beginners DSO questions  - Page 1
Forum section: electronics / testgear

author: picandmix
author_rank: Frequent Contributor
timestamp: July 29, 2016, 11:01:36 am
content: Hi,Helping myself and someone else select a beginners DSO and a couple of common questions arise.The Hantek DSO5102P and 5072P have been covered in a few reviews / posts but many of them are several years old.Wondered if these Hanteks have been improved in the last few years and do not suffer from the lockup problems etc. or have just remained the same with the same bugs ?(We know there is a 112 page hacking thread on them)Also the Siglent range SDS1052 to SDS1102CML do sound more reliable devices, but the display screens have a much lower resolution, is that really a drawback in operation ?We know the Rigol 1054Z is the prime budget choice, but at twice the price of the Hantek or over GB £100 dearer than the Siglents its a big gap.Also interested to know if anyone has bought any of the above scopes from the well known UK Ebay suppliers, though most seem, including the warranty, based in China.thanks

author: Cervisia
author_rank: Regular Contributor
timestamp: July 29, 2016, 12:07:01 pm
content: I'm happy with my SDS1052DL's screen.But note that Siglent recently introduced new "CML+" devices with 800 x 480 screens (and, in theory, the same price).There are official UK distributors:http://siglenteu.com/howtobuy.aspx

author: picandmix
author_rank: Frequent Contributor
timestamp: July 29, 2016, 01:44:15 pm
content: Quote from: Cervisia on July 29, 2016, 12:07:01 pmThanks for that, had not seen any mention of the CML + models having the higher res screens and see the 1102CML+ is in one UK stockist for just a little more than the 1052DL.The SDS1052DL was looking like our favorite, and good to hear first hand comment about the screen resolution being ok for "typical" use.Any other comments you could share about it that you have found good or bad even.Assume unlike the Hanteks, it does not lock up frequently, ( though gather this is common amongst many budget scopes)

author: pascal_sweden
author_rank: Super Contributor
timestamp: July 29, 2016, 02:09:00 pm
content: If you are not going for the Rigol DS1054Z, and want to stick with the low-end Siglent, at least you should go for the + model, as the other models are old, and replaced by the + model.

author: tautech
author_rank: Super Contributor
timestamp: July 29, 2016, 09:26:30 pm
content: Quote from: picandmix on July 29, 2016, 01:44:15 pmIf you can stretch to the CML+ models do so. The only 32Kpts of memory depth in the DL models is a serious limitation when a captured waveform is zoomed in on.CML models have been my best seller, they're a rock solid unit.My comments on the CML+ model can be seen in this post:https://www.eevblog.com/forum/testgear/siglent-technical-support-join-in-eevblog/msg987025/#msg987025

author: picandmix
author_rank: Frequent Contributor
timestamp: July 30, 2016, 03:08:45 pm
content: Thanks for the guidance , we have been looking at those links/posts and the new sds1102cml+ does sound good and importantly, the comments on reliablilty /build quality of the Siglents scopes does seem to be universal.The biggest problem for us is that neither of us has any practical experience of modern DSOs , just the old analogues, so we can read about such modern features and specs but cannot fully appreciate them.Had an email friend who had a Rigol 1052 from new and he had problems with the control knobs failing after a couple of years, seems its not an uncommon fault either, and though the newer 1054Z has 4 channels its only 50mhz , and though hackable to 100mhz not something we would want to attempt.While Davy and the forum nearly always go for the new Rigol 1054Z at 50mhz with the bigger memory and higher price, could you spare a few moments to say how the new 1102CML + compares against the 1054Z; just a simple comment about any key differences between them that you think we beginners might miss.Thanks

