Best oscilloscope right now under 500$

Discussion in 'Test & Measurement Forum' started by Teljkon, Feb 18, 2019.

  1. Teljkon

    Thread Starter Member

    Jan 24, 2019
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    I am thinking about getting a Oscilloscope. Under 500$ I am not sure if I should go used, new or really how to shop for one. Any recommendations on flat out purchases or a good trust worthy guide that wold teach a noob how to shop for one?
     
  2. Sensacell

    Moderator

    Jun 19, 2012
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    If you are starting out- you can buy a good used top brand analog scope like Tektronix on Ebay, use it for a year and re-sell it for what you paid.

    A Tektronix 2236 can be found for $300.00
     
  3. Teljkon

    Thread Starter Member

    Jan 24, 2019
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  4. BR-549

    AAC Fanatic!

    Sep 22, 2013
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    Last edited: Feb 19, 2019
  5. Wuerstchenhund

    Member

    Aug 31, 2017
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    I have to disagree with some of the previous posters here, and strongly recommend you don't get an analog scope. Seriously. Just don't.

    Let me tell you why:

    First, any analog scope you can buy today will very likely be 25+ years old, a time after which it has long passed the zenith of its natural service life, i.e. it's very likely to fail on you sooner rather than later. If it breaks then you need at least another working scope to fix it. That of course assumes that there are no unobtainium parts in it, which many scopes have. The fact that switches are mechanical (which makes them less reliable) and that it's usually full fo ageing and drifting analog components isn't helpful either.

    Then there's functionality. An analog scope shows you the signal in (somewhat) real-time. Unless you get one of the more rare analog scopes with storage tube (which comes with its own set of problems) then you have no way to record and store any events, short of you sitting in front of it with a photo camera (and then hope you press the shutter at the right time). On most analog scopesyYou get no measurement facilities (although some better ones had cursors with read-outs), you don't et any analysis tools like math or FFT, you don't get to decode serial data busses, and a range of other things that are common in digital scopes for over 2 decades now.

    The worst thing however is that an analog scope teaches you outdated methodology which when used with a modern digital scope can be inefficient or even counterproductive. Unless you want to work as a curator of antique test equipment you should learn how to handle current equipment correctly, not yesteryear's.

    Don't get me wrong, there's nothing against getting an analog scope as curiosity or collectors item, but even then it should be free or really really cheap (i.e. <50 bucks, everything else is money flushed down the drain). Still, spending big money on an antique boat anchor is ludicrous.

    An analog scope isn't the right scope to buy in 2019 as a first scope for a starter with a reasonable budget.


    Now, as to what to get for below $500, this is easy: get something new. While the 2nd hand market has some great bargains for advanced test equipment, there's rarely something in the below $500 class that can compete with modern new equipment in the same price range.

    For new gear, there are some good options:

    One is the Rigol DS1054z, a 50MHz 4ch scope for <$400:

    https://www.rigolna.com/products/digital-oscilloscopes/1000z/

    It's by far the cheapest new 4ch scope you can find that isn't a toy. If you google for "Riglol" you will find a website with a form where you can enter the scope serial number and unlock all the options (large memory, record & playback, serial decode) as well as a BW upgrade to 100MHz for free. The UI can be a bit slow at times and FFT is limited to 16kpts whcih is on the small side, but other than that it's a solid scope, manufactured at a surprisingly high quality standard. Also, because it's been on the market for a while, it's pretty much free of bugs (I think the last remaining bug is a spelling error somewhere).

    The alternative to the Rigol DS1054z is the Siglent SDS1000X-E Series:

    https://www.siglentamerica.com/digital-oscilloscopes/sds1000x-e-series-super-phosphor-oscilloscopes/

    For example, the SDS1202X-E is a 200MHz 2Ch scope which comes with serial decode, and while it's got only two channels it's built on a faster platform than the Rigol so it supports FFT up to 1Mpts, and offers additional functionality like Bode Plot (needs a Siglent signal generator as source, though). There's alsoa 100MHz 4ch variant that is $499 so still within budget.

    Both scopes are great beginner scopes and would serve you well for a long time. They also help you to learn how to handle a DSO properly, and because they come with 3 year warranty you also get peace of mind.

    Considering what you can get for your money, you'd be mad to spend $300 on a 30+ yr old analog boat anchor like a Tek 2236.
     
    Last edited: Feb 19, 2019
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  6. Yaakov

    Well-Known Member

    Jan 27, 2019
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    I love analog scopes. I even have, somewhere, a massive Tektronix storage scope which “works” but I sure wouldn’t want to try to use it if I had anything modern to choose.

    I have an HP 4-channel, 100MHz DSO as well, and older model, and it works but it can’t begin to compete with the Siglent SDS1204X-E I just bought (thanks to @Wuerstchenhund ‘s recommendation).

