Oscilloscope for an electronics learner - Page 1
Forum section: electronics / testgear

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 14, 2016, 12:52:30 am
content: Hi i'm looking for an oscilloscope that is below $1000 in learning electronics. I want to build my own circuits and PSUs.I dont think i will need 4 channels so 2 channels will be enough. The signaling frequency will be below 100mhz (it depends on the controllers being measured. Its not like arduino even the intel variants will be above 100mhz). I want to be able to see signal and power distortions and spikes. Being able to measure asymmetrical circuits would be good too.Im looking at buying a siglent SDS1202X but i would like to know of other variants to consider as well that would do what i am asking. I've read around the forum and seen various eevblog videos, there also seem to be brand fanatics for almost every thing. I've seen some oscilloscopes that connect to PC via usb3 instead of having their own screen but the software display isnt as colourful as the ones with screens. Another thing i am unsure of is are there any oscilloscopes with gigabit ethernet? It is very annoying that so many devices even all the raspberry pi still use 100Mb/s ethernet when they clearly have the capability and reason to use more.I think an oscilloscope with screen would be more convenient unless there is a better oscilloscope without screen for the same price that wont be bandwidth restricted by IO.I may be an expert when it comes to computer/networking hardware even processor architecture but a total noob when it comes to electronics and oscilloscopes.

author: tautech
author_rank: Super Contributor
timestamp: June 14, 2016, 01:15:32 am
content: Welcome to the forum.Your intention to go with a 200MHz 1000X series for a novice is a bold move IMO as it is hardly a beginners DSO, in fact a very capable instrument.Although the basic models in this series have only 2 channels the recently announced Plus versions have an 16 channel LA that can extend their capabilities on low voltage measurements dramatically.http://www.siglentamerica.com/pdxx.aspx?id=4688&T=2&tid=1

author: ebclr
author_rank: Super Contributor
timestamp: June 14, 2016, 01:19:32 am
content: The best deal for the buckRigol DS1054ZThe ones for rich startersTektronics DPO2012BAgilent DSOX2014A

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: June 14, 2016, 01:53:33 am
content: If you are considering the Siglent SDS1202X, definitely check out this thread on them. Lot of good info.https://www.eevblog.com/forum/testgear/siglent-sds1000x-series-oscilloscopes/

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: June 14, 2016, 02:01:58 am
content: Others to consider.Rigol DS1054Z, definitely the most popular around here. The cheapest Rigol DS2072A is in your price range as well, and can be easily be hacked to be the same as the DS2302A.The GW Instek GDS2000E models seem to be getting more popular. tequipment.net is having a good sale on these currently.Good threads on them can be foundhttps://www.eevblog.com/forum/testgear/gw-instek-gds-2000e-teardown-short-review-comparison-with-rigol-ds2000(a)/https://www.eevblog.com/forum/testgear/gw-instek-gds-2000e-released/The GW Instek GDS-1000B series also seem to be decent if you wanted a little cheaper.You probably can't go wrong with any of these.Edit: Stupidly linked same thread twice

author: EEVblog
author_rank: Unknown
timestamp: June 14, 2016, 04:43:36 am
content: Don't spend more than $400 on the scope.Spend the rest on other gear, parts, projects etc.

author: rstofer
author_rank: Super Contributor
timestamp: June 14, 2016, 04:51:04 am
content: Quote from: EEVblog on June 14, 2016, 04:43:36 amWhich means, buy the Rigol DS1054Z and decide later whether to hack it to get 100 MHz capability. It a very simple operation and takes about 5 minutes, start to finish.

author: ebclr
author_rank: Super Contributor
timestamp: June 14, 2016, 04:56:35 am
content: Hacking 1054Z is easy as drink water, 3 minute job

author: boffin
author_rank: Unknown
timestamp: June 14, 2016, 05:10:16 am
content: Quote from: System Error Message on June 14, 2016, 12:52:30 amFind yourself a used Analog Discovery (dave did a video on it). I picked one up for 100 Cdn Pesos from a uni student who needed it for a class

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 05:33:51 am
content: Quote from: System Error Message on June 14, 2016, 12:52:30 amFamous last words.Quote from: System Error Message on June 14, 2016, 12:52:30 am"Arduino"?You need 4 channels.Quote from: System Error Message on June 14, 2016, 12:52:30 amIn that case get the Rigol DS1054Z. It'll easily do everything you need for "Arduino" and PSU work.Save the big $$$ for when you know more and can make a purchase decision based on experience about what you really need. Buying thewrongoscilloscope (eg. not enough channels) can be an expensive mistake.Besides, you also need a bench power supply, decent soldering iron, nice multimeter, ten different colors of wire, lots of little tools, it all adds up. $1000 isn't a massive budget to get started in this.

author: ebclr
author_rank: Super Contributor
timestamp: June 14, 2016, 05:41:30 am
content: 4 channels is good specially for some serial protocol decoder after the hack

author: cio74
author_rank: Regular Contributor
timestamp: June 14, 2016, 05:55:35 am
content: That Rigol has a small LCD with a stupid tiny font that you cant change. Lets not say difficult to read (it could be if your eyesight is not perfect) but it's just painful small and hard to read.If you do a lot of CPU related stuff maybe a Logic Analyzer is more suitable for the task.CPU speed has very little to do with oscilloscope bandwidth. A 120MHz ARM MCU uses a 12MHz xtal and an internal PLL circuit. The maximum frequency you can achieve (and eventually want to measure) on the peripherals is way below it's running frequency, you may want to check the CPU datasheet for this.In my opinion you may be better with an USB oscilloscope, most of them provide you with an API that can be used to write simple software to control it; that's beside the provided software which is normally good for the job. Take a look at Picoscope series ending in D, those even come with a 8/16 channels logic analyser and 1 MHz signal generator.

author: TheSteve
author_rank: Unknown
timestamp: June 14, 2016, 07:09:09 am
content: Rigol DS1054Z, spend the rest on other equipment.

author: Karel
author_rank: Super Contributor
timestamp: June 14, 2016, 07:45:28 am
content: Definitely a Rigol DS1054Z. And ignore tautech because he's a siglent distributor and he's here to promote siglent.

author: tggzzz
author_rank: Super Contributor
timestamp: June 14, 2016, 08:35:38 am
content: Quote from: cio74 on June 14, 2016, 05:55:35 amTrue.QuoteFalse.The maximum frequency you need to measure dependsonlyon the rise/fall time; the period iscompletelyirrelevant. Then the rule of thumb is f3dB BW= 0.35/trisetime. FFIhttp://www.edn.com/collections/4435129/Bogatin-s-Rules-of-ThumbGeneral principle for digital electronics: use a scope to observe the (analogue) signals and to check the signals are behaving properly (N.B. all signals are analogue, unless you are dealing with fA or photon counting applications). Once you have verified the (analogue) signals are valid digital signals, use a logic analyser or printf to verify operation.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 08:40:44 am
content: Quote from: cio74 on June 14, 2016, 05:55:35 amHuh?Quote from: cio74 on June 14, 2016, 05:55:35 amMost people don't seem to have a problem with it. If your eyesight isthatbad you'll have problems with other oscilloscopes as well.PS: All Rigols have a menu item "Measure->Font Size" for the on-screen numbers.Quote from: cio74 on June 14, 2016, 05:55:35 amIf you have bad eyes? A huge PC monitor might be an advantage, yes.But:a) Not everybody has bad eyesb) It means you always have to have a PC around, switched on, and with the screen dedicated to being an oscilloscopec) Any Picoscope that's worth owning is an expensive piece of kit (compared to the equivalent oscilloscope)

author: ebclr
author_rank: Super Contributor
timestamp: June 14, 2016, 08:45:12 am
content: I own a rigol a Tektronics and a Owon, My prefered one is the rigol is for sure the best bang for the buck, sigilent , owon , hantek doe not match Rigol in anyway, only agilent ,Tektronics, Lecroy and other's big guys will surpass costing 10 times more

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 09:11:54 am
content: Quote from: cio74 on June 14, 2016, 05:55:35 amCPU frequency is irrelevant if you're only looking at a single transition on a data line. Oscilloscope bandwidth is stillveryrelevant to looking at that signal though.eg. I can't possibly see a 100MHz square wave on a 100MHz bandwidth 'scope. I'll see the lowest harmonic (sine wave) properly but all the higher harmonics (the things that make it square) will be attenuated. Result: It won't be square on screen even if it's square in reality. On screen it will look something like this:This is what oscilloscope "bandwidth" is all about and it's fundamental to using oscilloscopes properly. You need to understand that what the screen shows you is a bandwidth-limited version of what's in the wires. Thinking in terms of clock frequencies iswrong.

