Yet Another "Which Oscilloscope" thread (though slightly different, I promise) - Page 1
Forum section: electronics / testgear

author: Agouti
author_rank: Newbie
timestamp: February 16, 2024, 09:25:41 am
content: Hi All,I know a lot of these threads get started, at times as the first thing a newbie does when window shopping 'scopes (I've read through at least a dozen by now) but I've not yet seen one which hits the points I want to. I'm going to try and be as detailed as possible to save too much back-and-forth Q&A, but also organize to avoid a huge wall of text.I have a cheap and nasty tablet oscilloscope that I inherited off someone else who - like me - decided it's not worth keeping, and want to get something a bit more future proof. Now, I have a good idea what I want to do with it, but I'm not convinced I know what I need, so I'm as much after the specs to shoot for as actual models which hit that.What I want is an oscilloscope to support me in automotive and (more significantly) marine troubleshooting, including generators and power systems. I'll list below what I want out of the scope, in rough order of importance and achievability, what I think that means in terms of performance, and summarise by listing a few options I've been considering.1. Form factor - Portable preferred. As for USB vs Tablet, I already take dedicated laptop with me for most work for plugging into ECUs (STAR/DICE/etc), so a USB scope isn't a big issue for me, and even a desktop would be workable if justified. Basically, capability first and anything goes, but more portable is more convenient.2. Basic RF/signal/electrical system troubleshooting - voltage, waveform, and duty cycle of things like cam-angle sensors, O2 sensors, CANBus. Most sensors are low bandwidth, CANBus tops out at 1 MHz I believe, so none of this should be difficult for any half-decent 20 MHz scope. Most of this only needs 2 channels, but rarely I've had situations where it would have been nice to have a third (CAM/Crank/ignition) but it's not required to get the job done. The general sentiment from YouTube guys is 4-channel is very nice to have if the budget will stretch, but I don't (yet) see it as mandatory. The ability to read CANBus words would be neat, but it isn't something I can see myself needing very often (and I would think I could always just take a snapshot and do it by hand, anyway).3. Long-term logging - There's been occasions where I've had to do long-term (overnight) logging of things like generator voltage stability which I can borrow a dedicated device for (e.g. Fluke power meter) but I'd like to be able to do with my own scope. The total number of samples isn't high, 50k at most, but the samples need to be pre-processed/math outputs (e.g. min/max peak voltage & frequency for whole sample period) not raw. If it has to be raw samples, it'd be more like 1k samples per second for 6 hours or more. This is also another scenario where higher channel count would be convenient, but you can also get by with 2.4. Time domain reflectometer - being able to roughly estimate where a high resistance/short to ground is along a wire run would be particularly nice to have, ideally to within 0.2m or so. It's not really required for engine looms and the like, since you can just inject a waveform and follow the wire with a probe to find where the issue is, but for wiring that disappears into cavities knowing where to start would save a lot of time. I believe the propagation speed will probably be around 100m/us for everyday wiring, so both ways that would mean 0.2m would work out to 4 nanoseconds time-of-flight. To me this suggests that 1GS/s should give the accuracy I want, and a 100 MHz scope should be enough... but then there's no way untwisted pair can carry a 100 MHz signal so I'm not really sure if that's even relevant. I believe higher end scopes actually come with pulse generators for this sort of thing, but it looks like making a little pulse generator isn't very hard so it doesn't seem important.5. Starter current compression and timing testing - I'd like to be able to do quick compression and ignition timing tests for engines that are having problems starting. The idea is by looking at the current draw waveform on the starter you can get a estimate for relative compression between cylinders, and combined with ignition probe can check if the timing is at least close. With a sparkplug or injector compression probe you can even check for obvious valve leaks, cam timing issues, and excessive exhaust back-pressure. I don't think any of this would be particularly hard for an oscilloscope (sample rate would be what, 100kHz at most?) but having a good low band pass seems like it would be important to filter out all the noise from commutators and such. This would also be a case where a few extra channels would come in handy so you can check the crank angle sensor at the same time. However, this does also seem like a situation where small portable screens would really get annoying, and having a USB scope that output straight to my nice laptop screen would be good. I also like the idea of being about to export the samples out of the scope program into a Python script or similar and get it to spit out the data I