oscilloscope for bigginer - Page 1
Forum section: electronics / beginners

author: GUNIT1234
author_rank: Newbie
timestamp: July 07, 2012, 06:34:59 am
content: hello friends, first time here. i was looking to buy an oscilloscope under 500$. there are some tempting ones so far:http://www.ebay.com/itm/Digital-100MHz-Oscilloscope-Scopemeter-2Channels-1GS-s-USB-110-240V-ADS1102CAL-/280913688786?pt=BI_Oscilloscopes&hash=item4167c2b8d2http://www.ebay.com/itm/New-OWON-PDS5022T-Digital-Oscilloscope-Now-With-TFT-Display-Sale-Priced-/251096963858?pt=BI_Oscilloscopes&hash=item3a768b9b12#ht_2492wt_1189http://www.ebay.com/itm/New-OWON-100Mhz-thin-Oscilloscope-SDS7102-1G-s-8-LCD-w-3-yrs-USA-warrranty-/300601811693?pt=BI_Oscilloscopes&hash=item45fd43a2edhttp://www.ebay.com/itm/Rigol-DS1052E-digital-Oscilloscope-50MHz-1G-SG-/170794090149?pt=BI_Oscilloscopes&hash=item27c41efea5which one do you recommend? does the Rigol ds1052 hack reliable? stable? worth it?please help me out friends. cheers

author: vk6zgo
author_rank: Super Contributor
timestamp: July 07, 2012, 06:46:50 am
content: I would suggest an older Tektronix analog Oscilloscope would be more useful for general work,but you may need some of the facilities of a DSO.I don't have a DSO,but the Rigol ,& the Owon SD7102 seem to be fairly well regarded.

author: JuiceKing
author_rank: Regular Contributor
timestamp: July 07, 2012, 09:58:01 am
content: I went through this and have enough experience now to share an opinion.For $500 you can and should get at two scopes. I do recommend the Rigol. For an extra $50 you get the 100Mhz version, and you still have $100 which is enough to buy a nice old analog scope if you look around. Not that other DSOs are lacking, but the Rigol is wonderful: it's very easy to use, has built-in measurements (including a counter), and it hooks up to your computer for easy screenshots and remote operation. It even has a rudimentary spectrum analyzer--wow! Unlike an analog scope, it works well for very low frequency signals and long/complex signals where the portion of interest is distant from the trigger. But, it's not perfect: compared with a nice, sharp analog scope, its screen resolution is coarse, so you need to "zoom in" to make sense of digitized blobs that on an analog scope are more finely detailed and understandable at a glance. It's also harder, I think, to see and understand glitches in the Rigol than it is on a good analog scope (the Rigol can miss a lot) but facilities are there to help close the gap if you know how and when to use them. Finally, the Rigol does display "false" low-frequency signals that can confuse you if you don't know about them. That's another time when it's great to have an analog scope and then you can compare. I am much more skilled at using the Rigol because I have used both it and an analog scope in many situations and learned about the behavior as well as the nooks and crannies of the Rigol's capabilities in practice.I wouldn't get just the analog scope, even though for $500 you can get a truly excellent one, for the simple reason that because it's old and used, you can't trust it to be calibrated and stable like a new instrument. Having two means you get two perspectives, and if you think one is strange, you have the other to complement it. I would feel very limited with just one.You do need to budget for probes. Used analog scopes usually come with none or old beaters. You can buy cheap 100Mhz new probes on Amazon or eBay that seem to be well regarded, at least as nice as the ones that come with the Rigol. High-bandwidth probes are not cheap, so if you feel compelled to get a high-bandwidth old scope (200Mhz+), keep that in mind. The higher bandwidth is useful and important, but for learning I'd rather have the Rigol plus a $100 20Mhz analog scope with new probes than a $500 250Mhz (say) analog scope and new probes and no Rigol.

author: MumblingFumbler
author_rank: Newbie
timestamp: April 07, 2017, 08:55:10 pm
content: I'm a beginner. Would anyone be willing to hazard a guess whether the following might be a good value?https://sfbay.craigslist.org/sby/ele/6047362204.html

author: rstofer
author_rank: Super Contributor
timestamp: April 07, 2017, 09:06:55 pm
content: Quote from: MumblingFumbler on April 07, 2017, 08:55:10 pmYes! More emphatic: YES! I would buy that in a heartbeat.But it's not a DSO so it probably lacks some of the measurement features, single shot capability, serial link decoding, etc.

