1
Forum section: electronics / testgear

author: Plasmateur
author_rank: Regular Contributor
timestamp: May 13, 2019, 05:00:45 pm
content: We are having a bit of a debate in the lab as to which scope to purchase, personally I want to go with the Lecroy while another scientist wants the Tektronix just because that's the only scope brand they've ever used.Here's the specs that I've compared between the two scopes.Code:Lecroy - HDO4034ATektronix - MDO3104WinnerRelease DateApr-17Jun-15LecroyPrice$11K$14KLecroyResolution12bit - (15bit enhanced)8bit - (11bit Hi Res)LecroyMem Depth50 Mpoints10 MpointsLecroyBandwidth350 MHz1 GHzTektronixRise Time.75 ns.4 nsTektronixSample Rate10 Gs/s5 Gs/sLecroyEnhanced SR125Gs/s RepetitiveNot AvailableLecroyScreen Size12.1"9"LecroyNoise Floor145 uVrms @ 1mV179uVrms @ 1mVLecroyChannel Isolation1000:1 @ DC-200MHz100:1 @ DC-100MHzLecroyStray Capacitance15 pF3.9 pFTektronixAny opinions?

author: Kean
author_rank: Unknown
timestamp: May 13, 2019, 05:15:17 pm
content: What are your actual needs?Have you looked at R&S?

author: Plasmateur
author_rank: Regular Contributor
timestamp: May 13, 2019, 05:29:40 pm
content: Quote from: Kean on May 13, 2019, 05:15:17 pmMy needs and my colleagues needs are a bit different. I want to have the high bit depth because I will need to see relatively small signals buried within another relatively large signal.Also, I need to use a Harmonic mixer to mix down a carrier frequency (60GHz) resolve something close to the carrier, like 60.006GHz, to look for non-linear interactions.... but I would need a really high sampling rate to do this.

author: simone.pignatti
author_rank: Frequent Contributor
timestamp: May 13, 2019, 05:44:03 pm
content: wait 7 days from today and buy the R&S RTM3K-COM4 or the RTA4K-COM4RTM3K data sheethttps://scdn.rohde-schwarz.com/ur/pws/dl_downloads/dl_common_library/dl_brochures_and_datasheets/pdf_1/RTM3000_bro_en_5214-9144-12_v0600.pdfRTA4K data sheethttps://scdn.rohde-schwarz.com/ur/pws/dl_downloads/dl_common_library/dl_brochures_and_datasheets/pdf_1/RTA4000_bro_en_5215-1776-12_v0500.pdf

author: JPortici
author_rank: Super Contributor
timestamp: May 13, 2019, 05:54:23 pm
content: Ask for a test drive. Even better if you can get them in the same week

author: dzseki
author_rank: Frequent Contributor
timestamp: May 13, 2019, 06:47:39 pm
content: At work we have DPO3034 which is I believe a very close match to that MDO. After 10 years the rotary encoders went bad, the official repair quote was 3000€, of course we did not bought it, instead did it in DIY way. As for the hardware, not sure if the MDO is significantly better but ours is really not that fast when using the full memory depth, let alone I you switch on math and measurements... the default capture depth is 100kpts at which the scope fares well.

author: mk_
author_rank: Regular Contributor
timestamp: May 13, 2019, 06:52:43 pm
content: Quote from: Plasmateur on May 13, 2019, 05:00:45 pmI work with several LeCroys, own a Tek MDO3054.If the money is aviable I would never buy the TEK again but look to R&S or LeCroy.Reason: The userinterface of the MDO is one of the inconsistentest and ugliest UIs I ever had to work with, it`s getting slow when doing a little bit of math and the surrounding support is bad - compared with the LeCroy.One of my customers has a HDO6104 (12 bit, 4 channel, 1GHz with 250MB memory/channel). It`s great to have the raw data (which is huge when using all that memory) from the LeCroy downloaded via LAN and then running Octave or similar.At the customers site there are also about 10 or 12 year old probes from LeCroy, still useful on the newest units. Try this at TEKs... if you buy probes now - in 3-5 years expect them to throw them away because some clever guy decides to invent a new probe.interface.... This alone is a solid argument against TEK BTDT.And yes, ask for testsystems and enough testingtime. Start a competition inside your lab for difficult measurements... and see how it can be done with the different units..

