Fixin' to buy an Oscilloscope - Page 1
Forum section: electronics / testgear

author: Vortigan
author_rank: Contributor
timestamp: November 24, 2015, 06:05:45 pm
content: Hello,I am currently a Mechatronic Engineering student living in Bogota, Colombia. I am going to start the 6th semester (3rd year) of my studies. As of now I have already seen, Micro controllers (using the stm32f4 discovery board), Basic Circuits, Electronic Circuits and Digital Circuits. I have already learned the basics on how to use both the analog and digital oscilloscope (I understand that there is basically no difference in either). Aside from that I bought myself a DP832 Power Supply, Hakko 951 soldering station and a Fluke 87V (all recommended by Dave in his videos). In general I have set up a "beginner's lab" to be able to work on my projects at home when I need to.In the upcoming semesters i will be seeing: control, sensors, signals, power, ...etc. I feel I should buy an oscilloscope to continue to work on my projects at home when the University's Lab kicks me out at 9pm. I would like community's opinion on what oscilloscope I should buy. I watched Dave's rant on beginners wanting to buy the micro oscilloscopes and I completely agree with him. From there I thought I should buy an Analog oscilloscope because it would help in my learning experience and because it's cheaper.I've only looked at analog scopes at the moment because of their price mostly.Fluke 3092 Dual Channel @ 200MHz <--- (this one has called my attention the most)Fluke 3082 Dual Channel @ 100MHzBK Precision 2190B Dual Channel @ 100MHzTektronix 2236 Dual Channel @ 100MHzTektronix TAS 465 Dual Channel @ 100 MHzThe Fluke 3092 has called my attention the most and I would like the community's input on it please, aside from that if there are others that may be "better" please let me know. Aside from that, if you feel that a digital oscilloscope is more beneficial please let me know. Please keep in mind that I'm on a limited budget.Thank YouSide note: I am a US citizen (I lived 13 years in the US since birth) currently residing in Colombia. I'd just thought I'd let you know if you're worried about my English.

author: Fungus
author_rank: Super Contributor
timestamp: November 24, 2015, 06:21:02 pm
content: Quote from: Vortigan on November 24, 2015, 06:05:45 pmDave's rant is quite old now. His point about micro oscilloscopes is still valid, but ... the price and features ofdigital'scopes has changed alotsince then.Many people (including me) think it's changed so much enough that an analog 'scope simply isn't worth it any more. No unless you can get onereallycheap. Under $100.Quote from: Vortigan on November 24, 2015, 06:05:45 pmIt all depends on the price you're looking at, which we don't know.Quote from: Vortigan on November 24, 2015, 06:05:45 pmThey're all fine oscilloscopes but the point stands.In terms of real value: An old, 100MHz, 2 channel analog 'scope is worth less than $100 now. Don't pay more than that.200MHz is worth a bit more, but only about $150 and you have to be sure you need 200MHz.After that you go to the Rigol DS1054Z which costs $400. I know it's a big jump in price but it really is worth it. Beg, borrow, steal... do what you need to do. Just don't pay too much for an old analog 'scope when the money could go towards an amazing DSO.PS: Be sure to watch Dave's videos on the DS1054Z. He was so impressed by it that he did a whole series.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: November 24, 2015, 08:44:44 pm
content: I've done a whole series on the Rigol DS1045Z too. Seems like I find new "features" just about every time I use mine for actual benchwork.And yes.... they are impressive indeed.It's funny though... Dave hasn't mentioned any of the topics I covered in my videos.(Don't get me wrong, I'm still recommending this scope.... but "caveat emptor", do your research (not "just" Dave's videos!) and know what you are getting into.)The RIGOL DS1054Z screen display is really nice.....

