Help Choosing to buy an Oscilloscope for uni student - Page 1
Forum section: electronics / beginners

author: Syzeryuino
author_rank: Contributor
timestamp: August 29, 2020, 07:28:27 am
content: Im on my 3rd semester uni studying Mechatronics engineering, i was thinking to buy an Osciloscope but confused which one to buy between 2 scopesmy first choice is the Tektronix ths720a (used)priced at around ~170$and the second choice is ATTEN Digital Oscilloscope ADS 1022CL+ (used but like brand new )priced at around ~240$im leaning on the tektronix because its a more name brand, but its a handheld one, will this make me lose alot of features or not?

author: ceoxrad
author_rank: Regular Contributor
timestamp: August 29, 2020, 09:48:04 am
content: Atten isterrible, crap products and virtually no support.If you can up your budget a little bit the Rigol and Siglent offerings are another league entirely.Have a look at those, there are plenty of post in this forum

author: BravoV
author_rank: Super Contributor
timestamp: August 29, 2020, 10:11:41 am
content: Quote from: Syzeryuino on August 29, 2020, 07:28:27 amRegarding the Tektronix, as its used and probably aged enough (a decade or more) and there is no warranty, its known as aged affects it's offset and accuracy, also the backlight is also the weak point as its CFL, not LED.Just ask your self are you ready for trouble shooting it ?If you are, 2nd question, are you confident and qualified to fix or repair it ?

author: Syzeryuino
author_rank: Contributor
timestamp: August 29, 2020, 01:40:50 pm
content: Quote from: ceoxrad on August 29, 2020, 09:48:04 ami will keep this in mind, never knew atten is that badQuote from: BravoV on August 29, 2020, 10:11:41 amif u say am i qualified to fix it, probably not im just a uni student and a hobbyist,i wouldnt say im sure that the thing works perfectly fine nor do i have the equipment to calibrate the thing if its off.i have bought things previously from the seller and he seems like a trusted guy,and for buying other brands and saving up, the thing is the cheapest rigol/siglent in my country is at least (3~4)x the price of the tektronix

author: BravoV
author_rank: Super Contributor
timestamp: August 29, 2020, 01:50:01 pm
content: Quote from: Syzeryuino on August 29, 2020, 01:40:50 pmMake sure if the seller is willing to refund you should the THS720A out of cal, as this is used, and also officially discontinued, don't think the seller able to fix it.No, just turned on and shows no error doesn't mean it its still in calibration, also an accurate/new scope even its Atten, is better than branded scope but not accurate, as all your measurements becomes meaningless.I own THS720A and there is a big thread discussing it in this forum, just search for it read thru it, especially common problems.Good luck on your quest.

author: Syzeryuino
author_rank: Contributor
timestamp: August 29, 2020, 02:49:45 pm
content: Quote from: BravoV on August 29, 2020, 01:50:01 pmyeah while looking into the scope, i saw your post about the resistor mod(i saw alot of post about turning the 710A to the 720P, is the process also true for 720A to 720P?, and do you need to update the firmware or just removing the resistor works?). and about the ccfl screen, isnt it possible to change it to led? or is the driver of the backlight intergrated with the mainboard?also how much is the ths7xxx series worth in your opinion since you can mod it to the p version?cheers!

author: Jwillis
author_rank: Super Contributor
timestamp: August 29, 2020, 04:00:37 pm
content: Quote from: ceoxrad on August 29, 2020, 09:48:04 amI would like to know more about your experience with ATTEN products. I have a ATTEN function generator and haven't experience any problems . I was looking at the oscilloscope considering the how well my generator was performing. I can't find any reviews on any ATTEN products that aren't in Russian so I'm asking you for your experience .As for service I've found service from any company to be questionable and most cases a waste of time .It would nice to see Dave do a review on some of these lesser know ATTEN products .

author: ceoxrad
author_rank: Regular Contributor
timestamp: August 29, 2020, 04:34:25 pm
content: I admit my experience with Atten is limited to low end stuff and some reviews I saw (the most relevant is the one Dave did in #439).Their soldering equipment is between average and crappy (tired a soldering station), very similar to the ton of nonames you find on ebay.I bought two basic CC-CV power supply from them as a backup (don't remember the model number off hand) and ended up tossing both.Low quality PCB and components, and I suspect the control loop was unstable (at one point one of them showed oscillations under load).These experiences and the video by Dave sealed the deal for me, no more Atten stuff.On the other hand I had positive experience with both Rigol and Siglent (own a Rigol ds1054z and a Siglent sdg830), the build quality is better and overall they feel more professional using.I was bashing Atten because these inexpensive digital scopes have often bugs in the software, and while Rigol and Siglent may be slow to fix those at least they relase firmware updates periodically. I don't think Atten and other lesser brands do this regularly (somebody correct me if I'm mistaken)

