Nice, older DSO advice - Page 1
Forum section: electronics / testgear

author: 0culus
author_rank: Super Contributor
timestamp: May 25, 2019, 11:14:43 pm
content: I'm just going to try to distill down some of my scattered thoughts here. TL;DR I want to get a nice DSO for my personal lab, this year, to provide capability that my collection of CROs don't provide. Use case for the DSO will primarily be working with reasonably high speed (say ~100 MHz) digital logic and FPGA projects. I already have a benchtop logic analyzer, so I don't really need mixed signal.Budget-wise, short of winning a contest, a brand new high end DSO is pretty much right out. Way too expensive. So the next best thing is to do what I normally do and find something that's a bit older. I believe in purchasing the best tools that you can afford, thus I am looking for professional quality older used stuff from top brands. Sorry,tautech.Let's say that my budget for the purposes of discussion is $5000.Keysight and Tek are standard brands one thinks of, but honestly I'm very interested in looking at LeCroy and R&S as well. I found this, for instance:eBay auction: #232562487402Thoughts and advice are all appreciated. Again, not making this purchase soon but trying to learn as much as possible before I do so I'm ready.

author: Kosmic
author_rank: Super Contributor
timestamp: May 26, 2019, 01:56:13 am
content: Pssstt you can "unlock" all software features with most of the older Lecroy models. If someone is asking I didn't told youhttps://www.eevblog.com/forum/testgear/lecroy-options-recovery/And the software package on Lecroy oscilloscope is normally really interesting. Even the older one.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 26, 2019, 02:02:24 am
content: Quote from: 0culus on May 25, 2019, 11:14:43 pmIgnore Tek, they had great analog scopes but the DSOs were very poorIf you want to learn about Lecroy then there are lots of very good posts by former (now banned) member "Wuerstchenhund" (hope I spellt that right) who knows more about scopes than anyone else I have metI have a Lecroy LT574 which is the previous model from the one in your ebay link. With options unlocked it can do so much that I often still find something newAgilent/Keysight scopes are very nice, and there are some inexpensive options like the 54622A

author: DaJMasta
author_rank: Super Contributor
timestamp: May 26, 2019, 02:49:52 am
content: $5000 buys a lot of scope, you could probably manage a few hundred MHz bandwidth no problem on an R&S scope which is pretty high end for update rate and feature polish. That budget would also get you a fair bit of lower bandwidth (350MHz or lower) scope of the current generation, Don't know if Tek/Keysight/LeCroy have great options at the pricepoint, but Rigol and Siglent have modern strong contenders and R&S's lower end scope line would fit in that price bracket with some premium fit and finish.If you're looking for really high bandwidth, then older is the older way to go, and LeCroy probably has the highest value options for those 1GHz+ scopes. If you don't care about bandwidth... well there are a lot of options of various levels of performance.... $5000 for a used scope with no bandwidth requirement is a really big area to draw from if you don't have specific requirements.Maybe take a look at some of the bigger stores to see if they have something of interest? Keysight's got an ebay store and a non-keysight brand store, I think Tek and LeCroy have some sort of official thing too, then some of the bigger test equipment dealers have a good stock to see what's available and what you may be interested in. Maybe smaller form factor instead of boat anchor? Maybe 10+ bits (would have to be newer, there)? Maybe specifically a windows based (or not windows based) scope, or with some connectivity or specific option package?

author: 0culus
author_rank: Super Contributor
timestamp: May 26, 2019, 03:23:46 am
content: I'm thinking 1 GHz might be a good move, as I'd like to be able to see my digital signals with good integrity (i.e. be able to display all the harmonics). I'm liking the sound of being able to fully unlock a LeCroy.

author: tautech
author_rank: Super Contributor
timestamp: May 26, 2019, 03:36:53 am
content: Quote from: 0culus on May 26, 2019, 03:23:46 amYeah well with a $5k budget you're at the level were a decentandnew DSO is within reach like the SDS5054X that BTW also has a purchasable 1 GHz BW upgrade......and you say you wouldn't mind unlocking options.Info that has come to light has BW options hidden in the OS for all 5kX models from 350M -1G however no one has investigated taking the 350 all the way to 1 G AFAIK.Wanna be first ?

author: 0culus
author_rank: Super Contributor
timestamp: May 26, 2019, 03:45:02 am
content: I don't know. Convince me that the engineering in that scope is on the level of LeCroy, R&S, or Keysight. Personally, I prefer to spend my money on the best quality stuff I can.

author: DaJMasta
author_rank: Super Contributor
timestamp: May 26, 2019, 03:45:23 am
content: I don't know really how easy it is, I know there were reports of screwing things up and needing backups before but perhaps those issues have been sorted. Something like the 900 series (950 or 960) is quite affordable and uses the older dedicated interface, as is the DDA-125 (I think the 120 and lower have CRTs) - a bit obtuse in terms of layout for my tastes, but powerful and responsive. Newer scopes of theirs, the WavePro 7000/8000 series and DDA/SDA/WaveMaster equivalents are pretty powerful Windows 2000/XP based scopes that have had a fair bit of hacking and analysis done on the forum. Beyond that, and likely still in your budget, are the more modern smaller form factor scopes. You'll pay a fair bit more for the small form factor and newer model, but the base scope interface will be basically the same (X-Stream software on all their windows based scopes and some more modern non-windows ones), and you can still get a good amount of bandwidth for your buck.At least for the older, larger form factor scopes, they can be a bit noisy for fans, but it's not awful and can be improved with high flow replacements. Since they're basically just a microATX PC in a scope chassis on the windows models, it's pretty easy to upgrade to the max of the board for a bit better responsiveness/load times, and some upgrades of the mainboard to a whole new chipset (or to windows 7) have been documented in some threads around. I've worked with a DDA-125, WavePro 960, WavePro 7200, and WavePro 7300A and have found them all to be pretty nice scopes, the first two with the older display format and OS, the remaining two with windows and X-Stream, and the only real quirk of an issue is that on the 7300A, I get a relay click and recalibration (temperature compensation, presumably) on every new acquisition not in roll mode, which is really obtuse. In another thread it was mentioned that this was common and expected by some users, but my WP7200 never did that - just the occasional temperature compensation every few minutes like a SA alignment or similar, so I expect it can probably be figured out, I just haven't mucked around in the calibration menu to try and fix it myself, yet.In the case of any of those, there are a good number of units for sale with software options unlocked, but hacking if effective would take care of that, though the acquisition memory options are hardware based and are not software unlockable (it seems that very large memory options may even use different ADC boards that are larger for the extra memory chips).In any case, I'm sure there are some complaints with them, but for high bandwidth 8 bit scopes that offer a lot of bang for your buck, these used LeCroys have seemed like the best value proposition for a while now. I'd expect a WP950 to start a bit more than $1000US, with WP7200s closer to $2000, but there are sometimes deals floating around especially if you don't mind risking buying an untested unit.

author: 0culus
author_rank: Super Contributor
timestamp: May 26, 2019, 04:06:41 am
content: Is there a breakdown chart anywhere of the various LeCroy models?

author: pigrew
author_rank: Frequent Contributor
timestamp: May 26, 2019, 04:31:03 am
content: Although you specifically asked for scopes, it sounds like you need to also budget for a set of active probes, assuming a need to probe anything more than 150MHz. Active probes are mostly manufacturer-specific (though adapters do exist), and will easily eat up $US500 or more for a set.Myself, I've been using the Tek P6243 and P6205 (attached to a Tek TDS784D which has a very antiquated interface but works decently apart from few internal analysis modes).If working with LVDS or USB, you may also need a differential probe like P6247 (even more money). I'm sure LeCroy and Agilent sold good active probes, but I don't know their model numbers off the top of my head.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 26, 2019, 08:59:46 am
content: Quote from: 0culus on May 25, 2019, 11:14:43 pmfor my eye?... not good enough... try below... but ymmv in case if you have other preferences to 500MHz DSO instead of cheaper GHz DSO of the same age...$2K - 5GHz similar AFE as 6GHz version (SDA6000, i believe its upgradable) if you dont mind the BMA input (there's convertor to BNC and i'm developing myself)DDA5005A-XXLif somehow you hate the guy, there's another US seller @ $2.5KDDA5005A-XL$4K - if you insist on BNC input, then... 3GHz DSO... currently decent looking cheapest from Singapore, if you dont mind missing front frame, there's one $2K+ from Thailand...DDA3000-XXLthe sweet 6GHz SDA6000 (before a big jump in BW and price to SDA13000 and SDA18000), currently cheapest around $4K, maybe you can offer and lucky if seller accept at half the price (like i did)https://www.ebay.com/sch/i.html?_nkw=lecroy+6000i'm cursed

author: nctnico
author_rank: Super Contributor
timestamp: May 26, 2019, 10:36:24 am
content: Quote from: 0culus on May 26, 2019, 03:45:02 amThe hardware usually isn't the problem with scopes from China. The firmware OTOH can take long to fix. However if you have $5k to spend and 500MHz is enough I'd keep an eye on the Siglent SDS5000 series to see where the firmware development is going.If you need 1GHz or more then the older DSOs from Agilent and Lecroy are a good option but these won't be very useful as a general purpose oscilloscope due to (generally) no peak detect mode, big size and noise.Another option is to check for refurbished oscilloscopes. With a budget of $5k you get into a grey area where getting an old & loud boatanchor may not be the best option. Good deals can be found in Keysight's Ebay store and I'm sure other manufacturers have similar outlets. It does take some patience to wait for a good deal to appear.

author: Kosmic
author_rank: Super Contributor
timestamp: May 26, 2019, 04:17:19 pm
content: Quote from: nctnico on May 26, 2019, 10:36:24 amBig and noisy, yes. But, is the lack of peak detect really a problem ? My understanding was that, in peak detect mode, the oscilloscope was running as fast as possible sorting and keeping only the Min/Max samples. You can probably do something similar running at max speed and activating persistance.To detect glitchs another option is to exploit the triggering system. Interesting post on the subject from Wuerstchenhund:https://forum.allaboutcircuits.com/blog/the-truth-about-oscilloscope-waveform-update-rates-and-why-not-to-fall-for-it.1514/

author: 0culus
author_rank: Super Contributor
timestamp: May 26, 2019, 05:33:32 pm
content: Quote from: nctnico on May 26, 2019, 10:36:24 amEmphasis mine. I have a Tek 7904A, so pretty much anything in the DSO realm that's new enough to not have a crt is going to be smaller I'd think. Not a huge worry for me.

author: nctnico
author_rank: Super Contributor
timestamp: May 26, 2019, 08:41:30 pm
content: Quote from: Kosmic on May 26, 2019, 04:17:19 pmFor general purpose use you are often looking at signals which are way below the maximum frequency and need a lower than maximum samplerate. This means that a signal will get undersampled resulting in all kinds of signals on screen which have no relation to reality. Peak-detect is very useful to see at least the (vertical) extend of the signal and give the user a hint the signal of the DUT has higher frequencies.Edit: BTW a quiet lab is very easy to get used.

author: Kosmic
author_rank: Super Contributor
timestamp: May 27, 2019, 01:33:33 am
content: Quote from: nctnico on May 26, 2019, 08:41:30 pmBut then, you are limited by the memory available to your scope. With unlimited memory you could run at max speed at any time/div. So the requirement should be an healthy amount of memory or peek-detect.For example, with my Lecroy I can sample at 4GS/s for 4ms (0.5ms/div). This is one channel and it maxout the 16Mbytes of memory available. For my usage it is definitely acceptable and I don't really need peak-detect.

author: 0culus
author_rank: Super Contributor
timestamp: May 27, 2019, 05:45:29 am
content: So here's one thing I'm not clear on. For 'scopes that are really PCs with expensive peripherals, is the memory available for capturing waveform data shared with the system RAM or do some 'scopes have dedicated capture memory that's only used for waveform data?

author: DaJMasta
author_rank: Super Contributor
timestamp: May 27, 2019, 06:06:47 am
content: Acquisition memory of even moderate scope frontends outpaces the speed/latency requirements for conventional PC memory, especially when shared with other devices. Generally, acquisition memory is its own devices controlled directly by dedicated memory controllers connected to the ADCs and trigger system. It's this case in every one of the scopes mentioned so far, in the specific case of the windows based machines, depending on the architecture they usually connect through PCI, PCIe, or other high bandwidth interfaces (sometimes SATA), so the mainboard performs the acquisition and any hardware analysis/decoding/etc, sends that data to the PC portion, and the PC portion processes it further as needed and updates the display with it.It's effectively the same in a scope that doesn't have a separate PC - the ADC connects to a memory controller and acquisition memory, and that system interfaces with the application processor that drives the display and handles all the screen, control input, and analysis related functions.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 27, 2019, 11:15:32 am
content: Quote from: nctnico on May 26, 2019, 08:41:30 pmwhat can we ask more from 20GSps scope? (price $2-4K available used) to see glitches of more than 10GHz frequency content? any modern DSO say at 4GSps with peak detect feature can detect that kind of glitches? (priced way more than $4K new) but you have some point, high BW GHz DSO are specialized tool, we just want to get cheap here.

author: nctnico
author_rank: Super Contributor
timestamp: May 27, 2019, 01:19:09 pm
content: Indeed. My point is that the older scopes with high samplerates are less suitable as general purpose oscilloscopes.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 27, 2019, 01:51:12 pm
content: Quote from: Mechatrommer on May 27, 2019, 11:15:32 amjust to add more to avoid misconception.... are specialized tool... that the lower BW DSOs are not capable of and certainly have no way of workaround at all. ymmv.

author: David Hess
author_rank: Super Contributor
timestamp: May 27, 2019, 06:36:29 pm
content: Quote from: Kosmic on May 26, 2019, 04:17:19 pmPeak detection works on single shot acquisitions.Peak detection done using persistence is envelope detection across multiple acquisitions (1) or DPO (digital phosphor oscilloscope) type operation on one or more acquisitions which would be my personal preference. Peak detection might be considered a very limited DPO mode of operation that uses the shallowest histogram possible.This brings up a question about the right kind of DSO to suggest. Maybe you want a DPO type of DSO which is good at finding glitches?(1) DSOs which support peak detection combine it with envelope detection mode to make envelope detection more effective. But despite what Rigol says, they are distinct things.