author: Vortigan
author_rank: Contributor
timestamp: November 24, 2015, 08:49:30 pm
content: Thanks fungus and alsetalokin4017 for your input it really helped a lot. The reason why I want such a high frequency is because I have to do lots of signal analysis, control, fourier transform, z transform and all that annoying tedious jazz. Don't get me wrong I love that stuff, it's just really hard when you're limited on time and you don't have the right tools to "prove" your work and it's even harder when the lab kicks you out at 9pm when you REALLY need to work. It's mostly to be safe and not sorry. I just really need someone to guide me on buying the Oscilloscope.One of the biggest reasons why I wanted to buy and analog oscilloscope was because of the price an bandwidth it offered. I'm not trying to go over kill, I just want to be safe and not sorry. (sorry for repeating)Digital oscilloscopes are awesome, the problem is that they're very expensive.Most of the oscilloscopes in the University's Lab are 100MHz and up so it's quite worry some that I might end up having to present work with such high frequencies.I'm sorry if this sounds confusing, I just DON'T want to worried about not having the tools I need when I need them.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: November 24, 2015, 08:55:32 pm
content: I really don't think you are going to find an analog oscilloscope for $150 dollars that will do FFT, or save a screenshot to a digital image file.You really should get a digital scope like the Rigol DS1054Z. It can be "improved" to 100 MHz bandwidth, has several digital protocol decoders built-in, does realtime FFT of a sort, saves screenshots, setups, reference waveforms etc. relatively painlessly and quickly, and has many other advantages over a cheap used Analog scope.However there are some problems and bugs that you should know about _before_ you make your decision to buy.Would I still buy one today after all I know? Yes, I probably would. But then I also already own a couple of good, old, quality Analog scopes too.

author: Fungus
author_rank: Super Contributor
timestamp: November 24, 2015, 08:56:40 pm
content: Quote from: Vortigan on November 24, 2015, 08:49:30 pmI'm not saying don't buy an old analog 'scope, just be careful how much you pay. A lot of people ask for $150-$200 and they simply aren't worth that much.PS: The DS1054Z is 100Mhz really. You just have to enter a secret code before it removes the 50MHz low pass filter for you.(Actually: Measured DS1054Z bandwidth is much higher than that...)

author: Fungus
author_rank: Super Contributor
timestamp: November 24, 2015, 08:58:18 pm
content: Quote from: alsetalokin4017 on November 24, 2015, 08:55:32 pma) I don't think they're as serious as you imply.b) They might vanish in the next firmware update. Several more serious bugs already have...

author: alsetalokin4017
author_rank: Super Contributor
timestamp: November 24, 2015, 09:01:15 pm
content: Quote from: Fungus on November 24, 2015, 08:58:18 pmWell, you're quite the comedian aren't you. Right now Jason the RigolUSA tech is in a panic over the latest bug I've reported to them. He reproduced it on the first try. If that doesn't qualify as _serious_ I don't know what does.

author: Fungus
author_rank: Super Contributor
timestamp: November 24, 2015, 09:07:00 pm
content: Quote from: alsetalokin4017 on November 24, 2015, 09:01:15 pm'Panic'? Yeah, right.Quote from: alsetalokin4017 on November 24, 2015, 09:01:15 pma) Not everybody has it (I don't!), which is why they asked you to send themyourparticular scope. They couldn't even find a scope that did it at Rigol.b) Reproducible isgood- it means they can investigate easily.c) Are you denying they've fixed serious bugs before? Dave has made videos about it.eg.Jitter problem:https://www.eevblog.com/forum/blog/eevblog-683-rigol-ds1000z-ds2000-oscilloscope-jitter-problems/Jitter problem fixed:http://www.eevblog.com/2015/01/05/eevblog-699-rigol-ds1054z-oscilloscope-jitter-fix-testing/

author: Vortigan
author_rank: Contributor
timestamp: November 24, 2015, 09:14:01 pm
content: Alright then, I don't have a problem about entering a code, I had to do the same with my DP832 to get the "high res" setting. How do I get the code though? Do I have to buy it? Or do I have to ask someone to provide it? if that-s the case then it really makes it cheaper for me.

author: Fungus
author_rank: Super Contributor
timestamp: November 24, 2015, 09:15:58 pm
content: Quote from: Vortigan on November 24, 2015, 09:14:01 pmhttp://gotroot.ca/rigol/riglol/You can unlock all the serial decoders, extra memory, trigger modes, etc. as well. I think all the options are worth over $1000 if you buy them oficially.The only thing that doesn't work is 500uV per division vertical scale. It's best not to unlock that option so you can't set it accidentally and confuse yourself when it goes weird.

author: Vortigan
author_rank: Contributor
timestamp: November 24, 2015, 09:20:10 pm
content: oh wow, that's amazing! Than you so much!

author: rsjsouza
author_rank: Super Contributor
timestamp: November 24, 2015, 09:30:43 pm
content: The PM3092 is a fine scope (4 channels at 200MHz, dual timebase) and apparently there is aservice manualavailable in PDF.That said, I could not see any at a reasonable price (all were >$200 + shipping), therefore I agree with others: you either wait or save some more and get a DS1054Z.Analog scopes are great to learn and they force you to count grid marks, adjust trigger, horizontal, etc. and some are very pleasing to the eye. However, DSOs bring a lot more to the table, mostly in measurements and data processing. They add complexity to the displayed data when you are reaching the edge of their capabilities (aliasing, sampling rate, etc.). However, you can still count grid marks, manually adjust trigger, cal, horizontal, etc. just like an analog oscilloscope.