author: alsetalokin4017
author_rank: Super Contributor
timestamp: July 30, 2016, 06:32:13 pm
content: The biggest key difference is that the DS1054z has four channels and the SDS1102cml+ only has two. Depending on the work you do or anticipate, this may be the main feature to consider. I need four channels + math, you may not.The 100 MHz "hack" for the DS1054z (which also unlocks a whole slew of other features as well such as advanced trigger options, recording, decoding, more memory depth) is just a matter of generating a code from a web-based keygen and entering the code into the scope. It's simple to do and can easily be removed, restoring the scope to "virgin" 50 MHz with no options.The Siglent has separate H and V controls for each channel, while the Rigol has one set of controls that is switchable between the 4 channels. The Siglent has an external trigger input jack, while the Rigol does not. If you need external triggering with the Rigol you have to use one of its normal channels, making it effectively a 3 channel scope with external trigger in that case.The Rigol appears to have more math functions than the Siglent. Whether they all work as they are supposed to is a different question.While I do have some complaints about the DS1054z, knobs falling off isn't one of them.And if it ever does become a problem.... well, I have glue and I know how to use it.If I were looking for an alternative to the Rigol today, I would consider the GWInstek line before Siglent.An example of 4 channel use: Timing, propagation delay and rise/fall times in debugging a TTL circuit:

author: pascal_sweden
author_rank: Super Contributor
timestamp: July 30, 2016, 06:54:56 pm
content: One can wonder if the Siglent SDS1052CML+ and SDS1102CML+ really make use of the higher screen resolution in all aspects (waveform and menu structures), given that these scopes are based on the older non + models with a lower screen resolution.I noticed that the silkscreen printing on the front panel of the older non + models was actually better in several aspects. Of course I realize that this is probably a matter of personal taste.Here are some examples of the differences in the silkscreen printing between the old and the new models:1) MATH, REF, AUTO and other text is printed much bigger in the older non + models.2) CH1 and CH2 is used to indicate the respective channels, while the new + models just indicate 1 and 2.3) The text is centered above the BNC connectors in the older non + models, while it is not centered in the new + models.4) The arrows for horizontal and vertical position are much more subtle in the older non + models.5) The "Push" wording is used below the buttons to indicate that the button can be pushed in the older non + models, which is a much cleaner and better approach IMO than the big and funny symbol that they use in the new + models

author: alsetalokin4017
author_rank: Super Contributor
timestamp: July 30, 2016, 07:10:27 pm
content: Heh.... and the Rigol has that unambiguous "finger>arrow>knob" pictogram that tells the user that the knob is pushable, along with a word that tells you what you get when you push it .... it's really cute. All except for the Horizontal Scale button-knob that puts the display into "zoom" mode when pushed ... that's not indicated with a pictogram for some reason.

author: tautech
author_rank: Super Contributor
timestamp: July 30, 2016, 07:53:11 pm
content: Quote from: pascal_sweden on July 30, 2016, 06:54:56 pmThe SDS1000**L+ models have new+ series specific FWto support the new features of LANandthe higher res display.

author: tautech
author_rank: Super Contributor
timestamp: July 30, 2016, 09:28:13 pm
content: Quote from: picandmix on July 30, 2016, 03:08:45 pmI fully understand the "new world" that confronts you, but be assured the experience you have with CRO's will stand you in good stead. Just knowing what to expect on the display is an overlooked bonus and subconscious sanity check that scope newbies just don't have.Operation procedures are much the same except for more advanced use, you don't have a dual timebase as such but a Zoom, normally as a split-screen on the display. Trigger types are within menus and even basic DSO's offer more than CRO's and some have user definable parameters. Single shot and Normal triggering and especially when used in conjunction with definable Trigger settings are IMO the most powerful tools in a DSO.You will battle with new measurement methodologies until you get a handle on the different UI of a DSO, some say it's harder to change from a CRO but when I did I never went back, DSO's are just so much more powerful. It does help to Tee a DUT connection and input into both for a very short while until you are comfortable with a DSO UI but that won't last for long.DSO's do take a little more "driving" but really that's a result of their greater feature set. Learn it, use it.One thing that you may find disconcerting after CRO's is DSO trace thickness, you may have noticed it in the many DSO screen shots in various posts/threads. This is something one needs to understand, even overlook or ignore to some degree and Dave did a couple of good vids on this well known phenomenon.Search for "why do DSO's appear to be noisey". (part 1 and 2)QuoteWhere to start......Functionally the new SDS1k**L+ models are no different to the earlier versions, still a rock solid basic DSO and serves owners well that know how to use them to their potential.IF your needs are or will be more advanced in the future neither are "quite" the right choice.Both scopes have the same but different sampling rates with 1 (full) or 2 (halved) channels used, meaning the "data points" captured and then used in the interpolation algorithms for "accurate" waveform reconstruction. When more than 2 channels are used with a 1054 sampling rate falls to 1/4 of the full rate and far less data points remain for accurate waveform reconstruction.Most other differences are overly apparent with study of each datasheet excepting the ongoing threads of problems with measurements and infrequency of FW updates for the 1054.By small comparison the last FW update for the SDS1k**L series was 1 year ago, they've not been needed.Then there are threads of bricked Siglents or their rebadges where users have installed the wrong FW for the HW version.There's one more thread you would need to read before you have the full picture of comparison of HW and FW between these 2 models.Search the forum for Yaigol.Others will no doubt have more to add, threads such as this usually turn into a scope pissing contest, mine's better than yours....etc.Now I wonder how this thread will go.......

