What does your choice of oscilloscope manufacturer say about you? - Page 1
Forum section: electronics / general

author: Zodiac
author_rank: Newbie
timestamp: December 16, 2011, 09:24:28 pm
content: So I need a new oscilloscope. I have an old but good analog Tek2246. I am wanting a new DSO to take measurements and post screenshots to my blog and on forums.Now I have this bias that if I see a Tek or Agilent screenshot I immediately associate that with someone who knows what they are doing. If I see a Rigol or other mfg then I think...hmmm...this guy is an amateur.Do you agree or disagree?

author: Chet T16
author_rank: Frequent Contributor
timestamp: December 16, 2011, 09:34:13 pm
content: It's hard not to agree when you look at pricingBut the rigol really is a great bit of kit and deserves to be on anyones bench. Forgetting the machine itself the fact its so popular has lead to a great community around it and lots of supportFwiw I'm a (mature) ee student and i have a rigol and tek2225

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 16, 2011, 10:07:36 pm
content: another tool vs skill (craftmenship) thread. actually... i'm tired of this.

author: Time
author_rank: Frequent Contributor
timestamp: December 16, 2011, 10:18:11 pm
content: Just because you own a ferrari it doesn't mean you know how to drive it.

author: Unknown
author_rank: Unknown
timestamp: December 16, 2011, 10:36:46 pm
content: Absolutely, getting an expensive tool doesn't make you any more skilled. On the other hand, you rarely see a professional racing driver competing in an SUV.

author: johnboxall
author_rank: Unknown
timestamp: December 16, 2011, 11:12:50 pm
content: Quote from: Zodiac on December 16, 2011, 09:24:28 pmActually yes I agree to a point. From my own experience posting images to my site people either like the wide Agilent screen dumps or scorn me for having such a great MSO. If you are writing a book the Rigol screen dump size is not good enough for publishing.

author: EEVblog
author_rank: Unknown
timestamp: December 17, 2011, 02:15:24 am
content: Quote from: Zodiac on December 16, 2011, 09:24:28 pmIn reality there could very well be a slight stigma associated with cheap scope screen shots.e.g. if you looked at a datasheet and saw Rigol 1052E screen shots then you'd almost certainly go "wow, THAT'S the scope those pros are using?"But as others have said, it shouldn't really matter a rats arse.I wouldn't let stigma drive any buying decision, you should buy the right tool for your needs and your budget.If you are genuinely after good quality screen shots for documentation though, then the Rigol doesn't really cut it compared to some others, like the Agilent X series for example.Dave.

author: joelby
author_rank: Frequent Contributor
timestamp: December 17, 2011, 02:30:06 am
content: You could always save the waveform to a USB drive from the Rigol and then plot it in Matlab or similar. Or Photoshop the Agilent screen interface into the image?

author: Zodiac
author_rank: Newbie
timestamp: December 17, 2011, 03:58:55 am
content: People make judgements all the time based on their filters. Measurements taken with a Rigol and an Agilent may be exactly the same but people may interpret them different and give more credibility to one over the other based on the brand name associated with it.

author: slateraptor
author_rank: Frequent Contributor
timestamp: December 17, 2011, 04:31:31 am
content: Quote from: ZodiacI've come to a decisive conclusion that my choice of oscilloscope manufacturer is a tell-tale indication that I'm the type of person who actually enjoys instant coffee and looks forward to the holidays for the opportunity to purchase seasonal liquid creamer at a price significantly less than what Starbucks would charge.Let's be honest with ourselves now: the 50MHz analog bandwidth of a Rigol is more scope than most non-specialists would know what to do with. The overwhelming majority of hobbyist applications out there fall anywhere between DC and sub-25MHz digital anyways.

author: slateraptor
author_rank: Frequent Contributor
timestamp: December 17, 2011, 04:38:54 am
content: Quote from: Zodiac on December 17, 2011, 03:58:55 amI'm liable to question the credibility of an individual who weighs his judgement heavily based on brand name rather than sound science and sound engineering. We're not talking about RF applications here...we're talking about sub-200MHz economy class scopes.

author: Zodiac
author_rank: Newbie
timestamp: December 17, 2011, 04:49:52 am
content: Quote from: slateraptor on December 17, 2011, 04:38:54 amTrue true, but the average consumer IS influenced by brand name.For my application a 20mHz scope would be fine (powerline quality measurement).In any event I can buy almost four 50mHz Rigols for the price of one 2000 series Agilent.

author: slateraptor
author_rank: Frequent Contributor
timestamp: December 17, 2011, 05:30:41 am
content: Quote from: Zodiac on December 17, 2011, 04:49:52 amI feel like you've convinced yourself that the misinformed disposition of fools ought to dictate what you know is sound and within reason.For situations like this, a "quick review of prerequisite theory" is in order. If you know what you're talking about, then it won't phase anyone that matters, and it's a good way to discourage the unqualified opinions of those that don't.

author: PetrosA
author_rank: Frequent Contributor
timestamp: December 17, 2011, 05:41:28 am
content: A while back I wrote a comment about what type of DMM I need. In it, I stated that I need a good, TRMS meter because I sometimes have to call the power company and report problems. With my U1272A, my DMM credentials are well beyond just owning some no-name TRMS meter, but that's fine. One phone call from me might set into motion multiple power company trucks, a few line crews and tens of thousands of dollars for replacement gear. I don't want to be in a situation where the power company questions my diagnosis because I'm using a no-name meter although I could probably make the same diagnosis with the cheapie. If you have someone looking over your shoulder, then maybe you need the really expensive scope. If not, get what you need as cheaply as possible and to hell with what others might think.

