Best Digital Oscilloscope Under $400USD?  - Page 1
Forum section: electronics / beginners

author: LooseJunkHater
author_rank: Frequent Contributor
timestamp: May 16, 2021, 05:24:20 pm
content: I know this question has probably be asked (and answered) a lot, so feel free to link a topic with it.I'm looking for a good beginner DSO (not one with a CRT) under $400USD. I'd preferably buy from EBay, but that is not mandatory. I have no preference on used or new. I currently have a JYE-Tech DSO062, so I know some of the basics of oscilloscopes and how to avoid frying it.Required features:- Single-shot mode- Run/Stop- 2 channels minimum (I likely won't need 4 channels as this is a hobby, so it's not a required feature)- Measuring frequencies above 10MHz- TriggerNice-To-Haves:- Being able to hack the scope for additional features would be nice- Built-in variable signal generator- Built-in Spectrum analyzer (more important to me then a signal gen)- Bus decoding functions- PC USB Support (ex. to control and view the waveform on a PC)I currently mostly mess around with buck/boost converters, basic transistors, op-amps (audio purposes), and repairing of AC->DC Power supplies, but I'd like this scope to give me the opportunity to learn more in the future.Thanks strangers

author: ataradov
author_rank: Super Contributor
timestamp: May 16, 2021, 05:41:51 pm
content: I would say that Rigol DS1054Z still holds its value at that price point, you can get it even cheaper. And it is plenty hackable, now officially.And for the signal generator consider UTG962 (or UTG932, which may be hackable too) -https://www.eevblog.com/forum/testgear/uni-t-utg932utg962-200msas-function-arbitrary-waveform-generator-220394/

author: Doctorandus_P
author_rank: Super Contributor
timestamp: May 17, 2021, 12:57:04 am
content: You're at the bottom of where "good" scopes begin.I haven't kept up what the "unofficial" bandwidth of the Rigol 1054Z is.Maybe Siglent SDS1202X-E is worth looking at. It only has two channels, but it's got "200MHz" printed on the front, and from reviews I've read Siglent (not sure of this model) has a much better spectrum analyzer. The difference is "mostly a toy" in Rigol" and "pretty usable" in Siglent. (But not on par with a dedicated spectrum analyzer).

author: ledtester
author_rank: Super Contributor
timestamp: May 17, 2021, 01:27:14 am
content: Quote from: Doctorandus_P on May 17, 2021, 12:57:04 amIt's well above 100 MHz:https://www.eevblog.com/forum/testgear/rigol-ds1054z-bandwidth/msg1095407/#msg1095407

author: rsjsouza
author_rank: Super Contributor
timestamp: May 17, 2021, 02:05:35 am
content: Quote from: LooseJunkHater on May 16, 2021, 05:24:20 pmNo oscilloscope has a true spectrum analyzer but, at under $400, good FFT is present only on offers from the aforementioned Siglent SDS1202X-E and GWInstek (GDS1054B). The Rigol DS1054Z is very limited.If by "bus decoding" you mean serial, this is available but with some tradeoffs. The Rigol DS1054Z only decodes what is on screen, which can be very limiting depending on the length of the data capture. The Siglent has some decoding available but, being only two channels, restricts the number of signals to decode. The GW Instek severely limits the sampling memory when performing decoding. My suggestion? Think about investing in one of the cheap Saleae clones on the internet.As others also have said, think about an external AWG - the aforementioned Uni-T seems to be a very reasonable choice.AFAIK all oscilloscopes above are capable of connecting via USB.Good luck in your quest!

author: Doctorandus_P
author_rank: Super Contributor
timestamp: May 17, 2021, 03:14:34 am
content: For the "bus decoding"...I have an old Rigol myself (DS1052E), which does not have any logic analyser functions, but I do have a few Cypres CY7C68013A (saleaeaeae Clones) and they work quite well with Sigrok / Pulseview. Pulseview also has 100+ protocol decoders built in, and they're all written in Python (typically a few pages) so you also have 100+ examples to modify and derive your own.I have a bit experience with a PC based scope, and I found it quite horrible. A scope must have knobs and buttons. For a Logic Analyser however, working with a Mouse works quite good, and the higher horizontal resolution of a monitor is a real advantage for a LA (Vertical resolution is not so important, (especially if you only have 8 channels.Another advantage is the small box with short "dupont" wires. Good enough for low frequency measurement ( CY7C68013A samples only upto 24MHz) That sampling is not fast, but plenty for UART, I2C, SPI, low-speed USB, CAN, LIN and lots of other stuff you find in microcontroller world.If you're intested in LA functions on a scope, then two channels would be very limiting (even 4 is very low). Options for adding ( often 16) logic channels is available for a lot of scopes, but it's relatively expensive. It can be near the price of the scope itself, which is I think mostly for "historic reasons" or decided by "marketing", as it's often not much more then some signal buffering and fancy (and nice) cables.