want.I know the Autoscope IV does this, but I don't want to just trust a blackbox that spits out numbers with unknown assumptions and accuracy. It's also expensive.6. I want it to be reliable, trustworthy and not frustrating to use. Reasonably snappy controls, no stupid little interface foibles, and as little faking of data as possible. I'm really not a fan of how some scopes (like Hantec) seem to apply post-processing to their measurements to make it look more professional, things like smoothing and even (in reviews I've seen) in-between sample estimation to make a 500 MS/s scope look like a 1GS/s as advertised. I have to be able to trust what it is saying and trust it to work when it's needed.7. Lastly, and not lastly, budget. As with most people I don't really have a fixed budget, but I'd like to keep it under AUD$1k if possible. Like most shoppers, I'd rather spend less but I also subscribe to the "buy once, cry once" philosophy, so ultimately whatever needs to be spent will be.Right, so with all that out of the way, here's a few I've been considering.1. Picoscope ($500-$1700+)- I'm not sure which model would be the right pick here, but I'd probably pick the 8 bit 2 channel 100MHz 2208B for about $1k. Having four channels would be nice, but the 4 channel 2408B is $1700 which is really pushing the budget for something that is mostly convenience (I think). 12 bit is also just an unjustifiable luxury. If I ignored the TDR side of things, I'd probably go for the 50 MHz 4 channel 2406B for $950 (and maybe 50 vs 100MHz doesn't matter here? Maybe 20MHz would be enough?). I don't think I need to spend extra for their dedicated Automotive scopes and software, as they seem like a lot more money for not a lot more compared to a base scope with some cheap-ish leads and sensors. I could just be missing the use cases here, though.Pros: 4 channel options, seems more reliable/accurate/trusted.Cons: Expensive.2. DreamScopeLab ($400+) DS4T1012 150 MHz 2 channel hand-held for about AUD$400 (I think? Website says $250 but I'm assuming that's USD since other sites list for USD$200), or U3P100 100MHz 2 channel USB for about $600. This one is an annoying one, since the newer hand-held is obviously more capable than the USB with the former in some sort of permanent quasi-sale discount. There's definitely times when a hand-held would be nice to have but I'm worried I'll miss the ability to export and post-process the raw samples, and I believe the DS can only export screen captures. I'm also not really a fan of touchscreens in general, even getting my phone to play nice in a hot and sweaty engine room is frustrating enough without having to pinch zoom and swipe the oscilloscope, so I'm not sure if the convenience for quick jobs makes up for the frustration for long ones.Pros: Cheaper, seem well built compared with most Chinese baby scopes.Cons: Max 2 channel, not as easy to trust, touch-screen probably annoying for DS3. Autoscope IV ($1400+)- a lot more than I want to pay but comes with a lot of accessories and convenience factors. I can see the software being useful once trusted, but it feels like most of what you are paying for is dumbing down things for the mechanics who don't want to learn how to read oscilloscopes. I don't think the value is there for me at this stage. The high channel count (8 for the full job, 6 for the lite, plus various dedicated trigger/high voltage/pulse capture probes) is nice but the bandwidth is way lower than similarly priced Picoscopes (the AUD$600 Lite has a max sample rate of 250 KHz which is divided amongst the active channels).Pro: Convenience, probe & sensor ecosystem, clever softwareCons: Not very capable as an actual oscilloscope. Limited capability in diagnosing CANBus High.4. Siglent SDS1104X-E or similar desktop scope (~$600+) - most of the time I have a way to get 240V, and space I can stick a full desktop scope, but it would definitely be a lot less convenient than the equivalent USB scope, I think. I also worry about how dirt, grease, maybe even water might contaminate the insides via those big, open vents in the top. From what I can see in the spec-sheet and manual, it looks like it can be used as a pure USB scope, which would mean I could bag or box it in some way to protect it while using it like I would a Pico, but once you factor in the cost of a pelican case or risk for a soft bag - not to mention having to lug something that size around - I'm not sure it makes sense.Pro: Better value for money, more use outside automotive/marine diagnosticsCon: Vulnerable to damage5. The rest - OWON, Hantek, Multicomp Pro, FNIRSI, et al. All of these brands offer better claimed performance for less money, and sometimes better thought out things like hand-helds with actual buttons, but always with a caveat or always needing someone to actually check they aren't fibbing or make sure they are built right in a teardown. I really dislike the sort of dishonesty or relaxed approach to the truth that seems built into these cheap electronics manufacturers, and I'd rather just boycott them completely. If you think this is being too harsh or stereotyping too much by all means, I could be convinced otherwise... but.Pro: CheaperCon: Less reliable/accurate (?)