author: ebclr
author_rank: Super Contributor
timestamp: June 14, 2016, 09:16:33 am
content: Bandwidth is like moneyYou always want more........

author: tggzzz
author_rank: Super Contributor
timestamp: June 14, 2016, 09:30:10 am
content: Quote from: ebclr on June 14, 2016, 09:16:33 am... unless there's too much noise.

author: tautech
author_rank: Super Contributor
timestamp: June 14, 2016, 09:44:35 am
content: Quote from: tggzzz on June 14, 2016, 09:30:10 amYeah, like in this post:https://www.eevblog.com/forum/testgear/siglent-sds1000x-series-oscilloscopes/msg826345/#msg826345

author: nctnico
author_rank: Super Contributor
timestamp: June 14, 2016, 10:38:26 am
content: I'm missing GW Instek from the list. The GDS2000A and GDS2000E series are definitely good choices because they have the least bugs of all and many extra useful features.

author: pascal_sweden
author_rank: Super Contributor
timestamp: June 14, 2016, 10:52:54 am
content: Yes, but GW-Instek scopes look like toys

author: ebastler
author_rank: Super Contributor
timestamp: June 14, 2016, 12:27:27 pm
content: Quote from: nctnico on June 14, 2016, 10:38:26 amQuote from: pascal_sweden on June 14, 2016, 10:52:54 amGroundhog Day...

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 12:35:16 pm
content: Quote from: pascal_sweden on June 14, 2016, 10:52:54 amAnd you can't unlock a ton of extra features like you can with Rigols.

author: xrunner
author_rank: Super Contributor
timestamp: June 14, 2016, 12:42:22 pm
content: Quote from: System Error Message on June 14, 2016, 12:52:30 amWell, I know there's LOTS of very nice used scopes on Ebay that would be MORE than adequate for a new electronics learner. But, I suppose that's passe' to say so these days.

author: tggzzz
author_rank: Super Contributor
timestamp: June 14, 2016, 12:48:15 pm
content: Quote from: xrunner on June 14, 2016, 12:42:22 pmIt is still valid and still needs saying!There's a good argument for buying a cheapworkingscope, learning how to use it, learning in what way it and your other tools simply cannot measure what you need to see. And once you have that experience, you willknowwhat you reallyneedamdwhy.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 12:50:26 pm
content: Quote from: xrunner on June 14, 2016, 12:42:22 pmSome people enjoy owning 1970's cars, too. But not everybody...

author: xrunner
author_rank: Super Contributor
timestamp: June 14, 2016, 12:53:52 pm
content: Quote from: Fungus on June 14, 2016, 12:50:26 pmWhen I learned to drive, and for my first car, I didn't buy a new one, I had a nice used Datsun.Hmmm ...

author: cio74
author_rank: Regular Contributor
timestamp: June 14, 2016, 12:58:32 pm
content: Quote from: tggzzz on June 14, 2016, 08:35:38 amfalse?There must me some misunderstand , are you saying you can generate a 120MHz signal on the IO of a 120MHz clocked MCU?

author: cio74
author_rank: Regular Contributor
timestamp: June 14, 2016, 01:09:40 pm
content: Quote from: Fungus on June 14, 2016, 08:40:44 amIt's not only about bad eyes. Its about using a mouse to set a cursor, it's about copy/paste the screen output, using the scroll to zoom, direct image copy and post in a forum or email without connecting cables or memory cards. It's about convenience. I had a 7000 series Agilent and still used the back VGA connector. Some people run very fast laptops that can handle USB 3.0 and power quality USB scopes such as those Picoscope range.Yes, those scopes are not cheap but the OP has some $$ he wants to spend.I couldn't find text size in the Rigol I have owned, 1054Z, perhaps it's a new firmware upgrade?

author: nctnico
author_rank: Super Contributor
timestamp: June 14, 2016, 01:14:11 pm
content: Quote from: pascal_sweden on June 14, 2016, 10:52:54 amWell I rather use a scope which looks like a toy on the outside than one which IS a toy on the inside

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 14, 2016, 01:15:37 pm
content: Soo many replies so fast. Thanks for all the helpQuote from: Fungus on June 14, 2016, 05:33:51 amOther than the bench power supply i have a decent soldering iron (not needed if using prototyping boards), different colours of wires, lots of little tools, even a multimeter that seems to work fine. my issues with multimeters mainly is that i havent had one that lasted long.So the other models suggested:Analog Discovery (is this an analog or a model name or both?)Rigol DS1054Z (this is only 50Mhz with 4 channels, but like siglent the sample rate is shared)USB oscilloscope (i've checked a few including picoscopes, usb3 is definitely helpful for pc connection, very good memory depth but it requires a laptop for practical reasons and i lack space on my workbench).GDS2000AGDS2000E (they seem nice in features but both the A and E variants are above budget unless im looking in the wrong place. I could try see used). Specs wise they seem similar to a cheaper siglent unless all the channels dont share performance.LAN is very beneficial as i have plenty of that. So it seems my choices are either a siglent or a usb oscilloscope (that has usb3) or 2nd hand. The only issue i see with Siglent is that the performance is halved when using both channels so while not an issue if you have 200mhz to spare but definitely an issue for the sample rate and memory depth. I do however have a fast laptop and an 8 core developer tablet which has usb3 and 4K display.Bench PSUs are expensive so unless i need to calibrate an oscilloscope or the need to torture a circuit i can leave this out for now.Someone posted about more noise in the rigol DS1000z series.I dont think i would need to measure 4 things on the arduino at the same time. While arduino itself doesnt doesnt require much bandwidth to measure, measuring the noise and spikes do. With some good programming you can get a CPU to churn out data half as fast as its frequency. Hopefully by the time i would need a 4 channel oscilloscope i would be able to afford a good one. Nothing wrong with 2 oscilloscopes. I really just dont see the need for 4 channels when most of the use would be power and signal integrity related.Quote from: cio74 on June 14, 2016, 12:58:32 pmIf an IO is clocked at 120Mhz and a CPU also clocked at 120Mhz it can churn out 120Mhz of data. This is because some CPUs have a dedicated memory controller that can pass data around as fast as the IO. With some simple programming you can make a CPU churn out 120Mhz of data if you can make it run the same assembly instruction over and over again every clock but a CPU's clock rate isnt related to it's data rate as the clock rate is a measure of instruction rate or cycles and not data. The asynchronous use of instructions can also get more data flowing. These situations however are rare but it is very common for any CPU to fully use up the bus bandwidth for various things. Take PCIe for example, it allows communication from one device to another without going through the CPU but through the PCIe bus so if you had multiple controllers all talking to each other that would mean more bandwidth to measure.I think used would be a way to get a good scope on a budget but it is difficult to find used and i ditched ebay as there are just too many fakes and bad experiences there even when it comes to the quality of the used item itself such as if it really is working. People tend to hold on to their scopes for years until it dies. Really goes to show how much people value their equipment in electronics compared to computing.Edit: Regarding IO busses, regardless of the CPU speed the IO bus will always transmit signals at it's rated frequency. So even if you used 10% of the bandwidth that means that the signals will still be the IO frequency regardless since you will get rise and fall like a normal digital signal at that frequency but there will be lots of gaps or signals that indicate no data is being sent.Or perhaps i could get 2, the suggested rigol for measuring 4 different signals, and a good 2 channel scope for measuring signal integrity and spikes.

author: tggzzz
author_rank: Super Contributor
timestamp: June 14, 2016, 01:42:04 pm
content: Quote from: System Error Message on June 14, 2016, 01:15:37 pmIf you are using solderless breadboards then one or both of these will be true:you only need a 10MHz scope because all the frequencies (i.e. not bitrates) will bemuchless than thatyou will spend all your time debugging the intermittently poor connections and excess parasitics (e.g. 150mm wire => 150nH inductance, and you can do the arithmetic to see the impedance at a frequency that interests you)You would be well advised to learn dead-bug and/or manhattan prototyping techniques.QuoteThe "modern DSO/MSO" zealots will claim that you need 4 channels for protocol decodes of I/O interfaces. There's some validity in that, but there are also problems. Personally I know there's a lot you can do with 2 channels, some understanding and some imagination. The signal integrity issue is more clearcut, however.QuoteYou are in a state of sin: data is measured in bits/s, not MHz; the other useful unit in this context is "baud". The distinctions are important.If you use a modern TTL/CMOS device such as a 74LVC1G*, then even if your data rate is only 300bits/s, you will still have 1GHz components in the signal.Conversely, old modems used to get 57.6kbits/s through a telephone system that had a frequency response that rolled off above 3.4kHz, and was chopped at 8kHz. They did that by limiting the baud rate so it was <3.4kBaud/s, and transmitting multiple bits of data simultaneously.QuoteIt sounds like you are confusing peak bit rate (which is determined by the I/O peripheral clocks) and mean bit rate (which is determined by the application and CPU).In addition, don't forget that it can be possible, say, for a CPU to put/take 64 bits from a register in one parallel operation, and for the I/O peripheral to deal with them serially.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 01:54:20 pm
content: Quote from: cio74 on June 14, 2016, 12:58:32 pmYes!Anysquare-shaped waveform hasinfinitefrequency components inside it, even if it's just a single transition from low to high.

