Cheap Oscilloscope Is… Well… Cheap

We always enjoy watching [Kerry Wong] put an oscilloscope through its paces. His recent video is looking at a very inexpensive FNIRSI 1014D ‘scope that you can also find rebranded. You can usually find these for well under $200 at the usual places. Can you get a reasonable scope for that cost? [Kerry] has a list of issues with the scope ranging from short memory depth to low sensitivity. He did, however, like that it is USB powered so it can be operated from a common battery pack, which would make it truly floating.

The ‘scope looks like a lot of other inexpensive ‘scopes, but you can see some concessions to price. For example, the encoder knobs don’t have a push button function, making the scope more difficult to operate. While the specs are relatively modest, [Kerry] wasn’t sure the instrument was even living up to them.

The scope did start up fast and had responsive controls, which is good. There were some display oddities as the horizontal sweep changed. The scope claims to have 100 MHz bandwidth. However, it appears this is vastly overstated. In addition, there was some measurement offset as frequency increased.

The teardown shows there isn’t much on board and the design doesn’t seem very sophisticated. Granted, the scope is cheap, but maybe it is just too cheap. [Kerry] wasn’t impressed and, from what we saw, we weren’t either. His exact quote was: “I wouldn’t touch this ‘scope with a ten-foot pole.”

Last time we checked in with [Kerry], he was looking at cheap ‘scope meters which fared better for a similar price. It is amazing how much times have changed for cheap ‘scopes.

51 thoughts on “Cheap Oscilloscope Is… Well… Cheap

  1. I have learned to be very cautious of these cheaper digital scope. When I compare them to high end older analog scopes, I find the digitals miss quite a bit. Especially things like noisy signals or short events that the digital sampling misses.

    1. A 5G technician friend of mine recently said “These super cheap Chinese scopes are introducing error levels unheard of before” and after buying a stm32f103 based 8 channel scope recently I can agree.

    2. For just a little more money Owon has the HDS3010S 2 channel more honest 100 MHz (single channel 500 mega sample/S, shared ADC) scope meter. You also get a Cat III/IV 4,5!digit multimeter and function generator powered by two replaceable 18650 cells. The Owon is about the size of a Fluke 87 meter.

      I bought an Owon for my own use an I am impressed. Single channel response is flat to within 1 dB from DC to 100+ MHz. The internal frequency counter track s to 119.9 MHz. The scope triggers and locks to 200 MHz with reduced amplitude accuracy, but useful qualitative display. The 4.5 digit meter is accurate to 0.1% of better. The function generator appears to be 14 bit based on observation of the overtones prestent in the sine wave output’s spectrum.

      I recommend the Own as a much better pick than the Fnirsi scope for a hobbyist on a budget or for an everyday field instrument.

      1. I bought an Owon scope Sds7102v. It’s damaged, lost synchronization and the channels not working properly. I asked to Owon about repair, but they sent me to buy another one.

  2. I got my scope for free, a Tektronix 545, with some plugins, about 30 years ago.

    My first scope from shortly after WWII, cost me $5 about 1972.

    Neither are particularly portable. The 545 is decent, the otyer one was only good to play with.

    1. I loved the 545A I used to have. For its era it was one of the best ‘scopes you could get. But with a 30MHz bandwidth, no way to save the waveform to your computer, about 100 vacuum tubes to potentially fail, and enough waste heat that I’d turn it and my 535A on in my shop as heaters in the winter, I’m better off with a modern ‘scope.

    2. This to my mind is the way to go if you want an inexpensive scope. Even if you don’t get one for free, with a little patience you can get much better used ones for under $200 off eBay or local want ads like Craigslist. Also keep an eye on state auctions, since now and then colleges will upgrade their labs and have some to get rid of. Almost nobody there will need an oscilloscope so you’ve got good odds of winning a bid on one.

      1. How do you get individuals though? I’m always depressed because I want a decent analog scope for music and occasional video purposes but University of Washington gets rid of them in batches :/

        1. UW isn’t going to have anything that old unless it’s sold on a cart with a bunch of other stuff. Look for a Tek 465 or something on CL for a month, you’ll find one for < 150 no problem. Or wait until the Mike and Key ham show in March, folks usually sell them for < 50 bucks.

        2. Here they usually list things individually unless they’re something like chairs where you’d want a set or ten-yo Dells where they’re individually worth like 35 cents. But if they’re selling something you want in lots, the way to go is find some other people interested in the same thing and see if they want to sell you one of them if they win or just go in and split the cost.