author: tautech
author_rank: Super Contributor
timestamp: May 17, 2021, 03:43:46 am
content: Quote from: rsjsouza on May 17, 2021, 02:05:35 amBy using a Clk Timeout setting you can indeed decode protocols that would normally require 3 scope channels.4 channel X-E and the $399 4ch SDS1104X-U models can do this trick also which allows for dual decodes.If I had stock of SDS1202X-E a screenshot would be possible but totally sold out until new stock arrives in a few days.

author: rsjsouza
author_rank: Super Contributor
timestamp: May 17, 2021, 08:10:32 am
content: Quote from: tautech on May 17, 2021, 03:43:46 amThanks; I had this in mind but forgot to expand on it. Even still, using the Ext Trigger as the third channel does not actually display it, right? Thus requiring a few more probe changes to see all channels.I forgot the X-U model. Despite the actual 399 price in practice means above 400 with taxes shipping, etc., what is the main difference (apart from the channels) when compared to the X-E models?

author: tautech
author_rank: Super Contributor
timestamp: May 17, 2021, 08:27:49 am
content: Quote from: rsjsouza on May 17, 2021, 08:10:32 amDoesn't work, tried it. When I asked the product manager the signal path for Ext Tigger is not available for decoding like it is for the cheap HPAK which is 2x the cost.QuoteIn practice they are much the same to use however X-U has a single ADC so just one lot of memory also but it also hasn't got a lot of the fruits X-E models have.Best summary of X-E/X-U differences is here:https://www.eevblog.com/forum/testgear/siglent-1120-new-sds1104x-u-4-channel-100mhz-1gsas-economy-oscilloscope/msg3356644/#msg3356644

author: LooseJunkHater
author_rank: Frequent Contributor
timestamp: May 17, 2021, 09:57:58 pm
content: So I'm getting the oveall sense that the Siglent SDS1202X-E would be a good fit, and that instead of getting a scope with a dedicated signal decoder, I should get a seperate piece of hardware to accomplish said task, which makes sense to me.I've only seen recommendations for Siglent and Rigol scopes. Does Keysight, Tektronix, Agilent, LeCroy, B&K Precision, Keithly, or any other scope companies really not have any better value-for-dollar scopes? I have no brand loyalty, however, I do want something with a refined layout and interface, so I'd like to avoid the generic and cheap scopes by companies like Hantek, and definitely don't want a USB scope.

author: ataradov
author_rank: Super Contributor
timestamp: May 17, 2021, 10:07:53 pm
content: Quote from: LooseJunkHater on May 17, 2021, 09:57:58 pmTwo channels may get limiting even if you don't use protocol decoders.And yes, for the protocol decoding it is so much easier to get one of those $15 logic analyzers. Decoding protocols on the scope no matter how good it is, is still a terrible way to go. The only justifying factor is that you may need to correlate the data to some analog events (which would be out of the question with 2 channel scope anyway). If you just want the protocol decoding on its own, a logic analyzer is a way to go.Quote from: LooseJunkHater on May 17, 2021, 09:57:58 pmNope. They are sticking to the idea that brand somehow matters and worth charging more for. Their idea of affordable entry level scope is still at least $100-$300 more expensive than the closest real affordable options. And often they get the idea of the paid options to the extreme.They also sneakily send fully upgraded scopes to the reviewers making them review much better than they actually are in a basic configuration.

author: tautech
author_rank: Super Contributor
timestamp: May 17, 2021, 11:01:43 pm
content: Quote from: LooseJunkHater on May 17, 2021, 09:57:58 pmYou could well find the decode suite of SDS1202X-E is quite adequate unless you plan on lots of the 3 wire protocols.These have been our best seller for a few years closely followed by SDS1104X-E however SDS1104X-U is now getting some share for those that want a more reasonably priced 4ch DSO.

author: EEVblog
author_rank: Unknown
timestamp: May 17, 2021, 11:31:13 pm
content: Quote from: rsjsouza on May 17, 2021, 02:05:35 amYes, one of the main limitations of the Rigol. But the Rigol is usually the cheapest option, and probaly the only one under that $400 mark.And I know that you think you don't need 4 channel, but buy 4 channels. You mentioned PSU debugging. I've shown videos that require more than two channels doing PSU debugging.

author: EEVblog
author_rank: Unknown
timestamp: May 17, 2021, 11:34:05 pm
content: Quote from: LooseJunkHater on May 17, 2021, 09:57:58 pmNo, they don't bother to compete in that category. Keysight used the rebadge Rigol scopes (and helped pay for their development), but even then they were priced higher because of the name.

author: LooseJunkHater
author_rank: Frequent Contributor
timestamp: May 18, 2021, 12:38:09 am
content: Awesome, so I guess I'll be getting a SDS1202X-E in the near future!Thanks all!