author: skander36
author_rank: Frequent Contributor
timestamp: February 16, 2024, 10:45:08 am
content: For me Pico seem the best option, but why not Micsig? It has dedicated Auto models.

author: Agouti
author_rank: Newbie
timestamp: February 16, 2024, 02:28:12 pm
content: The ATO series? The most basic one, ATO1004, retails for AUD$1500 and, like the Autoscope, I don't see what it brings to the table apart from lots of software "wizards" which I don't really want. I can see how the myriad of software tutorials could be worth it for some but I'm not fond of it.The STO1004 and VTO2004 both at around the $900 look promising, I'm going to research those now. There's also a VATO2004? Might be a clone.

author: tunk
author_rank: Super Contributor
timestamp: February 16, 2024, 02:31:10 pm
content: Could this be an alternative:https://www.hantek.com/products/detail/16175

author: Agouti
author_rank: Newbie
timestamp: February 16, 2024, 02:36:38 pm
content: I had seen the little Hantek hand-helds, but the screen is a bit too small for me I think, and I'm not a huge fan of Hantek as a brand so it would need to be a compelling choice. If it had a HDMI out or such so you could use a larger monitor... maybe.Most of the "Automotive" oscilloscopes are a bit of a gimick, and I'm not interested in any sort of multimeter functionality - already have a handful of very nice ones.Looking at the VTO2004 USB one it looks like you can't use any sort of normal PC-based oscilloscope with it - they are using some sort of propriety interface that only talks to their custom Android 7 APK, so if you want to use it on a PC you have to run an android emulator and install the same. I'm guessing you'd also be out of luck with a modern Android tablet too given how old Android 7 Nougat is, and I don't know where to go looking for a decent tablet running that OS... I'd have to guess back to AliExpress again.It's very cheap for the paper specs though, AUD$400 for 200MHz 4 channel USB scope is pretty compelling, even if the PC side is really awkward. The equivalent Pico is the 3406D I think, since the 2000 series doesn't go to 200MHz, and only 9x the price at a cool AUD$3600 (but it can do some extra stuff so maybe not 100% fair). I really don't need 200 MHz for anything, though.So the manual talks about PC software for the ATO/STO/SATO scopes, but the only way to get that software is to google it - there aren't any links anywhere from the main or product pages on MicSig. Even then, it isn't proper remote control, seems to just stream the screen to whatever device? Unless SCPI lets you do it? Who knows. This is exactly the janky stuff that turns me way off these sorts of scopes.

author: maralb
author_rank: Contributor
timestamp: February 16, 2024, 02:51:50 pm
content: The Micsig STO1004 is running Android 11.0

author: skander36
author_rank: Frequent Contributor
timestamp: February 16, 2024, 02:53:24 pm
content: Yes VTO2004 is for Android.I've had STO1152C and it was pretty good. I've changed for TO3004 because of larges screen and 50 ohm input.Also for Micsig be aware that they are using proprietary battery format and because of that may not be so future proof.Maybe Picoscope with an external power source and a Windows/MacOS Tablet or a laptop is the best choice.

author: Agouti
author_rank: Newbie
timestamp: February 16, 2024, 03:16:14 pm
content: Good to know, looks like the batteries aren't horrendously priced for now, but who knows long term. Can't really blame them for propriety battery package, but would have been convenient if it had a bank of 18650s or something, but then you couldn't cycle batteries easily. I believe the STO1004 can't be powered off USB either, so if the battery did die you would need the power brick.Having said that, I'm sure if you was still desperate to keep it going you could always 3D print an adapter for a common laptop battery of some sort.

author: KungFuJosh
author_rank: Super Contributor
timestamp: February 16, 2024, 03:32:52 pm
content: Quote from: Agouti on February 16, 2024, 09:25:41 am4. If you're going to get a desktop scope, wait until next week or the week after as Siglent is releasing new 12bit scopes, including a couple models that may fit your budget. Siglent also has the SHS handheld scope series, though I'm not the guy to ask if it meets your requirements or not.5. 100% agree, not worth it, avoid those brands. They're toys.

