I am an EE student should I buy an oscilloscope? - Page 1
Forum section: electronics / testgear

author: riyadh144
author_rank: Unknown
timestamp: January 22, 2014, 09:03:15 pm
content: Hello,I have been wanting a scope for a while now for projects since the lab is not available to us all the time and only once a weak, should I buy a scope or not.I am now thinking about two OWON SDS5032E 30MHZ 250MS/s $300, and SainSmart DDS140 PC-Based 40MHZ 200MS/s $120.The second is cheaper but I know it is not a proper oscilloscope, the first one I can buy I would tighten my budget for a month and it will be over.Is it worth buying an oscilloscope now? Should I or shouldn't I please help.And as another point what other equipment should I get to make a small lab for myself.Note: I can't get an analog for cheap in this country(Turkey).

author: Icarus
author_rank: Regular Contributor
timestamp: January 22, 2014, 09:15:44 pm
content: You should ask their helphttp://www.netes.com.tr/They have realy good re-branded Siglent osciloscopes. I have bought one a year ago (100MHz 2Meg memory) and It's work adequately fine.I don't know any thing about Owon.

author: riyadh144
author_rank: Unknown
timestamp: January 22, 2014, 09:17:52 pm
content: Quote from: Icarus on January 22, 2014, 09:15:44 pmHow much did you buy it for.

author: electronics man
author_rank: Frequent Contributor
timestamp: January 22, 2014, 09:18:23 pm
content: whats your budget?if you can aford it buy the rigol ds1052e or get a used analog one on ebay for $100

author: riyadh144
author_rank: Unknown
timestamp: January 22, 2014, 09:24:09 pm
content: Quote from: electronics man on January 22, 2014, 09:18:23 pmThe problem I can't use ebay as much as a person in the US can, I am in turkey shipping would be hell for me.

author: mainman
author_rank: Regular Contributor
timestamp: January 22, 2014, 09:32:34 pm
content: We can't tell you if you need a scope or not, that is a question only you can answer. What we can tell you is that both scope options in your initial post are horrible. The Owon on has a sad 30MHZ band and a sorrier 250ms/s sample which mean the scope is only really 25MHZ. Add more insult to injury it only has 20K of memory depth which means you will only be able to get that max sample rate on a few timebases. I'm not even going to get started on PC based DSO.Bottom line spend a hundred more and get a more tried and true Rigol which will deliver better spec and future proofing.

author: Sebastian
author_rank: Regular Contributor
timestamp: January 22, 2014, 09:51:31 pm
content: I agree, don't waste your money on a crappy owon scope or something like that. Spend a little bit more and get a Rigol one (DS1052E is good enough for the beginning).If you really can't afford it get a good analog scope for $100-$200 (I think that is realistic with shipping) that's still a lot more useful than a bad DSO.Just my 2 cents.

author: electronics man
author_rank: Frequent Contributor
timestamp: January 22, 2014, 09:59:14 pm
content: Quote from: riyadh144 on January 22, 2014, 09:24:09 pmyou should put you country on your acount to make it easier for us to help you