author: nctnico
author_rank: Super Contributor
timestamp: June 14, 2016, 01:55:45 pm
content: Quote from: System Error Message on June 14, 2016, 01:15:37 pmI'd be carefull when going for Siglent. A lot of their features are limited (practically useless like their FFT and Hires modes) or pray ware (not yet/partially implemented with no forecast when or if it will ever be implemented).The GW Instek GDS2204E (4 channels, 200MHz complete with protocol decoding) is on sale for $1174 (http://www.tequipment.net/Instek/GDS-2204E/Digital-Oscilloscopes/). There is also an EEVblog discount from Tequipment so if you stretch your budget a little you can get a very good 200MHz scope.Personally I'd never buy a 2 channel scope again. Once you have experienced the benefits for having 4 channels you'll never go back to 2 channels. Ofcourse people will say you can 'make do' but 'make do' always translates to 'taking more time'.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 01:58:01 pm
content: Quote from: cio74 on June 14, 2016, 01:09:40 pmSome people would say that a mouse is a terrible interface, that physical knobs are much better.Quote from: cio74 on June 14, 2016, 01:09:40 pmI don't know how far back you're going in history but I think all new Rigols on sale have a font size setting (please correct me if I'm wrong about that)The DS1054Z being discussed here certainly has it.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 02:01:25 pm
content: Quote from: System Error Message on June 14, 2016, 01:15:37 pmIt's a model name.Quote from: System Error Message on June 14, 2016, 01:15:37 pmBut ... everybody around here unlocks their DS1054Z to 100MHz plus all extra options.http://gotroot.ca/rigol/riglol/

author: cio74
author_rank: Regular Contributor
timestamp: June 14, 2016, 02:06:46 pm
content: Quote from: Fungus on June 14, 2016, 01:54:20 pmThat's interesting, can you explain please?Thanks.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 02:07:05 pm
content: Quote from: System Error Message on June 14, 2016, 01:15:37 pmSPI bus decoding?If you're on a device with multiple I/O pins youwillneed more than 2 channels sooner or later.3 channelsmightbe OK. 2 is definitely not enough.

author: cio74
author_rank: Regular Contributor
timestamp: June 14, 2016, 02:12:05 pm
content: Quote from: Fungus on June 14, 2016, 02:07:05 pmSaleae LA or equivalent is a better choice for bus decoding than an oscilloscopehttps://www.saleae.com/Yes, there is a Chinese clone of it but may be interesting to read thishttps://www.saleae.com/counterfeit

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 14, 2016, 02:16:18 pm
content: seems like it would be better to go with 2 scopes, the suggested rigol for 4 channels and a good 2 channel one to measure spikes. Does the rigol share the frequency across all channels?While i do use breadboards for prototyping i do solder the finished product to a circuit board.So for the 2 channel scope all thats left is to find one thats good in performance, some features arent needed like waveform generators as i could use the money to get one of those PSUs used to test other PSUs by selecting the specific output voltage, current and waveform.I know for IO Mhz isnt bandwidth but when it comes to measuring that with an oscilloscope the frequency is important, that IO is frequency with a parallel bus of a fixed number of bits. So its not a matter of whether a CPU can fully used the IO but rather the IO will require an oscilloscope with higher bandwidth to measure it as it will output signals at that frequency regardless if there if the CPU is capable of fully using it or if it is half used. I know data is measured in bits/s, but we're talking about measuring it so the frequency is important.Physical knobs are better but if it means getting a really good oscilloscope for less, as long as it has usb3 it is something i would consider.Does Tequipment ship to the UK?So i guess its a choice between rigol + siglent SDS1000x, rigol + picoscope, GDS2204E

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 02:17:40 pm
content: Quote from: cio74 on June 14, 2016, 02:06:46 pmhttps://en.wikipedia.org/wiki/Square_wavehttps://xiph.org/video/vid2.shtml

author: cio74
author_rank: Regular Contributor
timestamp: June 14, 2016, 02:26:07 pm
content: Quote from: Fungus on June 14, 2016, 02:17:40 pmSo you were talking about harmonics inside the square? Sorry, that's so much theory and I am not an EE, I was asking for a practical explanation and how this would affect the 'common' use of such digital signals.For instance you were saying that I can have a 120MHz digital/square signal at the output of a say MCU clocked at 120MHz and I have said it's not possible. Can you give a practical example where the infinite frequency components inside it will affect the say output?Not trying to play the smart ass guy here just trying to figure out where and when what you are saying is going to have an impact in practical design.Thanks.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 02:26:56 pm
content: Quote from: System Error Message on June 14, 2016, 02:16:18 pmIn that case I'd start with the Rigol and look for a 2-channel if the Rigol isn't up to the job.Quote from: System Error Message on June 14, 2016, 02:16:18 pmYes, but the input bandwidth is 100MHz and it has a 1GHz sample rate.With 4 channels enabled (the worst case) this gives a 250MHz sample rate on each input channel, ie. 2.5x oversampling.2.5x oversampling just happens to be enough samples to reconstruct the input waveform perfectly on screen (see thevideoI linked a couple of posts ago for explanation).

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 14, 2016, 02:30:03 pm
content: What im asking is if using 4 channels on the rigol do i still get 100Mhz per channel or does it go down to 25Mhz?

author: nctnico
author_rank: Super Contributor
timestamp: June 14, 2016, 02:34:34 pm
content: Quote from: System Error Message on June 14, 2016, 02:16:18 pmThe 2 scope strategy is a good one but I'd go for a decent 100Mhz or 200MHz 4 channel scope for daily use and get a used >= 500MHz digital scope to look at high frequency signals when the need arises. Used >=500MHz DSOs (the older digitizing ones) are not extremely expensive nowadays and bargains which need some minor repairs can be found on Ebay.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 14, 2016, 02:39:45 pm
content: the combination of rigol + siglent makes GW hard to justify when considering single channel performance of the siglent unless it has lower noise on the inputs. if you know any good used 500Mhz digital scopes let me know. How much frequency and sensitivity is needed in order to measure spikes and signal integrity?Quote from: nctnico on June 14, 2016, 02:34:34 pmAre you saying the rigol is not decent?Just checked the digital analog, seems like a solid choice as it can be used for audio. So many choices.

author: rstofer
author_rank: Super Contributor
timestamp: June 14, 2016, 02:55:58 pm
content: Quote from: System Error Message on June 14, 2016, 02:30:03 pmYou still get the analog bandwidth but you won't get as many samples of the waveform.For all practical purposes, a fast square wave is composed of all the odd harmonics from DC to daylight. On a bandwidth limited scope, the edge is going to get messed up (more sinusoidal) simply because harmonics are being excluded.I have a used Tektronix 485 that I bought off eBay about 12 years ago. It's a fine 350 MHz scope, suitable for most of the things I like to do. But it won't capture waveforms, it won't display 4 channels (SPI: CLK, MISO, MOSI, CS') and that's the kind of thing I want to look at. Decoding is nice but not a requirement, for me, because I'm pretty handy with printf().The Digilent Analog Discovery is a complete workbench in a small box. I have one and I like it a lot. But it has limitations in bandwidth. Still, for most of my uC and analog projects, it is perfectly capable of displaying the image and a 27" screen is pretty nice. I can easily have multiple instruments open, especially when I use my workstation with twin 27" displays. It also works on my Surface Book and that's a sweet setup.http://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supply/One caveat about the Analog Discovery and my overpriced Surface Book: I need to be VERY careful about the voltage levels I probe. I do not want to fry my Book! This is not a real problem because, at most, I am dealing with +-15V signals and, more often than not, 3.3V signals. I don't mess around in HV power supplies.There are any number of alternatives. Analog scopes from eBay (if they work) can be a good deal (except for shipping) and will usually have great bandwidth. But no storage... They will be often be limited to 2 channels and even though I spent decades with 2 channel scopes, 4 channels is much nicer.For $400, it's going to be hard to beat the DS1054Z and a lot of electronics can be done using this scope. Over many years, it probably won't be the only scope but it is a good first scope. There's some interesting magic in DSOs.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 02:56:32 pm
content: Quote from: cio74 on June 14, 2016, 02:26:07 pmI haven't said that at all.What I said was: "Any square-shaped waveform has infinite frequency components inside it, even if it's just a single transition from low to high."Read that again:A single transition from low to highhas infinite frequency components inside it.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 02:58:08 pm
content: Quote from: System Error Message on June 14, 2016, 02:30:03 pmNo. Absolutely not. You get 100MHz per channel.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 03:03:19 pm
content: Quote from: System Error Message on June 14, 2016, 02:39:45 pmThe RigolIS"a decent 100Mhz or 200MHz 4 channel scope for daily use".Me? I doubt that you'll ever need to look at higher frequency signals but either way, the answer is the same: Start with a Rigol DS1054Z.