author: rstofer
author_rank: Super Contributor
timestamp: April 07, 2017, 09:13:07 pm
content: Quote from: GUNIT1234 on July 07, 2012, 06:34:59 amNone of the above...Today, the Rigol DS1054Z 4 channel hacked to 100 MHz with decoding options is probably the best bang for the buck around. It's right at $400. The 1052 is obsolete...You should be looking in the Test Equipment subforum for more information.There's a new 2 channel Siglent coming out this month (SDS 1202X-E) and it's a 200 MHz version with all the decoding ready to go, no fiddling around. But, still, it's only 2 channels and I bought my DS1054Z to get 4 channels. Dave just did a teardownhttps://www.eevblog.com/2017/04/06/eevblog-985-siglent-sds1202x-e-oscilloscope-teardown/

author: ebastler
author_rank: Super Contributor
timestamp: April 07, 2017, 09:53:09 pm
content: Quote from: rstofer on April 07, 2017, 09:06:55 pmWhat would the advantage over a DS1054Z be, which happens to sell at the same price?(And is much smaller, and is a DSO, and has a color screen to distinguish traces, and can do measurements, decoding...)Unless you are a collector, I don't think the Tek is "good value" today.

author: james_s
author_rank: Super Contributor
timestamp: April 07, 2017, 10:00:09 pm
content: The Tek is a nice scope, but personally I think the price is a bit high. $200 would be much more reasonable for a 100MHz analog scope. There is rarely a need for more than 2 channels with a single beam analog. Nice scope, but not something I'd recommend for a beginner. These days mid to high end analog scopes are a niche specialty item good for a few specific tasks. While I generally recommend a beginner start with an analog scope, it doesn't have to be anything fancy. A basic 20MHz dual trace scope is perfectly adequate for learning the ropes.

author: rstofer
author_rank: Super Contributor
timestamp: April 07, 2017, 11:49:59 pm
content: Quote from: ebastler on April 07, 2017, 09:53:09 pmYou buy a DSO for features and price. That big old Tek probably cost more than my first house when bought new.With the DS1054Z, you get 4 channels and I wanted that so I could watch all aspects of the SPI bus (CS',Clk,MISO,MOSI). I already had a 2 channel Tek 485 but I thought that 4 channels would be a lot more useful for certain projects. Of course, I can not only watch the transaction, I can decode it. That also applies to I2c and UART. So, decoding was my second criteria...I've come to appreciate the Measurements capability: Vp-p, frequency, pulse width and MANY others. The Math features are also pretty handy.But the thing I really like is the one-shot capability. I take one snapshot and it stays on the screen forever. I can scroll, zoom or just stare at it until I finally get what I wanted. And I can trigger on some truly obscure possibilities.Although I like analog scopes and the more knobs the better, there is simply no comparison with a DSO. There's a reason that you just about can't buy an analog scope anymore, DSOs have ALL of the advantages.Don't let anybody tell you that some low bandwidth scope is useful, it isn't. Mostly I work with square waves so I need to display at least the 7th harmonic so even after I open up the 1054 to 100 MHz, it's still only somewhat valid on a 15 MHz square wave. Ideally I would want to display out to the 15th harmonic or so. For this, I have the Tek 485 and it will handle 350 MHz. But it doesn't have ANY features, just bandwidth. Used 485s are in the $250 range on eBay with some wanting a LOT more.There are some serious limitations to that Tek 4226 but I would buy it anyway (if I didn't have the 485). Look at channels 3 & 4, they don't have V/div knobs. You get 0.1V/div or 0.5V/div (button selectable) which, with a 10x probe, gives you 1V or 5V/div. This is workable and a lot of scopes are built this way. But any way you look at it, those 2 channels are not equivalent to channels 1 & 2.The better 2446s on eBay are pretty well over $300 but not as high as $390. But, buying locally saves about $50 on freight and, presumably, you can test it out before leaving money behind. If I still lived down in Silicon Gulch, I might look into it. I used to live a mile or so from Saratoga. Alas, I don't live there any longer. And I don't need another scope...I would think first and foremost about the Rigol DS1054Z. The features of a DSO simply swamp the cool factor of an analog scope. I am not seriously thinking about a new scope (I really don't need one) but that new 2 channel 200 MHz Siglent would be a possibility since it is targeted right at the price of the Rigol. But it's only 2 channels...There are a lot of people on the EEVblog forum that have the 1054. Most are quite happy, a few are unhappy because it isn't as capable as a $1200 scope. And it isn't! At the edges, the DS1054Z has some limitations that the average user will NEVER encounter.I guess I shouldn't sound so enthusiastic about the 2446, the 1054Z is the right way to get into the scope game. Much as I like analog scopes, they are a dead issue. The DSOs have too many advantages.