author: bitseeker
author_rank: Super Contributor
timestamp: July 30, 2016, 09:52:24 pm
content: Good summary, tautech. I'll add that the just recently released firmware for the DS1054Z appears to have addressed most of the outstanding functional issues except Vrms measurement on non-triggered channels. The firmware review is still ongoing in the mega-Rigol thread, but so far, it's looking good.

author: pascal_sweden
author_rank: Super Contributor
timestamp: July 30, 2016, 09:57:38 pm
content: Regarding the Yaigol project. That thread is very long, and it is not so easy to grasp the current status and the overall outcome.Therefore I posted the following entry therehttps://www.eevblog.com/forum/projects/project-yaigol-fixing-rigol-scope-design-problems/msg993989/#msg993989

author: nctnico
author_rank: Super Contributor
timestamp: July 30, 2016, 09:59:38 pm
content: Quote from: tautech on July 30, 2016, 09:28:13 pmIn addition to that: it is always good to take some time and learn how an instrument works and how to trust it's readings. In case of a DSO a function generator with digital controls (like the ones from Feeltech) will be a very useful addition.

author: bitseeker
author_rank: Super Contributor
timestamp: July 30, 2016, 11:10:02 pm
content: From what I recall (too many posts to go back and read it all again), I'd sum up the Yaigol thread as an excellent and educational deep dive into an early-release Rigol 2000-series scope that had a PLL jitter issue and the subsequent hardware fix. Rigol released a firmware fix for the 1000- and 2000-series scopes to resolve most of the jitter (i.e., good enough). Others posted that their newer 2000-series scopes did not exhibit the same hardware issue. I don't know if the 1000-series hardware was also revised or just the firmware fix took care of it. No recent discussion of jitter on the 1054Z comes to mind.

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: July 31, 2016, 01:29:48 am
content: I never saw anyone show any proof that the "fixes" applied by the OP of the Yaigol thread made any improvement in actual use.

author: JPortici
author_rank: Super Contributor
timestamp: July 31, 2016, 06:06:14 am
content: Quote from: alsetalokin4017 on July 30, 2016, 06:32:13 pmNow until we get the same prices in europe you get from tequipment. The interesting GWis still started at 800+VAT instead of "about the price of the rigol"

author: tautech
author_rank: Super Contributor
timestamp: July 31, 2016, 08:26:27 am
content: Quote from: bitseeker on July 30, 2016, 11:10:02 pmEh hm.Read the Yaigol thread OP again and the post it contains a link to, and the attached screen shots.Yes the PLL had a jitter issue but what that caused you conveniently overlook, that was and potentially still is a serious trigger issue that in some conditions would not allow a stable waveform to be displayed.It was so bad that it prompted Dave to do a vid dedicated to the issue to hurry a FW bandaid to cover their HW mistake.To this day I have seen no evidence of HW revisions that indicate this has been corrected. Did I miss one?After all the ability of a scope to trigger correctly on a waveform is a fundamental requirement of any scope. Right?