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 27, 2019, 06:50:22 pm
content: If you're interested in an older LeCroy, it won't kill you to look at my signature (follow the eBay link).Currently there's a 9354 500MHz and a DDA-120 there (almost identical to the LC585 4Ch 1GHz Scope). There's actually also a WP950 that I'm currently repairing a display issue on (also 1G) but unfortunately that one doesn't have a bezel anymore

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 28, 2019, 08:23:47 am
content: Quote from: nctnico on May 26, 2019, 10:36:24 amHPeak detect? LOL!Peak detect was useful on the TDS3000 I once had to use because its memory was so small that it quickly ran out of steam (i.e. sample rate)Outside of underpowered Tek scopes I never touched it againMy Agilent Infinum 8064 has peak detect but with 128M of memory why would I use this crutch when even at very long timebases the sample rate remains high enough?I just got a Wavepro 960 which is a 2 GHz scope, and it comes with 64M memory. No peak detect but 64M memory which is enough to sustain a sufficient real-time sample rate at very long timebasesIt’s big but not very noisyAnd the size comes with a large displayMy Waveruner LT is very compact and not loud eitherQuote from: nctnico on May 27, 2019, 01:19:09 pmAll of the scopes I mentioned are way better general purpose scopes than the TDS3000 has ever beenI wonder what you are doing to require peak detect on a modern scope with sufficient memory and which can’t be done with real-time sampling and triggers if required? Or maybe you just use it because it’s what you are accustomed to?And I don’t think 1 GHz is still considered “high bandwidth” when scopes now go to 110 GHz

author: EEVblog
author_rank: Unknown
timestamp: May 28, 2019, 09:53:16 am
content: Quote from: DaJMasta on May 26, 2019, 02:49:52 amIt does indeed.I'd be looking outside of ebay at one of the auctions like Equipnet who advertise on the main site.If patient you should be able to get a really high end scope, as $5k is outside the budget of the hobbyists looking for a bargain.

author: EEVblog
author_rank: Unknown
timestamp: May 28, 2019, 09:55:40 am
content: Also, certified used Keysights on ebay, see the ad on the forum just above!They take offers and have guaranteed refurbished scopes. They will often through in options too.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 28, 2019, 10:52:20 am
content: any double digit and more GHz only she the royal majesty can afford them. used SDA 13GHz and 18GHz are still $9K+ way more than most of us can afford, let alone the matching probes. so they are not high bandwidth but high majesty.

author: nctnico
author_rank: Super Contributor
timestamp: May 28, 2019, 11:36:14 am
content: Quote from: Mr Nutts on May 28, 2019, 08:23:47 amIt is just ease of use. Switch to roll-mode and try to see if there are narrow pulses. Sure you can use triggers to hunt for narrow pulses but using peak-detect is just quicker because you can see everything in one measurement. Time = money. And in some cases pulses are so narrow versus their duty cycle that you can't see them without peak detect if you want to have the time in between them on screen as well. Think about a vsync pulse for a display interface. All in all I won't buy an oscilloscope for general purpose use if it doesn't have peak-detect.

author: 2N3055
author_rank: Super Contributor
timestamp: May 28, 2019, 12:30:16 pm
content: Quote from: nctnico on May 28, 2019, 11:36:14 amI also do this and agree with Nctnico on this. I have some products that have outputs that are changing quite slow, have PWM on them and it is nice to look at general timing while still able to spot glitches, overshoots and such.Peak detect mode will show you something is there, and then I drill down to that detail. Also, if you have PWM signal that controls the lamp for instance, and you are looking at lamp blinking pattern, with short memory you will soon undersample so much that you will not see proper P-P amplitude. Same with NFC and RFID.. They are generally changing very slowly (modulation and timing between packets) but need at least 50 Ms/sec to still see carrier without undersampling. With peak detect you will see modulation envelope without problem.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 28, 2019, 12:57:12 pm
content: Quote from: nctnico on May 28, 2019, 11:36:14 amI understand but all peak detect tells you is that there is something, the pulse will not resemble the true signal so if you want to do something with it then you need to re-acquire anywaysOn my Agilent Infinum 8064 I could extend the timebase to 6.4ms/div before the sample rate would start dropping enough to affect its analog BW. On my Wavepro I can still go down to 400us/div before the sample rate would drop enough to affect its usable BWJust for the sake of it let’s assume a signal that has pulses with 1.6ns rise/fall time (i.e. at 600MHz BW, so. right on the upper analog limit of my Infinum) every 100ms. At 20ms/div the sample rate would drop to 1GHz which leaves me with 300MHz usable BW and a lot of aliasing but I would still see two pulses, spaced exactly at 100msAnd this is probably an extreme example as the BW for the pulse itself is right at the scope’s analog BW. If the pulse flanks are slower (i.e. 5ns) then the analog BW drops and I could extend my timebase even furtherAs to faster, to get the above working all I need to do is press auto-set and then select the long time base. Going into the acquisition setup then selecting peak detect is in no way quickerAnd while I’d get aliasing the timing information would still be right, but that wouldn’t be the case with peak detectSo why do I need peak detect again?Quote from: 2N3055 link=topic=189150.msg2443050#msg2443050Emphasis mineMaybe the problem is that your scope lacks memoryFor example, with my Agilent at 50Msps I could capture 2.56 secondsAlso, what is the question you want to answer?Is it if the spacing between lamp on and off is right then peak detect won’t show you thatIf the question is if the PWM signal is within spec then peak detect won’t help you here eitherIf the question is if there are some pwm signals spaced at some distance then peak detect shows you that but so does your scope’s trigger indicatorSo what am I missing?

author: techman-001
author_rank: Frequent Contributor
timestamp: May 28, 2019, 01:35:12 pm
content: Quote from: Mechatrommer on May 28, 2019, 10:52:20 amMy 2Cents ...Yet we spend $9k + on a car or motorbike, things which only co$t us money, get banged up, rust and need endless maintenance.I think $9k+ for any double digit and more GHz DSO is a utter BARGAIN!In 1994 I paid $4600 for a demo model HP 54601A 100MHz DSO, with RS232 control module and the "9volt battery powered 'DSO waveform signal board" which is a 6"x6" pcb that outputs a number of real waveforms that analog scopes find hard to see.That scope is now 25 years old, (a quarter of a century) and works perfectly, it's my 'daily driver' and I still love using it because it operates just like a 'real scope'. As a old timer I just never liked my 300MHz Rigol menu system much, and was never comfortable with it, tho the screen picture was awesome and clear.The attached picture is one recreated from scope data and sent via serial port to my FreeBSD pc and recreated. When comparing it to the Rigol picture, remember this scope is 25 years old! Also note that although the Rigol pic is far prettier, how does the on screen information usefulness compare to my old HP?A few areas the HP is better than the Rigol 2072a I used to own, 1) the HP fan is a *lot* quieter, 2) The HP boots up almost instantly to working display, the Rigol was painfully slow going thru stages and beeping at each one.My advice is if you're planning to spend your life in electronics doing design, buy the MOST EXPENSIVE scope from a American manufacturer reputed for high quality scopes, and avoid cheap junk from China. Eliminate the word "bargain" from your buying mentality. You'll also get a DSO that's a pleasure to use where the scope controls and menu's have been designed by Interface Engineers with decades of high end experience, and you can believe the specs with confidence. If they say 2GS/s you can believe it!Do you really think that Rigol LCD will still be working properly in 25 years ?Plus once you have the unit, you'll have something that's the best of the current tech and in 25 years will probably still be very useful. Mine still is.Will you still have that $9k+ car in 25 years ?Finally a $10k DSO amortized over 25 years costs only $400 per year and is one of the most useful and precious instruments you will EVER own.

author: nctnico
author_rank: Super Contributor
timestamp: May 28, 2019, 01:38:44 pm
content: Quote from: Mr Nutts on May 28, 2019, 12:57:12 pmThe shape of a pulse often isn't very interesting. Just that it is there (or not). Ofcourse you can throw more memory at the problem but remember that having too much memory generally makes an oscilloscope slower to operate. Peak detect is very handy to have a responsive instrument as well. There is a good reason every oscilloscope manufacturer except Lecroy has peak-detect on their oscilloscopes.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 28, 2019, 02:28:30 pm
content: Quote from: techman-001 on May 28, 2019, 01:35:12 pm100% agreed with you IF this is your main profession to get money from, just get the best tool however pricey they are. we buy house, clothes and car so we can live comfortably and work everyday to get money every month. this is justifiable investment the money we can get back in few years to come.but here we are talking used equipments to cramp as much BW/features into our hobby bench from the small money allocated from our main job/income.1) the 9K figure is for used DSO that already spent its life 16 - 20 years somewhere else. how much life left is anyone guesses. only luck.2) the new double digit GHz DSO is 6 figures tag, we can choose a house (and a wife) or the high majesty DSO alone, not even a dangling probe. not many can afford both.3) cheap junk china/Rigol is not even in the picture, they not even exist in high end range used nor new.btw the thing that cursed me i think was the hobby grade 5.8GHz wireless video/antenna that i bought for drone/rc airplane stuffs few years ago and then got its amplifier chip toasted for unknown reason until i acquired (due to the 6GHz curse) some tools to diagnose. so a person who can get 6 figures stuffs for this kind of purpose is imho a very wealthy person. my 2cnts.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 28, 2019, 02:39:16 pm
content: Quote from: nctnico on May 28, 2019, 01:38:44 pmBut as shown I can do that just as fine without peak detectQuoteAt a given sample rate it takes longer to fill a larger memory than a small one, that is a givenBut other than that there is no scope with “too much memory”There might be cases of “user uses way more memory than necessary” but this is a different problemAnd my Agilent Infinum can manage the memory automatically, i.e. it only uses as much memory as necessary. There’s nothing slow about itI fully understand that peak detect can be useful on a scope with small memory (as I found out myself with that TDS3000) but my argument is that on a scope with large memory, (i.e. say anything with 16M and more) peak detect is no longer needed because you can get similar results with normal acquisition. And so far I haven’t seen a case which would convince me otherwise.QuoteNot more so than in normal acquisition. Remember we’re talking about the case of short pulses with very long pause between them, which requires a very long time base. And a displayed timebase of 200ms takes 200ms to acquire, no matter if in real-time or peak detectQuoteI’m sure the only reason it’s still there is that its simple to implement and its presence satisfies the expectations of users coming from a TekI’m sorry but I still can’t see why peak detect is supposed to be such an important feature in a modern scope with enough memory. Not even when talking about very narrow pulses with excessively large pause between them, a case that by itself is probably already a corner caseArguments like “it’s easier” are subjective (I don’t think using peak detect is any easier than just using real-time acquisition, not even on my Lecroy LT with manual memory management)So as shown on a large memory scope like my old Agilent Infinum I don’t even need peak detect to look at your corner case signals, and even less so for other signals that are a lot further away from such extremesSo it looks your afinity for peak detect is merely down to your personal preference, i.e. that’s the way you knowWhich is fine of course but I wouldn’t tell everyone that peak detect is such a crucial feature when it isn’t

author: rsjsouza
author_rank: Super Contributor
timestamp: May 28, 2019, 02:59:40 pm
content: 0culus, good suggestions all around. For quite some time I had my eyes on the Wavesurfer 24/44/64 series from LeCroy, which seems to be quite interesting when purchased used but still a bit steep. I also looked at the much more reasonably priced Waverunner 6000 series (6030, 6050) but they are CRT and not LCD TFT (my bench space is limited).One detail that I haven't seen it here is probes: if you are interested in high bandwidth and do not yet have the active probes, perhaps put that into the overall budget of your new oscilloscope.

author: techman-001
author_rank: Frequent Contributor
timestamp: May 28, 2019, 03:03:58 pm
content: Quote from: Mechatrommer on May 28, 2019, 02:28:30 pmUnbelievable !!! I mean really, where can you get a house AND$Wife for only 6 figures?

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 28, 2019, 03:29:18 pm
content: Quote from: rsjsouza on May 28, 2019, 02:59:40 pmThere are no Waverunners with CRTThey all have TFT displaysBut Waverunner 6000 has limited triggers (i.e. no runt trigger)The older Waverunner2 LT on the ither side has a great trigger suite

author: Kosmic
author_rank: Super Contributor
timestamp: May 28, 2019, 04:11:09 pm
content: Quote from: Mr Nutts on May 28, 2019, 02:39:16 pmTotally agree with you here. Personally, I think the amount of memory is far more important than having the peak-detect feature. However, in the end I guess it's a question of preference and how you want to use your scope.I think the rule of thumb is: Try to buy a scope with a lot of acquisition memory. If you don't, make sure it has peak-detect.

author: rsjsouza
author_rank: Super Contributor
timestamp: May 28, 2019, 04:16:21 pm
content: Quote from: Mr Nutts on May 28, 2019, 03:29:18 pmI stand corrected then. The depth of the scopes gave me the impression they were CRT.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 28, 2019, 04:55:44 pm
content: i figured peak detect is still usefull on my rigol DS1054Z i will always turn that ON unless i want to see cleaner triggered signal. high BW scope is an addition, not a replacement to a cheaper general purpose scope.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 28, 2019, 08:45:44 pm
content: Quote from: Mechatrommer on May 28, 2019, 04:55:44 pmAlways? But why?Peak detect may or may not have some use on very long time bases but on shorter timebases it makes no sense whatsoeverBesides, doesn't the DS1054z have 24M of memory? Even when hacked to 100 MHz the timebase would still have to be very long for the sample rate to drop below what's necessary to sustain the analog bandwidthSo why would you even keep it enabled?QuoteIf high bandwidth means a real high bandwidth scope (i.e. 8GHz or more) then I guess it depends, but definitely not for the scopes to 3GHz as discussed in this threadAside from the higher bandwidth, there's nothing which makes my 2GHz Wavepro 960 any less suitable for every-day tasks than any of my other scopes

author: David Hess
author_rank: Super Contributor
timestamp: May 28, 2019, 09:05:16 pm
content: Quote from: Mr Nutts on May 28, 2019, 08:23:47 amDSOs with memory of sufficient size? I don't think they exist.Peak detection or even better, DPO operation, is useful to find the glitch before I know what to trigger on. If I knew what to trigger on, I would have already fixed the problem.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 28, 2019, 09:11:40 pm
content: Quote from: Mr Nutts on May 28, 2019, 08:45:44 pmyou need to see the difference (between peak detect ON and OFF) when looking at glitchy signal in long timebase (sample rate tremendously reduced from 1GSps) to understand. its not about memory length, its about sample rate. at maximum sampling rate (short timebase) yes it will make no difference. i'm not sure how it works but i guess it explained by Kosmic in reply #12...Quote from: Kosmic on May 26, 2019, 04:17:19 pmthe workaround of cranking timebase to shorter or smaller value until maximum sampling rate is achieved sometime is less than ideal, esp on slow signal/communication rate, thats why i think high BW scope with no peak detect is not particularly good at this, doable but.. glitches may show up in say eye pattern during signal integrity test, but if we want to see where the glitches happening in the long timescale (slow bitrate signal), the no peak detect scope maybe short at this. that why i said high BW scope is an addition. each one with suitable purpose. for glitchy 1Kbps signal, there is no need for high BW dso (the no peak detect = old = cheap dso). ymmv.