author: tautech
author_rank: Super Contributor
timestamp: February 16, 2024, 03:37:37 pm
content: Quote from: Agouti on February 16, 2024, 09:25:41 amThese scopes have no top facing vents, none at all as they are fan cooled.Unlike older Tek TDS models that did have and PCB's can get contaminated and humidity quietly does the rest.Have a dead TDS2012B as proof !Have a look at SHS810X and its logging capability vs the 4ch X-E's.https://www.eevblog.com/forum/testgear/new-x-model-siglent-handhelds-coming/

author: rsjsouza
author_rank: Super Contributor
timestamp: February 16, 2024, 03:41:47 pm
content: I know the league of the devices considered is a bit higher, but Owon's VDS1022I is a basic USB oscilloscope that is quite capable, galvanically isolated and has software supported outside of the manufacturer. A long thread discussing its features is below (look for the latest developments, as the thread is quite old already).https://www.eevblog.com/forum/testgear/owon-vds1022i-quick-teardown-(versus-the-hantek-6022be)/I personally use it in the field where the cheapie portable I have (Zoyi 702S) does not cut it. Being isolated brings peace of mind as well.

author: Agouti
author_rank: Newbie
timestamp: February 16, 2024, 03:54:07 pm
content: Thanks tautech, good to know about the newer desktop scopes that are more protected from ingress - they might be worth thinking about more after all. I don't do much car stuff, and I've yet to need to test-drive anything with a scope hooked up so the 240v reliance shouldn't be a huge deal (there's always those battery-powered inverters too, I guess).I'll have a look at the Siglent SHS810X (2 channel, 100 MHz, 1GS/s, USD$980/AUD$1400) and see if it can tick all the boxes (except channel count, but that was never mandatory). A bit more than I was wanting to spend but it might be worth it.You are right too rsjsouza, there's absolutely an argument for a decent 4 channel in the workshop/van and a cheap little 2 channel 20MHz for all the basic gruntwork, and if it gets dropped a long way into something nasty no tears to be shed. Hmm. I had sworn off anymore "disposable"scopes but it'll probably be required at some point if I get a desktop one as the main.

author: DaneLaw
author_rank: Frequent Contributor
timestamp: February 16, 2024, 03:57:36 pm
content: Quote from: Agouti on February 16, 2024, 03:16:14 pmWhat gives you the impression that it can't run on USB? (TypeC)

author: tautech
author_rank: Super Contributor
timestamp: February 16, 2024, 04:07:40 pm
content: Quote from: Agouti on February 16, 2024, 03:54:07 pmAs Josh pointed out, in the next couple weeks the SDS800X HD models will be released and the 70 MHz 2 and 4ch versions are to be very well priced, have CAN decoding and a bunch of other features and could be convenient in the field with their touch displays.I'd link a video but it's in the final stages of editing/correction from Defpom down the road from us however it will be publicly available in the next week or 2.There's a short Siglent vid in the OP in this thread.....but nothing like the 60min monster Defpom has done.https://www.eevblog.com/forum/testgear/siglent-sds800x-hd-12-bit-dsos-coming/

author: Agouti
author_rank: Newbie
timestamp: February 16, 2024, 04:17:31 pm
content: DaneLaw: Kerry Wong said the USB-C port couldn't be used for charging, no explicit mention of that for the other two USB-A ports but it doesn't seem likelyhttps://youtu.be/VomgQfmjFBg?t=288The manual also weakly implies that only the brick can be usedhttps://www.micsig.com/uploads/Tablet%20Oscilloscope%20Smart%20Series%20User%20Manual.pdfPage 3:"Use adapter correctly. Supply power or charge the equipment by power adapter designated by Micsig, and charge the battery according to the recommended charging"I'm not seeing any mention in the manual of being able to charge through the USB-C, guess it was too much work to add that intautech: Agreed on waiting for those to come out, especially if there's any chance they could also push the price of the previous generation down a bit. I'm also not adverse to buying second-hand, most of my nice tools came pre-loved, and I would think a new shiny generation would cause help populate the for-sale sections. I don't think I need a 12-bit but a nice high-resolution screen never goes astray.

author: tautech
author_rank: Super Contributor
timestamp: February 16, 2024, 04:30:14 pm
content: Quote from: Agouti on February 16, 2024, 04:17:31 pmThey already have however like here in NZ the AU market is not large and when existing model stock is depleted the new 800X HD models will/should be of greater interest to stock than the older X-E's even at the reduced factory pricing.I don't believe the 100 MHz SDS1104X-E even at discounted pricing will challenge the new 70 MHz SDS804X HD pricing and while I have yet to test the 70 MHz model I have a feeling it could challenge the 100 MHz X-E.I base this on the recognised ~120 MHz BW of 100 MHz 4ch X-E vs my tests on SDS814X HD returning ~150 MHz.