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 13, 2019, 08:52:05 pm
content: We had Tek MDO3000s at the college I went to and they were truly horrible, not just because everything on them was so slow, the knobs and buttons lock up when the scope is doing something demanding like FFT or just serial decoding, and quite often it crashed, tooThe "spectrum analyzer" part in the MDO was poor, too, because it's just FFT and not a real spectrum analyzer like a swept spectrum on. I guess even a cheap SA made by Rigol or Siglent will perform much betterThe college only bought Tek because most of the profs didn't know any better and because Tek was the best thing since sliced bread last time they had contact with actual industry (which usually was in the 70s or 80s)One prof who was still an active engineer who also did part-time teaching introduced us to Keysight and LeCroy. What a world of differenceBTW, according to a former member who deals with lots of test equipment and knows these instruments inside out even Tek's latest scopes are still poor, and he said whoever considers Tek for a scope needs to get his heat examinedPersonally I ended up with Lecroy LT374 and Agilent Infinum 8064. Both are old by today's standards but still worlds better than the POS Tek scopes at college

author: nctnico
author_rank: Super Contributor
timestamp: May 13, 2019, 09:05:59 pm
content: Quote from: Kean on May 13, 2019, 05:15:17 pmI second this. R&S also has several different acquisition modes (including peak detect) which the Lecroy doesn't have.

author: dietert1
author_rank: Super Contributor
timestamp: May 13, 2019, 10:03:46 pm
content: I think your table was clear enough and if you put the extra 3K the Tektronix costs into a higher bandwidth version of the HDO, another two of the three Tektronix wins may disappear. As interesting as it is, the low input capacitance of the Tektronix vanishes as a win as soon as you want to measure above 100 or 200 MHz, since that probably means using active probes.Regards, Dieter

author: tautech
author_rank: Super Contributor
timestamp: May 13, 2019, 10:12:26 pm
content: Quote from: Plasmateur on May 13, 2019, 05:00:45 pmWhat happens when you throw a $7.5k 1 GHz 4ch Siglent into the mix ?

author: nctnico
author_rank: Super Contributor
timestamp: May 13, 2019, 10:38:31 pm
content: Nobody gets fired for buying Tektronix...Tektronix does have a new 4 series scope coming out in a couple of weeks which probably is a better alternative to the MDO3k/MDO4k series. These have 6 channel models as well. If there is time I would get one of these on loan to see how it compares.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 13, 2019, 10:55:27 pm
content: Quote from: nctnico on May 13, 2019, 10:38:31 pmYeah, right, if you're a government employee or work in education maybeQuoteIf the existing MSO5 and MSO6 are an indicator then the new Tek 4 series scope will again perform poorly and be full of bugsAnd it appears Tek support is poor, tooWhy would anyone buy Tek if there are much better alternatives out there?

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: May 13, 2019, 11:26:20 pm
content: I'd personally always choose a LeCroy over a Tek. Letting aside the GUI, the much better measurement possibilities and stuff like WaveScan: LeCroy has the same probe interface for some decades now while Tek changes it every few years. The only benefit I see for the Tek MDO line is the somewhat questionable spectrum analyzer (which is even more crippled in the MDO3000) and the existence of keygens for options (but 1GHz bandwidth is only possible on the the MDO3104).What about a compromise? Sacrifice the 12bit resolution but get the 1GHz bandwidth with a WaveSurfer 510.

author: DaJMasta
author_rank: Super Contributor
timestamp: May 14, 2019, 12:28:55 am
content: They are sort of in different classes in terms of bandwidth, but especially with the feedback from the thread so far.... the LeCroy is just obviously a newer generation scope. If you don't need the super high bandwidth, the specs are basically all in favor of the LeCroy, and it sounds like the UI, responsiveness, and connectivity options are a ways ahead of the Tek. FWIW, I think the MDO4000 series from Tek probably is a much better match, the MDO4034C is pretty close for price and bandwidth, but offers the 6GHz SA in place of the better frontend and acquisition of the basic channels on the LeCroy, and it should be a bit more modern feeling and performing than the MDO3000 series, which I believe was their first iteration of the MDO series.

