I want an ocelloscope and I cant go for high end one.. - Page 1
Forum section: electronics / beginners

author: ABHIRAMSHIBU
author_rank: Contributor
timestamp: May 24, 2016, 04:19:10 am
content: I am just an electronics hobbyist.. And I am have not chosen electronis, I study computer science... but I have a great intrest on electronics. I needed a scope so that I can stop all the blind works...In India Rigol, agillent, tektronics, etc are very expensive.. I have only some choices...1)Hantek 5102phttps://www.amazon.in/gp/aw/d/B01DQTQHC6/ref=mp_s_a_1_sc_10?qid=1464063169&sr=8-10-spell&pi=AC_SX118_SY170_FMwebp_QL65&keywords=ocelloscope2)Scienteck 100mhz ocelloscopehttps://www.amazon.in/gp/aw/d/B014W06K6Q/ref=mp_s_a_1_13?qid=1464063252&sr=8-13&pi=AC_SX118_SY170_FMwebp_QL65&keywords=oscilloscope3) Any other under 40K INRBase model of rigol I think 40 mhz cost about 50K INR in India... So please suggest me a good ocelloscope for me... I don't have any experience with any ocelloscopes.. So suggest me a good one... In my place scientek only has a service center...

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: May 24, 2016, 06:09:32 am
content: I searched a few minutes throuth Amazon.in, but you are right, the cheapest rigol ist around 50k rupees. But it isn't the all time favorite DS1054, which doesn`t seem to be sold at all. Maybe you should ask someone to buy it for you and send it to you? Here in germany you can get it for example for 400€ which is 30k INR. Shipping by DHL is 50€, which is around 4k INR. But I don't know about import taxes in india at all.Maybe that could be a possibility for you, if you would like to jump onto the DS1054z train.

author: tautech
author_rank: Super Contributor
timestamp: May 24, 2016, 08:21:08 am
content: Quote from: ABHIRAMSHIBU on May 24, 2016, 04:19:10 am^^^^ is a re-branded Siglent SDS1102CML with 1G sampling and 2M memory depth.http://www.siglentamerica.com/pdxx.aspx?id=27&T=2&tid=1These rebrands can be more expensive than the OEM product and it would be wise to do some more research.

author: Dr Wobble
author_rank: Contributor
timestamp: May 24, 2016, 11:11:06 am
content: Why not get an old Tektronix or other analog scope, they're a lot easier to use than a digital scope, well at least for a beginner. What sources do have in India for second hand scopes? I had a quick look on Ebay India, most stuff seems to be sold from the West. I have this vision of India having lot's of second hand electronic shops, not sure how true this is.The only other way for you to get a better deal I can think of, is to ask a relative who is visiting USA or Europe, to bring one back for you. Good luck.

author: rs20
author_rank: Super Contributor
timestamp: May 24, 2016, 12:02:52 pm
content: Quote from: Dr Wobble on May 24, 2016, 11:11:06 amWhat!?!? They might have more educational value, I grant you that, but the reason they have more educational value is because they'reharderto use and therefore force you to think more.

author: 3db
author_rank: Frequent Contributor
timestamp: May 24, 2016, 12:15:18 pm
content: Quote from: rs20 on May 24, 2016, 12:02:52 pmHow on earth can it be harder to use.It's an instrument so obviously you have to think about how to use it.It's like the slide rule and analogue meters with both you had to think about what you were doing.3DB

author: Mastrofski
author_rank: Contributor
timestamp: May 24, 2016, 01:24:26 pm
content: Quote from: 3db on May 24, 2016, 12:15:18 pmDigital Scopes are a lot more intuitive at first glance. An if you can't figure out how to set it up? You can Auto Scale that. Not saying that it's a good practice, but it happens. It's the same reason we went from Slide Rules to calculators. It's faster, more accurate, and the learning curve makes it a lot easier to get going with them.

author: 3db
author_rank: Frequent Contributor
timestamp: May 25, 2016, 07:24:06 am
content: So the display shows you something.You still need a brain and knowledge to interpret the results.If you use a slide rule you HAVE to have a feel for the result.Use a calculator and you are given a number.My main point is that instruments measure it's up to the user to interpret the result.3DB

author: ABHIRAMSHIBU
author_rank: Contributor
timestamp: May 25, 2016, 09:49:50 am
content: Quote from: Ysjoelfir on May 24, 2016, 06:09:32 amYeah.. that is an option but... I am also concerned about warranty of that product... If i do it your way... If i have to get warranty, I have to send the scope back to Germany... So i think i may not go for it... But i will consider your suggestionQuote from: rs20 on May 24, 2016, 12:02:52 pmYeah... You are correct.... I think analog scopes are harder to use and also harder to service... As i am a hobbyist i dont want to play with a thousands of volts in CRT.. If I go for a digital scope it will be relatively easy to service and use, would be much safer too (to service).I know analogue scope is better than digital, but i find digital more convenient because i can record most of data from oscilloscope using a pc or a laptop or may be a tablet...