author: Howardlong
author_rank: Super Contributor
timestamp: November 24, 2015, 10:12:39 pm
content: By far the most important aspect of a digital scope is single shot which is invaluable when debugging microcontrollers.Sure, you can mess about with a digital camera's exposure on an analogue scope but it's hardly convenient.At one time I had both a 400MHz analogue scope Tek 2465B and a 200MHz digital scope Tek TDS2024B. Due to circumstances at the time, one had to go, and it was the analogue that went on ebay. This was solely down to the single shot facility. But what I would say is that the analogue scope always got more use than the digital one at the time. Later on when I had a bit more space I reintroduced the analogue scope, and again it got more use than the DSO.Nowadays though, in fact pretty recently, things have changed, and I find that the facilities available on new DSOs even at the entry level are so good that a CRO doesn't even feature on my bench anymore. I have it on the floor ready to go but I use it less and less.

author: Vortigan
author_rank: Contributor
timestamp: November 25, 2015, 02:49:20 am
content: Thanks to all for your help

author: nbritton
author_rank: Frequent Contributor
timestamp: November 25, 2015, 07:57:30 am
content: Don't spend more than $100 on an analog scope. Honestly if it were me I would pass on an analog scope altogether. How much money do you have to budget? For $159 you could get the Diligent Analog Discovery. For $399 you can get the Rigol DS1054Z. For $3999 you can get the Tektronix MDO3014. I personally bought a Rigol MSO4014, but only because I got an awesome deal on it. For a student with a limited budget I'm going to recommend ether the Analog Discovery or the DS1054Z, you can't go wrong with ether one. Just realize that these are designed for beginners and hobbyists, if you are looking for a professional instrument that will last you ten years you will need to budget at least $3000. If you're willing to settle for two analog channels then the Rigol MSO2072A is a good deal because it can be software hacked to 300 MHz. The choice depends entirely on what you can afford to budget.

author: vk6zgo
author_rank: Super Contributor
timestamp: November 25, 2015, 08:42:50 am
content: "For $159 you could get the Diligent Analog Discovery""up to" 100MS/s?16kSa/channel memory?5MHz analog bandwidth?+/- 20v max?It might be useful for the other add-on stuff,but for looking at a square wave above about 1MHz,compared to the worst old analog or even early DSO,it's not an "Oscilloscope's bootlace"!

author: Howardlong
author_rank: Super Contributor
timestamp: November 25, 2015, 08:50:07 am
content: Quote from: vk6zgo on November 25, 2015, 08:42:50 amWhile I agree with your sentiments, the analogue 3dB bandwidth is about 30MHz on these things, they used 0.05dB as their bandwidth "limit" to avoid confusing students apparentlyOtherwise, these are a pretty useful addition to the bench, but they're not in the same league as a proper scope if a scope's what you're after. I use mine mostly on long journeys when you need an ultra compact bit of TE.

author: VK5RC
author_rank: Unknown
timestamp: November 25, 2015, 09:11:45 am
content: +1 for the Rigol; you will need more than an old analogue scope (as your only scope) will provide pretty quickly , sure the Rigol will be outdated in 5-10yrs or so (as is everything nowadays) but till then will be a pretty useful tool. A few bugs maybe but a LOT more use than an old 'room warmer' (i have an Tek 2245 for fun) but a new DSO for when I am serious.

author: Orion12
author_rank: Contributor
timestamp: November 25, 2015, 12:20:08 pm
content: Quote from: Fungus on November 24, 2015, 08:56:40 pmI've only had my Rigol DS1054Z.DS1104Z for a few days now & where it's not Absolutely Flawless ( Software Frequency Counter FLOATS around / But Hardware Frequency Counter's Solid ) . . .It's an Incredible 4-Channel DSO with the relatively painless upgrade to the DS1104Z / 100Mhz Status.Just playing around on Day One I was able to Storage Capture a SMALL 10-Ghz Signal within a Complex Wave-Form . . . That's Pretty Cool imho( See Attached Screen Capture )It's pretty hard to SEE in this Wave Complex & It's Right at the Edge of it's View-able Bandwidth BUT it's THERE . . . Just Amazing for a $379 / Delivered 100Mhz 4-Channel Digital Storage Scope.Definitely "JUST GET ONE" as Dave said in one of his Videos . . . I looked ALL around ( Including USED Analog Scopes ) & up & down & Finally ENDED UP with one . . . No Regrets !Cheers & Good Luck from Orion12

author: Fungus
author_rank: Super Contributor
timestamp: November 25, 2015, 12:47:30 pm
content: Quote from: Vortigan on November 24, 2015, 09:20:10 pmRigol's sales tactic claims another victim...!