author: tautech
author_rank: Super Contributor
timestamp: May 18, 2021, 12:45:45 am
content: Quote from: LooseJunkHater on May 18, 2021, 12:38:09 amWhile you are waiting for it to arrive an excellent thread on exploring its capabilities is here:https://www.eevblog.com/forum/beginners/what-an-oscilloscope-recommended-for-a-woman-passionate-about-electronics/

author: rsjsouza
author_rank: Super Contributor
timestamp: May 18, 2021, 01:00:13 am
content: Quote from: EEVblog on May 17, 2021, 11:31:13 pmNot anymore (at least in the US) all three are under this magic number here (off taxes and freight, of course).Quote from: EEVblog on May 17, 2021, 11:31:13 pmI agree with that as well, which makes such decision in the price range quite difficult either a very capable 2ch or a somewhat crippled 4ch.

author: LooseJunkHater
author_rank: Frequent Contributor
timestamp: May 18, 2021, 01:04:35 am
content: Quote from: tautech on May 18, 2021, 12:45:45 amOhhh nice, this will provide some great reading material!!!Thanks again!

author: LooseJunkHater
author_rank: Frequent Contributor
timestamp: May 18, 2021, 01:07:25 am
content: Quote from: EEVblog on May 17, 2021, 11:31:13 pmWhen reading everyones comments, I missed this part; is there a specific video (or set of videos) that can be linked that show the use of 4 channels for PSU debugging?

author: rstofer
author_rank: Super Contributor
timestamp: May 18, 2021, 02:21:41 am
content: Quote from: LooseJunkHater on May 18, 2021, 01:04:35 amIt isn't until around Reply 150 that Charlotte actually buys the scope. Then we let the games begin! I had a lot of fun in that thread and learned a lot about my DS1054Z at the same time. Corner cases where I had never been were all of a sudden a hot topic.I bought the DS1054Z because I wanted 4 channels to decode the SPI protocol. CS', MISO, MOSI and Clk - it's nice if these can be seen together. The Siglent wasn't available at the time and I already had a Tek 485 2 channel 350 MHz scope.

author: Anthocyanina
author_rank: Frequent Contributor
timestamp: May 18, 2021, 02:24:44 am
content: I'm quite curious about the rigol FFT, what makes it so bad? this is for example fft done on a 2.5MHz square wave. (one thing i don't like is how the center doesn't always let you select .5 but will allow .4 and .6, like in this case, center is 57.6MHz But still, it looks like a pretty good frequency domain representation of that square wave. I do have the rigol 1104z but i think it's the same as the 1054z? just pre-unlocked to 100MHz? What is bad about an FFT like this? Thank you!

author: rstofer
author_rank: Super Contributor
timestamp: May 18, 2021, 02:43:51 am
content: Quote from: rsjsouza on May 18, 2021, 01:00:13 amSDS1104X-E unlocked to 200 MHz would be my choice were I buying another scope today. It doesn't make the $400 price point but I would still work it out.

author: tautech
author_rank: Super Contributor
timestamp: May 18, 2021, 03:07:31 am
content: Quote from: LooseJunkHater on May 18, 2021, 01:07:25 amSome circuits are finnicky about the staging of power rails coming up at power ON which is where you would want to check they are staged correctly rather than exceed the input ratings of another device on a different rail before it's supply is fully up.Careful study of absolute max ratings in datasheets reveals these things.You might get away with 2 channels for such work by checking rail sequencing in turn but 4 channels makes this lots easier as you see them all rise together.Not exactly everyday use but another valid case for going for 4 channels should you think you might be doing this sort of stuff.Like most scope use some good thought should go into every measurement when getting set up as there are always traps for the inexperienced and other ways to skin the same cat.

author: rstofer
author_rank: Super Contributor
timestamp: May 18, 2021, 02:36:53 pm
content: This Sparkfun page is a decent tutorial in using a DSO. They don't get to 4 channels but they do a great job of explaining what shows up on the screen.https://learn.sparkfun.com/tutorials/how-to-use-an-oscilloscope/all

author: LooseJunkHater
author_rank: Frequent Contributor
timestamp: June 14, 2021, 03:01:14 am
content: Alright so I'm trying to decide between the 1202X-E, the 1104X-E, and the 1204X-E.Is there a physical, hardware difference between the 1104X-E and the 1204X-E? Once I upgrade the firmware of the 1104X-E, will it be identical to the 1204X-E?Second, are there different software features between the 1202X-E and the 1204X-E, or are they identical? I know that one has 2x channels and the other has 4x channels, but is that it?Thanks.

author: tautech
author_rank: Super Contributor
timestamp: June 14, 2021, 04:34:24 am
content: Quote from: LooseJunkHater on June 14, 2021, 03:01:14 amNo SDS1104X-U ?QuoteOnly supplied probes are different but not enough to cause any concern for any normal work.QuoteNo several differences.SDS1202X-E:No webserverNo Bode plotSingle ADCNo WiFiNo MSO or AWG options.Otherwise they are identical to use.Additional excellent table here:https://www.eevblog.com/forum/testgear/siglent-1120-new-sds1104x-u-4-channel-100mhz-1gsas-economy-oscilloscope/msg3356644/#msg3356644

author: LooseJunkHater
author_rank: Frequent Contributor
timestamp: June 14, 2021, 05:43:43 pm
content: Oh that's a good chart! Awesome, thanks for your help! Hopefully I can grab the scope next week!