author: nctnico
author_rank: Super Contributor
timestamp: May 28, 2019, 09:31:12 pm
content: Quote from: Mr Nutts on May 28, 2019, 08:45:44 pmGather some more experience on doing measurements and you'll see why peak-detect is a must-have feature (and why most manufacturers include it in their oscilloscopes). Memory runs out at some point but narrow pulses don't.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 29, 2019, 07:53:14 am
content: Quote from: David Hess on May 28, 2019, 09:05:16 pmI would say the 128M on my Agilent Infinum 600MHz scope is sufficientI would also say the 64M in my Wavepro is sufficientAnd many new scopes come with even more memory, i.e. this new Siglent SDS5000X (250M) or the Rigol DS5000 (500M)QuoteYou mean to find out if there's a glitch?But that method is unreliable as just because your scope doesn't show a glitch doesn't mean there is none, simply because your scope is still blind most of the time (approx 9x as likely to miss it than to find it)With triggers I find the glitch at the first occurrence, every timeQuoteI can set the trigger to show me anything that is outside my signal's specs, no problemAnd no matter how rare it is my scope will show meQuote from: Mechatromer on May 28, 2019, 09:11:40 pmBut peak detect will not show you the true signal form anyways because it's timing will be totally off due to the way it worksA hacked DS1054z with 24M memory should be able to sustain the full 1 GSps down to a timebase of 24msBut being a 100MHz scope, the sample rate can drop to 500MSa/s without limiting its usable BW which is a 48ms timebaseIf the pulses contain elements requiring 100MHz BW then further dropping the sample rate will cause aliasing but it's still better than peak detect because the start/pause timing will still be rightI don't have a DS1054z and I don't know if this scope has other limitations, thoughQuote from: nctnico on May 28, 2019, 09:31:12 pmI may not be the most experienced EE but frankly so far no-one has offered a really good reason why peak detect should be considered importantOne argument was to see narrow pulses (i.e. if they're there) but I can do the same in real-time sampling even when undersampling (and with the large memory on some scopes the timebase would have to be really damn long to undersample), and despite the aliasing the real-time sampling will still offer me true start/pause timings while peak detect will notAnother argument was to use peak detect in combination with persistence mode to find out if there are any glitches but this method is highly unreliable when the scope is blind for roughly 9x as long as the time it can "see" events, so what's the point? Setup proper triggers and you'll know with certainty if there's a glitch or notThen there was the argument to use peak detect at long timebases because of the higher sample rate but this seems to miss the point that peak detect will not present a true representation of the waveform or its timing parameters anywaysSo I'm sorry but to me it still boils down to "I want it because its what I'm familiar with"In fact, it's mostly only college (with profs long away from industry) and this forum where I was told that peak detect is a must-have feature. Asking the senior EEs at work I'm told it's only relevant on old scopes which often had little memory and there's not much need for it today. And a certain former member who shall not be named and who knows a lot about scopes said the sameSo how about one of the proponents of peak detect describes a real case and a real signal which clearly demonstrates the need for peak detect and which I could try to replicate?

author: tautech
author_rank: Super Contributor
timestamp: May 29, 2019, 08:06:31 am
content: Quote from: Mr Nutts on May 29, 2019, 07:53:14 am2x 250M. 250M for each 5GSa/s ADC.

author: 2N3055
author_rank: Super Contributor
timestamp: May 29, 2019, 01:08:14 pm
content: Quote from: Mr Nutts on May 29, 2019, 07:53:14 amI'm not proponent of peek detect. I just shared my experience (not opinion) that it is useful sometimes, and good to have.This is a bit like an old academic fight about GOTO statement. It was religious like dispute that completely obfuscated the fact that statement wasn't evil per se but was misused.Same here. I fail to see your reasons tofight againstsomething other people find useful. What is your reason for it?Academic purity of measurement process? Fact that Wuerstchenhund says so so it must be true?Fact that you do only limited scope of work with oscilloscopes and in your dealings you never had need for it?As I said before, sometimes you have to work at long timescale because that is what device does. Like I sad in example of blinking light. It's blinking in seconds scale, but is driven with kHz scale PWM, and powered with 1MHz switcher, CPU is running at 8Mhz, and there is radio module at 868 MHz.. And there were visible artefacts in lights at seemingly random intervals. It is given to you as ready made device and no support from original developer.So what are you looking at here? What trigger do you use... How do you correlate things? How do you do it quickest and most efficiently? What is normal and abnormal signal here? Before anything you first have to make sense of what is going on, get a feel for it..You don't need purity of measurements all the time. Sometimes it is just looking at the things...And peak detect is actually what you would see on analog CRT scope. CRT scope would retain full vertical deflection of incoming signal, regardless of timebase.Once the timebase was such that the trace width was larger than signal width at that scale, you didn't know anymore what was in there. Was it triangle, sine, or a whole SPI packet there? No it was just vertical line with correct P-P value. But something is there.If you grab something with 128 Mpoints and 4 Mpoint, it will still be mapped to 800-2000 (if you're lucky) horizontal pixel resolution. So if you set timebase that one pixel width corresponds to say 1us, anything happening in that 1 us will be simple vertical line. On both of them.And then you want to see what's in there. Yo can now use zoom, and while still capturing whole 2 seconds, zoom in to that 1 us. On short memory scope you will see garbage. On long memory scope you will see it all. Beautiful. But if signal is repetitive, you can just shorten the timebase and move around with trigger delay. Like we did for 50 years... And you will still see the same. And once scope start sampling full speed it will automatically disable peek detect and signal will be pristine.In practicalinteractivework there is no difference most of the time. Only thing you will see is that shorter memory scope will, in general, be snappier and feel better. Not a show stopper but some people will find that important. I don't find itthatimportant (I guess it has to do with each individual's patience) but it isnicethough.Only real difference is when you have to capture signal in its entirety, with full detail, for further analysis, to share it with somebody, for documentation etc.In which case you need:1. Long memory to capture whole event at sample rate that is good enough to capture all that is interesting.2. You don't want to reshape samples in any way, so you can apply any kind of signal transformation on mathematically correct signal. No filters, no peek detect, no high res....And that is why long memory scopes exist. That is bread and butter of LeCroy, Picoscope etc. for instance.Depending of what you do, you might just do interactive work (like servicing equipment) all the time. Or you might be some scientist that just sample and analyse all the time, no interactive scope work at all.Or like me (and Nico and many others) you have maybe 80% of interactive work and 20% of the time when you need long mem scopes.Funny thing is that you're arguing us, but both Nctnico and myself (if you care to look around the eevblog) are great proponents of long memory scopes, and warned many members about that.To explain, I have fully loaded Keysight MSOX3104T, and Picoscope 3406D MSO with 512 MPoints, and a Picoscope 4262 (16 bit low noise instrument). They all can do things other two cannot.But if I had to keep only one it would be Keysight. Despite small memory (in comparison), it is most useful in my everyday work. Even if you have to use peak detect sometimes.In summary:1. For different uses, use different tools.. There is no "one scope to rule them all". If you do really various things, chance is you will have a need for different scopes. I have 3 at the moment.2. Peak detect is a workaround for acquisition memory that is not long enough to sample fast enough to keep Nyquist criteria for longer time bases.3. If you get to the point that your scope undersamples, peak detect is more accurate representation of signal shape on screen than without peak detect, where you basically get random data. Actually, it isperfect visual representationof how signal looks .4. Peak detect is not good mathematical representation of sampled data. It shouldn't be used if you want to take data and mathematically analyse it further.4. If your scope doesn't have peak detect, and you undersample data, your data will be wrong both mathematically and visually.5. If you can choose between a scope with long mem and one with short mem, everything else being equal, by all means take one with long mem. It's better. Will you use it all the time? No.6. If you have more than 2-4 MPoints, most of the time you won't undersample in average work. In average work we look at the detail, not the whole thing.7. If you need to capture a data and "massage it" later on, high sample rate and long memory will give you more to work with. And not only there is no need for it hen, you can't use peak detect even if you want to.8. Peak detect gets auto disabled when scope starts sampling at full sampling rate. It is basically undersampling protection, while not perfect, it will prevent you from missing something in a signal sometimes.So I do like long mem. I also like peak detect. It's just another tool. It can be useful sometimes. Generally, you should look at what you do, and find scope that fits that workflow.Is it decoding? Do you need history/segmented memory? Max bandwidth? Do you need advanced math, jitter analysis? Do you create a lot of documentation? Do you do this or you that ?There are many fantastic older scopes. You should choose them by quality (they are already old, you want to squeeze few more years from them before they die) and ease of repair.You should choose them by their feature set and bandwidth. Peak detect is simply one of the tools. And in my experience, there is never too much tools and too much help. Just make sure you know how to use it and apply it properly.

author: David Hess
author_rank: Super Contributor
timestamp: May 29, 2019, 02:38:58 pm
content: Quote from: Mr Nutts on May 29, 2019, 07:53:14 amLarge acquisition memories come with a cost besides economics. They proportionally increase processing time and I have watched many of these DSOs grind to a halt when a large acquisition memory is selected. Otherwise why allow selecting a shorter record length at all? Why don't they always use the longest record length unless there is some advantage to be had by using a smaller one?QuoteDPO operation solves this issue and can be considered a superset of peak detection.Large record lengths do not solve the problem of blind time unless processing is fast enough to immediately start a new acquisition and if that was the case, then why is the long record length required in the first place? (1) Bounce buffering is a potential solution for this but still still limits the acquisition rate to the processing rate.QuoteQuoteGlitches can also include behavior which is within the signal's specifications. The point of DPO operation is to find every unknown by capturing every signal characteristic. It is useful when I do not know specifically or even exclusively what I am looking for. If you measure something 'funny,' record the amount of 'funny'. (2)QuoteOne is simply to detect aliasing. If the peak detected signal is not consistent with the sampled signal, then aliasing has occurred.Another place I have specifically seen it be advantageous is tracking the pulse per second output of a GPS under certain conditions (say after XOR or race condition edge detection) where even the longest record length is not sufficient because the capture time exceeds 1 second. Segmented memory could be even more useful here, however many DSOs have peak detection without supporting segmented memory. A dual delayed timebase may also be able to make this measurement.(1) My understanding is that LeCroy was the proponent of this type of design with massive processing backing up a simple acquisition system that had a long record length and this is supported by Moore's Law. I am inclined to think LeCroy's marketing disparaged peak detection simply because they did not support it (emphasize your strengths, understate your weaknesses) which makes sense but I am not convinced their method satisfactorily replaced it.I think Rohde & Schwarz is on the right path by decimating into multiple data sets. If all of that processing performance must be included, then applying it to decimation means longer effective record lengths and faster performance with less high speed memory.(2) Bob Pease.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 29, 2019, 02:48:35 pm
content: Quote from: 2N3055 on May 29, 2019, 01:08:14 pmThe simple reason I ask is that, litterally, every time the discussion is about older higher BW scopes, it's stated that these and those scopes are no good because they lack peak detectThat seems to be considered as a statement of fact without every questioning if it's still trueOut in the real world, when I ask distinguished EEs and test engineers about peak detect in scopes they all say I should ignore it, it's a crutch from the pastAnd while my own experience is limited, I worked with signals involving groups of long-spaced narrow pulses and was able to do everything I need without peak detectAs to Wurstunhund, yes I actually believe what he says is correct. Not only because he has tremendous knowledge but also because he can explain the reasons for his arguments so I can easily follow his reasoning. I really wished some of my former profs had such great skills to explain even complex things. He also sent me a few videos and pictures demonstrating things, and because of him today I'm much better in making use of the available functionality in a complex DSO than after collegeAnd this has already paid off several times in my jobSo yes, when he says that peak detect is a crutch from the past then I believe him, and even more so when my (very experienced) co-workers say the same and it also fits with my own experienceQuoteAs an engineer, I want to get behind the reason for things and see if I can improve my skills and methods, so I'm interested in the reason why certain members feel peak detect is so crucial. But so far all I see is "it's faster" and other subjective "reasons" which sound more like some of the profs at my former college which were mentally stuck in the 80s because that was the last time they had any contact with real industryAnd as far as I can see, specially nctnico lists peak detect every time the talk is about older scopes, even if it's about long memory scopesI had less problem if people said they personally prefer to use it because that's what they know and it fits their workflow, fine, but no, it's sold as if it was one of the most important features in a scopeSo I would really like to see some justification for itEven more so because just because you used the same method for decades doesn't mean it's not outdated or can't be done betterA bit like fishing for anomalies with persistence mode - highly unreliable but still recommended as the way to find out if a signal has anomaliesQuoteI would probably chose the same, just because I don't like USB scopes which need a separate PC on my benchAnd as far as I know, Picoscopes also lack interfaces for active probesBut that doesn't mean the memory of the Keysight isn't too small for a modern scopeIf I had to select only one scope to use then I'd take my Agilent Infinum DSO8064A over that MSOX3104T any day (if I needed MSO, then it would be an Agilent MSO8064A). Or even my Wavepro 960 (because I really don't need MSO). Simply because they are much more capable scopes than that Keysight 3104T, even without peak detectQuoteNo argument here. Especially since my own scope collection has also been growingQuoteNo argument here eitherQuoteI'm sorry but this is completely wrong. In peak detect mode the scope runs at full sample rate but not every sample is represented on the screen, in fact the scope only takes the Extrema (the highest and the lowest value) of a series of samples and uses them for display. This means that neither the shape nor the timing parameters of the waveform on screen may be correct. Maybe often you don't see the difference but that doesn't mean peak detect creates a waveform that is true to the input signalAlso, undersampling doesn't create random data. Undersampling is essentially mixing, i.e. frequency components outside the first Nyquist zone (i.e. frequencies below half odf the sampling frequency) which reach into the 2nd Nyquist zone are folded back into the first zone in reverse order (i.e. high frequency components become lower frequency components and vice versa). This is what is shown as aliasing, and there is absolutely nothing random about itIn fact, while peak detect won't give you true signal shape or timing, the aliased signal still retains the original true waveform, just with added frequency components. Even the general timing (i.e. starting and end point of the pulse, duration of pause) is correct, only the shape isn'tQuoteThis is another way of saying that peak detect is not representative of your input signalWhich is trueQuoteWrong. If I undersample then the pulse shape is wrong but general timing parameters are correctQuoteI While certainly true, I can't see the relevance hereQuoteI can't speak for others of course but in my "average work" I'm interested in both the detail (i.e. pulse parameters) as well as the "whole thing" (complete signal)And 4M is not a lot of memory, it's actually quite smallMost of the scopes discussed in this thread have a lot more memory than just 4MQuoteTrue, but why would I even want to use peak detect?QuoteThat is correctPeak detect was designed of a means for glitch detection in low memory scopes. "Glitch detection" as in "user sees glitch on screen", which in itself is a highly unreliable method of finding rare glitches when considering that your average scope is blind approx 90% of the timeSo peak detect doesn't give me true waveshape or timing, and it's useless to determine if a signal is really free of glitches. So why would I use it again? ;-//QuoteFunny you mention that because when the discussion about older scopes no-one proposes that certain models are no good because they don't do serial decode or MSO capabilities or anything like that. But for some reason, peak detect is the all deciding feature?