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: November 25, 2015, 01:26:57 pm
content: Quote from: Vortigan on November 24, 2015, 08:49:30 pmAnd you plan to do that with an analog scope exactly how?It's pretty simple, really, if you want to do signal analysis then you need a DSO, period. Analog scopes give you a view of (parts of) the input signal. Get one of the luxury models and you might even get some primitive short-term storage, and if you're lucky cursors with read-outs. That's pretty much it. There's no signal processing, no FFT, no real math (aside from primitive channel addition/subtraction), no save-screenshot-to-USB function, nothing. The waveform on the display is pretty much all you get, and the few measurements you can do from it pretty much depend on what you can read from the graticule. In regards of its measurement capabilities even an analog scope from the early/late '90s isn't really much different from a scope of the 1930's, and therefore pretty much incapable to do anything on your list. So if that's what you want to do then you can stop looking at analog scopes right away.Now, cheap bottom-of-the-barrel DSOs like the often recommended Rigol DS1054z already give you all the basics like storage, zoom, as well as very basic FFT (a few thousand points only), plus a good set of measurements. It still won't do any real signal analysis or complex math, which requires a more advanced scope. There are various options of new and used scopes, depending on your budget of course. But without knowing a bit more of what exactly you want to do it's difficult to make some recommendations. In addition, there might be limitations to what is available to you in Columbia.

author: Vortigan
author_rank: Contributor
timestamp: November 25, 2015, 01:56:28 pm
content: Like I stated before, the reason why I wanted to get an analog scope was because of the price and well after seeing Dave's rant about micro-oscilloscopes I couldn't help but think "I should buy an analog scope", but after seeing the DS1054Z, and since it's extremely recommended, I think I'm going to buy it.I wouldn't buy a scope here in Colombia, I would rather wait for my next trip back to the US. The prices in Colombia are even more ridiculous compared to the ridiculous 800+ prices for a analog scope on ebay. Infact the price for a general 100Mhz analog scope in Colombia ranges from $1000 to $1500. I am NOT going pay for something like that.I don't mind doing the math, I already had to take a huge 2hr test with 3 fourier series, 3 fourier transforms, 3 z transforms and 3 fourier transforms with differential equations with a simple scientific calculator. "Simple" yet tedious stuff. Here they really stress about doing things by hand which is good and bad at the same time. Good because I learn about hows and whys, bad because in the end I'll have equipment that already does it for me and yet the professor still stabs my butt about having hand written proof. It's ridiculous. In the end I'll be happy with something that makes my life a little easier, even if it isn't one of those $3000 DSOAnd sadly, Rigol's sales tactic did screw me over, I ended up buying the Hi-Res function on the DP832 when I first got it...... I won-t be doing that again

author: EEVblog
author_rank: Unknown
timestamp: November 25, 2015, 02:07:08 pm
content: Quote from: Fungus on November 24, 2015, 06:21:02 pmThat was my point back then as well, it's much better to spend $50-$100 on an analog scope than one of those crappy pocket or kits digital scopes.That was true back then and it's still true now.Hence my other follow-up video on how to find a $50 analog scope.Quote from: Vortigan on November 24, 2015, 06:05:45 pmQuoteYes, no one should pay over $100 for an old analog scope, the value just isn't there.QuoteThere are brand new $250 digital bench scopes that will do a reasonable job.

author: vk6zgo
author_rank: Super Contributor
timestamp: November 25, 2015, 03:10:35 pm
content: Quote from: Vortigan on November 25, 2015, 01:56:28 pmYour Professor wantsyouto be able to do Fourier Analysis,not your Oscilloscope!Many thousand's of EEs did it before such functions were available on test equipment.

