Which oscilloscope / function generator combo for learning ? - Page 1
Forum section: electronics / testgear

author: kultakala
author_rank: Regular Contributor
timestamp: March 24, 2017, 02:15:11 pm
content: Hi all,Two months ago i asked for a good Scope/DMM combo... i bought a DMM which i still like but decided to wait with the Scope.Now its time to get oneMain purpose would be to play around with waveforms and learn all the oscilloscope stuff.Therefore i need a scope and a function generator.I guess it would be good to have kind of a teaching function in the scope and cool to have some built in arbitrary waveforms in the function gen.The one i had in mind was the Siglent SDS1102X+ with the built in waveform generator for about € 600.-.Or i could take the SDS1102X plus a SDG1032X which would be at around €740.-.Or the SDS1102X plus the SDG2042X for about €875.-.But in the meantime Keysight launched the DSOX1102G which would also have a built in function generator for €780.-.My budget would be at 800 Euros...If i would have to prioritise between signal quality, features and usability i would go for ease of use first, then features and then quality.I dont mean build quality but signal quality if you put it under the microscopeSo is there a better scope for learning than the siglent and the keysight ?If not for which combination would you go ?Would be good to get some opinions because i cant estimate what really matters.Thanks!Cheers,Olaf

author: slurry
author_rank: Regular Contributor
timestamp: March 24, 2017, 02:33:40 pm
content: For learning?Why a new scope and a new function generator? -the basics are all the same.You will get a good used scope and maybe two functiongens for €500 if you have some patienceWithout hesitation, i would go for the Keysight DSOX1102G, good second hand value, good interfaces and BenchVue (although license costs)

author: kultakala
author_rank: Regular Contributor
timestamp: March 24, 2017, 02:42:05 pm
content: Quote from: slurry on March 24, 2017, 02:33:40 pmOkay, replace "learning" with "toying with"In fact i looked for used scopes at e**y and some used equipment dealer.But i didnt found anything which was sufficient in my opinion. And for the same price i would rather get a new device than a used one.

author: nugglix
author_rank: Regular Contributor
timestamp: March 24, 2017, 02:45:15 pm
content: As I explained here:https://www.eevblog.com/forum/beginners/how-much-abuse-can-a-function-generator-on-a-dso-withstand/msg1164461/#msg11644612-in-1 doesn't really cut the mustard.

author: irakandjii
author_rank: Regular Contributor
timestamp: March 24, 2017, 02:58:11 pm
content: Quote from: boffin on March 24, 2017, 02:54:23 pmFor pure learningthisor its newer brother Analog Discovery 2, You also get access to lots of supporting materials & capability, for example a version of LabVIEW for about $50, tutorials etc. And some online University courses use it in their curriculum.If you are doingsome other work and need the bandwidth and memory, it is worth the additional expense for the Keysight as mentioned earlier.

author: kultakala
author_rank: Regular Contributor
timestamp: March 24, 2017, 06:36:17 pm
content: Thanks for the hint but i definitely want a standalone device, no usb/pc oscilloscope.The second hand value ist not so important for me, but from the specs the siglent is better in some parts, isnt it ?I mean in that case, SDS1102X+ against the DSOX1102G, the Siglent has 100 MHz instead of 70.It has a memory depth of up to 14 Mpts against 1 Mpts, but has only 1 GSa/s instead of 2 for the keysight.The Siglent has a larger screen (didnt find the resolution of the keysight display ?) and the wave gen goes up to 25 MHz instead of 20 (doesnt matter) but the Siglent has arbitrary waveforms up to 5MHz.What i cant judge is the "responsiveness" of the user interface and the ease of use, but why is the keysight the better choice ?Disregarding the brand name and the better second hand value... Siglent seems to be getting more for the money ?