author: rstofer
author_rank: Super Contributor
timestamp: August 29, 2020, 05:03:29 pm
content: If I were a student, and I'm not, I would say "None of the above!"I really believe the Digilent Analog Discovery 2 is the way to go for all student and most hobbyist instrumentation.It is my favorite tool! I have the Rigol DS1054Z (and it's a great scope) and a Tek 485 350 MHz scope but I use the AD2 more than the two of them combined. Imagine doing mechatronics with a Raspberry Pi 4. You can run the Digilent Waveforms software on the same board you are troubleshooting with the AD2 connected to one of the USB inputs. Everything involved with the project runs on the Pi. Pretty slick!Mechatronics? I'll bet you get involved with the SPI and I2C protocols. Some modern DSOs will do something that resembles a decode but, generally, when the time/div is large enough to see the decode, the number of packets on the screen is very limited. The AD2 does all that but it also produces a table of every byte in the transaction. You don't look at traces, you look at what is sent and received. Very handy, especially when a transaction is more than just a few bytes.Two channel scope, two channel arbitrary waveform generator, 16 channels of digital IO that can also be used as a Logic Analyzer plus a BUNCH of software defined tools like the spectrum analyzer, Bode' plot (network analyzer), dual adjustable power supplies (limited to 5V), etc.Before you make a decision, spend some time looking for AD2 videos. Digilent has an entire series of them.https://www.youtube.com/playlist?list=PLSTiCUiN_BoLtf_bWtNzhb3VUP-KDvv91This is not a toy! It is a very serious piece of equipment, particularly for the student. Drop it in a backpack along with a laptop and you are carrying a pretty decent lab - anywhere you want to go.The Pro Bundle is the way to go because you will need the BNC adapter and scope probes if you want to work above 5V. I have it but I'm mostly working with uCs so it isn't necessary.https://store.digilentinc.com/analog-discovery-2-pro-bundle/Student discounts are available but I had to pay full price!

author: Howardlong
author_rank: Super Contributor
timestamp: August 29, 2020, 05:28:57 pm
content: I totally agree regarding the Analog Discovery. It's certainly not a toy.I have three of them, a result of being out in the field without one, and unexpectedly needing to purchase yet another one when on site to fix or diagnose something.The difference between the I and II is that the II has variable power supplies, the I is fixed voltage.I find I get by perfectly well without the BNC adapter board & probes.The main feature it lacks is deep memory, but otherwise it's a super handy bit of kit. It's a Swiss Army Knife for the electronics engineer.

author: Syzeryuino
author_rank: Contributor
timestamp: August 29, 2020, 05:45:02 pm
content: Quote from: CJay on August 29, 2020, 03:31:17 pmthanks for the input this really puts me into a new light,i will need a scope that has that many functions. but scopes of such caliber must cost a fortune!Quote from: rstofer on August 29, 2020, 05:03:29 pmOh wow never hear of such cool equipment, it has so many functions for such a tiny device!, but the problem is the price and non-availability of such device in my country. of course i can import it, but the import tax in my country is such so high! i would probably need to pay ~200$ of import tax alone!im planning to have a holiday with my family to japan next year ( if by then the quarantine is over!) do you know where they sell these things there? but with such high demand i dont have much hope other than online retailer.|Quote from: Howardlong on August 29, 2020, 05:28:57 pmoh man you make me want these things even more!

author: rstofer
author_rank: Super Contributor
timestamp: August 29, 2020, 07:14:44 pm
content: I would think that for Mechatronics, you might get more use from a logic analyzer than from a scope. Decoding SPI and I2C. There are some $11 logic analyzers on eBay like:https://www.ebay.com/itm/USB-Logic-Analyzer-24MHZ-8-Channel-12C-UART-SPI-IIC-CAN-1Wire-Debug-For-ARM-FPGA/124238666414You rip the driver from Saleae (the device enumerates as a 'Saleae Logic' type of device) and you can use the open source SigRok | Pulseview software. It takes a lot of time to get up to speed.In any event, the gadget is cheap and will decode all the standard protocols. I bought one a couple of weeks ago and have it running on my Raspberry Pi 4. I can debug the I2C protocol coming off the Pi 4 header and this seems important. Yes, I have other ways to do it but I wanted to see if the cheap LAs are worthwhile. I guess they are but they sure don't compare to something like the Analog Discovery or, better for digital, the Digital Discovery. Still, they're cheap!I do not prefer this device.

author: rstofer
author_rank: Super Contributor
timestamp: August 29, 2020, 07:24:06 pm
content: Google for 'Arduino oscilloscope' or'Raspberry Pi Oscillosope;Or, check out this:https://www.instructables.com/id/PiScope-Raspberry-Pi-based-Oscilloscope/Sound Card Oscilloscope:https://www.instructables.com/id/Use-Your-Laptop-as-Oscilloscope/For Mechatronics, I wouldn't think high bandwidth is required. There are always other ways to get things done.Do the decoding thing with a cheap logic analyzer and use a laptop for a scope. That would have been a LOT better than what I had back in college.