author: nctnico
author_rank: Super Contributor
timestamp: June 14, 2016, 03:05:52 pm
content: Quote from: System Error Message on June 14, 2016, 02:39:45 pmThat depends on your circuit but a 100MHz to 200MHz scope is enough to work on common circuits like microcontrollers, displays, ADCs, switching power supplies, etc. Only if you go into high speed designs like digital busses running at several hundred MHz you'll need more bandwidth. For now I would not worry about that at all.Quote from: System Error Message on June 14, 2016, 02:39:45 pmThe Rigol 1000Z series wouldn't be my choice because of the low samplerate, limitations (short FFT, only-decode-what-is-on-screen, etc) and bugs it still has. I did look for a more portable scope a couple of months ago and decided not to buy the DS1000Z and spend more money to get a better scope (which doesn't need hacking). The scopes from Rigol and Siglent will display a signal OK but they go wrong when it comes to the more advanced features like measurements, decoding, FFT, math, etc.Since almost all microcontroller based circuits use SPI and or I2C in some way having good decoding is a must have nowadays. It makes checking the communication much easier and quicker.

author: rstofer
author_rank: Super Contributor
timestamp: June 14, 2016, 03:12:54 pm
content: Quote from: System Error Message on June 14, 2016, 02:39:45 pmThe DS1054Z is a $400 scope. It is NOT the equivalent of a $10k scope. It's nice but it isn't 'superb'. For most experimenters, it will be more than adequate. For those needing bandwidths up in the GHz, it's the wrong tool. There are many scopes that have twice the capability for five times the cost. It's a choice...The Analog Discovery has a very nice 'Network Analyzer' which sweeps across a range of frequencies and produces a display of gain and phase angle. This would have been terrific when I was in school! I had to use the IBM Circuit Analysis Program to analyze the frequency response and plot the results on a drum plotter. Well, I didn't own the computer, my employer did. Nothing like a 60 mile round trip on the weekend to do homework. It's one thing to talk about RC filters and the corner frequency. It's another to be able to breadboard it and SEE the corner. Small signal amplifiers? Yup! The AD can work with those as well. It is far more than just a dual channel scope.The logic analyzer is a nice touch but having two Arbitrary Waveform Generators is pretty useful. Those digital IO channels can also be a pattern generator simulating external events for a uC.But be careful to work within the limitations. Voltage being the primary concern.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 03:21:30 pm
content: Quote from: nctnico on June 14, 2016, 03:05:52 pmWhat low sample rate is that?The DS1000Z is a 100Mhz oscilloscope, tested and measured in these forums. Nobody has found it lacking (it's actually closer to 150Mhz in reality).The sample rate is exactly what it needs to be to show a 100Mhz signal on screen with 4 channels enabled. It's far in excess of what's needed when you only have 1 or 2 channels enabled.If you have any data that shows otherwise, feel free to post it.

author: tggzzz
author_rank: Super Contributor
timestamp: June 14, 2016, 03:45:50 pm
content: Quote from: nctnico on June 14, 2016, 03:05:52 pmUnfortunately that a little too simple.Signal integrity can bite at lower bitrates; even bog-standard CMOS devices can generate "entertaining" overshoots/undershoots.Setup and hold time violations are independent of bitrate, as is ground bounce.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 14, 2016, 03:47:34 pm
content: Quote from: EEVblog on June 14, 2016, 04:43:36 amdidnt see your post from the rest of it. Good advice for starters but I already spent on parts, all thats left is to get gear and the only gear remaining is oscilloscope. Parts can be cheap as capacitors, resistors, LEDs, transistors, basic chips.If i need 4 channel i think the rigol would do well for the signals although as someone pointed out printf, i am a programmer so thats not a problem for me to get output from code.So now i want to get 3 scopes, the analog discovery, the rigol and one good oscilloscope which will either be 2nd hand or something like the siglent. Not saying the siglent is a good scope but for what i want it to use it has the hardware specs for it. For measuring spikes and signal integrity you only need 1 channel, 2 channels if you are trying to look for a relation but for a single channel the siglent has the performance for a lower price, unless 8 bit is not accurate for measuring spikes.So when you say the siglent isnt good at measuring do you mean in taking values? All i need is for it to be sensitive, the math functions arent important as that seems to slow down any oscilloscope so i'd rather connect it to PC and have the PC do the math. Any better 2nd hand ones? While it may not be necessary the analog discovery seems that it would be more accurate than the rigol because it is 14 bit but the rigol has 4 channels, so get all 3 as the analog discovery seems like a really cool piece of kit to use. So i'll get the scopes one at a time unless theres a big discount for all 3. Still not settled for the 3rd one yet on which sensitive scope to get.The rigols poor sample rate for 4 channels isnt a bother if you measuring binary values at a fixed frequency.

author: boffin
author_rank: Unknown
timestamp: June 14, 2016, 04:04:22 pm
content: The Rigol is nice, but a simple USB scope will provide the bandwidth you want, along with logic analyzer and simple waveform generation. It's pretty hard to beat something like the Analog Discovery, especially if you can get it at the student price (hint -- find a university that uses them, students sell them off cheap). Red Petiya is another optionUse the extra money to buy TWO DMMs (preferably one w/ a frequency counter/mark space ratio like the EX330), a good bench power supply, and $200 worth of base components and storage for the above. If you don't have a good soldering iron, that's another essential

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 14, 2016, 04:28:54 pm
content: Still trying to figure out the performance for the GDS2204 with all 4 channels used. Is it 200Mhz for all 4 channels? 1Gs for all 4 channels? 10M for all 4 channels? If it werent for tax and shipping the discount would make this cheaper than the rigol + siglent. Still i could select UPS and rip them off instead since i would be moving soon as these companies pay the customs for you and than charge you the tax + admin.What storage and components for them? They'll be on a shelf/table, not planning to bring them all around.A bench PSU is useful but not an immediate need. Electronics seems to be quite expensive that it may be better to get things as things progress. I already have multimeter. I have a good soldering iron on the way though its more of a multi tool that can be adjusted to do various tasks well so in total i have 3 soldering irons, 2 of them adjustable.It seems only the scopes and bench PSU is the most expensive bit.

author: nctnico
author_rank: Super Contributor
timestamp: June 14, 2016, 04:38:39 pm
content: Quote from: System Error Message on June 14, 2016, 04:28:54 pm- Always 200MHz bandwidth (unless bandwidth limiting is switched on)- 1Gs/s with 2 channels, 500Ms/s with 3 or 4 channels and unlike other scopes you can enable any 2 channels and have 1Gs/s- 10Mpts per channel is available no matter the number of channelsI wrote a lengthy review on the GDS2204E:https://www.eevblog.com/forum/testgear/gw-instek-gds2204e-%28200mhz-4-channel-dso%29-review/I recently did an interesting experiment with a 125MHz SPI bus and this shows what happens with high frequency square waves:https://www.eevblog.com/forum/testgear/gw-instek-gds2204e-%28200mhz-4-channel-dso%29-review/msg941933/#msg941933edit: typo (I think)

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 14, 2016, 05:09:00 pm
content: The GW seems good and its even cheaper right now from Tequipment including the safe route of tax+shipping. I hope they still have it in stock and discount when i order. This is better than using a rigol + siglent for about the same price.Does Tequipment have discount codes?I guess the bench supply and analog discovery can wait. I will have to modify the scope though to make it quiet if it is very noisy, you wouldnt believe but i actually got a mikrotik CCR1036 and made it entirely silent, its one of those high end routers used by ISPs and in racks for fast controlled networking.I think people just adore rigol because of it being hackable so that they can get more value. At the price EEV suggested its like hes saying i should get the rigol.