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 29, 2019, 04:19:04 pm
content: Quote from: David Hess on May 29, 2019, 02:38:58 pmSounds like the Tek scopes at collegeBut yes, at a given sample rate it takes longer to fill a larger memory than a smaller one. There's no way around thatAs to "grinding to a halt", that depends on the scope's processing capabilities. My Agilent 8064 does certainly not "grind to a halt" when using the full 128MQuoteBecause a smaller memory comes with a higher screen update rate, which is important if you want to use the scope visuallyOn my Lecroy scopes I usually select a size of 100k if I want to get fast screen updates. If I need it for more than just staring at waveforms then I select the full memoryThat is why better scopes allow manual memory managementQuoteNo, it does notEven in DPO mode a Tek scope is still suffering from huge blind time, as does every other scope in persistence modeWith these methods you have no idea if your signal is really free of anomalies because most of the time you'd just miss itQuoteNo-one said it does. Triggers solve itRead the article on WH's blog I postedQuoteI really like to see an example for that because if it's a glitch (i.e. an unwanted element) then by definition it's outside your signal specificationQuoteBut it doesn't. It only shows glitches that appear outside the blind time, the latter which is roughly 9x as long as the time the scope actually "sees" somethingThe chance to miss a glitch is approx 9x as high as the chance that the scope captures itI just setup my triggers and capture any anomaly at the first occurrence with 100% reliabilityQuoteA PPS signal is just a pulse or a square wave with 1Hz fundamental, many scopes should be able to resolve that with acceptable accuracy over several seconds. With peak detect the shown signal may look like the input signal but the timing information and waveshape are not true to the input signalI can't see why I should use peak detect over normal acquisition hereQuoteMost of the scopes discussed in this thread have segmented memoryQuoteOld Lecroy scopes had peak detect, I think the last one was the 9384 which is very old. But back then memory sizes were a lot smaller than they are today

author: DaJMasta
author_rank: Super Contributor
timestamp: May 29, 2019, 04:35:23 pm
content: Given the size of the posts on this page, I'd say we need a peak detect thread, then again, I'm a bit terrified at the prospects for such a threadMaybe a poll to see who uses it and finds it useful. I don't think I've used the feature yet, though that goes for some of the other more exotic triggering schemes.....anyone have a new scope model to look into?

author: nctnico
author_rank: Super Contributor
timestamp: May 29, 2019, 05:01:46 pm
content: Quote from: Mr Nutts on May 29, 2019, 02:48:35 pmHis reasoning is usually in favour of Lecroy... working around the limitations of Lecroy's products in ways which are not necessarily the most optimal way of doing things in general... and if Lecroy says... Also I think he is more involved in the sales side of oscilloscopes than in actually using them to make a living.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 29, 2019, 05:29:10 pm
content: Quote from: DaJMasta on May 29, 2019, 04:35:23 pmbetter the title is "Nice older DSO with peak detect advice highest BW/GSps at $5K or less" then we should clearly see which one is important, the peak detect or the money.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 29, 2019, 05:37:05 pm
content: Quote from: David Hess on May 29, 2019, 02:38:58 pm1s capture time?QuoteHow about a modern scope with just enough memory?I had a look at the PPS signal of my China GPSDO with my Agilent DSO8064 set at 64MHere's how it looks like with a capture time of 2 seconds:This is a capture time of 5 seconds:Or how about 50 seconds of capture?Or how about 200 seconds of capture?All without peak detectAnd here's the bonus: the signal timing is still correct, i.e. pulse width and the pause times are still correct, something that's not necessarily the case with peak detectSo where was the advantage of peak detect for seeing a 1PPS signal again?

author: rsjsouza
author_rank: Super Contributor
timestamp: May 29, 2019, 05:41:23 pm
content: Quote from: Mr Nutts on May 29, 2019, 02:48:35 pmI don't think it is a matter of true/false but instead a preference. When talking about old oscilloscopes the more limited memory certainly adds weight to the case for peak detect. Modern oscilloscopes and their larger memory reduce the advantages.A similar case can be said about protocol decoding; although convenient to have it featured on an oscilloscope, the current offers for cheap and easily configurable PC-based logic analyzers greatly reduce the need to have it built into the scope - it certainly is not as worth as the option prices of the A-brands, where a few of the options can easily go beyond the price of a full featured Saleae or a ZeroPlus.A while ago Iinterjected a discussionwhere both Mike and Nico explained to me their preference for having a peak detect oscilloscope. Despite the explanation made sense to me and backed by two very experienced users, I still haven't seen the need and use it sparsely. I have a 140Mpts DS4014, though.Quote from: DaJMasta on May 29, 2019, 04:35:23 pmMany threads already tore this subject to shreds. Don't even go that route...https://www.eevblog.com/forum/testgear/lets-talk-about-lecroy-scopes-aka-the-wuerstchenhund-holds-court-thread/msg1026148/#msg1026148https://www.eevblog.com/forum/testgear/a-possibly-dumb-q-on-digital-oscilloscopes/msg1257270/#msg1257270https://www.eevblog.com/forum/testgear/want-faster-and-newer-oscilloscope/msg1884350/#msg1884350...and many more!

author: 2N3055
author_rank: Super Contributor
timestamp: May 29, 2019, 05:53:34 pm
content: @Mr Nutts:So basically you reason for this discussion is that you like riling people up and you like to be right at all cost.We gave you plenty of reasons why peak detect is not evil and can be useful sometimes, but you chose to ignore it all, and basically concluded that we use peak detect because we are backwards, luddites and generally not smart enough to know that there is a better way, your way....Now I'm gonna go to a dark place, sit in a corner, crying softly and reflect upon my life, deeply touched by this great revelation..NOT.

author: jjoonathan
author_rank: Frequent Contributor
timestamp: May 29, 2019, 06:02:28 pm
content: Aliasing sucks.Even if the Nyquist criteria is met, sampling without an AA filter sucks.Gambling that you aren't aliasing sucks. You'll win 9 times out of 10 but you'll have enough fun on that 10th time to make up for everything you missed out on the other 9 times.Doing due diligence to make sure you aren't aliasing sucks. You have to ensure that mF+nFs for all expected input frequencies F and integer m,n is >> 1/Tfeature for all relevant features you want to see. Sure, you can do it, if you know which input frequencies to expect. If you're an RF guy you might even be good at this calculation, but is it really what you want to spend your brain cycles on? Peak-hold lets you invest those brain cycles in something more productive, like daydreaming, or thinking about the problem you are hunting.> (paraphrasing) If your scope has enough memory it's not a problemSee that scope above? It has 800Mpt of memory and can draw 1 million Wfm/s. By default, it has a 10Mpt acquisition depth limit enabled in its settings. If you zoom to longer timebases, it will decimate to keep depth at 10Mpt (or whatever you configure the limit to). Why? Because one typically prefers fast updates and deep history  to full resolution long acquisitions. See that third knob in the timebase section, in addition to the usual scroll and zoom knobs? The third knob controls acquisition depth, and if you want to sacrifice your history and Wfm/s to get very deep acquisitions, it's easy, you just turn that knob to the right. I prefer not to turn the knob to the right.I prefer fast updates and deep history and I also prefer not to calculate beat frequencies vs feature frequencies. Peak detect lets me have my cake and eat it too. Thank you, peak detect! It's segmented unless you tell it not to be and they call it "history." If you hit stop you can browse to previous acquisitions. It really makes more sense than throwing away previous acquisitions by default.

author: 2N3055
author_rank: Super Contributor
timestamp: May 29, 2019, 06:10:50 pm
content: Quote from: jjoonathan on May 29, 2019, 06:02:28 pmThank you for explaining what I couldn't. That is one fierce scope..Best regardsSinisa

author: Kosmic
author_rank: Super Contributor
timestamp: May 29, 2019, 06:15:34 pm
content: I think the problem is not if people like peak-detect or not. Or if it's useful some time to some people.The problem is more that some people freely declare to everybody "you can't buy an oscilloscope without peak-detect". Which I think is not entirely true. Really, depend of your usage and personal taste.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 29, 2019, 06:22:53 pm
content: Quote from: rsjsouza on May 29, 2019, 05:41:23 pmIf it was preference I had no problem with it. But it's not that. You can go into any discussion about slightly older scopes as in this thread and there is at least one person who constantly bring up peak detect as a necessity - not as a personal preference.QuoteAnd still in those threads no-one complains that older scopes don't have protocol decoding or dismisses certain scopes because they don't have protocol decodingQuoteI did read that, too, but so so far I haven't read anything beyond "I use it because I'm used to use it". I'm not saying it doesn't work for these users, but there's nothing in there showing how peak detect in a modern deep memory scope solves a problem that without it would be unsolvable or even just more difficult to solve.QuoteNa, I'm not going thereQuote from: jjoonathan on May 29, 2019, 06:02:28 pmI'm sorry to say this but so does your way of attaching pictures because I can't see them.Someone recommended to attach images to the post and then use the image link in the text to make sure other people can see themQuoteNot sure what you want to say here. Of course there is aliasing in my screenshots. So what? Peak detect is even less true to the original signal, which is why proponents claim to use it only to see if there are pulses or if there are glitchesBut as shown in my screenshots I don't need to select peak detect to see the 1PPS pulses, and the fact that the signal has some aliasing doesn't change the fact that the basic timing parameters of the waveform are correct, something that would not be the case with peak detectQuoteNo, unless it looks like two blue blobsIt would have caused no harm had you at least stated brand and modelQuoteThat sounds like one of the new R&S scopes WH has told me about. I think they can only use a small part of their memory in normal mode and can only use the large memory for I believe history and other special modes. Is that right?1 million waveforms per seconds sounds great but to me that's just marketing wank (others have done it before, too). Update rates are way overratedQuoteIf you prefer that, who am I to tell you it's not OK?I have no experience with R&S scopes but frankly if you need to use a lot of brain power just to use extended memory or do frequency calculations (what fo, btw?) then I would say the scope isn't very goodOn the Agilent Infinum I created the screenshots with, using Peak Detect would need slighty more effort while giving me inferior resultsQuote from: Mechatrommer on May 29, 2019, 06:29:40 pmI would't do that with that setup, that's what advanced triggers are forQuote from: 2N3055 on May 29, 2019, 05:53:34 pmSo in short, instead of answering my question you decide to go all drama queen on me (David Hess has at least given a real example I could replicate, kudos for that). Fair enough, although considering your clear and obvious misconceptions about peak detect and sampling theory it appears you're pretty butt hurtI think I slowly start to understand what Wurstunhund meant when he said "you'll find out yourself" when I asked him about the kick-out (he didn't tell me except that I'd find out myself if I hang around here). Clearly one shalt not ask too many questions if it touches established mantra it seemsSo I'll grant you your safe space and bow out of this thread

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 29, 2019, 06:29:40 pm
content: Quote from: Mr Nutts on May 29, 2019, 05:37:05 pmgood luck (or retry) finding 10MHz glitch (100ns pulse width) with that setup. (glitch = something we didnt program nor expect but circuit went haywired)

author: rsjsouza
author_rank: Super Contributor
timestamp: May 29, 2019, 07:08:40 pm
content: QuoteYes, from time to time we get some heated discussions around here. However, in all fairness, while searching for the threads above I found Nico softened his speech over the years - from "must have" or "useless" to "I prefer" or "I would never buy". From what I recall, he is the one that was the most vocal for PD.Quote from: Mr Nutts on May 29, 2019, 06:22:53 pmYes, but decoders are quite optional and a much more recent feature of oscilloscopes.