author: nctnico
author_rank: Super Contributor
timestamp: May 14, 2019, 01:21:17 am
content: Quote from: Mr Nutts on May 13, 2019, 10:55:27 pmThat is a bit early to say. I'll admit the MSO5 and MSO6 didn't seem to work very well when released but it would be reasonable to expect most of the teething problems have been ironed out by now. However I don't have any information on the current state so the best advice is to get one on loan if you are looking at a scope in this price range. Maybe it is perfect for the job. Maybe not. Either way no harm is done and at least you went through all the possibilities.

author: snoopy
author_rank: Frequent Contributor
timestamp: May 14, 2019, 01:32:36 am
content: Quote from: Plasmateur on May 13, 2019, 05:00:45 pmwaveform update rate and dedicated spectrum analyser ?

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 14, 2019, 02:46:49 am
content: Quote from: nctnico on May 14, 2019, 01:21:17 amThat's what people who evaluated these scopes on multiple occasions say. It appears Tek has added some more options but the basic firmware is still full of bugsAnd then there's also the user interface, which it seems on the MSO5 and MSO6 is as illogical as on other Tek digital scopes. And there's even less chance that this will be fixedQuoteLast time I used the MDO3000 at college the series was on the market for over three years, and still with the latest firmware there were crashesLast I heard, this has barely changed with today's firmwareI guess you'd have to be a hardcore Tek fan to overlook all these thingsQuote from: DaJMasta on May 14, 2019, 12:28:55 amThe MDO4000 my college had were not much better than the MDO3000. I think the biggest benefits were the larger display and that the "spectrum analyzer" could be used at the same time as the scope function (on the MDO3000 you can have either scope or spectrum analyzer). It was still slow and the user interface was basically the same as on the MDO3000

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 14, 2019, 02:56:39 am
content: Quote from: snoopy on May 14, 2019, 01:32:36 amI don't know the exact data but the trigger rate on the MDO was very low, like a few thousand updates per second. There's fastaq but that works with data reduction and excludes most of the scope's functionality when activeAlso:https://forum.allaboutcircuits.com/blog/the-truth-about-oscilloscope-waveform-update-rates-and-why-not-to-fall-for-it.1514/It appears the trigger rate of the MDO300o is 2200 per second in normal mode.The "spectrum analyzer" is very poor, not just in its performance. It's just FFT and like everything else on the MDO3000 is so slow that it hurts

author: Plasmateur
author_rank: Regular Contributor
timestamp: May 14, 2019, 03:55:10 am
content: Quote from: tautech on May 13, 2019, 10:12:26 pmWhat's the highest sampling rate you can give me?

author: tautech
author_rank: Super Contributor
timestamp: May 14, 2019, 04:10:54 am
content: Quote from: Plasmateur on May 14, 2019, 03:55:10 am5 GSa/s.https://www.siglentamerica.com/digital-oscilloscopes/sds5000x/

author: snoopy
author_rank: Frequent Contributor
timestamp: May 14, 2019, 11:39:45 am
content: Quote from: Mr Nutts on May 14, 2019, 02:56:39 amYes the Teks normally default to slow update rates as usual but the Tek has Fast Acquisition mode or DPO mode as well as a Fast Frame capture mode using segmented memory. Don't think the Lecroys have ever offered fast acquisition rates. The Intensity graded display of the Tek is useful to display AM waveforms etc or anything that you would use a normal CRO to display.I believe the spectrum analyzer on the MDO is more like a normal spectrum analyzer rather than FFT so there are some benefits of doing this in hardware.cheers

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 14, 2019, 06:14:28 pm
content: Quote from: snoopy on May 14, 2019, 11:39:45 amBecause Tek's architecture is slow as hellQuoteNo?And as far as I know this intensity mode works with the full sample rate and all scope functions are still available when it's enabled - unlike Tek fastaqQuoteYou say that as if intensity graded display was something special - it isn't. Even my old Lecroy LTs have it, in monochrome (analog scope style) and color, and even as a waterfall display And these scopes are over 16 years oldQuoteYou may believe this (probably because of Tek marketing BS) but the reality is the "spectrum analyzer" of the MDO3000 and MDO4000 is just FFT, not a real swept spectrum analyzer. And it suffers from the same limitations re. span vs RBW as the scope FFT due to the limited FFT sizeAnd like the scope FFT, the SA is painfully slow unless you select a very short span with a large RBWA cheap Siglent or Rigol spectrum analyzer is a much better investment if you work with RF than using the MDO3000's built-in "spectrum analyzer" POS