author: ABHIRAMSHIBU
author_rank: Contributor
timestamp: May 25, 2016, 09:51:56 am
content: What do u think about diy scopes... Will it work great....

author: tautech
author_rank: Super Contributor
timestamp: May 25, 2016, 10:38:29 am
content: Quote from: ABHIRAMSHIBU on May 25, 2016, 09:51:56 amQuote from: ABHIRAMSHIBU on May 25, 2016, 09:49:50 amThat's why ^^^

author: alsetalokin4017
author_rank: Super Contributor
timestamp: May 25, 2016, 07:00:49 pm
content: Quote from: 3db on May 25, 2016, 07:24:06 amThat's right.Digital scopes are great... they give you "numbers in boxes" so you don't even have to think about what you are seeing .... right?

author: rstofer
author_rank: Super Contributor
timestamp: May 25, 2016, 07:35:28 pm
content: Quote from: ABHIRAMSHIBU on May 25, 2016, 09:49:50 amThe analog scope might actually be easier because there are schematics and such. I don't think the low end digital manufacturers provide much documentation. Kind of like the old days of TV servicemen. They could buy schematics for any television. Try to get one today! It's a disposable world and that includes scopes.QuoteAn analog isn't 'better' than a digital, nor is the 'digital' better than an analog. They really are two different approaches to making measurements. Furthermore, other than storage, I can get a used analog scope with a lot more capability for the same money as a digital. I only paid $200 for my Tek 485 about 12 years ago - about half of what I just paid for my DS1054Z. There's nothing I can't do with the 485 (that I care about) except I really wanted 4 channels, even at a significantly lower bandwidth. The measurements are nice and, over time, I may come to find a use for them. But since I have had an analog scope of one kind or another for about 60 years, this digital thing is quite a change. Yes, I built a scope when I was 10 years old. I got the plans out of the ARRL Handbook, I believe. It didn't have much of a front end but I could display Lissajous patterns and that was pretty cool. My folks were indulgent...

author: 3db
author_rank: Frequent Contributor
timestamp: May 25, 2016, 08:25:16 pm
content: Quote from: alsetalokin4017 on May 25, 2016, 07:00:49 pmYou obviously failed to get my point.

author: tautech
author_rank: Super Contributor
timestamp: May 25, 2016, 08:27:59 pm
content: Quote from: 3db on May 25, 2016, 08:25:16 pmNa, you missed his.Study the screenshots.

author: rstofer
author_rank: Super Contributor
timestamp: May 25, 2016, 09:17:13 pm
content: Yes, the Vrms calculation is hosed! But it is clearly wrong, wrong by a whole lot. Just looking at the number and spending even a second thinking about it and you would just reject the value and try to get at it some other way. Like maybe a True RMS multimeter.If builders built buildings like programmers write programs, the first woodpecker to come along would destroy civilization."No matter how cynical you get, it is impossible to keep up."-- Lily Tomlin

author: ADent
author_rank: Newbie
timestamp: May 25, 2016, 09:42:04 pm
content: Well analogue scopes is good for learning and "feeling" whats happening. But if you are just a little bit into digital stuff and programming a digital scope is much more useful for it's single trig capabilities. You can sometimes struggle along with an analogue one if rewriting your code to repeat whatever it's doing so the analogue scope can show it. Or you can get an anlogue scope and a usb logic analyzer, covers a lot but not all.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: May 25, 2016, 09:49:15 pm
content: Quote from: rstofer on May 25, 2016, 09:17:13 pmThat's not the only thing that's wrong on that scopeshot .....As you say, the RMS error is glaringly obvious to anyone who knows what "RMS" is. But what about the other error?

author: alsetalokin4017
author_rank: Super Contributor
timestamp: May 25, 2016, 09:59:14 pm
content: Quote from: ADent on May 25, 2016, 09:42:04 pmYes, for sure the DSO's Single Shot trigger mode is really easy to use, as is the ability to save and display screenshots with lots of information.But:Don't you ever wonder why all those old analog scopes even _have_ a single-shot trigger mode?Hint: Camera with adjustable shutter speed ....

author: LazyJack
author_rank: Frequent Contributor
timestamp: May 25, 2016, 10:11:59 pm
content: Quote from: alsetalokin4017 on May 25, 2016, 09:49:15 pmWell, the frequency of 2kHz seems to be a tiny bit strange if the horiz sweep is 500us/div and one cycle is 2 divs long.Are you saying that all of these are standard features of Rigol scopes? I'm glad i've got a couple of mature Tek scopes.