    If your budget allows it, the SIglent (or Rigol) will bootstrap you into a modern scope with facilities that earlier, excellent gear couldn’t even imagine. The question will be what bandwidth you need to do what you want. If 100Mhz is sufficient, you can go cheaper, but do consider this carefully. You might need more, and you can’t just add it later. The same goes for channels, though, I suspect that 2 channels is not as much of a limitation as half the bandwidth.

    I can recommend the Siglent. It’s far from perfect, and has a few interface quirks that rankle, but what an amazing bargain for what you get! It would be a great start on an instrumented bench, and a great tool to learn how a DSO operates.

    As a hobby, or for nostalgia (for those of us with that problem) an analog scope is fun—as an instrument, getting an analog scope today would be like buying a cheap soldering iron to “learn” soldering.

    Good luck.
     
  7. rsjsouza

    Active Member

    Apr 21, 2014
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    I echo @Wuerstchenhund and @Yaakov's comments on the matter, with one caveat: if you can get an analog scope in working condition for free or a very low price (<$50), then it is a good start - the problem is evaluating if it is in good working order.

    Another option that is still quite usable and, if you can get for a very cheap price (<$100), is the Rigol DS1052E, which has more modest features when compared to the other two models mentioned above but it is quite a solid product. I had one and it is quite a great beginner's digital oscilloscope on a budget.
     
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  8. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    My first scope was an analog scope. It was a Tek. It failed shortly after I bought it. Luckily I was able to fix it (bad op amp). Fortunately it was not that difficult to do the actual repair. The chip was in a socket and it was in a place that was easily accessible. But that experience scared me. I saw how compact everything was. It is actually kind of fascinating that a group of engineers could design such a thing all before modern computers and design software.

    The worst was the PSU. It was buried. I got to thinking about replacing those enormous filter caps that were long past their useful life. I decided to sell it and glad I did. I was pretty much able to get what I paid for it. I am on my second digital now. I think the first I sold for around $50 less than I paid for it. Not a bad deal.

    The bad news about a digital scope is that you will likely not able to fix it if it dies. The good news about an old analog scope is it can be repaired but not without a whole lot of cursing. :)
     
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  9. jpanhalt

    Expert

    Jan 18, 2008
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    Made me laugh. That $50 must include free shipping, right?

    I have 3 analog Tek scopes and haven't turned them on in years. (I got the extra's for spare parts, both worked, but I parted one out as it was taking up too much space.) My TDS210 (Tek) is still used occasionally, as it doesn't have the lag that Rigol (and presumably Siglent) have. The trigger features and recording features on the digital scopes would sell them to me again. I have the Rigol DS1054Z updated to 100 MHz and including all triggers. I don't use 4-channels often, but having more than 2 channels is really nice.
     
  10. Teljkon

    Thread Starter Member

    Jan 24, 2019
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    Thank you all for all the great answers.
     
  11. Wuerstchenhund

    Member

    Aug 31, 2017
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    Even if it is, you still end up memorizing outdated methodology.

    It got better now, but there was a time when a number of applicants for our junior EE positions were unable to use a DSO properly because the college they went to still clinged to their analog scopes. One of the aptitude test we used was sitting the applicant in front of a digital scope (usually an Agilent/Keysight, as they are the most widespread DSOs) which is showing a modestly complex waveform and asking them to provide the signal parameters. You could instantly recognize those that were taught on analog scopes because they would start looking for cursors or start counting bars in the graticule, instead of just using the measurement suite.

    Seriously, we no longer teach medical students to perform bloodletting or Lobotomys, why should a starting EE (and here I include hobbyists as well!) how to operate a class of test equipment that has long been obsolete? That makes no sense whatsoever.

    I agree, a 2nd hand Rigol DS1000E Series could be an option if you can find one cheap (<$100), it's very limited in functionality but it's still a better buy than an analog scope. The same is true for Siglent old SDS1000CML/CNL Series (<$150).

    In addition, the HP 54645A/D can often be found <$150 in working condition and makes for a decent entry-level DSO. While the 'A' model is a 2ch scope, the 'D' model is an MSO (actually, the first MSO ever). The 54645A/D was also the first scope with HP's MegaZoom ASIC, which gives it a usable memory size (1M) and very high update rates.


    Actually, this isn't true. I fixed a number of DSOs myself, and there are lots of people on the various forums repairing DSOs. It's not necessarily any more difficult than fixing an old analog clunker, just that some of the failures are different. Most of the problems in DSOs come from leaky caps, expiring backup batteries, defective encoders or a dim/dead backlight, usually all fixable with some soldering skills. But mostly, DSOs are very reliable, even the cheaper ones from Rigol and Siglent, all much more so than any analog scope.
     