author: Electro Fan
author_rank: Super Contributor
timestamp: August 29, 2020, 07:29:33 pm
content: I think the software has matured/steadily improved over the years....https://store.digilentinc.com/waveforms-download-only/Beyond the oscilloscope and waveform generator these (and more in the series) are impressive:VoltmeterNetwork AnalyzerSpectrum AnalyzerLogic AnalyzerProtocol Analyzer

author: Syzeryuino
author_rank: Contributor
timestamp: August 30, 2020, 01:04:30 pm
content: Quote from: rstofer on August 29, 2020, 07:14:44 pmdo you think a LHT00SU1 would be worth the upgrade ? because its not that much expensive and i rather buy a better one than regret it later.Quote from: CJay on August 29, 2020, 06:59:34 pmwell yeah its not super expensive, but the equipment i bought are spend with my leftover allowence and getting a part time job in my country is not really an option.( i could ask my parents ofc, but i always feels bad )and thanks for the input about the calibration, i dont know why i think a very precise calibration is a must!Quote from: rstofer on August 29, 2020, 07:24:06 pmthanks for the input, i will buy the LHT00SU1 logic analyzer, or do you have a better option?Quote from: Electro Fan on August 29, 2020, 07:29:33 pmsadly the price of the device is ridicilous in my country, but thanks!

author: cdev
author_rank: Super Contributor
timestamp: August 30, 2020, 02:32:57 pm
content: If you can handle your logic analyzer needs with a cheap LA that works with sigrok, thats helpful to the budget. I got one for $6 on ebay. Its nice to know that it I destroy it its easy to replace.

author: Electro Fan
author_rank: Super Contributor
timestamp: August 30, 2020, 07:29:54 pm
content: Lots of cool choices for LA capabilities including Digilent and maybe some of the entry Rigol and Siglent scopes but for the price of an eBay LA plus Sigrok PulseView it's pretty much a no brainer to start there and see what you can learn for less than $15 including shipping. It might get some work done and also help better inform a user of what to look for next. Plus, even if you add another LA in some form or fashion later it can sometimes be helpful to have a second device just to see if you can reproduce the same results on both devices - so it's not likely to be a throw away.

author: wizard69
author_rank: Super Contributor
timestamp: August 30, 2020, 08:05:11 pm
content: I think as a Mechatronics student you may not be being asked the right questions. For instance if you are working on anything with high voltage motor drives you will want a scope with floating scope channels and a CAT rating. Safety is important when working around such electronics. While you can get by with less in other parts of an automation system such scopes really shouldn't be used on drives where you need to reference none grounded buses. You can of course use isolating probes but that becomes another issue.I bring this up because "Mechatronics" can imply such systems. The problem is these sorts of scopes, such as Fluke's Scope Meters can be expensive. I don't see a lot of them on the used market either. On the flip side, in industry you can go for years even in a large plant, before you actually have a drive that will require you to work on it.As for your specific questions I haven't used either model. However when I first started hearing about ATTEN it wasn't good news. As for Tektronix they seemingly have abandoned the market for this type of scope. At least CAT ratings are hard to find as are other parameters for scopes suitable for high voltage use.As for loosing features you need to determine what features you need in the first place. I could be completely wrong about your Mechatronics focus. More so it sounds like you are in the early part of your college career and as such cheap is probably more important than anything else. This is where the comments about USB based devices come into play, with your PC (a requirement for school these days) such solutions can be a cheap and effective way to get through college. They are not however maybe not as useful as traditional scopes. I say maybe because USB based instruments are improving almost daily, especially with USB3/USB-C with all of its various types. Some of the first USB based devices where pretty bad. Another thing to consider is that USB based scopes, at the higher end, can pack neatly into a back pack with your laptop. I'm thinking PicoScope 2000 here as a low end solution and of course hey have far more expensive units.Lets face it, even Keysight has USB based instruments these days not that I'm suggesting those high priced units. The point is you can find well done USB solutions, I'd just make good and sure you understand the state of the hardware AND software you are buying into. At some point though your hardware and software costs matches more traditional scopes so you need to consider that.Now for a different opinion; Dave over on the EEVBlog has a rather negative view of USB scopes expressed in a 2009 video. It may be worthwhile to consider what he has to say, realizing of course that the video is a decade + old. I'm a bit old fashion so I must admit to liking buttons and knobs, however compactness is a real quality and I might consider a USB solution for an electronics lab setup simply to save on space - space taken up by a big PC screen. The PC is pretty essential to electronic development these days and as such has a place on the electronics work bench, if that PC can do double duty as an instrument interface it can be a significant plus. At least in some cases. Sometimes spinning a knob is more useful than struggling with a PC interface.One other thing to realize is that if you buy an Analog Discovery or a very low end Picoscope they don't suddenly become worthless when you buy a real scope. Rather they just become another component of your electronics Lab. It is sort of like having multiple multimeters, there is good reason to have more than one even if you have a favorite that gets used all the time.Quote from: Syzeryuino on August 29, 2020, 07:28:27 am