Should I buy an oscilloscope ? - Page 1
Forum section: electronics / testgear

author: prayag2010
author_rank: Contributor
timestamp: March 02, 2013, 05:08:20 pm
content: Hello everyone,I am a beginner in electronics and I am looking forward to set up a workbench. But, I had a question;Should I buy an oscilloscope ? It is too costly and I am not sure if I truly need it. Instead, should I buy two decent multimeters and other necessities ?

author: c4757p
author_rank: Super Contributor
timestamp: March 02, 2013, 05:13:48 pm
content: Quote from: prayag2010 on March 02, 2013, 05:08:20 pmThen don't buy one. An oscilloscope can be incredibly useful at times, but if you genuinely can't afford one, remember - hobbyists got by without them for decades before the price made them accessible. A lot of things can be done without an oscilloscope by applying a bit of cleverness.That said - I don't know where you live, but if you look in the right places and have patience, you should not be surprised to find one for free or very close to it. It won't be a 350 MHz four-channel monster, but it will be an oscilloscope.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 02, 2013, 06:02:23 pm
content: Definitely yes - even an old, cheap/free analogue one is a lot better than nothing.A scope IS a necessity for any non-trivial electronics work, and will help you learn.Remember test gear generally holds value well.

author: prayag2010
author_rank: Contributor
timestamp: March 02, 2013, 06:55:14 pm
content: Quote from: mikeselectricstuff on March 02, 2013, 06:02:23 pmQuote from: c4757p on March 02, 2013, 05:13:48 pm

author: BravoV
author_rank: Super Contributor
timestamp: March 02, 2013, 07:01:11 pm
content: Quote from: prayag2010 on March 02, 2013, 06:55:14 pmSince you mentioned analog, I assume you're aiming for used and cheap one.Two most important questions regarding asking for suggestion on buying used / analog scope :- Where do you live ?- What is the max budget ?Nothing to suggest if these are not answered.

author: nctnico
author_rank: Super Contributor
timestamp: March 02, 2013, 07:36:10 pm
content: Quote from: mikeselectricstuff on March 02, 2013, 06:02:23 pmI strongly agree. I got an oscilloscope when I was 14 and it served me extremely well.QuoteI strongly disagree. Test equipment in general devaluates faster than a mobile phone. Just look at the selling prices on Ebay and do the math. So buy something with the specs you need now and spend more money later when necessary.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 02, 2013, 09:28:35 pm
content: I sold my last scope for about what I paid for it, and based on current Ebay prices, I could quite easily expect to make a profit on my current scope even though I've had it for a couple of years. Buy something old but decent and working and you should be fine.

author: EEVblog
author_rank: Unknown
timestamp: March 02, 2013, 09:32:51 pm
content: YES.Beg or borrow an oscilloscope.It is possible to buy an old analog oscilloscope for the price of a cheap multimeter.Dave.

author: MetraCollector
author_rank: Regular Contributor
timestamp: March 02, 2013, 09:42:53 pm
content: When I have some visit at my's and comment my osciloscope I reply "A home without a scope isn't real home."

author: Hydrawerk
author_rank: Super Contributor
timestamp: March 02, 2013, 09:45:19 pm
content: Quote from: prayag2010 on March 02, 2013, 05:08:20 pmYes, you should. But not soviet H313 model. I have it since I was a little child... It was my father's scope... But this scope is crap. It has unstable trigger and much more... Note the small screen and strange input connectors. They are not BNCs.(Picture not taken by me!)Anyway, this was my first scope and it still taught me something... I saw the sine wave for the first time. So if you have little money, buy a cheap simple old scope, it will be even useful for you...

author: AndyC_772
author_rank: Super Contributor
timestamp: March 02, 2013, 10:03:07 pm
content: LolMaybe not, but a scope like my old Fluke PM3082 would have been ideal - 4 channels, 100 MHz, a proper analogue scope but with a few more modern, useful features like on-screen cursors. I sold it including a complete set of probes for £150.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: March 02, 2013, 10:23:40 pm
content: Quote from: nctnico on March 02, 2013, 07:36:10 pmUnless you have an iPhone or something super exclusive like a phone from Vertu that is not true, and even iPhones deprecate much faster than brand name test equipment. Most cell phones have lost any noticeable market value within 2 or 3 years, some models may extend that to 5 years, but that's it. A 15 year old scope like say a HP 54542C (4Ch 500MHz 2GSa/s) which, when new, was probably around $20k mark, still goes for $1500+. It's the same for most other test equipment, often enough even stuff from the 60's/70's still fetches remarkable prices.That most certainly will be different for China T&M like Rigol, Atten/Siglent, Hantek or whatever new name they come up with to sell their toys.QuoteThe best is to look at the prices stuff is actually sold, not the overinflated asking prices of many (mostly US) dealers that relist the same item again and again for over a year in the hope they find an idiot who pays their ridiculous prices.