author: DaneLaw
author_rank: Frequent Contributor
timestamp: February 16, 2024, 04:33:06 pm
content: I dont know how it is with the new joystick series (STO1000) but with the older STO½000C/E that had knobs - you can use power banks to your heart's desire with an appropriate PD cable..That's how I use mine, I never use AC or its noisy incl. power brick..got 3 of these 28.000mah powerbanks below. (fitted with 8x 18650 cells.) I tend to use a 12v Power delivery cable DC to TypeChttps://www.aliexpress.com/item/1005006018729093.html?Any power bank with Power Delivery protocol that supports 12V PD and can deliver enough wattage will work, or just an AC power supply to fx your 20v laptop with (PD) power delivery-protocol will also work, as they usually have support for the lower power-delivery protocols like 15V, 12V and 9v .. - that is the exact PD-voltage you're activating with a PD trigger handshake in the cable above.or I use the adjustable DC barrel out on these power banks - that goes from 3v to 24.4v at max 5A with a DC-barrel to DC-barrel cable, and I just dial in the voltage I need, but the power delivery trigger cables are preferred, as its plug & play, and I can use many other power banks.Micsig STO1104C consumes around 25W to 30Watt, so a tad over 2A at 12V.....I do love the portability & freedom I get with a hybrid solution like Micsig units, - something that is critical for me, and other Hybrid alternatives like Tek2 are too much for my wallet.The 3dB was around 135 to 140Mhz if I remember correctly (STO1104C) while the peak-update rate was 95k to 100k.. one feature that surprised me in usefullness, and I often fiddle with, is bandwidth filters.While some of the biggest weaknesses in these lower-end hybrid Micsig scopes, is the lack of statistics, not to mention a lackluster support, but here +4 years down the line, I gotta admit I do like my STO1104C a lot...its hybrid nature (bench+portable) fits my use-case ideally, the non-tethered aspect is a joy, having all my relevant gear in the optimized bag.

author: csuhi17
author_rank: Frequent Contributor
timestamp: February 16, 2024, 04:46:22 pm
content: As far as I know, all Micsig scopes are Android.Except for the older series, TO is Linux based as far as I know.I tested my STO2002c scope without a battery, using an external 12V power supply and it worked without any problems.Micsig is well done, the only problem I have with them is that they don't include a few basic functions. Mine has no histogram, pass/fail, etc.Which would be good for me. and I see no chance that he will ever know.I see that the newer editions bind them more than if they improve the old ones as well.The only difference between VTO and VATO is that half of VATO's probes are automotive probes with banana plugs, and the Android program is also different if I understand correctly, VTO does not contain automotive measurements.And there is only an Android application for VTO, VATO.It must be emulated for Windows.If I understood correctly.

author: Agouti
author_rank: Newbie
timestamp: February 21, 2024, 06:38:06 am
content: Well, I've found the reason how Pico justify £2,000 for a 25MHz 4 channel 'scope - they lock some pretty useful functions in the software to them. The big one for me, that I can't seem to find anywhere else, is graphing peak to peak frequency for a square wave. It's really useful in identifying misfires (by graphing RPM during each cylinder compression/power stroke) and for things like MAF sensors which are usually frequency modulated these days.I remember hearing a few years ago about hacks to get the Automotive software to work with the base picoscopes, but I'm not sure if I want to go down that route. Is there no AUD$1k or under oscilloscope that can do FM graphing?I suppose another option would be using the python API for a USB scope software package, or even trying to shoe-horn it into OpenHantek or one of the OpenOwon packages, but that feels a bit unachievable for me at the moment.

author: Performa01
author_rank: Super Contributor
timestamp: February 21, 2024, 08:54:06 am
content: Quote from: Agouti on February 21, 2024, 06:38:06 amYes there is, even well within your price range. The 12 bit Siglent SDS800X HD (2 or 4 channel versions up to 200 MHz, available by the end of February) have high sample rates, deep memory and proper analysis capabilities, including track- and trend-plots for measurements.You can use a track plot for the automatic frequency measurement to do FM demodulation on various waveforms. Here's two examples (dont get distracted by the weird axis labelling from the autoscaling - I was just too lazy to set up the axes manually):500 Hz square wave, frequency modulated at 10 Hz with +/-300 Hz deviationSDS824X_HD_Measure_Track_500Hz_FM_10Hz5 kHz square wave, frequency modulated at 100 Hz with +/-300 Hz deviationSDS824X_HD_Measure_Track_5kHz_FM_100HzBtw, for catching misfires in a combustion engine, the hardware accelerated full-speed mask test could be even more useful.Detailed information about these instruments can be found here:https://www.eevblog.com/forum/testgear/sds800x-hd-review-demonstration-thread/