author: james_s
author_rank: Super Contributor
timestamp: April 08, 2017, 12:20:54 am
content: One thing I do still use my analog 465B for is XY mode to display vectors, my DSO doesn't come close in performance in that respect, but that's not a very common need.Not sure why you'd say that low bandwidth scopes are not useful, not too long ago 50MHz was high end, people accomplished a lot with 20MHz and less scopes. Sure they're not as useful as something with more bandwidth but as a learning aid they are perfectly fine. A student can learn just as much by using a 10MHz scope as by using a 1GHz scope, the controls and features work exactly the same, signals within the usable bandwidth of the scope look exactly the same. I'm not saying they're particularly valuable but that's part of the attraction, it's fairly easy to find working low end analog scopes for under $50, sometimes free. That's perfect for a hobbyist who may get bored and decide they don't even want to pursue electronics, maybe they'll make a rookie mistake and blow up their scope, maybe they just want to work on audio gear or other low frequency applications. Maybe at some point they'll outgrow it and by then they will probably have a pretty good idea of what kind of scope they need and they can pass the old analog scope on to another beginner or keep it as a backup, etc.

author: rstofer
author_rank: Super Contributor
timestamp: April 08, 2017, 01:08:15 am
content: I think Rigol finally got the X-Y mode working on the DS1054Z as it will now go full-screen. When I do X-Y, the signals are usually quite slow and I find my Digilent Analog Discovery more useful. Particularly when it comes time to print the graph without all the 'scope' artifacts.Bandwidth: I built my own oscilloscope back in the late '50s from plans in the ARRL Handbook. I have no idea what the bandwidth was but it wasn't much. Then I graduated to a Dumont scope (100 kHz) and then a 10 MHz Heathkit and on to the Tek 485 (300 MHz). I did some pretty cool stuff with the Heathkit including building and debugging a floppy disk controller for my Altair 8800. But I could never really see the signals, all I knew was that something happened. I never knew what. And the Altair only ran at 2 MHz. This was really a situation where single-shot would help a lot. A 1 uS signal coming along every second or so - very hard to see.At each step in my transition upwards with bandwidth, I was very happy with the scope. But my needs increased over time and some things just don't survive.Today, modest uCs are running at 16 MHz and others are running at 100 MHz or higher. Most all of my FPGA projects clock at 50 MHz although I might pick up the pace a bit in the near future. I NEED to see what's happening. I need to be able to relate timing between the various signals. A logic analyzer is useful but so is a scope - if it is fast enough.It seems to me that a 10 MHz scope will, at best, display a 1 MHz square wave (I have no interest in sine waves) and that simply isn't high enough.Yes, it is often possible to pick up a low bandwidth scope for < $100 but it won't be adequate for very long. It will do some things, no doubt, but even the Arduino will be beyond its capability for some signals.The OP suggested a budget of $500 (if I am in the correct thread) and I see no reason to recommend something in the < $100 region when budget is available for something that will serve for quite a long time. But it's always about resources, requirements and tradeoffs.

author: pieman103021
author_rank: Contributor
timestamp: April 08, 2017, 01:43:44 am
content: Quote from: MumblingFumbler on April 07, 2017, 08:55:10 pmI have one of these Teks at home, it is my first scope which I got a year ago for $70 and a trade of ~80 bucks worth of gear. The scope itself isn't worth the price listed, but with all of the things that come with it, it very well could be. I would try to negotiate the price down a bit, but if you are in the market for an analog scope this is a great find.As a beginner with the 2246, it was a learning experience. It is nothing fancy like modern scopes, but what it can do it does really well and really easily. I highly recommend it if you prefer to go analog over digital.Sent from my Nexus 5X using Tapatalk