author: 2N3055
author_rank: Super Contributor
timestamp: May 29, 2019, 07:46:15 pm
content: Quote from: Mr Nutts on May 29, 2019, 06:22:53 pmYou are the one that refuses to understand despite being explained many times. It tells more about you than anything else.Also first you call me stupid and backwards and now you're implying you buttfucked me. Strike two.And as Wuerstchenhund was, you are abrasive, rude and disrespectful. He wasn't banned because of his knowledge that was wast.The man is a walking encyclopedia of scopes. Shame he's gone, really.He was banned because he was getting in constant fights with members, and because he was asshole about it.And it seems he's your mentor in more than scopes.You are not a judge, I don't have to explain myself to you. I explained enough. It seems it was understandable enough to everyone else except you.So let me repeat once more: peak detect is useful. Even if you have lots of memory. It helps with undersampling, and when using it, you can get good visual representation of signal. Yes, many people are using scopes visually, not only as a offline data analysis tools.Actually that is how scopes are mostly used, sorry.I don't think peak detect is most important feature of the scope. I disagree with that.I also strongly disagree this crusade against it that you are doing. I disagree with that too, together with your manners.I hope you will agree we stop here. I don't like personal attacks and insults. And certainly I'm not the one to turn the other cheek.I feel we are not going the right way.Also it is really off topic. If we can't keep it nice, it should not be at expense of spoiling it for other people.Sinisa

author: Kosmic
author_rank: Super Contributor
timestamp: May 29, 2019, 08:19:38 pm
content: Easy now, you're the one insulting others.This is probably a translation problem. Ther's a big difference between "butt hurt" and like you said "buttfucked"Quote

author: nctnico
author_rank: Super Contributor
timestamp: May 29, 2019, 08:54:10 pm
content: Quote from: 2N3055 on May 29, 2019, 07:46:15 pmI agree. Sometimes you just have to walk away. You can lead a thirsty horse to water but the horse has to decide to drink or not.

author: 2N3055
author_rank: Super Contributor
timestamp: May 29, 2019, 09:14:11 pm
content: Quote from: Kosmic on May 29, 2019, 08:19:38 pmThank you for explanation and concern.. My English is not much, surely, I appreciate any help that I can get.Just a simple explanation. Being butthurt is something very derogatory. Ethimology of that word is that somebody anally raped you and now you're hurting. With time, it was used in context " stop whining, it's not like you're buthurt" implying that your whining is not proportional to what you experienced. And while carrying distasteful symbolism, that would have the meaning you said. Not nice but, hey, OK.What he said, in English means what I understood, especially in the otherwise derogatory tone. I don't care if there is some local slang that takes that and interprets it differently. Citizens of the world cannot know all of that. You take sentence by its word meaning, not some arbitrary phrased meaning you don't even know exist.Again, thank you for caring and trying to help. Much appreciated.I don't want a fight with anybody. Especially about something not very important.So if I went overboard and overreacted I apologize to everybody, including Mr. Nutts.I'm not gonna go back and delete or edit anything. I will leave it as it is so all is clear. If I make a mistake I own it.Maybe someone else will learn how easy is to go wrong direction.Thanks Kosmic.Regards,

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 29, 2019, 09:17:33 pm
content: someone who live on a desert will say the world is yellow, someone else who live in the rain forest will say its green, someone on the ocean will say its blue, and then everyone of them...and then the admin is the one who has the kill switch and left with fewer members, who win? nobody... some wiser people around here from whom i learnt are already left/inactive, sad.

author: David Hess
author_rank: Super Contributor
timestamp: May 29, 2019, 10:24:56 pm
content: Quote from: Mr Nutts on May 29, 2019, 04:19:04 pmSounds like every long record length DSO I have tested.QuoteIt does not take any longer when the extra record length is filled at a faster sample rate.QuoteWait, so which is it? Does it slow down or not?QuoteWhat are you talking about? DPO mode reduces blind time.The original DPO oscilloscopes manged 50 thousand acquisitions per second which is comparable to an analog oscilloscope but later ones were 100s of thousands.QuoteMore recent DPOs acheive blind times of less than 5% even at high sample rates.Quote from: Mr Nutts on May 29, 2019, 05:37:05 pmNow go back and do it again with the signal I suggested.Your capture time of 2 seconds could miss a 40 nanosecondsecond pulse and it just gets worse from there. Even my almost 30 year old Tektronix 2232 with 100MS/s can do better than that with a 1 kSample record length.

author: jjoonathan
author_rank: Frequent Contributor
timestamp: May 29, 2019, 11:21:52 pm
content: Quotehttps://en.wikipedia.org/wiki/AliasingWe are not talking about signals becoming blocky but otherwise remaining true to form as a result of lower sample rate. We are talking about the effect where the sample frequency and signal frequency have a relationship that "conspires" to turn a signal of one form into a signal of a completely different form, thoroughly corrupting its shape and timing parameters.Consider the attached example. Aliasing causes a 100MHz burst to appear as a 10kHz burst. Note that peak detect mode is immune to this problem.QuoteIt is possible to mathematically prove that the above effect will not corrupt your particular signal at your particular sample rate. If you don't use peak detect mode, you will either need to do this math or you will need to gamble on a favorable result. It sounds like you have been gambling and winning. That's fine, but it isn't for everyone.QuoteI have a literal knob that lets me choose between fast update rates and deep memory. This puts me in a good position to be impartial. I usually choose fast update rates.

author: jjoonathan
author_rank: Frequent Contributor
timestamp: May 29, 2019, 11:52:59 pm
content: QuoteNo, it is not correct. RTO1000s with 800Mpt of memory can take single 10GS/s 800MPt captures no problem.Someone unfamiliar with R&S scopes might get the wrong impression after playing with one for a few minutes, though. By default they are configured with a relatively low "Record length limit" of 10MPt or so. If you simply scale out the timebase, it will begin to decimate so that the record length does not exceed 10Mpt. This maintains a fast update rate (like a Keysight scope) and uses memory depth for history. If you want a single 800Mpt record, you must reconfigure the limit, but it will absolutely let you do so.

author: Kosmic
author_rank: Super Contributor
timestamp: May 30, 2019, 12:04:45 am
content: Quote from: jjoonathan on May 29, 2019, 11:52:59 pmOk jjoonathan, you have to stop posting pictures of your scope. You will have me starting shopping for a new one

author: james_s
author_rank: Super Contributor
timestamp: May 30, 2019, 12:43:16 am
content: For $5k I'd be looking at new or high end used scopes, or maybe spend $3-4k on the scope and $1-2k on probes and other accessories.Personally I've been really happy with my TDS784, 1GHz and nice familiar Tek interface for about 1/10th your budget however the newer Tek DPOs are nice too and a lot more compact.

author: 0culus
author_rank: Super Contributor
timestamp: May 30, 2019, 01:02:37 am
content: Wow....this thread escalated quickly....lots to read. I'm leaning towards finding something used + investing in probes as james says.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: May 30, 2019, 01:09:02 am
content: Oculus, keep straight please. LeCroy stinks badly, especially the user IF. I told about that trigger setting somewhere.I have never personally encountered one of those R&S scopes, so I can't say.I have the TDS644 at home and it is doing good service. Of course, I have a DPO70604 at work, which is beautiful.But my suggestion would be the newer version of the DPO3054, with the larger screen and USB.

author: 0culus
author_rank: Super Contributor
timestamp: May 30, 2019, 01:24:26 am
content: Quote from: Neomys Sapiens on May 30, 2019, 01:09:02 amTell us how you really feel!!!In all seriousness, I'd prefer to see why you think that (with evidence) rather than just stating that it stinks. UI preferences are highly subjective.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 30, 2019, 01:27:58 am
content: From $5000 100MHz scopes for FPGA work to this.Quote from: 2N3055 on May 29, 2019, 07:46:15 pmI always figured he was in sales. He was on me about how installing SSDs into my DSOs would never work. Then it was about how adding a 1Gb Ethernet card would cause problems. After several years of flawless work, I have to say his advice was flawed. He was going on about not using a PC to post process data, which of course I continue to do.. Of course he would fight these sort of points to the bitter end. I just don't think his ego could handle it and it would make him get aggressive. Personally, I didn't mind and enjoyed poking him with a stick every now and then. I'm sure he felt the same about me.I would rather have people like him around as he brought a lot to the table.

author: james_s
author_rank: Super Contributor
timestamp: May 30, 2019, 02:12:15 am
content: I don't think any of the big brand scopes "stink", but rather some have an interface clearly descended from earlier analog scopes while others take more liberty starting with the standpoint of a completely new type of instrument. It largely comes down to preference and your style of working. I like the classic Tek UI personally and dislike scopes that are an embedded PC running Windows but there are lots of good scopes out there, some with less of a brand premium on the price than others. I find for example that the older low end Tek DSOs seem to have hugely inflated prices, they're not bad instruments but they offer nothing to justify the high price. Higher up the scale there is less discrepancy.If you are contemplating dropping $5k on a scope I would assume you have a pretty good idea of what you need it to do.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: May 30, 2019, 02:22:43 am
content: I was working on solid state power controllers (remote controlled switch + overcurrent protection) at the time. I used a setup with a fast thyristor and a pulse generator as a delay to place a 'short' all over the waveform under various conditions (resistive, inductive, capacitive loads, in the current or voltage maximum, etc.) Then someone 'stole' the Tek scope that I was using and I had to make do with the available LeCroy. With this scope, trigger point setting was coupled to vertical scale factor, so I could not change V/div without having to reset my carefully found trigger. This drove me crazy, as I consider it a total mistake.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 30, 2019, 05:17:25 am
content: Quote from: joeqsmith on May 30, 2019, 01:27:58 ami thought you were on sales too selling brand name fuse. after several years of happy living with some strand of wire as fuse, I have to say your advice was flawedbut that just a joke, an idiom that i dont know how to say in english.... returning what a person says about other back to him... you maybe think the world is only blue, and for him the world is only yellow. but assumption with lack of investigation is not a good assumption imho, check his posts on Lecroy's DSO upgrade he was happy about...https://www.eevblog.com/forum/testgear/upgrading-mainboard-in-lecroy-dda-3000-(aka-wavepro-7300a)/msg967649/#msg967649so my "assumption" was that he lacks of knowledge on how to upgrade a DSO, so he thought its impossible, but sadly its only for him, that he cannot see, he thought there is only one color, until he saw the other color. after looking at most of his post, i dont think he is an oscilloscope angel nor guru nor a walking encyclopedia, he is maybe just an overly enthusiastic and experienced Lecroy DSO user, he maybe have more knowledge and details on that, but if we ask him about Tektronix or Agilent DSO, then he can be as clueless as others. otoh i tried to find which Wuerstchenhund's post that was really insulting but i cant find one, so i guess some fools who think the world is only blue made a report on him.Quote from: joeqsmith on May 30, 2019, 01:27:58 am

author: tautech
author_rank: Super Contributor
timestamp: May 30, 2019, 05:47:04 am
content: Quote from: Mechatrommer on May 30, 2019, 05:17:25 amThis ^I too looked for somegoodreason Dave banned him as W had toned his posts down some after a short term ban as a warning.There weren't any !Dave maintained the ongoing reports to mods against W tipped the balance for him to issue the ban.W and I share the odd email about stuff and he's moderately active on the allaboutcircuits forum.Now EEVblog is larger and hosts a more informed membership Wuerstchenhund's presence here could be tolerated and keep things way interesting, possibly even drawing more members to come aboard.

author: DaJMasta
author_rank: Super Contributor
timestamp: May 30, 2019, 05:54:09 am
content: This thread has taken yet another unexpected detour, but it's entirely possible that said posts are deleted, or there were instances of that behavior in private messages. From moderating forums like this, there are a lot of ways to remove problematic things and there are a lot of ways to keep tabs on members frequently stirring up trouble that are invisible to normal users.No particular experience in the aforementioned case here, but I doubt anyone not receiving the reports or seeing deleted posts has enough of the full picture to really make the call either way, and I don't expect that us regular forumgoers will ever be privy to all the relevant details.... it's an unrealistic expectation.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 30, 2019, 09:49:13 am
content: I just came back and saw this thread has got some new replies, many about Mr Wurstunhund. As someone who has read all he has ever written in that forum, some of the claims that were now made appeared bogus to meLike this one:Quote from: joeqsmithI was not able to find any message where he said that installing SSDs in your DSOs would never work. In fact, he often recommended to replace hard drives with SSDsHowever, I did find this in your thread about your Lecroy scope which I guess is what you meant:https://www.eevblog.com/forum/testgear/teledyne-lecroy-waverunner-64xi/Quote from: joeqsmithLater in the same thread he replied to you with this:https://www.eevblog.com/forum/testgear/teledyne-lecroy-waverunner-64xi/msg679459/#msg679459QuoteHe pretty much just said that he had problems in his own attempt to convert a specific scope to SSD, and explained what the culprit was. It turned out that when you did your conversion you used a SSD that wasn't affected by the problem.That reads a lot different than "He was on me about how installing SSDs into my DSOs would never work". Care to explain?Then there's that:QuoteI believe this is the thread you are talking about:https://www.eevblog.com/forum/testgear/show-us-your-square-wave/msg597515/#msg597515QuoteThis also reads a lot different. He doesn't say it will cause problems, he says it won't be very fast and may well have side effects.Later in the thread he replied to you with this:https://www.eevblog.com/forum/testgear/show-us-your-square-wave/msg597693/#msg597693QuoteSo his point was really that the faster adapter is unlikely to give you a notable speed boost but comes with the risk of side effects. That reads a lot different from "Then it was about how adding a 1Gb Ethernet card would cause problems."So would you mind to clarify your statements? Because that reads a lot like you're twisting factsQuote from: joeqsmithCan you please point to that message because I could not find itQuote from: MechatrommerI guess you refer to this post:https://www.eevblog.com/forum/testgear/upgrading-mainboard-in-lecroy-dda-3000-(aka-wavepro-7300a)/msg931891/#msg931891QuoteI may be biased but to me that reads like he's saying just replacing the mobo with a multicore processor is not going to work in that scope. And if you read through the whole thread then you'd see that he was actually right because to make a modern mainboard work people had to write new drivers and make modification to the LCD interface to get it working, so actually he seem to have known pretty well what he was talking about, and it didn't take long until some people who modded their scopes experienced hardware issuesIn the same thread he was also made aware of a mistake and he quickly accepted and apologized, which is more than what I've seen from many of the regulars hereAlso, from his other posts I gathered that he generally only recommended modest upgrades (like CPU, RAM, SSD) to keep the scope still in a supported configuration because the point of test equipment after all is to provide reliable and dependable data and not a project in itselfMaybe it's just me but I can understand why he feels that way. If I started modding scopes at work I would get into so much troubleAs someone who had a lot of contact with WH and got more help from someone who's literally a stranger than I would have ever expected I have to say I find it very disappointing that some members not only are kicking someone who can't defend himself but also do so with twisted facts. That is lowQuote from: DaJMasta on May 30, 2019, 05:54:09 amI once asked him and he said everything is there to see. No hidden private messages or deleted posts. So I don’t know