author: nctnico
author_rank: Super Contributor
timestamp: March 02, 2013, 10:29:06 pm
content: Quote from: AndyC_772 on March 02, 2013, 09:28:35 pmThere are always exceptions to the rules. Sometimes you can get lucky and have a chance to buy equipment from someone who has no clue about what he is selling or what it is worth.

author: PaulAm
author_rank: Frequent Contributor
timestamp: March 02, 2013, 10:42:05 pm
content: You ought to be able to find a usable analog scope from the 70s-90s with 100MHz bandwidth or better, two channel, delayed sweep for under $100. That will do everything you need to do for a while. If you have more money, you can look for a Tek 24xx series which has onscreen cursors. If the scope breaks you can fix it, which is an even better learning experience. HP and Tek scopes of that era have all kinds of service information easily available as well as communities of people who like to work on them. Advice, sometimes useful, is easy to get. I have bought numerous scopes of that era for $50 or less. Some of those have even been 100% functional.I think scopes are very useful in understanding what is happening with a circuit you built. You can put probes on the input and output of a circuit and see what happens as you change component values. It's a great teaching toolWhen you get to the point when the analog scope doesn't do everything you need, then you can move up to a DSO, but you'll have a pretty good understanding of what to look for at that point.I just bought a Tek 422 off of craigslist for $35 the other week. It's only a 15MHz scope, but it's small, dual channel and portable, as well as being an antique. I'm going to throw it in my shop next to the cnc equipment.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 03, 2013, 12:33:42 am
content: Quote from: nctnico on March 02, 2013, 07:36:10 pmI should maybe have qualified that with "used" equipment - everything loses quite a lot from 'new' to 'used', but the useable life of a reasonable scope or other test gear is an order of magnitude longer than any consumer electronics. Comparison with a phone is just ridiculous.

author: nctnico
author_rank: Super Contributor
timestamp: March 03, 2013, 01:41:57 am
content: Quote from: Wuerstchenhund on March 02, 2013, 10:23:40 pm20k-1500=14500 which is about $1000 a year. I wouldn't call that keeping its value. A car depreciates at about the same rate. Besides, in some countries there is a big market for second hand phones because people simply can't afford new ones.QuoteThat is what I tried to say. Selling prices, not asking prices

author: c4757p
author_rank: Super Contributor
timestamp: March 03, 2013, 01:48:17 am
content: Quote from: nctnico on March 03, 2013, 01:41:57 amThat's like saying that if somebody is 100 years old and weighs 100 pounds they gained one pound per year. The depreciation is highly nonlinear, and by the time you buy that used scope, its value will be relatively fixed for the time you own it. By the time you go to sell it again, it will not have lost much.

author: prayag2010
author_rank: Contributor
timestamp: March 03, 2013, 07:37:16 am
content: Thank you everyone for your help.I live in Mumbai, India, and I will try to look for one although I highly doubt that I will find any. I think that will start looking for good deals on ebay...

author: mzzj
author_rank: Super Contributor
timestamp: March 03, 2013, 09:17:00 am
content: Quote from: prayag2010 on March 03, 2013, 07:37:16 amThat changes things a bit. In my experience used professional tools are (lot) more expensive in developing countries, things developing fast and there is always someone in the need of equipment.Shipping for any of the bigger, older models is going to be expensive if you order from abroad. Plus you may have to pay suprisingly high taxes or be prepared with some "tea money"I just checked indian ebay and did not see anything reasonable locally.Cheapest usb-scope that looks usable:http://www.ebay.co.uk/itm/New-DSO2090-PC-USB-40MHZ-100MS-s-Digital-Storage-Oscilloscope-/230770204768?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item35baf9e060.Or stand-alonehttp://www.ebay.co.uk/itm/Atten-Digital-Oscilloscope-60MHz-ADS1062CAL-1GSa-s-Sampling-2-CH-LCD-/280946420533?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item4169b62b35#shId