    Last edited: Feb 20, 2019
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  12. Teris

    New Member

    Nov 4, 2017
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  13. Wuerstchenhund

    Member

    Aug 31, 2017
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    Not that it's a bad scope (we have a few DSOX1102G which are the 'grown up' model of that scope and which we got for free when buying other Keysight gear), but with the Keysight DSO-X1000/EDUX1000 you are paying through the nosie for an underspec'd low end scope with the Keysight name on it.

    It's not just that the EDUX1002A has only 50MHz BW, the worse thing is that it only offers a measly 100kpts sample memory which, quite frankly, in 2019 is a bad joke. And thanks to the MegaZoom architecture, this 100kpts will divide down to 1/2 or even 3/4rd in certain measurement situations, making sure your sample rate drops like a rock on even only slightly longer time bases.

    The included probes are also pretty poor, although at least this problem can be solved cheaply.

    When for $379 [1] you can buy a Siglent SDS1202X-E with 200MHz BW, 14Mpts of memory and with serial decoders and better probes included for free then quite frankly you'd have to be mad to spend $550 (or even the $450 Keysight asks on its website) on a Keysight EDUX1002A.


    [1] https://www.amazon.com/Siglent-Technologies-SDS1202X-Oscilloscope-Channels/dp/B06XZML6RD
     
    Last edited: Feb 20, 2019
  14. danadak

    Distinguished Member

    Mar 10, 2018
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    I would go with the Rigol, Siglent recommendations.

    But I keep around, and occasionally use, a Tek 7000 mainframe scope.

    It bridges analog to DSO, but more importantly for me its specialized plugins
    make it a broad based instrument. Some of the plugins are -

    1) uV differential preamp with selectable hi/lo cutoff filter
    2) Several spectrum analyzer plugins (pricey on ebay, but amateur radio flea markets
    I have gotten some very good deals), 70 db noise floor kind of capability. Audio thru
    18 Ghz versions. 60 Ghz with external mixer.
    3) Sampling plugins to 10 Ghz
    4) Real time straight analog version to 1 Ghz
    5) Basic curve tracer
    6) Optical plugin

    To name a few.

    So if you can get it cheap worthwhile to keep around. But consider this secondary.


    Regards, Dana.
     
    Last edited: Feb 20, 2019
  15. Wuerstchenhund

    Member

    Aug 31, 2017
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    Ah yes, the 7000 Series of modular scopes. When they were current back in the days we had lots of them in various test sets, and while they were highly flexible they also were by far the most unreliable test instrument we had. The frames were fine but some of the modules spent more time in repair than in the scope.

    But yes, you can definitely get a lot of functionality with the Tek 7000 Series analog scope. Most scope frames are pretty cheap as are the modules, although some of the more rare ones are still very pricey, as they seem to be picked up by collectors.

    But leaving aside for a second that most of the functionality on the list is way outside what a beginner wants anyways, the fact that the modules all go into an analog scope frame alone limits their usefulness.

    For example, uV sensitivity is great, but it doesn't change the fact that the scope is still devoid of any of the very useful functionality of a DSO, like the one-shot capability, the storage, the ability to save a screenshot or waveform data, or the measurement, analysis and math tools. So while the plugin might help you to see a signal, it still can't be processed further as on a DSO.

    Or the spectrum analyzer plugins. A technical marvel in the '70s. In today's standards, with plugins like the 7L18 you get a wonky spectrum analyzer with a truly horrible RF performance and inability to sweep through the full BW. And as before, the drawbacks of the analog scope frame, i.e. the absence of any analysis and real sensible storage function still remains.

    And there is really not much use for a 10GHz sampling plugin, which is only useful for perfectly repetative waveforms or TDR, in an analog scope frame, and this not only because the limitations of the analog scope frame are also valid here. There isn't a lot of use for sampling scopes these days, and where there is there's also the necessity to perform some further analysis on the signal (i.e. jitter). Which you can't do on a 7000 Series analog scope.

    The same is true for optical signals.

    Every better DSO can act as a curve tracer, and scopes like the Siglent SDS1000X-E already come with a Bode plot function. Not to 1GHz, but for that you'd need a 7104 scope frame, which sometimes fetch up to $600 or more alone.

    In addition, while most 7000 Series plugins are somewhat cheap (although prices seem to be increasing), one or two 7000 scopes with all these plugins will still cost you a not insignificant amount of money, and you are still left with antiques that perform shoddily in most of today's applications, even when compared with gear from the '90s.

    If you work with uV level signals then a pre-amp or an active differential probe together with a DSO with active probe interface will do what you need. And when buying 2nd hand even without breaking the bank.