author: james_s
author_rank: Super Contributor
timestamp: April 08, 2017, 07:21:54 am
content: *You* have no interest in sine waves and low frequency stuff, that doesn't mean that's the same for someone else. Sure the edges of a square wave might get a bit rounded on a really old low bandwidth scope does that matter? Sometimes yes, sometimes no, it depends what one is doing. With a few exceptions, a scope is not all that useful for FPGA development. It's good for checking signal integrity in your PCB layout but for debugging the built in logic analyzer and simulation in the IDE are *far* more powerful and versatile, and you don't have to hook up test leads. While I have a formerly high end 1GHz DSO, I find that for most things I do I don't need nearly that much bandwidth, and I certainly didn't when I was a beginner. It's quite often that I'm debugging something that runs at a few to a few hundred kHz, switching regulators, resonant converters, amplifiers, PWM motor drivers, IR signals, oscillators, all stuff that requires relatively little bandwidth. I learned how to use an oscilloscope with an ancient Tek 531A that I got at a garage sale when I was a kid, only 15Mhz but it taught me how to use a scope and I used it for at least 10 years before I got a 465B.I look at it much like teaching a kid to drive a car. If you've got any sense you don't go out and buy a teenager a brand new sports car, you get them an old beater, manual gearbox, no assistive gadgets, they learn to drive it, learn to maintain it, hit a few curbs and whatnot, make the mistakes in that and then once they're proficient they get something better and fancier. Learning on a basic unit forces you to actually learn what you're doing rather than relying on shortcuts.

author: rstofer
author_rank: Super Contributor
timestamp: April 08, 2017, 04:23:14 pm
content: Yes, I have been careful to say that "I" am not interested in sine waves and, as you point out, many others are. But they might be in the square wave business in the very near future. Future proofing...Here's my issue: Why spend any significant amount of money on something that is unlikely to be useful in the near term. Now, for the audio folks, a 10 MHz scope is more than they will ever need. They will never try to decode a serial stream, single-shot may or may not be useful and an old beater analog scope is ideal. Unless they want measurements. Or Bode' plots of amplitude and phase versus frequency (Digilent Analog Discovery).But as soon as they get to the Arduino and SPI, the advantages of the DSO (like the DS1054Z) become very important. Even without decoding, the ability to take a single shot using CS' for a trigger becomes very important. We have a thread running somewhere around here where a fellow is tearing his hair out because he doesn't have a scope or a logic analyzer. It can be nearly impossible to get I2C working without some way to decode the stream (trigger on the START condition). SPI isn't quite as bad.One way I have done SPI with an analog scope is to write the transaction in a tight loop so that the same image is displayed on every iteration. I can see what's happening (CPOL CPHA, Clk vs MOSI/MISO) but it is less than optimal. Yes a logic analyzer works well and I have one but that's kind of an advanced topic for beginners. And, yes, a scope is not the best tool for debugging FPGAs and as that became more apparent, I built up a 200 MHz logic analyzer. But I still wound up debugging SPI between an FPGA and an ARM - 12.5 MHz as I recall.So, given a $500 budget by the OP, why go for anything less than the DS1054Z? The money is there, the scope is NEW and under warranty and it has more capability than a similar bandwidth analog scope. Buying anything used is a potential problem. I sure don't buy used cars!As to kids learning to drive, I always thought highly of '58 Buicks. I just don't sign up for the idea that a person MUST start with an analog scope. Most of us did because we've been at it a long time. But there's a reason that analog scopes aren't readily available. Time moves on...I like analog scopes and I have used them for nearly 60 years but if I could only have one scope, given the DSO prices/capabilities, it certainly wouldn't be analog.

author: David Hess
author_rank: Super Contributor
timestamp: April 08, 2017, 11:22:34 pm
content: Quote from: MumblingFumbler on April 07, 2017, 08:55:10 pmThat is a pretty steep price for a 2246 even with the cart, cover, and accessories.

author: TNorthover
author_rank: Contributor
timestamp: April 09, 2017, 01:09:03 am
content: Quote from: james_s on April 08, 2017, 07:21:54 amOn the other hand, you probably don't give them a double-declutching manual either (unless you're a sadist). As with most things, there's probably a happy medium.

author: james_s
author_rank: Super Contributor
timestamp: April 09, 2017, 04:43:41 am
content: Quote from: TNorthover on April 09, 2017, 01:09:03 amSure, I mean I'm not suggesting he go out and get a 1950s Eico 500kHz scope with no triggered sweep.