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: March 03, 2013, 09:24:37 am
content: Quote from: nctnico on March 03, 2013, 01:41:57 amHmm..my math says that 20000 minus 1500 is more along the lines of 18500, but never mind.So clearly by your logic, buying a house (which costs you more than a grand a months just to pay it off over 20 years) is never good value because you can get other things like cars, rubber boats, cell phones for a lot less, right?Well, unfortunately that's not how it works. There's a reason why in finance depreciation is usually calculated in percentage of an item's purchase price over a defined period. Looking at your $600 cell phone which after four years is worth say $50 (which is approx. 8.3% of its purchase price), you end up loosing $550 (or approx. 91.7% of its purchase price) over 4 years or, annually (at linear progression) roughly $137.50 or approx. 22.92%. So in short, your precious little phone loses almost a quarter of its purchase price a year.Let's look at the scope: $20k when new and still selling at $1500 after 15 years. That means that, over 15 years (a usage time which btw far extends the one of your average cell phone!), at linear progression it lost $18500 92.5% of it's value. That sounds like a lot but actually the annual progression is just around 6.2% of its original purchase price.And out in the world, an item that in average only looses 6.2% of value a year is considered to be much more value retaining than an item that looses 22.92% a year.Of course this is a very simplified view, and there are a wide range of progression methods (most items depreciate in a non-linear way), but it covers the essentials. Just because even a small progression means a large amount of money for an originally very expensive item doesn't mean it is not holding value well. The absolute amount however comes into play when you have to consider if getting a $20k scope is worth it for the job. You take the purchase price, estimate the remaining value at the end of the usage period (which for T&M equipment usually is somewhere between 5 to 7 years), and calculate the annual progression. If the calculation then shows that the scope costs you more than it actually 'earns' for the job, it's not worth it.QuoteSure, like for almost any other items that do not degrade, disintegrate, explode or become otherwise useless after a short amount of time. But that doesn't change the fact that cell phones hold their value rather badly (the market offerings is much larger than the demand, something that is not generally true for T&M kit).

author: SeanB
author_rank: Super Contributor
timestamp: March 03, 2013, 10:50:06 am
content: Vehicles depreciate the most in the first year, typically losing 20-30% of value, then the curve flattens off. In some cases after 20 years the value will be more than the original cost, just due to inflation. As an example a $30k BMW will typically be $25k after a year, and $20k after 4 years ( 10k after 6 years because then Motorplan has run out, which causes a big drop in perceived value) while after 10 years the value will be still around $8k and then depend on condition. Test gear follows a similar curve, while it is supported by the manufacturer it has a lot of value, but will drop when support ends to a lower level and then trend to stay at that point for a long time until they become scare and then trend up as spare parts for those still using them.

author: prayag2010
author_rank: Contributor
timestamp: March 03, 2013, 12:28:24 pm
content: Quote from: mzzj on March 03, 2013, 09:17:00 amI think that I can buy that atten one. What are your views regarding that oscilloscope ?

author: nctnico
author_rank: Super Contributor
timestamp: March 03, 2013, 02:42:28 pm
content: Or maybe a Siglent which is a bit cheaper:http://www.ebay.com/itm/Siglent-SDS1062C-Digital-Oscilloscope-60MHZ-DS1052E-/330872374375I think this will be a good entry level scope. BTW Lecroy sells rebadged Siglent equipment to cover the lower end of the market. Based on the teardowns on this website I have a feeling Siglent is a bit better than Atten.

author: prayag2010
author_rank: Contributor
timestamp: March 03, 2013, 03:02:40 pm
content: What about Rigol DS1052E ?

author: mzzj
author_rank: Super Contributor
timestamp: March 03, 2013, 03:29:58 pm
content: Quote from: nctnico on March 03, 2013, 02:42:28 pmI was going to mention about Siglent, but it didn't show up on ebay search for some reason when I was searching with "postage to India" option. Now I did another search and actually found some. I agree it is probably somewhat better than Atten.http://www.ebay.co.uk/itm/Siglent-SDS1052DL-7-50MHZ-500MSa-s-32Kpts-Digital-Storage-Oscilloscope-/170997697398?pt=AU_B_I_Electrical_Test_Equipment&hash=item27d041cb76I would imagine that there is electronic equipment stores also in Mumbai worth checking local price level for Siglent/Atten/Rigol/Owon scopes. Finding those stores might be a different thingAs I remember diyaudio.com has some active users from India sourcing components and tools, iehttp://www.diyaudio.com/forums/parts/176167-parts-mumbai-india.htmlEdit: Rigol is for sure tried and proven product, if it fits Your budget I think it's a excellent alternative.