    If you really need a spectrum analyzer then there are many standalone units that easily outperform the wonky SA plugins for the 7000 Series, even new low-cost units like the Siglent SSA-X or the Rigol DSA800. On the 2nd hand market there are many SAs from HP, Anritsu, R&S or Advantek that offer solid RF performance with good analysis capabilities for not too much money. Not necessarily to 18GHz, but if you really need 18GHz BW then you will have the money to pay for it as pretty much everything from cables to attenuators and adapters is very expensive if rated to that frequency.

    If you really need a sampling scope or TDR, the HP 54120A/B+54121T digitizing scopes can often be found for very little money and can even go to 20GHz, all while offering many of the advantages of a digital platform.

    So yes, the Tek 7000 Series of modular analog scopes may look like a good low-cost solution for many more niche tasks, however if you want to do serious work then the poor performance and the many limitations of that antique platform just won't cut it, and after having to spend money for a working chassis, all the plugins and maybe some spares the financial side may no longer look that attractive, too.
     
  16. rsjsouza

    Active Member

    Apr 21, 2014
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    Well, free shipping or local, that would be my recommendation.

    Wuerst, by that logic why have grids at all? Why actually show the waveform if you are only interested in the parameters? In my experience with new hires, dexterity with the menus and options is something much easier learned than actually having the critical thinking about a measurement gained by counting graticule subdivisions or using cursors. As the old saying goes: there are lies, damn lies, statistics and what is displayed in the screen of your oscilloscope. :D

    Despite I agree with your assessment that we need to critically think about how we learn and teach more modern techniques and tools, I wouldn't go as far as saying this skill or its tools are useless as a lobotomy. It is a complementary skill that will still save your bacon in many situations. Obviously that, with such analog background, there is also a ramp to be learned to teach the discrete numeric approach of modern data acquisition systems.
     
  17. danadak

    Distinguished Member

    Mar 10, 2018
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    Our experience with them quite different than yours in terms of reliability.

    The Rigol and Siglent are, as you say, also “way outside what a beginner wants anyways”, But then that clearly states you and I know what the beginner wanted. That’s a stretch.

    The 7000 has measurement capability, 7854 extensive. And various plugins/frames allow for storage and digitization.

    The 7L18 have digital storage, as do several others. Basic spectral measurements also an inherent feature as well. I would suggest you read the operators manual before posting on this any further,. As well as the 7854 manual. I will have to read the 7L18 manual to look at sweep capabilities.



    DSOs are sampling scopes, what are you talking about ? You do not have use for a sampling plugin, others do. 7000 series with appropriate plugins can perform jitter measurement.

    Wrong again for all the prior reasons.


    Curve tracer = device curve tracer like NPN, PNP, MOSFET, JFET…..that takes specific power capabilities and forcing functions not in typical DSOs.

    As stated in the post you have to buy carefully. As far as cost if I had to buy the equivalent of every specialized plugin in other instruments I would be able to pay off the debt of the EU…..

    Not going to argue with you about utility of the 7A22 or the costs to buy active diff probes, I have them both, use them both.

    I have 3 plugins, total of all 3 were $ 120. And I have HP, but as you say its probably wonky even though they all get frequent use. Challenge for you, go buy the range of capabilities and tell me what you purchased.

    I have an HP54100 and think it sucks. About to literally dump it. I have one of their storage portables. It sucks. But did what I needed at the time.

    Yes, a nations GDP spent on test equipment will bring you everything. Clearly the type of design work and specifications drive test equipment needs. A 100 – 200 Mhz cheapy Rigol or Siglent is fine for some,. Not for others. A LeCroy LabMaster 10 Zi just barely adequate for others at $ 150 K, just the basics.


    Regards, Dana, not an expert on what everybody needs or thinks.
     
  18. MrChips

    Moderator

    Oct 2, 2009
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    Agreed. I see readings off the digital scope that are totally wacko. I choose to verify readings by looking at the trace against the grid markings.

    The one useful big advantage a digital scope has over an analog scope is the ability to capture a single event and to freeze it on the screen. An analog scope is better than no scope at all.

    My choice, depending on your budget and scope availability would be (not in any order of preference):

    1) A used scope for under $50, e.g. TEK 2213, 2225.
    2) A used digital scope for under $150, e.g. TDS210, TDS220
    3) A new digital scope for under $400, e.g. Siglent SDS 1202X-E.
     
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  19. nsaspook

    AAC Fanatic!

    Aug 27, 2009
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    The DSOX1102G is a nice scope for the money.
    https://forum.allaboutcircuits.com/threads/oscilloscope-features.152317/#post-1307422

    The X Y mode even looks good.

    Vector graphics


    Phase shifting sine using DDS
     
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  20. Teljkon

    Thread Starter Member

    Jan 24, 2019
    66
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    LoL its fun to see a little shop banter and I am probably stepping in it here. But, are there any build your own oscilloscopes that would be worth the cost for the education?
     
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