    1. Story time. At an old job, when working on a testbench for arrays of high-performance, relatively high-power valves (24x 60W valves typically fired a few times a second) and their related pistons, I kept getting really nasty shocks when changing out the modules under test. After the third time it happened I decided to stop being a dumbass and figure out why. The owner of the company had been known to rip out the third prong on extension cords to float scopes, and what do you know, my machine was plugged in via one of these cords.

      1. The owner should be forced to lick the end of the cable. That is not how you float something. That’s how you assassinate someone and come in after to swap the lead and make it look like an accident.

    2. It’s perfectly fine to use battery power which means it’s also floating. Your link is about using an isolation transformer to scope on mains, which was the preferred method in vacuum tube era but is not best practice or as safe for the user.

      With a battery(and certain DC supplies) the scope is floating whether you like it or not. If you also then float DUT you’ve just made everything more dangerous for yourself and your device if a short occurs for zero benefit.

      1. That depends on the plugins you use and the age of the unit. If I remember correctly, the original 545 had UHF connectors on the unit itself, later 545As had BNC. It’s hard to remember though, it’s been years since I’ve used one or repaired one.

    1. Pah! Real men use 4mm banana connectors! 😁
      Gratefully, I’m a proud user of a Trio CO1303D which has them, too! 😀

      Here’s a video of a similar unit, albeit modified.
      – Get your cup of hot chocolate, watch and learn, my kids! It’s not too late.

      1. @Joshua said: “Dick Smith Q-1280/Trio CO1303D 6.5mhz 1980s Oscilloscope”

        Wow that stirs up some memories. Trio is the predecessor of the Kenwood Corporation in Japan, now know as JVCKenwood.[1] So that scope was made in Japan by Trio then re-badged and sold by Dick Smith Electronics in Australia and New Zealand. When I was living and working in Indonesia I would visit Australia and New Zealand often on business. No trip was complete without a visit to Dick Smith to buy some parts and things that were hard to find in Jakarta’s Glodok Electronics Market. I thought Dick Smith went out of business. But it seems they live on in some form, at least online.[2][3][4] Dick Smith Electronics was like Radio Shack in the U.S. back in the day.

        * References:

        1. Kenwood Corporation

        https://en.wikipedia.org/wiki/Kenwood_Corporation

        2. Dick Smith (retailer)

        https://en.wikipedia.org/wiki/Dick_Smith_(retailer)

        3. Dick Smith Australia

        http://www.dicksmith.com.au/

        4. Dick Smith New Zealand

  3. It depends, like always, what you need it for and how deep your pockets are. We use a couple of these scopes in the shop, and we sell quite a few in the store. No negative comments, no breakdowns. A Chevy Spark, in the eyes of the BMW X5 owner, will perhaps be a terrible car. But for the single mom who needs a cheap but reasonably reliable ride to haul her toddler around, it is not.

      1. This isn’t trying to ‘flex’, fake rolex/bmw style.

        It’s just obviously cheap test equipment, nothing new here.
        Wait for the knockoffs if you need trail scope. Spend savings on probes.

        GP misunderstands purpose of ‘flex’. Chuck doesn’t have a Savile row clad ‘minder of the royal toilet seat’ because he’s fussy. X5 ‘drivers’, don’t drive, only know cheap/expensive cars (wouldn’t know a good one, bought X5!). It’s all a _stupid_ flex contest. Winner gets to be worm food, hookers and blow optional.

    1. thanks for the link where i could actually buy one ;)

      from the review, it sounds to me like this scope is a step down from the siglent sds1102 i have? i don’t know all the brands but it seems like there are a bunch of rigol / siglent sort of things that make a 2-channel 100MHz scope right around $300, which generally people have positive feelings about for the price? anyways, i know i love mine.

      so what i’m trying to understand is, if you can buy this FNIRSI scope for $300, why would you? i am just struggling to understand the value proposition. i understand the appeal of the wide variety of extremely inexpensive portable scopes that look like cellphones, like the miniware mini you can get for $50. and i love the next step up, $300 for something that looks and works like a real bench scope but with some limitations. i don’t understand why you would want something in the middle, when that $300 scope is so great?

    2. You need a 100MHz scope if you buy a 100MHz scope. Quite simple.

      If you needed a 10MHz scope, why shell out more for a 100MHz scope? Well, if you expect to have need for a 100MHz scope in the future, of course. But if you buy the scope now, you are in need of a 100MHz scope.

      So, if you buy a 100MHz scope, you need a 100MHz scope. If you buy a 100MHz scope, you are not in need of a 10MHz scope.