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: June 14, 2016, 05:41:35 pm
content: I wouldn't over think it. I still say any of the scopes mentioned so far will do what you want them to do and you can't really go wrong.

author: rstofer
author_rank: Super Contributor
timestamp: June 14, 2016, 05:56:52 pm
content: Quote from: System Error Message on June 14, 2016, 05:09:00 pmYes, the GW is probably twice as good for 4 times the cost. There's kind of a quadratic thing going on...I'm sure if I look around, I can find a scope twice as good as the GW for again 4 times the cost.The issue is what does an average HOBBY user really need? There's really no single answer for that.QuoteAnd Dave isn't the only one saying it!Yes, getting the features for free is a sweet deal. It's pretty clear that Rigol intends this to happen because they do nothing to prevent it even when they make firmware upgrades. It's kind of a wink-wink sort of thing. They WANT to encourage the students/beginners because they become the market at some point. It's a PR thing... You haven't heard about any Demand Letters trying to force a halt to the web page with the code generator.And it's not just the DS1054Z, the DP832 power supply also has some unlockable features. To me they don't appear as essential as the features of the 1054 but they are there nevertheless. I'll probably buy the power supply simply because it can be upgraded but I doubt that I will actually do it. Maybe to get the 1 mV resolution vs 10 mV. That might be something... It's a power supply! Do I really care about 1 mV resolution? Darned if I know but the real 832A is a lot more money just to get the resolution I can unlock in the 832. It's interesting that TEquipment has a bunch of 832s in stock and not a single 832A. They KNOW nobody is going to buy the 832A when they can just unlock the identical features in the 832. Rigol has to know this as well.

author: msraya
author_rank: Unknown
timestamp: June 14, 2016, 06:17:33 pm
content: Rstofer:I does not agree with you..Someone will want to buy a DP832A in the first time. Me for exampleNo, I'm not dumb...Only that I want to have all features unlocked Right Now and I don't have time to play with the hacking...... In this case, because I confess you that I have a hacked MSO1074-S..RegardsManuel

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 14, 2016, 06:29:18 pm
content: Thanks for all the answers, quite a lot to think about. Choosing is half the problem, figuring out where to buy it where it is not overpriced is another as a lot of things sold to the UK tend to have their prices jacked.Choosing is hard. My main use for the oscilloscope is mainly to measure signal integrity, spikes and fluctuations (basically making sure that the signal that goes in or out is the one i am expecting) so 4 channel isnt a necessity. The GW may cost more but it is very sensitive whereas the rigol costs 3x less for half the bandwidth and sample rate but also isnt as sensitive as the GW.Currently with Tepquiment discount of the GW it is cheaper to buy from them and pay shipping + tax than it is to buy from the UK by about £200 otherwise i wouldnt consider GW.Math functions, really not important right now. Right now whats important is that the oscilloscope performs as analog as possible in sensitivity and measurement (not missing details).

author: nctnico
author_rank: Super Contributor
timestamp: June 14, 2016, 06:33:42 pm
content: Quote from: rstofer on June 14, 2016, 05:56:52 pmUntil the Chinese counterpart of this guy at Rigol decides enough is enough and has the hole plugged in newer firmware versions.AFAIK Keysight is actively plugging the holes in their scopes so you have the choice between using an older (buggy) firmware version or say goodbye to the extras.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 06:48:25 pm
content: Quote from: System Error Message on June 14, 2016, 03:47:34 pmI wouldn't really class the Analog Discovery as an "oscilloscope". It does have an analog recording mode but its main use is for messing about with and learning digital electronics. Plus it's also programmable. It's kinda expensive unless you can get the student discount but it's nicely presented and you can do an awful lot of things with it.Quote from: System Error Message on June 14, 2016, 03:47:34 pmWho said it has a poor sample rate? It hasexactlythe sample rate needed for 4 channels at 100MHz bandwidth. No more, no less.Want proof? Here's the math:https://en.wikipedia.org/wiki/Whittaker%E2%80%93Shannon_interpolation_formulaThe important line is:QuoteFacts:* The Nyquist frequency of a 100MHz signal is 200MHz.* The DS1054Z has 250MHz sample rate with 4 channels on* 200MHz is less than 250MHzThe DS1054Z does sinc reconstruction of the signal therefore a DS1054Z can displayany100MHz input signal perfectly, even with all 4 channels on.Conclusion: The EEVBLOG forum is as full of nutcases as any other part of the Internet, don't believe everything that's posted here.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 07:10:12 pm
content: Quote from: nctnico on June 14, 2016, 06:33:42 pmNever going to happen.(because it's not a 'hole' - the 'scope isdesignedto be upgraded via license keys)

author: rstofer
author_rank: Super Contributor
timestamp: June 14, 2016, 07:19:18 pm
content: Quote from: msraya on June 14, 2016, 06:17:33 pmI actually went looking for the 832A but, as I said, TEquipment doesn't have them. Just the 832... It turns out that all I need is the basic unit. Maybe the enhanced resolution means something, maybe not. All I need is a simple tracking dual output supply.But if I get the extra features for less than 5 minutes of effort, that's pretty cool!

author: rstofer
author_rank: Super Contributor
timestamp: June 14, 2016, 07:37:05 pm
content: Quote from: Fungus on June 14, 2016, 06:48:25 pmI thought there were two other constraints: The incoming signal has to be continuous in time and the incoming signal has to be strictly bandwidth limited to less than 1/2 the sampling frequency. A square wave is not so bandwidth limited and will not be perfectly reconstructed even with an extremely high sampling rate. The only question is: How good is good enough?

author: nctnico
author_rank: Super Contributor
timestamp: June 14, 2016, 07:47:51 pm
content: A digital oscilloscope has anti-aliasing filters to bandwidth limit the signal. With the samplerate at 2.5* the bandwidth these filters have to be steep to prevent aliasing. However steep filters have peaking and phase shift so they can distort the signal. Ideally you want a higher samplerate to bandwidth ratio. Older (digitizing) DSOs usually have a Gaussian roll-off which has a minimum amount of peaking and phase shift (https://en.wikipedia.org/wiki/Gaussian_filter) but realtime sampling DSOs have to resort to steeper filters in order to keep the samplerates low.

author: Lightages
author_rank: Unknown
timestamp: June 14, 2016, 08:00:22 pm
content: Quote from: Karel on June 14, 2016, 07:45:28 amIgnore Karel, Karel is just here to make accusations about the honesty of others without basis. Do you want to tell people to ignore Dave because he is here to promote his business? Do you want to tell people to ignore me too? How about the other large number of people here who also sell electronic related things?Perhaps you might want to reconsider slandering another person here who is an active and contributing member.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 08:09:30 pm
content: Quote from: rstofer on June 14, 2016, 07:37:05 pmThe incoming signaliscontinuous - simply because of the inductance in the wires.It's also bandwidth limited by the inductances and capacitances in the oscilloscope's input circuitry before it ever reaches the sampler.(reducing those inductances and capacitances to get higher bandwidth is what makes higher bandwidth oscilloscopes more expensive).Quote from: rstofer on June 14, 2016, 07:37:05 pmRight ... and I spent the entire first part of this thread explaining why a perfect square wavecannotbe reproduced onanyoscilloscope.There's entire threads on here with people comparing square waves on exotic equipment:eg.https://www.eevblog.com/forum/testgear/show-us-your-square-wave/

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2016, 08:16:32 pm
content: Quote from: nctnico on June 14, 2016, 07:47:51 pmAnd ... you can provide an example showing this problem on the DS1054Z, right?

author: nctnico
author_rank: Super Contributor
timestamp: June 14, 2016, 08:35:30 pm
content: Quote from: Fungus on June 14, 2016, 08:16:32 pmIt is a generic problem for any realtime sampling digital oscilloscope!