author: picandmix
author_rank: Frequent Contributor
timestamp: July 31, 2016, 08:38:12 am
content: Thanks all, partic TauTech, for all the information, a lot to go at !Will let you know what we end up with....

author: tautech
author_rank: Super Contributor
timestamp: July 31, 2016, 08:43:35 am
content: Quote from: picandmix on July 31, 2016, 08:38:12 amYou own CRO's you said, what voltage rating are the channel inputs, as you probably know not all scopes are equal in this respect.

author: picandmix
author_rank: Frequent Contributor
timestamp: July 31, 2016, 09:04:15 am
content: QuoteThe CRO is a Hameg HM604 with a 1-2-5 from 5mv - 20v rated at 400v which seems comparable to the SDS1102 2mv - 10v at 400vAll other spec seem to be greater than the old Hameg, which after 30years it hopefully is

author: nctnico
author_rank: Super Contributor
timestamp: July 31, 2016, 10:44:50 am
content: Quote from: JPortici on July 31, 2016, 06:06:14 amIf you comparehackedRigol versus GwInstek: yes but the GW Instek 1000B series is comparable to the Siglent CML1000+ series and the pricing is pretty competitive between the two so it comes to things like memory depth, channels (4 versus 2) and so on. For fun I dug a little deeper into the Siglent CML1000+ series and it seems the 50MHz version doesn't have the 2Mpts memory. Also you need to enable the long memory mode explicitly.

author: Fungus
author_rank: Super Contributor
timestamp: July 31, 2016, 11:52:26 am
content: Quote from: tautech on July 31, 2016, 08:26:27 amNo, but to this day nobody has demonstrated that this "huge design flaw" has any effect whatsoever on the function of the 'scope.Quote from: tautech on July 31, 2016, 08:26:27 amYes, but it's been fixed since about a year ago.Quote from: picandmix on July 31, 2016, 08:38:12 amBut ... as he himself notes, that's anoldproblem that was fixed in a firmware update. It doesn't happen any more.

author: Fungus
author_rank: Super Contributor
timestamp: July 31, 2016, 11:54:16 am
content: Quote from: nctnico on July 31, 2016, 10:44:50 am...whicheverybodydoes, so it's moot.The GW-Instek isn't competitive with the Rigol on featuresorbuild quality.

author: nctnico
author_rank: Super Contributor
timestamp: July 31, 2016, 12:03:38 pm
content: Quote from: Fungus on July 31, 2016, 11:54:16 amRepeating a false assumption doesn't make it right. If what you wrote where true then why would I have bought a GW Instek? After all I'm Dutch and Dutch people don't spend money unless there is a really good reason to do so.

author: Fungus
author_rank: Super Contributor
timestamp: July 31, 2016, 12:59:52 pm
content: Quote from: nctnico on July 31, 2016, 12:03:38 pmNo idea.Quote from: nctnico on July 31, 2016, 12:03:38 pmI'm not saying it's rubbish, I'm just saying it's got half the bandwidth, it's mostly not competitive on features (see below) and build quality is worse (Dave's conclusion, not mine - see his teardown video).The GW-Instekdoeshave a couple of strong points: eg., If FFTs are very important to you then it may be a better choice. The Rigol's FFT function isn't as good.It also has a proper push button to make a menu selection instead of using a twisty knob. Is that worth more than double-bandwidth? It's up to you...PS: It's not me "Repeating a false assumptions", it was the GW-Instek fanboys that started it. As usual.(this time they started with a repeat of the 'Yaigol' PLL nonsense - which has never been shown to have any adverse effect on anything)

author: bitseeker
author_rank: Super Contributor
timestamp: July 31, 2016, 10:48:40 pm
content: Quote from: tautech on July 31, 2016, 08:26:27 amIt was not my intent to overlook anything, conveniently or otherwise. That's why I included the disclaimer that I hadn't gone back to re-read the Yaigol thread and was only summarizing from memory.Thanks for the additional info. Anyone who wants to know exactly what was done and what outcomes occurred, if any, should read the whole thing.