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 30, 2019, 11:24:06 am
content: Quote from: Mr Nutts on May 30, 2019, 09:49:13 amno argument agreed 100% nevermind on re-reading that thread, i've read that thread from page 1 till the end, me and dajmasta are some members who involved in the DSO mod in that thread. i've waited many weeks/months/years until i found GHz DSO and VNA that suit my need and price, thats why we are giving advice. i also read WH posts in many other threads, very useful and helpful. except his advise are based on his own experience (and thats normal as we all do the same when posting in forum), thats why he didnt recommend multicore system as he has no knowledge building drivers. but sadly some people may take this too literally (that the world is not yellow period). i believe if he is still around, he will be happily link to the multicore driver and changed his mind. he is just a normal mortal like us, still i dont see any good reason why he is banned, his post contained many useful facts, but relating to Lecroy DSO only.otoh yes this thread has went sour when someone started troll on unrelated issue, but yet havent provide a better alternative. granted it can be used for food for thought but we need solution rather than dont do this, dont do that. this thread is about "Nice, older DSO advice" i've (and some others) provided links where we can buy 1-6GHz 16-20GSps DSO at less than $4K mainly because preferences to BW and sample rate that is not available in other brand at the price and cant be emulated in any kind of workaround. if someone else think other feature such as peak detect is more important, he should provide an example to which used scope to buy and let the reader decide. i may change mind if there is better alternative even if its say 20% more expensive etc. but as far as peak detect is concerned, i considered that matter is solved for me with my $400 DS1054Zthere maybe older 500MHz Keysight DSO with peak detect at $2-4K, but if someone prefer BW and GSps, i dont think there is alternative other than LeCroy in current used market, if you miss that, i wish you people good luck with your projects, the offers have become rarer. you maybe happy with lower BW peak detect scope and sucks on LeCroy scope, but thats the decision you've made and should be respected, but then we also should respect others opinion, there is no need for butfark fight, fwiw...

author: rsjsouza
author_rank: Super Contributor
timestamp: May 30, 2019, 02:46:11 pm
content: Quote from: Mr Nutts on May 30, 2019, 09:49:13 amAlthough you have some fair points, IMHO this one is not. In my eyes, Wuerstchenhund's above post pretty much discourages any attempts to modifications with pure opinion and not facts. That is a typical manufacturer's speech against modifications to any piece of hardware.Quote from: Mr Nutts on May 30, 2019, 09:49:13 amIt is easy to look at someone else's posts many years after the fact and forget the emotions involved during the debate at the time. There is a chance Joe and Mecha didn't look back at the posts and were only recalling what they felt at the time, which is a fair mistake but not low. Anyone else here could have made the same mistake.Quote from: Mr Nutts on May 30, 2019, 09:49:13 amAlthough I saw some of his posts as bellicose/angry at times, he was really not the only one responsible for this - many other users that most probably reported him were equally part of the problem and are still around. At the time he was given timeout one or a few times to cool off and went back at the same pace with the same attitude - we don't have the full story here, and the moderators simply became fed up with the number of reports as it was mentioned at the time. It may have been a mob attack, but I can only speculate.

author: David Hess
author_rank: Super Contributor
timestamp: May 30, 2019, 03:35:03 pm
content: Quote from: Mr Nutts on May 29, 2019, 06:22:53 pm1 million waveforms per second is about high acquisition rates for low blind time. There is some minimum dead-time between acquisitions which limits it. This is what matters when searching for rare signal characteristics.Screen updates rates are completely different and about human factors and usability. Ultimately this will be limited by LCD refresh rate yet most DSOs are considerably slower under all or some conditions.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 30, 2019, 05:09:51 pm
content: Quote from: Mechatrommer on May 30, 2019, 05:17:25 amI only sell the finest counterfeit SIBA fuses and UNI-T meters. All joking aside, I doubt I would have ever made that wire powered cork gun had it not been for your posts. It's amazing to see just how much expansion you can get out of a little wire.I also don't remember him insulting anyone but I wasn't following his every post.Quote from: Mr Nutts on May 30, 2019, 09:49:13 amThat's a lot of effort you went to. Sadly it was wasted on me.I would need to try and hunt down his posts about me using the PCs to post process the data. He was suggesting this all be done on the DSO. Of course, my scopes are all old and don't have much computing power compared with a modern PC. I did make a couple of videos demonstrating the throughput gains after changing over to 1Gb. A very nice upgrade.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 30, 2019, 05:38:29 pm
content: Quote from: rsjsouza on May 30, 2019, 02:46:11 pmPartly why I was guessing he was in sales. Seems he mentioned traveling to many large companies. Sales.... He made a few videos but I think the ones were to sell the 64Xi he had.Quote from: rsjsouza on May 30, 2019, 02:46:11 pmVery possible. Seems I poked him a few times on this site afterwards. Mainly to let him know things were still working fine and I hadn't ran into troubles. I don't recall this leading to any sort of conflict. It's really just a data point after all.Quote from: rsjsouza on May 30, 2019, 02:46:11 pmThis is what I remember as well. I was amazed they banned him and not some of the others he would debate with.While cleaning up the DMM thread, there was a member "Oldway" who was also banned. I started reading their posts and again, really didn't strike me as someone I would have thought would need to be banned. I just assume its based on their targeted group.I've somehow escaped being banned. Although, Dave did pull some of my comments. I don't remember what the topic was or why he pulled them. It seems I posted, he pulled it, I thought I had forgotten to press enter and reposted, he pulled it again.This was about the closest I think I have got as Simon fired a warning shot.https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/msg1045994/#msg1045994

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 30, 2019, 06:02:34 pm
content: Quote from: joeqsmith on May 30, 2019, 05:09:51 pmanother entertainment for you (attached) that has seen action recently. i wont say much as it will encourage others, the purpose is written on there, just note the atomized copper around the inner side of the transparent case. saved me a fortune from buying legit stuffs. all these learnt when i saw a techy shop replaced his mains fuse (before the dist. box) many years ago.Quote from: joeqsmith on May 30, 2019, 05:38:29 pmthats why i feel cold on this forum ever since i saw such occurences. better to only reply to threads of really interesting/related. even some simple technical issues/questions in beginner or technical sections i will choose to ignore, let others solve it, as this forum has gotten famous anyway and the #1 admin is doing the same, so i've blended the culture to myself, i think thats the wiser thing to do around here. if there is conflict, better stay away esp if its ambiguous yellow or blue, only reply to whats obvious such as facts and that probably cant be encountered back by replier. a wise man once said... i can debate with a wise guy and win, but i will lose debating with a fool. you can be right on this forum but yet you still can get banned. fwiw.

author: jjoonathan
author_rank: Frequent Contributor
timestamp: May 30, 2019, 09:28:35 pm
content: QuoteCommunity management isn't always about doing what's fair to the individual. If a community has a problem with contentious discussions and those contentious discussions tend to nucleate around a particular individual, the rational choice for the community manager is to remove the individual, even if the manager agrees with everything the individual is saying, even if the individual conducts themselves appropriately while their sparring partners do not. It's not fair, but the community comes first.There's a chilling effect, but the stakes are low, and this doesn't just scale down the consequences, it also makes them less negative. When the government or a corporate executive create a chilling effect, it often works to suppress inconvenient but important truths. It encourages problems to fester and grow until they can't be ignored. Here, there are no big, inconvenient problems to fester and grow. We're debating oscilloscope models and features. A lack of peak detect does not fester and grow until it topples a company or an economy. You just work around it if you have to and that's the end of it. The chilling effect discourages escalation but doesn't encourage hiding dirty laundry because the stakes are too low to generate dirty laundry in the first place. Therefore, the chilling effect is less of a problem than your intuition might suggest, because your intuition is calibrated against chilling effects in the workplace or in society, whereas this is a chilling effect in a hobby form. More of a "chill out and peace" effect than a "chill and freeze to death" effect

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 30, 2019, 10:58:26 pm
content: Quote from: jjoonathan on May 30, 2019, 09:28:35 pmso let the community decides? if its filled with fools, then getting banned is actually a relieve from a cursepartly i believe your point has something to do with "monetization", this forum is the admin's full time income, so its no wonder why.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 31, 2019, 12:54:05 am
content: Quote from: Mechatrommer on May 30, 2019, 10:58:26 pmI think in some cases, yes! After that bit of drama on the UT210e, I posted about those last few hardware changes I made and never visited that thread again until yesterday. It gets to a point it's just not worth the effort. As suggested, the stakes are low and the only consequence is that I am no longer part of the discussion. A blessing for some I'm sure.It appears like "breaker tester"??Back on topic, I'm still lost about the 100MHz FPGA projects. I was running some home made wire wrapped boards at 100MHz back in the 90s. It's not uncommon anymore to clock them above 500MHz. Then again, I will fully admit I have a problem with speed and a soft spot for old test equipment.

author: 0culus
author_rank: Super Contributor
timestamp: May 31, 2019, 12:58:01 am
content: You need a fast scope to properly see even a 100 MHz clock signal. That's the benchmark I'm using. My 7904A, using a 7A19 amplifier with a P6201 FET probe isn't even enough.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 31, 2019, 01:23:13 am
content: True. I have a couple of differential FET probes for digital, but mostly use resistive probes. I was playing around with a cheap Arty board a few years ago. Pictures were taken with a LeCroy 64Xi. Now that I have owned it for a few years, it's not a bad scope for it's age. The case is poor quality. There are times it's nice to have something a bit faster. Pictures showing that same home made oscillator on the 64Xi and the 8500A.I wouldn't mind having a new DSO for home but by budget is not nearly as big as my addiction requires.https://www.eevblog.com/forum/microcontrollers/typical-speed-of-fpgas/msg1274875/#msg1274875

author: james_s
author_rank: Super Contributor
timestamp: May 31, 2019, 04:31:15 am
content: Quote from: 0culus on May 31, 2019, 12:58:01 amA lot of people seem to get really hung up on this. It's true of course, technically speaking, but it doesn't mean you can't get by with a more modest instrument. All test equipment lies to you under some circumstances, the key is knowing the limitations of your gear and knowing how to interpret what it's telling you. A square wave with very fast rise and fall times will be rounded slightly on any scope, in most cases this is not really an issue, unless you specifically need to measure the rise or fall time.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 31, 2019, 07:35:09 am
content: Quote from: joeqsmith on May 30, 2019, 05:09:51 pmDisappointing but can't say I'm surprisedQuoteI couldn't find anything about that so maybe you could point me towards this message that shows "how he was going on about not using a PC to post process data"Especially since as shown your other complaints clearly weren't exactly truthfulQuote from: joeqsmith on May 30, 2019, 05:38:29 pmHis company is managing a few large labs around the globe and he regularly buys test equipment for them which is probably why he knows so much about test instrumentsHe also mentioned what he’s doing several timesI don’t think any sales guy would have that amount of knowledge, not just about Lecroy but about all the other big brands as well, and certainly not to that level

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 31, 2019, 07:42:04 am
content: Quote from: David Hess on May 30, 2019, 03:35:03 pmHigh update rates seem to be pretty pointless for searching rare eventshttps://forum.allaboutcircuits.com/blog/the-truth-about-oscilloscope-waveform-update-rates-and-why-not-to-fall-for-it.1514/

author: joeqsmith
author_rank: Super Contributor
timestamp: May 31, 2019, 10:39:36 am
content: Quote from: Mr Nutts on May 31, 2019, 07:35:09 amAs you shouldn't be.Quote from: Mr Nutts on May 31, 2019, 07:35:09 amIf you are really interested in finding this information, it may be difficult. Besides this one forum, there were a couple of others that we were both on. He used a different name. You could try asking him to see what he remembers.*** Also, you used the word complaints. that's your perception and not something I stated. I'm not thinking I had any real problems with the guy. I know he had contacted the moderators at least once about problems he was having with a member and the fact he was banned, no doubt there were complaints from both sides. I doubt he had ever contacted them over anything I posted. I did respond to a recent post he made to let him know the SSDs were still alive but he didn't respond. I no longer use the groups so our paths don't cross very often.Quote from: Mr Nutts on May 31, 2019, 07:35:09 amHe NEVER once showed using the equipment to do ANYTHING. I brought this up a few times. Again, a sign of typical salesman, not that it matters. Just my observation.