author: rstofer
author_rank: Super Contributor
timestamp: May 25, 2016, 10:31:31 pm
content: Quote from: LazyJack on May 25, 2016, 10:11:59 pmI did notice that earlier but I didn't know what to think. I can't replicate the problem on my scope and I thought maybe there was a software glitch with whatever created the image (said without have a clue about capturing scope images). I even tried messing around with the trigger threshold to get it as high as in the image but the frequency counter stays stable at 1.000... kHz.

author: metrologist
author_rank: Super Contributor
timestamp: May 25, 2016, 11:47:19 pm
content: I guess in this example, if you did not know the actual frequency of the signal, you would not know if the freq counter is off or if the horiz time base (graphic display) is off.

author: LazyJack
author_rank: Frequent Contributor
timestamp: May 26, 2016, 06:39:08 am
content: Quote from: metrologist on May 25, 2016, 11:47:19 pmI think it would be really sad if an oscilloscope time base were off by a factor of 2.For the freq counter I can of course accept false reading, if the trigger is confused by ringing, etc. I cannot accept if the programmer thinks that frequency is the number of zero crossings in a second. Obviously, I do not know why that reading on on that screenshot.

author: rstofer
author_rank: Super Contributor
timestamp: May 26, 2016, 03:15:44 pm
content: Well, I know more than I did about that screenshot. First of all, the menu icon for Vrms and Vavg show a sine wave, not a rectangular wave. Most of the direct values like Vp-p and so on show a rectangular wave.According to this page, the Vrms of a square wave is Vp * sqrt(t(on)/T) which for a symmetric square wave would be Vp * sqrt(1/2) or 0.707*Vp. Vp = Vp-p in this case. Equation 11http://masteringelectronicsdesign.com/how-to-derive-the-rms-value-of-pulse-and-square-waveforms/For the calibrator, Vp = 3V so Vrms should be 2.12VIf we put the calibration signal into channel 3 and adjust the display to 1V/div to match channel 1, the scope gets the right answer for Vrms, more or less. The signals are not an exact match (probe compensation) so the RMS doesn't exactly match either.I still can't replicate the problem with the frequency counter.

author: ABHIRAMSHIBU
author_rank: Contributor
timestamp: May 26, 2016, 03:22:48 pm
content: Now everyone is going offtopic.. Please suggest me a good scope ( DSO preferred ) under 40K inr in India... It was the topic of the discussion....

author: rstofer
author_rank: Super Contributor
timestamp: May 26, 2016, 04:21:41 pm
content: Hantek is a recognized name and here is a review on the 5102B.https://www.circuitspecialists.com/blog/product-review-hantek-dso5102b-100mhz-digital-storage-oscilloscope/I wonder why they used steps of 2,4,8 instead of 1,2,5 like most other scopes. I have a problem with 8 uS per division - I can't get to frequency as easily as if it were 5 uS or 10 uS. Binary multiple are great for some things, not so great for mental math.I can't find out too much about the Scientech but the Hantek has some math functions likd FFT, *+- etc, It may also turn out that the Hantek has more triggering modes but at first glance I can't be certain.Of the two, I would pick the Hantek.You have a price limit, search around YOUR country for scopes in that range. You have already found two, perhaps there are more. Then search for reviews. It may be difficult to get a specific recommendation for a scope in India.

author: tautech
author_rank: Super Contributor
timestamp: May 26, 2016, 08:02:05 pm
content: Quote from: rstofer on May 26, 2016, 04:21:41 pmAs mentioned it's a rebranded SDS1102CML.http://www.siglentamerica.com/pdxx.aspx?id=27&T=2&tid=1Datasheethttp://www.siglentamerica.com/Uploadfile/file/20140925/SDS1000CML_datasheet_en.pdfUser manualhttp://www.siglentamerica.com/Uploadfile/file/20140925/SDS1000CML_UserManual_UM01011-E05A.pdfService manualhttp://www.siglentamerica.com/Uploadfile/file/20140925/SDS1000CML_ServiceManual_en.pdfAll other documentationhttp://www.siglentamerica.com/prodcut-wd.aspx?id=27&tid=1&T=2

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 27, 2016, 12:07:56 am
content: Wasn't sure what an ocelloscope was, so I looked it up. Has oscillators too.

author: newbrain
author_rank: Super Contributor
timestamp: May 27, 2016, 08:07:36 am
content: OTQuote from: HackedFridgeMagnet on May 27, 2016, 12:07:56 amOhh Leo Theremin!Still used in music making, though not in its cello form.In the attached picture, Robert Wheeler with Pere Ubu in Rome, April 2016 (crappy phone == crappy picture).Quote from: ABHIRAMSHIBU on May 26, 2016, 03:22:48 pmSorry!

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 27, 2016, 01:09:41 pm
content: Quote from: newbrain on May 27, 2016, 08:07:36 am'Used to have a couple of Pere Ubu albums, they got well played.