      In short: this scope is overspecced just to lead you into thinking that you’re buying a 100MHz scope, while you are actually buying a 10MHz scope while needing a 100MHz scope.

  4. I’m glad he finally put a terminator on that line for the frequency response measurement. Almost had to call him out.
    Except he didn’t use it with the pulse generator, so I’m still calling you out Kerry. You know better than that.

  5. I haven’t seen a review that verifies this, but I suspect that this is NOT a 1GSa/s scope. Dave at EEVBlog did probe the FNIRSI 1013D and verified that the ADCs were only clocked at 200MHZ – I suspect it’s the same for this model. BUYER BEWARE!!!

  6. I was just looking for a reasonable entry-level oscilloscope and checked a couple of reviews of this one. I’ve literally never used an oscilloscope, I have no idea how to use one or what specs I need to care about, but at least the reviewers seemed to know what they were talking about and the general consensus seems to be “meh” for this one.

    It’s too bad; the scope isn’t outrageously expensive and is just about within my budget’s reach, if I save up a little. Another entry-level scope I came across was the Hantek DSO2D15, which has gotten more positive reviews, but it’s 80€ more expensive.

    1. A good ‘scope will last you decades.
      A cheap one will collect dust. (I know, I have a few).
      For the same price or budget, you’re probably better off buying a second-hand one with better specs.
      Dirt-cheap digital scopes have, in my experience, too many issues with aliasing, such that even the cheapest analog scope with one channel is more useful.
      So spend wisely :-)

      1. Buying second-hand isn’t really an option here. We basically have zero market for such niche devices as oscilloscopes — I just looked and I found….7. Only 3 of them were used, the rest were just further marked-up brand new scopes, including the same scope this article is about.

        1. I don’t know where your “here” is, but have you checked your local (radio-)ham community? Alternatively, is importing from abroad an option? Won’t be super cheap for old analog scopes since they are heavy (with added gravity and a side-dish of lead bricks) but might still end up cheaper than this scope.

          1. Well, my “here” is Finland and I don’t know of any ham-radio community here. Importing abroad would only be an option from Europe; importing from e.g. the US would mean shipping fees + 24% VAT + customs fees, easily making such an endeavour a whole lot more expensive.

            The prices for used scopes in Europe, plus shipping, on e.g. eBay quickly get to around the same as brand-new ones from more reputable companies and it just doesn’t seem worth it.

      2. I don’t know that you would get better specs, high spec scopes seem to have kinda low depreciation. $200 around here gets you a 10Mhz dual trace if you’re lucky. Built like a tank and will last through the next nuclear war, but not highly featured. Then cheaper than that goes to rock bottom real quick with 1 and 2 mhz ancient behemoths either way overpriced or free. You’d be up to $500 for half what we figure this can actually do, over a thousand for what it’s advertised for. Many of us just want a general idea of the waveform shape something is spitting out, not an exact calibrated measurement of the exact amount of overshoot on the leading edge of a 5ns pulse.

        So really the question that this article would best answer would be “Is this better than buying one of those $50 pocket scopes and overclocking it or meddling with the firmware, or is that basically what it is, one of them hyped up?”

  7. The biggest trouble with this fnisrsi stuff is that it’s so bad that you can not trust what you see on the screen.
    The big artifacts that look weird to Kerry Wong are caused by averaging. My Rigol DS1052E can show very similar artifacts if you turn on averaging and average a lot of traces.

    The wobbly waves the tops of even a 10MHz sinewave are another strong hint for averaging. You can only guess at what the actual samples this toy takes of your circuit look like.

    I’m not even sure if this thing is capable of single shot operation.

    The 50mV/Div is another quite significant limitation. That turns into 500mV/div with a 1:10 probe, which you need to get a decent bandwidth.

    And if it can’t even display a simple sinewave properly, what will it do to a real signal you want to measure?
    An important function of an oscilloscope is to be able to capture occasional glitches, but with all the signal processing this gadget does to hide it’s own limitations it’s very unlikely it would be capable of showing those at all.

    But even worse then all of this is probably that this manurefacturer blatantly lies about it spec’s. It’ can’t even display a sinewave of 1/3 of it’s reported bandwidth properly.

    Everything together, it’s not even advisable for a beginner on a tight budget. Beginners are unlikely to recognize the ways in which this thing is lying to them and this is likely to result in frustration when they try to use it for any non-trivial task.

    So please save up your money and get at least a Hantek or Owon entry level scope.

    ————————–
    The only thing this may be useful for is to review the reviewers. If a reviewer gives this thing the thumbs up, then it’s time to add that reviewer to your blacklist.