author: 2N3055
author_rank: Super Contributor
timestamp: May 31, 2019, 12:44:54 pm
content: Quote from: Mr Nutts on May 31, 2019, 07:42:04 amBefore writing anything else, I'm sorry we got into argument. And what I write further is not a provocation or anything.I just want to discuss this, fact based, like you (and also me) like it.Let me go by the numbers it is easier to be clear and to avoid language barrier.1. 1 MWfms/sec IS a marketing gimmick, and for more than a few reasons. Most of all, at most timebases it won't be that fast, if you have trigger holdoff it won't be that fast, if you have trigger delay it won't be that fast.2. Short retrigger time IS NOT a gimmick. Short retrigger time is a positive consequence of them chasing 1 MWPS. That is a real benefit they don't market. In interactive, visual mode scope feels analog like. Also in segmented mode, you don't miss sequential events..3. If you are trying to characterise some signal that is well defined as how it should look (serial comm bus, clock etc ), something for what you have a clear specification, then staring in the screen for something to happen is definitely NOT best way to capture anomalies and best use of your time. With that kind of signal and based on specification you can devise set of triggers, searches and stats that you let run for few hours (or days, doesn't matter) and when you come back you get stats and your offenders will wait for you neatly stored in history buffer.He is SOO right about that. Funny thing is, you can do the same thing on Keysight and all other scopes. Heck, little Rigol 1000Z has so many advanced triggers like many of the midrange scopes of the yore (not very good documentation that will explain how to use it though). That kind of workflow is nothing exclusive to LeCroy. It's just since on LeCroy that is prefered workflow, they explain it and endorse it, because it plays to the strengths of their platform.BUT also, in a pinch you could enable persistence and go to lunch and, when you get back, you take a look at the screen to see if there was a glitch. It will catch it, but my biggest problem with that is that you won't know when it happened, how it happened and have no way to know that. You will just know something did happen, and now you still have to catch the culprit. So you still have to devise detection protocol, set triggers etc.So that is only partially useful. But it does provide differential diagnosis, meaning that if you don't catch anything with persistence, and you didn't catch anything with a protocol of various triggers, it enhances probability you are glitch free. So IT IS useful for that. By itself NOT much.4. If you are working on designs where you are scoping (is that a word?) just some nodes in a circuit, or you are designing something, signal will be nothing like clock or something that can be easily explained with few rules. In that case it is all about you and not the scope. Any scope will at that moment have some good and some bad things. Generally, what is useful is good measurements, history(segmented) buffers, search, stats... Some will LIKE fast interaction, some will NEED deep analysis. I like both, Keysight for interactive, Picoscope to get data on PC and then i can do anything I like. Use of brain is not optional here, no universal answer. Workflow will depend both on problem at hand and every individual skill-set, habits, and how people LIKE to work. Some people have no problem whipping up a custom analysis in Mathlab or Labview in just few minutes, and may actually prefer it that way. Some will insist that scope has to have certain analysis built in so they can just use it. Your mileage can vary.5. Thing about Mr W. is that he doesn't explain why and how he came to the conclusions he proclaims "The Truth". It is not that he's wrong about the topic (he is not right about everything but mostly he makes a good point.), but also didn't provide not even a thought process how he came to his conclusions, much less concrete examples to make his case stick. He just say "this is stupid and waste of time" and "this is solution for all problems". Long time ago when I read his original posts here, I got curious and did a little research. And I realized that he made a lot of good points but his causalities were not always correct. He was basing his assumptions on marketing material and positions of manufacturers. So he concluded that short memory / high WUR scopes (like Keysight) are inferior to long memory / low WUR (like LeCroy) scope, because on LeCroy you CAN use triggers to accomplish so much more than on Keysight with high WUR and persistence. Which was misdirection in terms.Correct conclusion is thatstaring at the screen, looking for a glitchis INFERIOR and LESS productive way of doing it, as opposed to setting triggers, segmented memory and automating search for anomalies. Problem is that Keysight can do that to, the trigger way, for most of the part. Lecroy scopes in that price range and class (Wavesurfers) have none of the advanced features of high end Lecroy machines that makes them so awesome. On lower end Lecroy triggers are not more intelligent than ones on Keysight (or Rigol to that matter), and Wavescan is just fancy name for a search.Fact that Keysight trumpets about WUR and catching glitches with persistence doesn't mean I have to use it that way. So I use Keysight like he uses LeCroy, with prudent choice of triggers and segmented memory, using pretty advanced search capabilities to drill down further. And it works, well. He was right about it, thanks a lot for that. But his dogma was you need a LeCroy to do so. You don't. On high end Lecroy with advanced analysis options enabled, you will do it faster, better, easier. But that workflow works well even on lowly Rigol, and it works well.Actually, exactly that type of workflow enables scope that doesn't have much memory (like Keysight) to not show that. Long memory is not that important in that case because you only capture what is of interest and ignore hours of signal you don't care about. So it actually complements Keysight well, hiding it's imperfections, instead of making it unusable.We could go on for years like this. Everybody will protect their choices, their cognitive biases, their way.Fact is that a good, working LeCroy Waverunner in a good shape is a hell of a scope. If you can enable advanced analysis options, you will have a scope that you can develop stuff NASA would be proud of. OTOH, some people only need scope for servicing stuff, and they want fast and familiar.All the best,

author: David Hess
author_rank: Super Contributor
timestamp: May 31, 2019, 03:14:14 pm
content: Quote from: Mr Nutts on May 31, 2019, 07:42:04 amThat article is discussing the difference between low blind time (high acquisition rate, low rearm time) and specialized triggers. If I do not know what trigger I need, then special triggers are useless. If I use the magical "trigger on weird", then it can still deliver a false negative. Who knows what it is triggering on? With DPO operation, it just comes down to statistics.Both methods are suitable for finding rare events but under different circumstances. Triggers work 100% of the time for finding the known. High acquisition rates work 95% of the time (this depends on the design and application, 100% is possible) for the unknown.

author: 0culus
author_rank: Super Contributor
timestamp: May 31, 2019, 04:49:12 pm
content: Quote from: james_s on May 31, 2019, 04:31:15 amYes, I know this. Accurate rise time measurement at 100 MHz is why I want a scope that's fast enough to do it.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 31, 2019, 05:03:21 pm
content: Quote from: 2N3055 on May 31, 2019, 12:44:54 pmForget it, as far as I am concerned it's historyQuoteQuoteI agreeQuoteI think you said it right, the scope feels analog likeAnd for some people that is important because it allows them to use methodology they know. And there's nothing wrong with thatQuoteI think this is true for every repetitive signal where the user knows how it's supposed to look like (i.e. it's not probing a completely unknown signal)QuoteHe did state that this can be done with many modern scopes, he even mentioned Rigol and Siglent, thoughAnd Lecroy never talked about WUH in their marketing material. I think the only time I saw a Lecroy sales guy talking about WUR was in an older YT video filmed at a demonstration in a company or at a reseller's placeBut you are right, it works with other scopes, too. And I guess that was the point of his article, i.e. to show people the flaws of an old method born in times when there wasn't anything else and a better alternative more suited to what modern scopes can doQuoteThat's the thing, it *might* catch it if the glitch happens to occur during the 1/10th of the whole acuisition time where the scope can actually see itIf the glitch is truly rare, it is 9x more likely to show up during blind times and will be missed by the scopeOnly triggers provide absolute certainty for the whole time the scope "looked" at the signalQuoteThat is an additional problem. Even if the scope caught the glitch, you still have to re-acquire in a real-time mode to be able to examine itQuoteThat is only partial correct. The persistence method is very likely to not show rare events because 9 out of 10 times it is completely blind, so if you don't catch anything with persistence then you still have no idea if your signal is glitch freeWith triggers n the other hand, you'll find a anomaly 100% of the time. So it's the only method to make sure a signal is actually glitch freeQuoteNo arguments here, people have their own methods they are familiar with based on their individual backgrounds, and if it works for them more power to themThe only time I'd draw a line is when it comes passing on personal preference as undeniable facts to less experienced engineers like myself, because learning outdated methodology isn't helping usQuoteI'm sorry but here I have to disagree. I believe most of the time he explains the reasons very well, based on logic and a solid background of math and physics. In fact, he seems to go to great length to not recommend something because he "feels" its better, but only because there is an objective reason for itWhat I gathered in discussions with him is that many topics he discussed, like the blog post about WURs, is not based on marketing materials but on his own experience and the experience (and frustrations) of the many of the engineers working for him. He once told me that one of his biggest pet peeves is when engineers treat a modern high performance scope like an analog scope, basically foregoing all its capabilities for what essentially is methodology from the electronics dark agesWhich I think is also why fe often fought so passionately, because he wanted newcomers to learn how to handle a DSO properly and not like a modern version of an analog scopeAnd if you look around, finding rare glitches with persistence is still the standard recommendation in this forumI can see why he put up some fight, and as a young engineer I'm grateful for thatAfter repeatedly reading all he has written in this forum I have to say that, while he certainly was a great source (the only one for a very long time!) about Lecroy scopes, he didn't come across as brand biased to me. In fact, often he recommended something else than Lecroy or advised against a Lecroy because the individual use case was better off with something elseQuoteI don't know about Wavescan (my scopes are too old for that) but back to the topic of older high end scopes, today I don't believe it matters much if you buy a decent Keysight/Agilent Infinum (not the simpler Infinivision scopes) or a newer Lecroy X-Stream scope (the older ones apparently had poor trigger suites), you will get a fast high performance scope that can do a vast amount of analysis and still makes a great everyday scopeQuoteI knowQuoteI think you will have a hard time finding something where he said that you need Lecroy to use triggers to find rare occurrences. In fact, he often mentioned that any modern advanced scope can do thatAnd there's no word in his blog post saying you can only do that with a Lecroy scopeQuoteWhich is pretty much what he saidQuoteIt complements any scope that has a good trigger suite (maybe not Tek as I've seen them missing triggers other scopes didn't) but again that's what he was sayingQuoteI agree regarding Lecroy waveruner, my LT is a fantastic scope and it's not too big, heavy or loud and makes a great every-day scope. But my new Wavepro 960 is still nicer because of the large screenMost of the time though I use my Agilent Infinum 8064 because it's a great scope, too, and has very good triggersSo it's not just Lecroy who makes great scopesBut again, you will have a hard time finding anything where Mr WH said otherwise

author: Mr Nutts
author_rank: Regular Contributor
timestamp: May 31, 2019, 05:18:59 pm
content: Quote from: joeqsmith on May 31, 2019, 10:39:36 amHe doesn't like to talk about details but what I gathered is that he must be working in defense stuffHe once mentioned that he often regrets not having much time building stuff in his home lab, that the little time he spends there is mostly for fixing instruments that broke, and that the limitations of British style housing are getting on his nervesHe said there are some projects he wants to do but he's much more likely to be able to realize them at work than at homeWhich I found rather sad. Building stuff is where the real fun isBut he said that the little free time he has he rather spends with his family, and that once he has finally left England he will have more space and more time doing fun things

author: 2N3055
author_rank: Super Contributor
timestamp: May 31, 2019, 06:44:32 pm
content: Quote from: Mr Nutts on May 31, 2019, 05:03:21 pmNo, in that blog post no, and in most posts here on EEVBLOG, not in so many words. Bu he was always implying it, using sentences like: " ....for instance , on my LeCroy i could do this and that..". I agree it could be just a figure of speech, but if you keep repeating it it starts having a meaning. To be honest, his current posts on other blog are much more balanced and he seems to try to sound more balanced.Quote from: Mr Nutts on May 31, 2019, 05:03:21 pmNeither will give you 100% POI per se. You cannot capture something with a trigger if you don't know where to aim. When you do, you'll have 100% POI. If you don't know what to look for, you're shooting in the dark.With old school persistence "trick", and by using mask testing too, you can catch things you didn't expect. I said CAN not YOU WILL 100% of time. As you correctly said even really fast scope is blind most of the time on certain timebases. But, trick is that blind time is not synchronous in relation to signal. It's time relation will be random to random glitch. So glitch will eventually hit at the time it's not blind. Also if your glitch is synchronous, on 3000T there is a trigger hold-off randomization function to ensure you're not blind always at the same time relative to signal. That will make it more likely to show. Really, it does work, if you wait enough, it works. After enough time POI starts to approach 100%. It is statistical game. Problem is what I said, you have no clue where it came from and that makes it of very limited usefulness.Truth is that those "schoolbook" glitches from scope marketing doesn't exist in real life. It is either some kind of crosstalk, in which case shape and amplitude will be different and events will be quite frequent. Or it will be some kind of malfunction or something in software or errata in CPU or something.... Point is they will either be almost obvious, or very obscure and will show only at certain very specific set of circumstances. Creating good test scenarios is the key.. And that includes calculating in your equipment capabilities.Regards,

author: tautech
author_rank: Super Contributor
timestamp: May 31, 2019, 10:23:18 pm
content: Yes well finding glitches is no longer only the domain of expensive gear with extensive/expensive and advanced trigger suites.In this post I did an exercise example to find a slope glitch with Infinite Persistence and Color so that Search settings could then be adjusted for it to find its repetitive frequency and then transfer those settings to the Trigger.Search revealed it was repetitive and some 6+ms apart.https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg1370717/#msg1370717And with a $ 499 DSO.

author: james_s
author_rank: Super Contributor
timestamp: May 31, 2019, 11:31:26 pm
content: It's kind of a pointless debate really. More features and capabilities are never really a bad thing, but just remember that people have been accomplishing great things for many years using equipment that is absolutely primitive next to the low cost hobbyist test gear of today. Like the craftsmen that created amazing ornate carvings with primitive hand tools, it's more down to the knowledge and abilities of the person using it than how fancy the tool is.Everything from computers to CD players to microwave communications gear to rockets have been developed and debugged with analog scopes.

author: nctnico
author_rank: Super Contributor
timestamp: June 01, 2019, 12:25:09 am
content: And pyramids where constructed using lots of manual labour...

author: 0culus
author_rank: Super Contributor
timestamp: June 01, 2019, 03:29:45 am
content: Quote from: james_s on May 31, 2019, 11:31:26 pmTrue, but if we desire, should we not avail ourselves of modern tools? I am not getting rid of any of my CROs. Whatever digital 'scope I get is intended to complement them, not replace them (at least for my uses).I'm currently trading off using an HP 8405A vector voltmeter in lieu of a VNA, which is another big purchase I want to make eventually as I put away a bit of money every pay period to fund hobbies.

author: David Hess
author_rank: Super Contributor
timestamp: June 01, 2019, 04:21:30 am
content: Quote from: 2N3055 on May 31, 2019, 06:44:32 pmSomething I get out of discussions like this is an opportunity to reevaluate my own designs.It is a very small step from the DPO algorithm I have been working on which takes maximum advantage of the available hardware performance to something which has both zero blind time and can automatically identify rare glitches ... simply because they are rare. The dog did not bark and that was the odd thing.It is too bad that there is no way to know what modern DSOs are doing but I find that this is an increasing problem with all kinds of instruments since about 1990. They might as well say they include magic, and sometimes they do.

author: james_s
author_rank: Super Contributor
timestamp: June 01, 2019, 06:37:10 pm
content: Quote from: 0culus on June 01, 2019, 03:29:45 amThat's not the point.The point is that while modern features are great, it doesn't mean that they are all absolute necessities. People get very passionate about this or that feature that everyone needs and fully dismiss anything that doesn't offer that particular feature. That doesn't mean the new features have no value, only that a given individual should evaluate what they actually need for the tasks they're trying to accomplish.

author: 2N3055
author_rank: Super Contributor
timestamp: June 01, 2019, 07:57:29 pm
content: Quote from: james_s on June 01, 2019, 06:37:10 pmI believe point is that many new scopes have so many protocols, measurements and analysis that many of those might not be of any use to your actual work. I really don't need AERO protocols, and some of the other stuff. So those things don't add any value to me despite having a list price. Fully loaded high end modern scope is only useful if used to its full potential. If you are using only basic stuff you only need basic scope..