author: phil
author_rank: Regular Contributor
timestamp: January 23, 2014, 03:29:49 am
content: Depending on what projects you work on, you might consider theanalog discoveryfrom digilent.To be clear here: If you have projects that require you to measure high speed signals, fast (<30ns) rise times, signal integrety above 1MHz and stuff like that: skip my post, this is not what you are looking for. Get a decent, stand alone scope with at least 50MHz, better 100MHz.But if you need a tool to test small µC circuits, SPI/I²C/RS232/... , low frequency analog stuff (<5MHz) or similar things (or just to try out all the stuff the lectures are about): read on.Unlike most other USB scopes, this one does have some decent software. Also, since you asked what to get for a small electronics lab: This scope has a quite useful arb function gen, a usable (read "not great, but enough for most µC-based projects") logic analyzer, pattern generator (not that useful generally, but does come in handy sometimes) and a small +-5V supply.For the scope itself: It is limited by its 5MHz analog bandwidth (to be fair, my unit's -3db point is at nearly 9MHz). That means, you cannot judge the signal integrety of any square wave above ~1MHz. You will still see the shape, but things like amplitude, rise/fall time, ringing and such will appear different that they are in reality. That will sooner or later also happen with a better scopes, but it won't be as noticeable in this frequency range.It will, however, do just fine for audio level analog stuff, most serial communication used by microcontrollers and general purpose probing/repairing. I use mine for most of my work. The only things I use a better scope for are switch mode PSUs and similar stuff.The PC interface is quite neat, no comparison to the trash you get from most chinese "scopes". It's calles "waveforms". The software has a demo mode which lets you try it out without the hardware attatched (pre-programmed signals, but enough to get a feel for the thing).Also, the function generator is really useful. Although limited by a minimal rise time of ~33ns, you can use it for pretty much anything below 1MHz. Above that, be careful with square waves. Sine can go up to 10MHz (with the usual attenuation of course)The logic analyzer has some sampling issues at bigger time bases, but you can work around that. I haven't used the pattern generator much, so I can't really say if it meets it's specs.The software claims to have a "spectrum analyzer" function, but it is more a glorified FFT. Useful, but not outstanding.The "network analyzer" on the other hand is useful for measuring the frequency response of filters/analog circuits. It's intended as a function to teach you how filters work in real life, but it is also useful for designing and testing filters for your projects. Low pass filters for ADCs for exampleIf you have any questions, feel free to ask. As I said, this is not the right tool for you if you have any advanced circuits in mind. But it can be a great starter tool for your basic electronics needs.If you do get one, be sure to buy the BNC adapter. You won't be able to use real scope probes without it.Phil

author: Dave
author_rank: Super Contributor
timestamp: January 23, 2014, 03:45:42 am
content: Avoid Owon. Trust me, I have one.

author: phil
author_rank: Regular Contributor
timestamp: January 23, 2014, 03:52:21 am
content: Quote from: Dave on January 23, 2014, 03:45:42 amThis. The interface is horrible and the firmware is buggy as hell. The only good thing the SDS series has to offer is it's battery capability and deep memory (which is offset by it's horribly slow update rate!)Phil

author: mainman
author_rank: Regular Contributor
timestamp: January 23, 2014, 03:58:57 am
content: Quote from: Dave on January 23, 2014, 03:45:42 amWhich model. I have been watching vids and reading specs and I have not seen a non high end scope match the latest Owen models memory depth, it's the only entry level scope with 10meg of depth and a optional portable battery considering it's a bench scope.

author: phil
author_rank: Regular Contributor
timestamp: January 23, 2014, 04:13:54 am
content: SDS7102 in my case. Yes, the memory is impressive. But its incredibly slow screen update rate makes it just awful as a everyday scope. We are talking about 25Hz best case! That makes pass/fail and glitch hunting a joke.The hardware isn't bad, but the slow update rate and the sluggish interface just kill it for everyday use. There isn't even a fine horizontal/vertical control, even though the encoders are pushable - they just do not do anything!These scopes need a serious firmware overhaul!Phil

author: digsys
author_rank: Unknown
timestamp: January 23, 2014, 04:14:41 am
content: Quote from: DaveI have a SDS7102 (as well as 2x 30K LeCroys). It has minor limitations, every DSO I've owned has. Are they worse?Who cares, I learn to use it and it does the job FINE. It even triggered better on a job that I had HELL trying to trigger on aRigol 4034. The large screen, battery, IO and memory make it a MUST HAVE for me ... which means it excels on some jobs,and is OK or good enough on others.