  8. The BEST scope IMHO is the Tek 2465 : best analog for the price with a digitally-assisted interface, a breeze to use ! It is the culmination of an era at Tektronix, more than 20 years ago. Available too with ultra-bright screen for spotting transients and GPIB.
    It’s the one I power on before the others to check the signals since the user interface is so easy to use.
    Then I use a digital scope if I want to make screenshots.

    1. True. I don’t have a Tek, but a Philips PM3262 analog 100MHz scope. It’s from 1977 ;). But the point is that I use it for almost everything. I know that it doesn’t lie to me. As it’s all analog, the screen displays exactly what it measures. No options for freezing the display, but I really rarely find myself in need of that.

      What puts me off though, is that it’s huge and takes up a lot of desk space. And for that reason, I’m thinking of buying a Rigol or something. But the desk space is the only incentive, so I’m procrastinating the purchase. ;)

      1. thanks for “no options for freezing the display”, because i am trying to understand what i’m missing with my middle of the road digital scope and i think that might be the crux of the matter?

        i use the ‘single’ trigger mode (trigger then hold) the most, and even when i’m using the repeating trigger mode, it’s almost always triggering on discrete events 1s+ apart (rather than examining the output of a free-running oscillator), so i really get a lot out of storage/hold features. i don’t actually use my scope very often, and when i do use it i’m likely to be debugging a digital circuit hanging off of a microcontroller, or alternatively trying to understand/confirm simple analog circuits. i don’t do anything RF. but sometimes i look at digital signals that are fast enough that i wonder if zooming in on the leading edges is giving me meaningful information or just scope sampling phantoms. i’ve definitely gotten useful/actionable information out of it when looking at leading edges but i wonder.

        the one thing i do know i don’t like about my current scope is, as others have said, it simply isn’t very reliable about triggering on transients. when you use single shot mode enough you really notice things like that. but are accessible analog scopes really much better at that if the transient doesn’t repeat regularly to refresh the trace? i guess i don’t have any basis for imagining what it’s actually like to use one.

  9. I almost hate to give away any secrets, but in the United States, there’s a website called shopgoodwill.com where second had stores post things for auction. Bought two Tek digital scopes there. Other brands usually go pretty cheap. Check the shipping cost to make sure it’s not too high and remember that you’re buying untested (sometimes powered on – read the description and look at all the photos closely) second hand as-is, so be prepared to repair or don’t spend more than you can afford to lose.

  10. My experience with a Hantek DSO2D15 it has been more than frustrating. This oscilloscope has Trigger Level issues with signals under one Volt. A sine wave of 1 KHz/500 mVpp is not triggered at all, it runs continuously on the display from left to right and vice versa. I tried slope triggering, it helped only a tiny bit, there’s no way to keep the trace steady on the screen.
    I have been discussing with Hantek’s after sale for more than a month, a huge waste of time. They asked me to send a video showing the defect and so I made it and sent. No sign of life from their part for two weeks. I contacted them a 2nd and a 3rd time and they asked me to send a video, again! Today, July 24, 2022, after six weeks of chatting back and forth, they sent me a firmware update dso3kb_20220517 which hasn’t changed the situation at all. The frustration continues…
    After an analysis on Amazon and YouTube, I’ve seen that several buyers had the same Trigger level problem with the DSO2D15. Some customers have been lucky that Amazon has taken back the product, others like me who have had it shipped from China, after six months they do not take the product back. In six months I have used the machine four times and not for measuring small signals. I would never have imagined of a such disappointing purchase, I have an oscilloscope that is totally useless for measurements of low amplitude signals. I definitely do not recommend this model to anyone and rather invest on other brands that have been in the field for more than thirty years.

  11. I think too many people are missing the point here. It’s a cheap entry level model that is ultra easy to use and learn from. Ideal for a beginner or someone just trying the basics, or wondering if an electronics hobby is for them. Everyone is banging on about bandwidth but beginners are more than likely wanting to use it with analogue audio or low frequencies where it is more than adequate and I find it good for my needs in the dc to 30mhz range for ham hobby. The screen and measurements are clear. I struggled to learn with a traditional scope but now I’ve learnt so much so quickly. Yes I may well upgrade in the future but it’s shown, with minimum outlay, what oscilloscopes can do and I’m now hooked. There seems a bit of professional snobbery here, you wouldn’t buy a Rolls Royce to learn to drive in. So it’s an old banger in their opinions but don’t lose sight of the very low cost, some people are not made of money and are at low end hobby level. So its great value and the fact it also has a built in waveform generator is another perfect bonus.

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