author: nctnico
author_rank: Super Contributor
timestamp: June 01, 2019, 08:51:34 pm
content: Quote from: james_s on June 01, 2019, 06:37:10 pmI think it is the point exactly. Let's rephrase the question: Would you buy a Model-T Ford to commute to work for (say) 50km every day?

author: darkstar49
author_rank: Frequent Contributor
timestamp: June 02, 2019, 09:00:26 am
content: The mentioned auction is indeed a nice scope for the money...But aside from all the comments in the previous messages, for 'hobbyists', there's another criteria which is no less important (sometimes)... : 'hackability'...With whatever major brand, options can very quickly exceed the base price by orders of magnitude.As already said before, 5K buys you a lot of scope... so about hacks:Lecroy: anything with firmware below 8.x (downgrading is possible in most cases, with very recent models, I'd be careful, though...), some have apparently managed to crack 8.x, but nothing of that is publicly availableKeysight: 5-6-7000: patched firmware and/or service mode (in SM, you can activate whatever you want), 9000 and S-Series: patched firmware (but not publicly available on the net to my knowledge), DSOX2-3-4, see thread in this forum, all soft-options are available, for higher-end Windows-based scopes, no clueTek: DPO3K, 4K, MDO3K: keygen available or via h/w modules (very easy), MDO4K: a bit the same, but not sure whether the private keys are freely available on the net (these are model-dependent), for Windows-based scopes, no clue... not seen anything so far (no keygen, no patch)R&S: nada, no hack available whatsoever. RTO's & RTE's have the crypto stuff on a smart-card inside the scope, RTB & RTA use encrypted firmware files (and maybe also use a smart-card to store the private keys inside the scope), not seen anyone able to hack these so far (it still should be possible to patch the software, but that requires being able to decrypt it first...)To come back on Lecroy, be advised also that all suit-case format scopes (Xs, Xi and all derivates) are out-of-support... what I mean is that Lecroy (and their suppliers) is out of parts for these models, in particular do they use a custom-made Mini-ITX motherboard, with a PCI-104 connector (instead of PCI), which is unobtainium (really ! confirmed by Lecroy). Only WaveSurfers with serials >= LCRY0320xxxxx use another type of mainboard, with a standard connector (for the interface board), for those, mainboards ares still available.It's fairly easy to check: if there are PS/2 connectors for mouse and keyboard, it's the old-style mobo, and mobo failure = you're in deep sh!&tThe 6000 series is indeed nice, there's plenty of room for a mobo upgrade, and it uses standard PCI for the interface board, but there are however two things to know:1) the driver for the interface board really has its issues with SMP, i.e. you can activate multiple cores, but can have various and weird effects (freezes, crashes,...)2) the USB chip for the front-panel has some 'bugs', which makes it incompatible with many (more recent) mobo's, Intel's series 6 is the latest that works (although some have managed to circumvent that with an additional USB controller board...)And while the Ebay scope mentioned is fine, for a grand less, you can have the exact same model from Lecroy themselves (Lecroyfinds on Ebay), although some 'tuning' will be required... ;-Cheers

author: YetAnotherTechie
author_rank: Regular Contributor
timestamp: June 02, 2019, 12:29:39 pm
content: Quote from: darkstar49 on June 02, 2019, 09:00:26 amRTB, RTM, RTA and FPC don't have smart card, only nand flash, and options is stored there, this info comes from instrument security pdfs.I don´t understand why no one is looking, they put nice 3 pin connector on board(serial?) next to labelled jtag connectors, and labelled test points for flash chip, There is also scpi commands to load firmware to ram, has anyone tried to telnet even?

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 02, 2019, 01:56:24 pm
content: someone PM me but i prefer to share the answer here....Quotenow i only have brief moment with LeCroy DDA/SDA DSO, still rearranging/repairing stuffs here and there, so i have no real world experience yet with these DSO. but so far from what i've tested, can they be used for general purpose scope? my answer is yes, if specialized feature such as peak detect or bode plot is not critical for you, the excellency lies on their double digit GSps sampling rate and > 1GHz BW, some applications really demand for this. DDA3000 has normal BNC input, 100Vp on 1Mohm input and 5Vrms on 50ohm input. coupled with hi-Z 1/10X probe you can probe normal household mains circuit (1000Vp max), so i believe this figure is enough for general purpose hobby use. ymmv.Quoteyou can check that lecroy license recovery thread. the answer is "very yes" you can do software upgrade feature such as SDA, SA capability etc but not the hardware (AFE memory etc). (see attached) if someone mock you that you dont have peak detect, nevermind you can show them or mock them back with that USB2 (dedicated HW required) or the Ethernet/Electrical/Power/SA measurements feature.Quotecurrently in progress but it has gone behind the queue as some other more demanding tasks is in order cutting the queue. there is thread discussing it you can search. i think i have all the parts needed ready, i already have one working 3d printed prototype but i need to further refine it. DDA3000 doesnt require this as it is BNC input already. fwiw.one thing to note, that the other brand dont have but unique to older LeCroy scope, they have input auto calibration timeout from time to time, when you change timescale or voltscale etc, this can be annoying to some people, this can delay progress or smoothness of our measurement. the OP of the 3000 upgrade thread already sold his dda3000 just because of this. if you cant live with this, then its not suitable for you. we learn to get by with it and how to minimize it or entirely make it out of the way (pick the optimal time/volt scale for your measurement and dont ever change it until next stage of measurement). poking @YetAnotherTechie

author: joeqsmith
author_rank: Super Contributor
timestamp: June 02, 2019, 05:26:37 pm
content: Quote from: nctnico on June 01, 2019, 08:51:34 pmI guess if I lived and breathed Model-T Fords. Funny how on forums, TE always seems to relate to cars. I think my VNA would be a horse and buggy. You want to talk about a lack of modern features. It doesn't take a shit very often like a horse would but it does still get me around, proving once again the power of Labview and a hobbyist with half a brain.

author: Kosmic
author_rank: Super Contributor
timestamp: June 02, 2019, 05:41:10 pm
content: Quote from: Mechatrommer on June 02, 2019, 01:56:24 pmDDA-120 and DDA-110 have BNC inputs with 400V max on 1M\$\Omega\$, 5V max on 50\$\Omega\$. If you just ignore the extra buttons (disk drive analysis functions) they are similar to lecroy LC series scope but with more memory.

author: Kosmic
author_rank: Super Contributor
timestamp: June 02, 2019, 05:44:49 pm
content: Quote from: joeqsmith on June 02, 2019, 05:26:37 pmI just realized that NI is selling a labview bundle for home user. And it's pretty cheap.http://sine.ni.com/nips/cds/view/p/lang/en/nid/213095

author: joeqsmith
author_rank: Super Contributor
timestamp: June 02, 2019, 05:53:31 pm
content: Quote from: Kosmic on June 02, 2019, 05:44:49 pmI have a few friends who bought that kit from Sparkfun just for Labview. $50. It was water marked but we tried running some pretty complex code on it and saw no problems. It did not appear to be crippled.

author: Mr Nutts
author_rank: Regular Contributor
timestamp: June 02, 2019, 06:03:43 pm
content: Quote from: darkstar49 on June 02, 2019, 09:00:26 amThe Lecroy WR6000 may be a nice scope but it’s trigger capabilities are very poor as it only offers a very limited set of standard triggersThere isn’t even aglitchrunt triggerSo unless you’re fine with something simple like edge trigger or logic trigger then its not a great choiceFor some reason Lecroy has given the WR6000 (and I believe the WP7000, too) only simple triggers while the predecessor models WR2 LT and WP900 had very versatile trigger suitesAnd the successors to the WR6000 (WRXI?) also got better triggersSo a WR2LT or Wavepro 900 might be a better alternative. And the build quality is better, too

author: darkstar49
author_rank: Frequent Contributor
timestamp: June 02, 2019, 08:42:35 pm
content: Quote from: Mr Nutts on June 02, 2019, 06:03:43 pmIt's a long time I didn't start my WR6K, but I can't recall the trigger options to be as limited as you depict it...And the data sheet also shows a somewhat less pessimistic version...?? But agreed, there are better scope nowadays, the point is: a WR6050A (4 x 5GS/s) sells at Lecroy for 1700 USD, which is pretty OK, one of the last 104MXi on Ebay sold for about 3.5K USD, certainly a better choice...http://www.libertytest.com/assetmanager/uploaded/pdf-2008418-135844-lecroy_wr6100a-wr6200a.pdf

author: darkstar49
author_rank: Frequent Contributor
timestamp: June 03, 2019, 09:32:37 am
content: Quote from: YetAnotherTechie on June 02, 2019, 12:29:39 pmAre you 100% sure of that ?? RTB/M/A firmware files are definitely encrypted, and you're suggesting that the (private) key for decoding these is simply stored on some flash inside the scope...R&S is serious about privacy and security, this would be a serious design flaw in that regard... but I never owned an RTB/M/A (only an RTO1024).Having access to a JTAG debug connector is most probably not sufficient to gain sufficient understanding of the (binary) code, and find out where to patch to fool the key verification (or something similar), assuming the way it's coded makes it possible...

author: YetAnotherTechie
author_rank: Regular Contributor
timestamp: June 03, 2019, 03:03:34 pm
content: Yes, i'm sure about no SIM and options storage location. However there is OTP area in the flash, there is encryption/or compression OTP key on the big FPGA, and there is presumably a ARM9 physical core in the system fpga, that for sure also has OTP key encryption/or compression, trusted boot, etc. That´s not really hackable. However, there can be exploits at the OS system level, like for other scopes. As extra incentive, there is no difference in total memory between RTM and RTA, so it must be software choice....

author: free_electron
author_rank: Super Contributor
timestamp: June 03, 2019, 03:45:01 pm
content: Get a used Agilent 7000 series. unlock it... for 5K you will have a top end machine with a humonguous screen , deep memory and 4 samplers ( as opposed to many other older dso's that interleave their samplers to save costs .. )bonus: if you get an MSO type device you can do mixed signal as well.

author: darkstar49
author_rank: Frequent Contributor
timestamp: June 03, 2019, 04:15:27 pm
content: Quote from: free_electron on June 03, 2019, 03:45:01 pmIf you 'unlock' it, you've got MSO....All 6000 and 7000 have the MSO hardware, whatever the model, only the 5000 not.

author: egonotto
author_rank: Super Contributor
timestamp: June 03, 2019, 04:41:08 pm
content: Hello,free_electron wrote "Get a used Agilent 7000 series".This can not be MSO/DSO705xB, 710xB: 4 GSa/sec half channel*, 2 GSa/sec each channelMemory depth 2 channels/4 channelsStandard 8 Mpts/4 MptsWhat scope do you mean?Best regardsegonotto

author: nctnico
author_rank: Super Contributor
timestamp: June 03, 2019, 05:02:09 pm
content: Quote from: free_electron on June 03, 2019, 03:45:01 pmI used to own an Agilent DSO/MSO7000 series. It is quite noisy (even with bandwidth limit on) and rather cumbersome to operate if you want to setup things like decoding.

author: free_electron
author_rank: Super Contributor
timestamp: June 03, 2019, 06:11:05 pm
content: Quote from: egonotto on June 03, 2019, 04:41:08 pmyup. those. they have 4 a/d converters running at 2Gs/s . in 2 channel mode they interleave two converters to get double rate. I personally use a 7104 as my daily workhorse. It is very responsive , has a large screen ,works with most of the infiniium active probes , has protocol decoders , sufficient memory and fast update rate. It does not need to boot from a harddisk or run some operating system that gets in the way and slows down the machine (like lecroy and RS)( it does , it runs vxworks , but boots from flash in a few seconds and you don't know there is an OS running. It follows good ol Agilent philosophy : do things in hardware)This is different from having only 2 converters and interleaving channels. Those kind of machines (can) lie to you ( like the TDS5xx series from tek ) as they sample one channel , then on the next trigger sample the other. so what you see on the screen is taken from two different time origins ! this only works on repetitive signals. and you can forget about catching glitches...in old analog scopes you could run in alt or chop mode but many of the early generation digital scopes ran in alt mode only. And that is VERY dangerous as the time correlation is lost.

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 03, 2019, 08:48:36 pm
content: where do you get it at $5K. i checked in ebay MSO7104B 1GHz 4GSps currently cheapest is $8K, normally $12Kis this what you mean?well it should be nicer if they interleaved it to 16GSps @ 1CH.

author: free_electron
author_rank: Super Contributor
timestamp: June 03, 2019, 09:15:33 pm
content: Quote from: Mechatrommer on June 03, 2019, 08:48:36 pmYeah, make it 16Gs @ 1ch with 2 Terasample of memory per channel and all for the low price of 99.99$ , but wait , if you order now we will double the memory, just pay shipping and handling ...You should be able to find a 350Mhz version of that machine for around 5k. ( A version,not B version )

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 03, 2019, 09:27:36 pm
content: thats funny... make it $49.99 or...500GHz ($17/GHz)

author: rsjsouza
author_rank: Super Contributor
timestamp: June 03, 2019, 09:42:08 pm
content: If you need the bandwidth... 204MXi for $4.5k.https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F153435599160I found some DSO7034/7054 for more than $6k and above, thus it may be a matter of patience.

author: nctnico
author_rank: Super Contributor
timestamp: June 03, 2019, 10:25:02 pm
content: Quote from: Mechatrommer on June 03, 2019, 08:48:36 pmThat is insane. These should go for between the $3k and $4k mark. None have sold during the past 3 months so it is another case of delirious Ebay sellers. And besides that I'm not sure it is the best buy as a general purpose oscilloscope.

author: darkstar49
author_rank: Frequent Contributor
timestamp: June 04, 2019, 04:26:22 am
content: Quote from: nctnico on June 03, 2019, 10:25:02 pmCouldn't agree more... the 6000 & 7000 were nice scopes, but they don't keep up with the 3000X, which typically sells for less...Most of the 7000 models are ridiculously priced, and have been on Ebay for years (not months... years !!!)