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 14, 2016, 09:49:53 pm
content: So for the 4 channel one its a question of the $400 rigol or the $1100 GW, one being double the other.Comparing only the function as oscilloscope the GW would be better and i guess will make do. I thought bench PSUs were expensive, seems only the really high end ones are so while it is nice to have LAN on all equipment i guess i could go for cheaper bench PSU that doesnt have usb or LAN.Will see when finally buying. If the discount for GW is over than i'll go for the rigol and depends on Tequipment discounts too.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: June 14, 2016, 09:56:32 pm
content: Quote from: Karel on June 14, 2016, 07:45:28 amIs this a joke? Sure, he is a Siglent distributor, but he is a big time contributor to this forums. He has helped me with repair multiple times, spending a lot of his time studying schematics and working through stuff. He is a good source of info.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: June 14, 2016, 10:15:13 pm
content: Personally, I went the old-school route and bought an old Tektronix 2465. Yes, I had to repair it, and yes I learned a ton doing so. Also, yes I use that 300MHz of bandwidth for many things.I do believe that four channels is INCREDIBLY helpful. I also have a Tektronix 2232 2 channel early DSO. I often end up going to the 4 channel scope just to get more info at once. I even find myself trigger with the 2465, viewing 4 channels there, and then passing the external trigger to the 2232 to have 6 channels at once on two CRTs. This is really helpful when debugging bit-banging stuff if you like to work out protocols yourself.Someday I will break down and buy a modern DSO, but I don't care for the inexpensive (<$1k) ones (not enough bandwidth/channels/screen resolution, though they are getting better every year). But I have other much more expensive hobbies to fund, like an airplane

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 14, 2016, 11:30:26 pm
content: This isnt a flame war, just because someone is a distributor doesnt mean to ignore him, if it means i can get good deals on scopes why not? Its not like Siglent is a bad quality or overpriced brand.Unless a digital oscilloscope skips measurements by taking only burst readings of all the input compared to analog theres really no need for MSO. It is convenient but it really depends on your need for a scope. The rigol would do what i need to do in seeing what binary is a signal. The GW and siglents are more sensitive and have more bandwidth so would measure spikes and signal integrity better aside from being able to see the binary value of a signal. Binary i am familiar with i dont have a need to use an oscilloscope of telling me what values are going through, what i do need to know is if after i place a resistor or a capacitor is power what i want it to be and is the signal value correct.Currently the GW seems a good value at discount. At full price if i need 4 channels i would take the rigol. I think i'll try ordering the GW first.Im not really a complete beginner but a more sensitive scope is helpful when you want to build circuits that handle spikes and have good signal integrity and would do well when building PSUs for your circuits.The analog discovery is a nice piece of kit, Once i have more money i will order that as the 14 bit resolution even with 100Mhz can be used for audio, i could at least repair one of my older soundcards.

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: June 15, 2016, 12:03:45 am
content: I have been a happy owner of a Rigol DS2072A-S for well over a year now, but if I was making the decision right now to get a new scope in that price range, I probably would get the GW Instek GDS-2204E. Especially with what they are priced at right now on tequipment.Edit: Wanted to add that my decision would probably be different if the GDS-2204E was full price, $1570 on tequipment without the current discount.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 15, 2016, 12:46:02 am
content: Ordered a GW, i hope it gets here in 1 piece as UK customs are cranky. Theres still 4 left on Tequipment.As for my bench PSU i went with the usual one that doesnt have usb, ethernet, etc, just basic voltage and amp adjustment with 2 outputs. Dont exactly need a rigol bench PSU that was mentioned. I can use the oscilloscope to accurately measure watts instead by looking at the volt amp input of the circuit, but other than for use in quadcopters extreme power efficiency isnt a requirement for me.I know Dave advises a number of people which is why he suggested $400 or below but some of us know what we want (despite being a beginner at electronics) and have the budget. I should've mentioned at the start that my budget was for the oscilloscope and that i had bought everything else. upon looking at what you need for electronics i think a good scope is necessary just like when buying a PC for gaming, the GPU is the biggest part of the system. Its also the most expensive thing out of all the tools. Im not the everyday noob that Dave has to deal with.Its a good thing i have already have extra fans needed to mod the scope for silence and rubber fan mounts if it is too noisy or hot, though i dont plan on keeping oscilloscopes turned on all the time. I always through analog scopes were vintage, expensive but more sensitive than digital but seems like digital has surpassed analog in detection and sensitivity.If Oscilloscopes use FPGAs i wonder if it is possible to hack them and program those FPGAs, maybe even overclock them and use better cooling. When i watch the reviews and the math function is turned on the math function doesnt update as fast as the oscilloscope itself. Definitely lack of computing power.I hope GW has APIs that i can use with their software. If i ever need math or anything compute intensive nothing like a GPU to handle the workload, i'd rather not burden the oscilloscope with any compute intensive things. I know they are FPGAs but this isnt bitcoin mining.

author: FlyIt!
author_rank: Contributor
timestamp: June 15, 2016, 01:56:37 am
content: Not to be a wet blanket, but:QuoteVery significant challenge, that.QuoteFPGAs are not like CPUs (in terms of over-clocking). You would throw off all the timing and measurements, rather than 'just increase performance'.QuoteWhile I would truly love to be wrong, I've never seen any of these Chinese scopes have any deep API support. Do they have 'Remote control', and 'automating pass/fail tests', yes. Absolutely.But you're talking about off-loading analysis to a GPU...? Not so much in the way of that kind of API support.Just buy a scope that does what you need. It is quite unlikely you'll be "modding it" to improve performance.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 15, 2016, 03:46:12 am
content: GPU support isnt needed. If i can take the readings from the scope than i can make my own program to do things and use multicore programming or even GPUs if available. All the software needs is to allow direct access to the scope such as in getting values, it would mean i could analyse the results the way i want when i want the detail. The scope will do what i want when i normally use it without a PC for measuring things but for use with PC being able to make your own programs to make use of the oscilloscope can do wonders.

author: Fungus
author_rank: Super Contributor
timestamp: June 15, 2016, 04:59:15 am
content: Quote from: nctnico on June 14, 2016, 08:35:30 pmSo it will also happen on your GW-Instek GDS2202E (which has the exact same 2.5x oversample ratio), right?

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 15, 2016, 05:32:42 am
content: Quote from: Fungus on June 15, 2016, 04:59:15 amThe GDS2202E doesnt suffer from it as it has the same sampling rate on both channels. The GDS2204E is the one that will have the same problem with all 4 channels used. However if you compare to the rigol which only does 100Mhz, at 4 channels in 100mhz the sampling size is 250M per channel, For the GDS2204E using 4 channels at 100Mhz the sampling rate is 500M per channel. At 200Mhz the GDS2204E will have the same problem but that would be at 200Mhz not 100Mhz.

author: Fungus
author_rank: Super Contributor
timestamp: June 15, 2016, 05:33:58 am
content: Quote from: System Error Message on June 14, 2016, 09:49:53 pmI'm not sure which 'GW' you're looking at but tequipment has this one for $1174:http://www.tequipment.net/Instek/GDS-2204E/Digital-Oscilloscopes/That's a pretty good deal at that price.Twice the bandwidth, 3x the money it's up to you. If you've really got nothing better to spend it on, then...On a technical level: The Rigol's 100MHz bandwidth and 1GSA/s is easily enough for the job you're proposing, but ... "you can never have enough" as they say around here.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 15, 2016, 05:49:41 am
content: already bought it, now the wait for it to arrive. The agony of waiting, but ordering from Tequipment says takes up to 9 days, much faster than what even some even sellers do that sell all the way from china.I cant wait to get started. If only kickstarter projects shipped this fast as one of my soldering irons (the 3Dsimo) is an interesting tool that hasnt yet arrived despite ordering it 2 months ago.I know the rigol DS1054Z could be hacked to get 100Mhz and unlock many features and do what i need it to do. If Tequipment didnt have the discount for the GDS-2204E i would've gone with the siglent first for more sensitivity with 200Mhz as single channel can be used to catch spikes, see the signal integrity better, then the rigol for when i need 4 channels for digital signals. Could always use 2 oscilloscopes at the same time. Still if there is a better scope within budget i see no reason not to get it instead especially because i already have all the other tools.One thing about having a digital oscilloscope and a multimeter, can a digital oscilloscope do everything a multimeter does? I know the multimeter is great for quick measurements whereas the oscilloscope would require some fiddling before switching between different types of measurements.