author: prayag2010
author_rank: Contributor
timestamp: March 03, 2013, 04:05:39 pm
content: Decided - I will buy the Rigol DS1052E !

author: Hydrawerk
author_rank: Super Contributor
timestamp: March 03, 2013, 06:56:54 pm
content: Rigol DS1052E has few buttons and encoders... No separate encoders for each channel. NoSinglebutton. I am not a Rigol fan. Consider buying DS1104B.

author: prayag2010
author_rank: Contributor
timestamp: March 03, 2013, 07:01:40 pm
content: It's too expensive....

author: Unknown
author_rank: Unknown
timestamp: March 03, 2013, 07:16:44 pm
content: Quote from: Hydrawerk on March 03, 2013, 06:56:54 pm16 or 8 kpts per channel in 2013? Really?

author: nctnico
author_rank: Super Contributor
timestamp: March 03, 2013, 07:25:34 pm
content: Well Tektronix just introduced a new series of oscilloscopes with 2500 points of memory per channel...http://www.tek.com/oscilloscope/tbs1000-digital-storage-oscilloscopeEven the Siglent is a better choice because of the bigger screen and slightly longer memory!

author: Unknown
author_rank: Unknown
timestamp: March 03, 2013, 07:31:54 pm
content: Yes, Tektronix have already been ridiculed over this scope. Note, however, that nobody was recommending the TBS1000 series over the DS1052E. Hydrawerk was recommending the DS1104B over the DS1052E, however, apparently based on the number of knobs.

author: Hydrawerk
author_rank: Super Contributor
timestamp: March 03, 2013, 07:33:02 pm
content: Well, it is difficult to find a perfect cheap scope... Then consider some GW Instek... It has 2MB memory, but no zoom (delayed timebase) mode, that Rigolhas. Maybe GDS-1102A-U.http://www.gwinstek.com/en/product/productdetail.aspx?pid=3&mid=7&id=1298But it is not possible to switch off the right on screen menu.

author: prayag2010
author_rank: Contributor
timestamp: March 04, 2013, 05:55:24 am
content: Guys, I am not an engineer, but a 15 year old hobbyist, aiming, to become one. And I am not that rich either. I have a budget of USD 350-400. So please give me one answer, because this is getting more and more confusing.....

author: AndrejaKo
author_rank: Frequent Contributor
timestamp: March 04, 2013, 07:51:59 am
content: @prayag2010So you want one answer? Well let's take a look at what information you provided us: We know that you're possibly interested in a scope, you have $350 to $400 and that you're a hobbyist looking to become an engineer. After reading all other posts in this thread, I was unable to find any more concrete information.So we don't know what type of projects you're going to be working on and what kind of projects you are working on. Therefore we can't give you a sound recommendation for a scope since we don't really know what feature is THE most important for you. I do understand that you may not know this yourself at this moment, so you may have to settle with recommendation of lower quality.For example my scope has "large" memory (10 Msamles per channel), but it has no tools to search the memory, meaning that I have to capture interesting event, then zoom out using timebase setting, move the center of the screen to potentially interesting location and then zoom back in to see what's happening. So far this has worked fine for me since the point of interest is usually obviously visible, but say if I had to hunt down a glitch in digital communication, I'd have to spend quite a lot of time rewinding the capture memory on the screen using a little knob that moves the data at low speed. This could be a deal-breaker for many but it isn't for me.Then there's the other factor as well: You asked people for opinion and people here can't agree on what exactly is the best solution. This is normal and is to be expected, especially if you're going to be an engineer in the future. In fact many people may feel very strongly about their opinion which would lead to even more argument and even less clear "general" opinion.After all that, there's also the local stuff too. How are you going to get service for a new scope? Which companies will provide local repairs and which will not? For example shipping a scope to manufacturer can be a significant fraction of its price, if you have to pay for it. If you can choose between a scope with with local support and one supported from China, it may be better to spend a bit more money on one with local support.In the end, there you may even discover that there isn't a perfect solution and that you'll have to live with one which is less than perfect. Also keep in mind that any scope you buy now will be relatively old by the time you get to engineering school and while it will most likely be usable, it will be much less capable than scopes which will be available at that date.

author: Fezder
author_rank: Regular Contributor
timestamp: March 21, 2013, 07:51:51 am
content: I got mine analog dual channel 2Mhz, (if i remember correctly) scope from school, free. Its bit old and stuff, but works fine. But i'm looking to buy digital one because of memory and other advantages too.