author: james_s
author_rank: Super Contributor
timestamp: March 24, 2017, 07:54:05 pm
content: From what you describe, my recommendation is to find a decent analog CRO, the Tektronix 465B is an excellent instrument, as are the related models. The 465 is 100MHz, dual trace, has delayed sweep, XY mode, pretty much everything needed, for years it was the gold standard of general purpose oscilloscopes. Frankly you could learn almost as much from a basic 2 channel 20MHz scope you can probably pick up in working condition for less than $50. Once you know your way around you may decide to get a newer digital scope but in my opinion it's valuable to learn how to use an analog scope proficiently and then it will make a lot more sense why the DSO works the way it does.Don't run out and drop big money on fancy new gear just to learn the ropes. There is a lot of perfectly good older equipment out there that will teach you just as much or more, and by the time you outgrow it you will have a much better idea of what you want when you decide to upgrade.Also don't worry about a built in function generator, really a separate unit is preferable. You can easily get a decent used function generator for under $100, probably much less if you're patient. You can even build your own fairly easily from parts or a kit, a reasonable option if your goal is to learn. Another source of interesting waveforms to look at is various junk electronic devices you can find on the curb or at garage sales.

author: Dubbie
author_rank: Unknown
timestamp: March 24, 2017, 08:12:40 pm
content: An analog scope kinda sucks if you are messing about with embedded and digital stuff.

author: james_s
author_rank: Super Contributor
timestamp: March 24, 2017, 08:51:50 pm
content: It has limitations yes, but so does any instrument. The key is to understand the limitations and learn how to work around them.At any rate the OP said they are interested in learning how to use an oscilloscope and function generator, nothing about digital stuff. This is why I suggested picking up an analog scope first, learn the basics and then later get a DSO if/when one is needed. Analog scopes are so cheap that it doesn't have to be a major purchase decision.Likewise if you want to learn to fly, you're probably going to start out in something like a single engine Cessna with all manual controls and "steam gauges" and learn the fundamentals before you start learning to fly a Boeing 737 with a glass cockpit and fancy autopilot.

author: DaJMasta
author_rank: Super Contributor
timestamp: March 24, 2017, 09:19:07 pm
content: When I had the choice, I went for a separate scope and generator, as you get a more capable generator and a second channel going with that route and I wanted flexibility in the long term and wasn't too concerned with portability. You also get the external inputs (like the reference clock) which can be very useful for synchronization and other applications.That being said, if you're going with one for learning and it being integrated is important - I think the demo signals on the Keysight are an advantage, and the integrated analysis functions with the function generator are a nice add in.If the price is roughly the same, I would (and did) go with two distinct units. If you can get a good price (like an options bundle or something) or there are significant benefits for getting one unit (like bench space or a portability requirement), then I think the Keysight 1000X series offers the best combination product unless the specs of the generator or the scope are outside of any of your requirements.There's a lot to be said for learning the basics on simple equipment, but there's something to be said for getting a scope that will last - and I'd take the math functions and bandwidth of a decent entry level DSO over an analog scope any day for most of my general usage tasks.Maybe if you really aren't experienced with using a scope, you could get one with a scope demo board - if you can find a second hand one or something, you can get a source for a lot of different signals and some instructional material for probing and understanding them. There's a lot of 'on a budget' sort of options, but not many of them end up with equipment that won't be replaced if you have the intention of putting together an electronics bench... though even then it's all to your requirements.

author: james_s
author_rank: Super Contributor
timestamp: March 24, 2017, 09:31:46 pm
content: Not to mention €740 sounds crazy expensive for a beginner. That's more than I have invested in my TDS784C, probes and function generator all combined, and that's a 1GHz scope with all the options, original list price close to $40,000. Ok so it's big and bulky, but it has a really cool field sequential color CRT display.Plenty of older scopes that can be had for a song, I recently got a TDS340 with a dead power supply for $100 shipped, took less than an hour to repair and I found it had only logged 41 powerups, under the layers of dust the thing was practically brand new. Yeah it's old and primitive by current standards, but it will outperform any of those toy hobby grade DSOs from China, you'd have to spend several hundred bucks to get something new in that class.I've seen numerous analog CROs given away for free in working order. If one just wants to learn how to use a scope there is no reason to start out with something fancy. It's not unusual for a beginner to blow up their new scope before they even learn how to use it, just a few weeks ago someone posted here about a flash & bang when they tried to scope a non-isolated SMPS.