author: 2N3055
author_rank: Super Contributor
timestamp: May 14, 2019, 06:39:48 pm
content: Quote from: snoopy on May 14, 2019, 11:39:45 amMDO3000 and MDO4000 doesn't have FastFrame or any type of segmented memory...It's spectrum analyser is direct sampling type using Z-chirp transform.It is exactly similar to FFT based solution, but it has user interface that is SA like and it is optimized for best performance possible with built in A/D. It's performance is a bit better that usual FFT on a scope but is significantly worse that real SA.Fast Acq mode has nice waveform rate, but display has sampling artefacts (it looks like it's rendered from short horizontal lines not dots) and it's biggest problem is that when you use it ALL measurements are disabled.Except 1 GHz, there is nothing going for Tek MDO3000 series. LeCroys are superior in every way, Keysight 3000T too, R&S 3000 series also, if money is tight new Siglent 5000X series is orders of magnitude better ..

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: May 14, 2019, 06:47:22 pm
content: Some (?) LeCroy had/have a special mode called "WaveStream" which is meant to simulate an analog scope (like "digital phophor" etc.).Actually an older/lesser XP based Wavesurfer 64xs (or so, can't recall the exact model number) has this feature, while a more modern and higher end Win7 based Waverunner 6zi doesn't.I somewhat assume that for the lesser scopes it was some kind of FPGA feature while for the higher end scopes they rely on the CPU power to do intensity grading in SW.For sure though the intensity grading is much less pronounced on a LeCroy than on any Agilent/Keysight.To be honest, I'm not a big fan of this anyway. While it's true that you might spot glitches because of fast update rate, a glitch is always very dark due to the intensity grading logic. On a LeCroy, you would rather use advanced measurement/analysis/trigger features to spot issues than to stare at the screen.

author: 2N3055
author_rank: Super Contributor
timestamp: May 14, 2019, 07:10:24 pm
content: One thing that is good with fast retrigger is that when you are measuring a parameter and gathering statistics is that with fast rettriger you gather data faster.It all depends what you do. For interactive work Keysight concept is king. If you tend to grab data and massage it, LeCroy concept is better.Also, problem with LeCroy is that cheaper scopes don't have many advanced analysis options that you would use it to make up for lack of speed.There is no such thing as perfect scope. For instance, little Rigol DS1000Z has some triggers Keysight 3000T doesn't have. But, combined with Zone Trigger, I yet have to find something I can't trigger on..Best advice is what Nctnico said: get few candidates on a loan and try doing your job.. Showstoppers will reveal themselves.

author: nctnico
author_rank: Super Contributor
timestamp: May 14, 2019, 07:58:52 pm
content: Quote from: 0xdeadbeef on May 14, 2019, 06:47:22 pmI agree that triggering is the best option to capture unexpected events. Staring at a screen is not a good use of time. BTW the R&S RTM3000 has an inverse intensity grading mode. The rare signals stick out like a sore thumb. IMHO having many levels of intensity grading is nice eye candy but there is very little practical value. 16 levels starting at 50% brightness is more than enough. There is only so much visual information you can process.

author: Someone
author_rank: Super Contributor
timestamp: May 15, 2019, 12:30:42 am
content: Quote from: Mr Nutts on May 14, 2019, 06:14:28 pmThat shows the trigger rate, which can be unrelated to what data is actually arriving at the screen. There are many brands of scope which can be put into configurations where the trigger output shows impressive rates, but the data isn't arriving on the screen. There isn't a simple way to test the waveform update rate in those cases.The value of those different modes and waveform update rate are entirely down to the user and their applications.

author: Someone
author_rank: Super Contributor
timestamp: May 15, 2019, 12:37:09 am
content: Quote from: snoopy on May 14, 2019, 11:39:45 amYou have come to the same juncture as many before you, the division between scopes with an emphasis on realtime display, and those with an emphasis on deep memory and analysis of that offline.Lecroy WaveJet is one of their few realtime designs, and has a really good graded display that works simultaneously with segmented memory so you can also step through the individual waveforms when stopped. A great basic scope but its quite an old platform so may not be as competitive as other options.