author: Fungus
author_rank: Super Contributor
timestamp: June 15, 2016, 06:18:24 am
content: Quote from: System Error Message on June 15, 2016, 05:32:42 amYes, I meant the 4-channel version.Quote from: System Error Message on June 15, 2016, 05:32:42 amSo... you're saying the GDS2204E is a 200Mhz 'scope and the DS1054Z is a 100MHz 'scope?It's hard to argue with that logic.That wasn't the claim being made though. The claim was that the DS1054Z had an inadequate sample rate for its bandwidth. Not true: It has the mathematically correct sample/bandwidth ratio, as used by everybody else.On both those 'scopes you can turn off a couple of channels and get double the sample rate. Four times the sample rate on a single channel.Signals don't suddenly disappear when you go over the rated bandwidth, they just get smaller. You can actually see 300MHz signals on a single channel of a DS1054Z, no problem (there's a discussion on here with people doing it but it's the the middle of a 100-page thread and I can't find it).Does that mean you can see 600MHz signals on a GDS2204E? No, because things start to go weird above 300MHz. Above 300Mhz(ish) is where you need exotic probes, fancy probing techniques and stuff.But still, the GDS2204E is a nice scope with twice the bandwidth. Itwillshow 100Mhz signals better than the DS1054Z, no argument there. If you already have everything else you need and the extra $700 isn't an issue then go for it.(and if you have a tiny bit more money there's areallynice 'scope I can recommend...)

author: Karel
author_rank: Super Contributor
timestamp: June 15, 2016, 06:25:21 am
content: Quote from: System Error Message on June 14, 2016, 11:30:26 pmDon't buy anything from Siglent if you are not sure you don't want to sell it on Ebay later...https://www.eevblog.com/forum/testgear/siglent-they-filed-a-'wrongful-trademark-claim'/

author: Fungus
author_rank: Super Contributor
timestamp: June 15, 2016, 06:32:01 am
content: Quote from: System Error Message on June 15, 2016, 05:49:41 amNope. They're completely different things.Multimeters are for measuring, oscilloscopes are for looking at theshapesof signals.Multimeters can measure voltage, resistance, current... oscilloscopes only show an approximate reading of voltage (usually about 5% accurate).The oscilloscope is useful because it shows that approximate voltage plottedover time.

author: JPortici
author_rank: Super Contributor
timestamp: June 15, 2016, 06:58:07 am
content: three times the price, the gw has-twice the bandwidth-twice the sample rate (unless you only use one channel)-nearly twice the memory (10M per channel -> 1,67 times the memory, instead of 6M per channel on the rigol, though having one single 24M is nice)-better fft, 1Mpts (at least on paper, but judging from the reviews it seems to be better)-CAN decoding-protocol decoding, triggering, etc. already installed. not sold as an option, no "hacking" bullshit, loss of waranty etc.the only downside is that in europe GWi prices are absurdly high, nearly twice (and before taxes)

author: TheSteve
author_rank: Unknown
timestamp: June 15, 2016, 07:08:09 am
content: Congrats on the purchase, I hope it does everything you need. Maybe we should have upped your budget further and gone straight to a Keysight.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 15, 2016, 08:11:53 am
content: i bought the GW from Tequipment for $1100 + shipping and taxes, still much cheaper than buying it from EU or UK, about £200 less including shipping and taxes.What i mean by bandwidth to sample is when you have all 4 channels used as both the rigol and GW have it but when it comes to measuring a signal of the same frequency the GW would still have twice the sample rate despite the bandwidth to sample rate with all 4 channels only being 2.5 at maximum bandwidth setting,If you have a better scope for slightly more better tell me fast so that i can tell Tequipment to hold off on the order before they send it so i can order it (assuming if it is only slightly more than $1100.

author: tautech
author_rank: Super Contributor
timestamp: June 15, 2016, 09:03:57 am
content: I hope you've had a real good study of datasheets.....while the apparent features of any scope can seem appealing it's not until some time is invested in technical comparison that differences become clear.Eg. Siglent SDS1000X Plus range:16 Digital channels (MSO), Maximum waveform capture rate up to 500 MSa/s, Record length up to 140 Mpts25 MHz DDS arbitrary waveform generator, built-in 10 kinds of waveforms (Standard for SDS1000X+ models)Decoding is available via Digital channels, not only the 2 DSO channels.But as normal this thread has partially turned into a DSO pissing contest when facts and datasheets should speak for themselves.Thanks to those that have felt my efforts to inform are worthwhile, all any of us can do is provide info based on facts or experience for those that struggle to find it for themselves.Good luck Sys Err MesPlease carry on.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 15, 2016, 10:01:16 am
content: Are you sure about 140Mpts for siglent? Im sure i read it was 14Mpts.MSO and signal generator isnt something i need.Tautech i did compare the entire range of the SDS1000X even the plus range as well. I didnt consider the plus variants because they were so much more (check siglent EU) and i all i am going to use the scope for is for seeing waves. For the MSO i will use something different to use with my PC in the future when if i do need it. For me the deciding factor was how good it is for analog measurements for the price. I did consider your input as well.The GW on discount + tax and shipping is £1000, from siglent EU it doesnt include tax and all the plus variants are above 1000 euro, So for £300 more than the initial siglent i chose i get 4 channels, halving of sample rate over 4 channels but frequency is kept, parallel 10M memory. Not sure how to really compare the waveform update rates.For digital needs the analog discovery seems really good.I know everyone loves their brands (if you read my threads on networking/brand specific (For the one i use) forums you will see me complaining about the brands i like instead). I give the brands i use a hard time doing the usual complaining hoping they would improve/fix the issues even though for example the router i use at home is capable of 28Gb/s of software NAT and gigabits of encrypted VPN speeds i do complain a lot about it while a normal person would be impressed, happy and loving.edit: and i did watch the various reviews and read the gritty details.Thanks all for your advice and input.

author: tautech
author_rank: Super Contributor
timestamp: June 15, 2016, 10:38:28 am
content: OK you got me there.... checked the datasheet and websites:Website:16 Digital channels (MSO), Maximum waveform capture rate up to 500 MSa/s, Record length up to14 Mpt/CHDatasheet needs correcting....I'll see to it.@SEM....equipment is equipmentthey all have their plusses and minuses, these days manufacturers are very involved in competitive "one upmanship" cramming as much functionality into gear as they can.....that has distinct advantages for those that want compact equipment or have limited space but in many cases adds significant cost to purchasers as you can see by going through this exercise.I'm very much the KISS type however manufacturers want arangeto appeal to the biggest market sector with all this added functionality.....I'm not convinced, it makes the buyers decisions much harder.In the end it's your money and you have to be comfortable with your decision....it seems you are.

author: Fungus
author_rank: Super Contributor
timestamp: June 15, 2016, 11:01:58 am
content: Quote from: TheSteve on June 15, 2016, 07:08:09 amI'd have got an R&S if I was going to spend much more, but whatever.For $1200 the GW-Instek will do. That's a very good price.Quote from: tautech on June 15, 2016, 09:03:57 amAt least it was onlypartialthis time.

author: saturation
author_rank: Super Contributor
timestamp: June 15, 2016, 11:20:21 am
content: Consider giving us a review once you are done, you can post on any of several threads on the GDS scope.Quote from: System Error Message on June 15, 2016, 08:11:53 am

author: nctnico
author_rank: Super Contributor
timestamp: June 15, 2016, 11:31:14 am
content: Quote from: Fungus on June 15, 2016, 11:01:58 amI wouldn't because it is an utterly stupid thing to do. Short memory, expensive options, small display. The HMO1222 (2 channels 200MHz) including decoding sets you back over $3000 at Tequipment. That is more than double the money for 10 times less memory/channel, >10 times slower waveforms/s and half the channels compared to the GDS2204E.

author: Fungus
author_rank: Super Contributor
timestamp: June 15, 2016, 12:09:37 pm
content: Quote from: nctnico on June 15, 2016, 11:31:14 amHuh?http://www.tequipment.net/Rohde-&-Schwarz/HMO-1222/Digital-Oscilloscopes/Price: $1,830Where: At Tequipment.Quote from: nctnico on June 15, 2016, 11:31:14 amPlease take off your Instek blinkers: Nobody even mentioned your darling, we were talking about Keysights.

author: nctnico
author_rank: Super Contributor
timestamp: June 15, 2016, 01:09:26 pm
content: Quote from: Fungus on June 15, 2016, 12:09:37 pmNow add the decoding options to the priceThe same goes in lesser extend for the Keysight scopes. The value for money just isn't there in the 50MHz to 200MHz range primarily due to the extremely short memory in the Keysight scopes. BTW if you have the cash to spend then Lecroy's Wavesurfer 3000 is a much better deal than what Keysight has to offer in the >200MHz segment.

author: Fungus
author_rank: Super Contributor
timestamp: June 15, 2016, 03:07:24 pm
content: Quote from: nctnico on June 15, 2016, 01:09:26 pmI wouldn't want CAN bus decoding, so....Still, serial bus is extra so call it $2000. Still nowhere near $3000.