author: pickle9000
author_rank: Super Contributor
timestamp: January 23, 2014, 04:18:15 am
content: I'd avoid the pc based scope at all costs.If there is a Siglent dealer near you the SDS1052DL comes in around the same price as the Owon and is 50 mhz. Siglent seems to be pretty good about their firmware. I have a low end 100mhz version that's a couple years old and it's been very reliable.As for the Owon many hate it, I have tried it myself and honestly it's a very basic scope. That said any scope at this level is basic. If your choice is between a digital or used analog and you have no plans to buy another scope in the near future, go for the Owon.

author: phil
author_rank: Regular Contributor
timestamp: January 23, 2014, 04:49:34 am
content: It's not about hating the owon scopes. It's just that the owon has so many problems that other scopes in that price segments are a better choice for every day use.If you need the battery for field work, go with the owon - nothing else available.If you really need such a deep memory, take the owon.But if you just want a scope for all your random projects, repairs etc - avoid the owon. It's uses are just to situational. If they release a decent firmware update that solves the update rate issue (at least for the lower memory settings, it has 25Hz even at 1kpt! Just for comparison: The Rigol 2000 series has up to 50kHz!) it may be an alternative. But not as it is now.PC based scopes are considered bad, because the software usually sucks. While there are exeptions (waveforms, try it!), most of them are not worth it and it is indeed better to save up for a real scope.However, we still don't know what the OP needs exactly.Phil

author: pickle9000
author_rank: Super Contributor
timestamp: January 23, 2014, 05:16:10 am
content: Sorry I wasn't referring to you in particular when I said hate. The Owon is lacking anyone that has pushed one of the buttons on it knows. Many people are disappointed with it.That aside, the OP has limited access to gear and wants more. Ideally for anyone starting out you would like to have the best gear possible. Unfortunately this is one of those cases of "best you can afford". It probably will not do everything he wants. But any scope is better than no scope, I used some very crusty gear in my younger years, it makes you better at what you do not worse. For what it's worth, that's where I'm coming, and have come from.

author: mainman
author_rank: Regular Contributor
timestamp: January 24, 2014, 08:07:09 am
content: Quote from: pickle9000 on January 23, 2014, 05:16:10 amYou should never invest in a piece of equipment which barely meets your minimum needs at that one moment in time. Come tomorrow next new project you will find out that piece of junk you invested in and bought literally yesterday to help you with that one project is not going to help you with today project. If money is a issue save up to buy a piece of equipment which is a middle ground between cost and future needs as far as specs.

author: Dave
author_rank: Super Contributor
timestamp: January 24, 2014, 03:22:58 pm
content: Quote from: mainman on January 23, 2014, 03:58:57 amOn older one, 60MHz dual channel DSO. Can't remember the exact model.I bought it because the specs looked really good on paper, but the reality is slightly different. The update rate is rather appalling, the triggering is slow, it lacks functionality, and the firmware can't be updated.

author: Bassman59
author_rank: Super Contributor
timestamp: January 24, 2014, 05:39:42 pm
content: Quote from: phil on January 23, 2014, 04:49:34 amEven worse: the vendor will probably not bother to support it when Microsoft or Apple release the next version of their OS.In a drawer here at work, we have an HP PC-based logic analyzer and an old laptop running Windows 95 to support it. (I suppose we could install VMWare and a Win95 VM, but that's somewhat absurd.) So it never gets used.The HP1661 on my bench always works.

author: pickle9000
author_rank: Super Contributor
timestamp: January 24, 2014, 08:14:52 pm
content: Although I have no way knowing the Owon the OP is talking about my guess is that it available from a local vendor. That is an item you can buy cash and walk out the door with, no credit card, no import fees, no shipping.I don't know what shipping and vendor fees are like in Turkey but 50 bucks for shipping is probably normal. No idea about import stuff. It would be interesting to know .As for buying below what you need or just what you need. Isn't that the story of life? If not bandwidth, then serial decoding, that story can go on forever.My advice for a person with low income. Get what you can, start repairing stuff (for whoever) and charge enough to buy more gear. In the end you will learn. Don't quit your day job, be that school or whatever.