author: kultakala
author_rank: Regular Contributor
timestamp: March 24, 2017, 10:36:43 pm
content: Okay... thanks for all your opinions so far, but...The main question i have is which of the oscilloscopes would be the best, especially in the ease of use departmentI will definitely get a standalone unit, and i want to buy a digital one, and a newone, although i did look for used ones.I really like "fancy" stuff, modern, large display, lot of things to play with.It was a long time ago, but originally i am kind of an electronics engineer, specialised in mainframe computers.Back then i worked also (a little bit) with oscilloscopes, for example with HP 54100 series if i remember it right.Since 25 years i have to do with networking and i am a pro in firewalls and and IPS systems.I did almost nothing related to electronics in private and nothing with scopes but i find everything which has to do with measurement equipment still fascinating and like to play around.The budget for playing with a scope etc. is just set to about 800 Euros because thats what i want to spend and does not matter.If i would seriously need a scope for working i could buy a keysight 4000 series but that would be like taking a sledgehammer to crack a nut.I just want to get busy with some scope stuff and would like to get something neat which has the best value for money inside my budget.I dont want to offend anyone but there is no need trying to convince me to something else or to worry about my moneySorry if i tread on someones feet and forgive me if i am not able to express exactly what i mean but english is not my native language so...I really would like to have a dealer nearby where i could get my hands on different scope models but unfortunately thats not the case.Hopefully Dave will review the keysight 1000 X-series soon and compare it with the Siglent !?And who knows, maybe i will win a 1000 X-series scope from the Keysight scope month... that would spare this thread i guess

author: SingedFingers
author_rank: Frequent Contributor
timestamp: March 24, 2017, 10:40:37 pm
content: Quote from: Dubbie on March 24, 2017, 08:12:40 pmKids these days. When I was at university I built myself a pattern trigger. Fast comparator array programmed with dip switches and some sync logic. Worked up to 20MHz capturing digital signals on an analogue scope reliably.TBH I'd buy an old analogue scope and am old analogue function generator. You'll learn more keeping them alive than you will with a new DSO.For ref, also in the IT side of things. Bringing a DSO home is what we call a "busman's holiday" here in the UK. The guy who drives the bus during the day gets to drive it on holiday too leading to a shit holiday.if you're making money out of it, buy a shiny fancy new DSO as that'll do the job quicker.

author: Mr. Scram
author_rank: Super Contributor
timestamp: March 24, 2017, 10:57:06 pm
content: Quote from: SingedFingers on March 24, 2017, 10:40:37 pmNowadays you buy a 20 MHz(ish) logic analyser for 5 dollar on a Chinese website. Let's say it actually does half. Still a good buy. Compared to even just 20 years ago, being a hobbyist of professional is so much more convenient. If you want to do it the hard way for fun, you still can.

author: nctnico
author_rank: Super Contributor
timestamp: March 24, 2017, 11:15:56 pm
content: I'd go for a seperate function generator and DSO because the generators inside a typical DSO can typically drive 5Vpp max. which is not enough in many cases (for example something simple like driving a 5V logic input). Also the user interface can be a bit clunky when it comes to the signal generator in a DSO. Feeltech has several interesting ultra-low cost function generators and otherwise Siglent also has several low cost generators which are quite mature (but not without quirks).If you want a DSO with lots of features at low cost then also look at the GW Instek GDS1102B. It has deep 10Mpts memory and features like input filtering, free math equations, 1Mpts FFT and a very easy user interface. Also don't get blinded by the samplerate. For 100MHz anything over 250Ms/s is enough.

author: kultakala
author_rank: Regular Contributor
timestamp: March 25, 2017, 11:11:05 am
content: Thanks, i will have a look at the GDS1102B.I tend to get DSO and Function generator seperately...