author: vk6zgo
author_rank: Super Contributor
timestamp: November 25, 2015, 03:29:16 pm
content: Quote from: Wuerstchenhund on November 25, 2015, 01:26:57 pm!930s Oscilloscopes:-http://www.supremeinstruments.org/catalog1937-39page2.htm

author: Vortigan
author_rank: Contributor
timestamp: November 25, 2015, 03:33:35 pm
content: Quote from: vk6zgo on November 25, 2015, 03:10:35 pmThat's perfectly understandable, like said I understand why they would make me go through all that tedious work. It's just really "shoot myself in the head" when the students realize there is something out there that does that work for them. You know what I mean? Personally, I find it fun most of the time. It can be tedious and also a bit annoying, especially when you're short on time, but for me it can be quite fun. The written proof part of what i said mostly has to do with the actual Lab classes. The professor ends up checking 4 out of the 20 students in the lab because he wants the analysis done by hand during the class because he doesn't like student's doing at home. This wouldn't be a problem if the class wasn't so short and if the professor managed his time well with every student at the time of checking the student's analysis. It's all about the time mostly.Over all I'm studying to become an engineer, not a technician. (not that there's anything wrong with being a technician),

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: November 25, 2015, 08:09:34 pm
content: Quote from: vk6zgo on November 25, 2015, 03:29:16 pmDon't know what it's supposed to show but it doesn't show much for me:

author: rsjsouza
author_rank: Super Contributor
timestamp: November 25, 2015, 08:15:33 pm
content: Quote from: Wuerstchenhund on November 25, 2015, 08:09:34 pmI guess the link is wrong:http://stevenjohnson.com/supreme/catalog1937-39page2.htm

author: nanofrog
author_rank: Super Contributor
timestamp: November 25, 2015, 09:18:10 pm
content: PM sent.

author: Vortigan
author_rank: Contributor
timestamp: November 25, 2015, 10:37:09 pm
content: Thank you very much nanofrog, I really appreciate it.

author: vk6zgo
author_rank: Super Contributor
timestamp: November 25, 2015, 11:54:45 pm
content: Quote from: rsjsouza on November 25, 2015, 08:15:33 pmNothing wrong with the link---it works every time for me!

author: vk6zgo
author_rank: Super Contributor
timestamp: November 26, 2015, 01:08:13 am
content: Quote from: Vortigan on November 25, 2015, 03:33:35 pmYou've got that backwards.Technician Courses usually only touch lightly on Fourier Analysis--just enough to get an reasonable "handle" on the concept.EEs are the ones that have to do it by hand--a Tech wouldn't have the time,so FFT would be more appropriate.The Tech Officer course I did back in the '80s (after being a Tech for years) was a bit of a hybrid.We had to determine the equations for various (not very) complex waveforms.

author: SLJ
author_rank: Frequent Contributor
timestamp: November 26, 2015, 01:24:57 am
content: Quote from: vk6zgo on November 25, 2015, 11:54:45 pmAnd here's the real thing although these usually go for a few hundred dollars now.

author: Vortigan
author_rank: Contributor
timestamp: November 26, 2015, 03:49:41 am
content: Quote from: vk6zgo on November 26, 2015, 01:08:13 amI'm studying Mechatronic Engineering, and well this semester I had to use fourier transform to use the ADC on the STM32F4 developers board in my micro controllers lab. Aside from that this semester I also had an advanced math course in which they introduced Z-transform, fourier series, and fourier transform. My seniors tell me that I'm going to have to use both of them in later courses like Control and Signals. The inconvenience of time has to do with actual lab class time. I would be more than happy to come with EVERYTHING ready and prepared for immediate presentation, but i have to go with what he wants which is "do ALL you (student) need to do during class and after you finish, you can present it in what ever time you have left. If I (professor) can't make it to you then I'm sorry, you should've worked faster." and most of the time he has time to present to 4 students out of 20, 5 if the students are lucky. Worst part is "if he no like, you no pass"I hope I don't sound rude.

author: tautech
author_rank: Super Contributor
timestamp: November 26, 2015, 05:24:28 am
content: Quote from: Vortigan on November 26, 2015, 03:49:41 amMight be a good idea to ask him the brand of scope he prefers.

author: VK5RC
author_rank: Unknown
timestamp: November 26, 2015, 10:49:38 am
content: Re the grumpy Prof ,reminds me of some sage advice from C3PO in the original Star Wars "let the wookie win!"

author: Vortigan
author_rank: Contributor
timestamp: November 26, 2015, 01:25:09 pm
content: Quote from: VK5RC on November 26, 2015, 10:49:38 amyup, that's exactly what we're doing