author: nctnico
author_rank: Super Contributor
timestamp: June 15, 2016, 03:21:37 pm
content: Quote from: Fungus on June 15, 2016, 03:07:24 pmThat doesn't matter. You need to compare equivalent functionality and besides that you can't cherry pick the most expensive option from the equation to make the point you are attempting to make more favourable. If you don't need any decoding options then there is also the much cheaper GW Instek GDS1000B series. Either way the R&S HMO series is just way overpriced. Tequipment.net has no R&S scopes in stock at all so it seems they don't sell very wel either.

author: Fungus
author_rank: Super Contributor
timestamp: June 15, 2016, 03:36:29 pm
content: Quote from: nctnico on June 15, 2016, 03:21:37 pmSo are Mercedes Benz cars, designer jeans, etc., but they sell plenty...If I was rich I wouldn't choose a GW-Instek. Not a chance.

author: rsjsouza
author_rank: Super Contributor
timestamp: June 15, 2016, 11:18:55 pm
content: Congratulations on the purchase! I followed this thread on the sidelines and commend you for turning on your notch filter and getting useful information among the noise (catfights).As someone else pointed out, if time permits please post your first impressions about the Instek.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 16, 2016, 12:48:36 am
content: I definitely will. The first thing i want to measure is how stable some of the PSUs i have are.I've visited Rohde and shwarze before, seen a van they sell to govt for tracking pirate radio, should've asked them if i could bring home a scope.Tequipment wasnt the only place i look, I look at as many places as possible to compare prices, at least 10 different online stores.

author: tggzzz
author_rank: Super Contributor
timestamp: June 16, 2016, 08:06:26 am
content: Quote from: rsjsouza on June 15, 2016, 11:18:55 pmWhile I certainly agree that too many statements are too absolutist to the point of being unbalanced, there is useful information in most of them. But I agree that a narrowband bandpass filter is necessary to select only the points that are relevant at this time.Later the OP might find the other points helpful in different circumstances.

author: Fungus
author_rank: Super Contributor
timestamp: June 16, 2016, 08:53:48 am
content: Quote from: rsjsouza on June 15, 2016, 11:18:55 pmSome of the resident Rigol-Bashers were absent this time, that helped too.

author: tggzzz
author_rank: Super Contributor
timestamp: June 16, 2016, 10:41:10 am
content: Quote from: Fungus on June 16, 2016, 08:53:48 am"Rigol-bashers" are a necessary counterbalance to "Rigol-shills", and vice-versa. Everything is gray, there is no black and white

author: wraper
author_rank: Unknown
timestamp: June 16, 2016, 11:13:17 am
content: Quote from: pascal_sweden on June 14, 2016, 10:52:54 amI have DS2000 and GDS2000E standing nearby, and what looks and feels like a toy is Rigol.

author: ebastler
author_rank: Super Contributor
timestamp: June 16, 2016, 01:46:46 pm
content: Quote from: Fungus on June 16, 2016, 08:53:48 amQuote from: wraper on June 16, 2016, 11:13:17 amHey, you made it to this thread just in time!

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 16, 2016, 03:23:56 pm
content: Why would an oscilloscope looking and feeling like a toy be an issue? Its meant to be played with.

author: rstofer
author_rank: Super Contributor
timestamp: June 16, 2016, 05:53:13 pm
content: Quote from: System Error Message on June 16, 2016, 03:23:56 pmIn the old days, quality was bought by the pound. The heavier the scope, the better the quality/features/bandwidth, etc. More weight was good!Now it's all done with a couple of DACs and an FPGA plus a display. Of course it looks and feels like something from Mattel.Actually, the lack of weight is a problem. When I try to push the power button on my DS1054Z, the unit slides across the bench. It takes two hands to turn it on or off. That is NOT a problem with my Tektronix 485 sitting upright on the floor. That scope is heavy enough to sit anywhere it wants!

author: TheSteve
author_rank: Unknown
timestamp: June 16, 2016, 06:21:20 pm
content: Simple solution - get yourself some drawer/shelf liner. Even my Keysight DSOX3014A slides easily on a shelf. A couple pieces of the liner under the feet and I can add/remove probes etc without it moving.

author: nctnico
author_rank: Super Contributor
timestamp: June 16, 2016, 06:29:59 pm
content: Sliding can be a problem in general. I stuck extra rubber feet on several pieces of my equipment to prevent it from sliding.

author: rsjsouza
author_rank: Super Contributor
timestamp: June 16, 2016, 06:33:11 pm
content: Quote from: ebastler on June 16, 2016, 01:46:46 pmQuick! Let's turn on the notch filters again!Quote from: System Error Message on June 16, 2016, 03:23:56 pmI don't dislike Instek's looks. As I stated inDave's teardown thread, the aspect I like is they don't multiplex controls like other brands. Form does not trump function.It's like the old adage: if "looks" is the main criticism against your test equipment, you can live in peace.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 17, 2016, 12:40:12 am
content: well i know how you feel about metal and weight. The heavier it is the more "real" it feels. Thats why a lot of cheap chinese counterfeit products fill their product with lead, powder and other sort of materials. Take a look inside an ultrafire battery for example.

author: Fungus
author_rank: Super Contributor
timestamp: June 17, 2016, 08:24:40 am
content: Quote from: Fungus on June 16, 2016, 08:53:48 amQuote from: wraper on June 16, 2016, 11:13:17 amWhere were you? We missed you!You'll be very relieved to know that the OP bought a GDS2000E at a very good price - tequipment seems to be dumping that model.

author: Fungus
author_rank: Super Contributor
timestamp: June 17, 2016, 08:29:52 am
content: Quote from: System Error Message on June 17, 2016, 12:40:12 amYeah, but that's because they didn't put any actual "battery" inside them. An empty case would feel very wrong.PS: Rigol build quality is fine. "Pleasant surprise" is how I'd describe the overall feel.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 24, 2016, 03:41:01 pm
content: My oscilloscope just arrived, Tequipment sure has a funny way of packaging by placing it within 3 boxes.Scope performance is really nice, at 1ms timebase at 200Mhz i get the full spec of 1GSa/s and 10M, any longer and only the sampling rate halves. It could definitely use more apps and software but i havent managed to update the firmware yet. This scope is very sensitive, what i thought the scope was very noisy but currently until i move into a much bigger room i have so many electronics around such as my wifi AP sitting next to it, putting the probes near the back of my monitors or even near the bench PSU showed similar AC like noise. This is down at 1mV. It is also nice that i can get the scope down to 1ns timebase. USB and ethernet work the way i want them to although i cant set a proxy but at least i can force it using my router.I didnt have trouble with the interface, i could instantly access and use it without reading the manual and not having used a scope before. I guess some of you are too used to certain interfaces.One thing i really wish they would add is NTP and locale setting as it set itself to china/taiwan's time. Once i move in July i will do a review on this as i would have a much bigger room, more space and perhaps set up a faraday cage.quite impressed with the scope and it even has DMM functionality but it seems to measure differently than my handheld crappy DMM. Measuring 24.5V at bench PSU display during load, my DMM showed 24.3V, my router being powered by it showed 24.1V (putting DMM on cables showed a 0.1-0.2V loss). putting the oscilloscope showed around 23.8V at the output.Edit: thanks Tequipment for the extra boxes, i now have more boxes i need for moving.

author: rstofer
author_rank: Super Contributor
timestamp: June 24, 2016, 05:10:48 pm
content: Quote from: System Error Message on June 24, 2016, 03:41:01 pmSo, you are off by 0.7V at 24.5V or 3%. The Gain Accuracy spec is 3% for signals >= 10 mV. And that's 3% of full scale, not 3% of the reading. Your scope seems fine!In my view, scopes are 'qualitative' instruments, not 'quantitative'. Admittedly that is from an analog scope point of view but I trust my DMM measurements a lot more than those from my DSO.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 24, 2016, 05:24:26 pm
content: that was using the DVM app on the scope. Im not sure if i connected it right because i only connected the probe to the + and didnt connect the ground to negative.

author: tautech
author_rank: Super Contributor
timestamp: June 24, 2016, 09:21:35 pm
content: Quote from: System Error Message on June 24, 2016, 03:41:01 pmJust set the RTC to your local time.

author: nctnico
author_rank: Super Contributor
timestamp: June 24, 2016, 09:58:55 pm
content: Quote from: System Error Message on June 24, 2016, 05:24:26 pmYou have to connect ground to negative but always make sure you don't make a short through the oscilloscope. All the BNC connectors' outer shells are connected together and mains ground.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 25, 2016, 10:13:56 am
content: I'll give it a try again after i move. Considering i am currently in student flats its likely ground will always have something going on that will throw off readings.