author: snoopy
author_rank: Frequent Contributor
timestamp: May 15, 2019, 02:09:28 am
content: Quote from: Mr Nutts on May 14, 2019, 06:14:28 pmProper intensity grading ? lets see what it looks like on an AM waveformbtw I have an old Tek TDS784A from the 90's that can capture waveforms at a rate of 390,000 wfs and display rare events. Donlt think any of the competitors had that at the timeAnd a TDS7054 does proper intensity grading with up to 200 K wfs with all measurement ability available. Both scopes have equivalent time sampling of up to 250 Gs/s. Unfortunately they dropped this in the later scopes.cheers

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 15, 2019, 03:35:41 am
content: Quote from: snoopy on May 15, 2019, 02:09:28 amIf you want me to post a screenshot of an AM modulated waveform then you'll have to wait until next week when my lab redecoration is finishedQuoteI'm no expert (and I think waveform rates are way overvalued) but wasn't there the HP 54600 series with MegaZoom that was even faster and didn't even need a special mode to reach high waveform rates?But that doesn't matter because no matter how fast your scope is you still never know if there's that very rare anomaly because it most of the time it's still completely blindMy old LT will capture rare anomalies every time because of its sophisticated set of triggersTDS7000 are ancient, and as far as I know they run the code of early TDS scopes on a separate computer inside the scope and wrapped a Windows GUI around it which is why all these scopes are so horribly slow. My college had Tek DPO3000 and MDO3000 (which were the standard scopes), a few MDO4000, I think two TDS6000 and a DPO7000 (and maybe others I can't remember), and all of them were slow as wading through molassesAnd ETS at 250GSps, who cares? It's not giving you any advantage over the 200 GSps in ETS as on the Waveruner xi, or even the 20GSps I could get from my LT. And who cares about ETS anyways?I'd rather use an Agilent Infinum or Lecroy X-Stream scope over any Tek scope - no matter if TDS, DPO or MDO. Less frustrating and better performance

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 15, 2019, 03:37:18 am
content: Quote from: Someone on May 15, 2019, 12:37:09 amLecroy Wavejet is not Lecroy design. It's a rebadged Iwatsu scope (was mentioned often enough in this forum)

author: Someone
author_rank: Super Contributor
timestamp: May 15, 2019, 04:30:54 am
content: Quote from: Mr Nutts on May 15, 2019, 03:37:18 amDidn't say it was, Lecroy offer and still sell a scope of the realtime design even if it is rebadged or co-designed.

author: JPortici
author_rank: Super Contributor
timestamp: May 15, 2019, 06:14:36 am
content: Quote from: snoopy on May 15, 2019, 02:09:28 amwho cares? unless all you need to do is look at AM sine wavesColor temperature intensity grading is much more useful IMHO. I may be wrong but in the lecroy WS3K i could also decide the colours for hot/cold so i could also achieve the inverted colour grade. For my experience i have to agree with nico, 16 levels have been plenty in the real world for me.Even better, launching an histogram of that area shows me much more than what intensity grading tells me.

author: snoopy
author_rank: Frequent Contributor
timestamp: May 15, 2019, 12:57:38 pm
content: Quote from: Mr Nutts on May 15, 2019, 03:35:41 amBy all means show us then ! And that HP scope scope you quoted is a sub-sampling scope with a 20 msps max sampling rate for a quoted bandwidth of 100MHz. I very much doubt that claim you made about it because I used one of these scopes once and its single shot performance was terrible showing a sparse collection of dots or jagged lines on the screen which made it pretty much useless for single events !And there is no point in trying to capture an anomaly using triggering if you don't know what kind of anomaly it is ! Once you characterize the anomaly then you can setup your trigger to capture itThat's why Tek brought out Instavu on some of its early scopes, one of which I have. And it does capture rare anomalies that other scopes completely miss.Also ETS scopes display information much more accurately approaching the nyquist frequency compared to scopes that use interpolationAnd your description of the TDS7000 scopes is way off too. You can sse in this video differences in performances of scopes with different WUR !https://youtu.be/2465uN-qpIY?t=1316