author: vk6zgo
author_rank: Super Contributor
timestamp: December 17, 2011, 06:03:50 am
content: Quote from: slateraptor on December 17, 2011, 04:38:54 amYou mean all those big hairy,MF,HF,& low band VHF transmitters I worked on over 40 odd years aren't RF?Thank you for the enlightenment,Oh Great One!!VK6ZGO

author: slateraptor
author_rank: Frequent Contributor
timestamp: December 17, 2011, 07:29:05 am
content: Quote from: vk6zgo on December 17, 2011, 06:03:50 amYou forget that the propagation medium itself makes an RFapplication, not the operating frequency, Oh Sage Master.

author: vk6zgo
author_rank: Super Contributor
timestamp: December 17, 2011, 07:40:48 am
content: Indeed,Oh Honorable One,If you made a large enough antenna,you could radiate 60Hz.VK6ZGO

author: slateraptor
author_rank: Frequent Contributor
timestamp: December 17, 2011, 08:08:19 am
content: Quote from: vk6zgo on December 17, 2011, 07:40:48 amI leave you in charge of engineering an antenna that stretches half the distance of the equator as a 1st-order approximation.

author: vk6zgo
author_rank: Super Contributor
timestamp: December 17, 2011, 09:13:49 am
content: I am unworthy of such a task,Oh Thrice Anointed One!VK6ZGOGee this is fun!,but I guess we'll attract some Moderator type attention.

author: wkb
author_rank: Super Contributor
timestamp: December 17, 2011, 09:20:10 am
content: Quote from: slateraptor on December 17, 2011, 04:31:31 amInteresting comparison... I own both a Tek 2465CTS and a Rigol 1052E. I also own a nice Jura F50 espresso machine, while at the same time I drink the Nutrimat(...) junk from the machine at the officeSo what does this say about me?

author: EEVblog
author_rank: Unknown
timestamp: December 17, 2011, 09:33:42 am
content: Quote from: Zodiac on December 17, 2011, 04:49:52 amSure. But the Agilent has about 50 times the update rate, is up-gradable in bandwidth and function gen, and has a bigger and better screen among other things.Comparing scopes ain't just about the bandwidth.The Agilent is of course a MUCH better scope than the Rigol in most respects, and has a higher price to match.It's probably not even fair trying to compare the two.Probably a majority of individuals buy based on price range - "what's the best scope I can $xxxx"The Rigol is a top pick in the sub $500 category, and the Agilent is a top pick in the $1000 to say $3000 category.Dave.

author: joedevola
author_rank: Contributor
timestamp: December 17, 2011, 10:54:50 pm
content: Here you go, a reasonably respected Australian-based EE who provides audio advice and PC boards has posted the response of his Linkwitz-Riley active crossover boards on his site with a Rigol screen shothttp://sound.westhost.com/project09.htm

author: ivan747
author_rank: Super Contributor
timestamp: December 18, 2011, 12:14:22 am
content: Quote from: slateraptor on December 17, 2011, 08:08:19 amTechnically... the length of the antenna must be 4500km, or the US from coast to coast, in 1st order approximation.

author: slateraptor
author_rank: Frequent Contributor
timestamp: December 18, 2011, 12:31:22 am
content: Quote from: ivan747 on December 18, 2011, 12:14:22 amApproximation was guesstimated from an antenna whose length is 1/4 of carrier frequency wavelength as a rule of thumb, and wave traveling in a vacuum...so yeah, that equatorial distance was a bit of a fib.

author: Unknown
author_rank: Unknown
timestamp: December 18, 2011, 12:54:28 am
content: Quote from: Zodiac on December 16, 2011, 09:24:28 pmSome of us agree, some disagree. But I think we can all agree that you should buy an 'established brand' scope if you are to feel good about your purchase. For some, the tool is as important as the measurement.

author: bfritz
author_rank: Regular Contributor
timestamp: December 18, 2011, 02:36:53 am
content: Quote from: slateraptor on December 17, 2011, 04:31:31 amI disagree with your statement.Let us think about an I2C interface in Fast Mode. This is 400KHz, not exactly out of the realm of a hobbyist. Many I2C devices, and many of the Dallas 1-Wire parts are in this area.To meet the I2C specs, the data setup time must be 100ns. So, based on Nyquist, we can determine the bandwidth at: BW approximately = 0.35 / TrSo: 0.35 / Tr = 0.35 / 100e-9 = 3.5MHzBut note that is based on a sine wave, and an I2C signal is far from a sine wave. To get a good view of the signal our banwidth will need to be about an order of magnitude larger or 35MHz! This is for an I2C communication bus at 400KHz.When viewing digital signals, or looking at signal modulation, you can run out of bandwidth very quickly! These are well within the realm of hobbyists.

author: slateraptor
author_rank: Frequent Contributor
timestamp: December 18, 2011, 03:20:03 am
content: @bfritz: How you've inferred setup time = rise time is beyond my comprehension.P.S. Exactly what part of "Nyquist" dictates the rise time approximation of a single stage RC low pass?

author: bfritz
author_rank: Regular Contributor
timestamp: December 18, 2011, 07:11:50 am
content: Quote from: slateraptor on December 18, 2011, 03:20:03 amIf you are going to see the data setup time, you will be monitoring both clock and data of the I2C. The waveform will therefore ideally look like a square wave. To accurately measure setup, requires the waveform's look like the real waveform, not a sine wave. If the scope doesn't have enough bandwidth to show rise time much faster than 100ns, then how are you going to measure the setup time, when it can be as short as 100ns. You can't measure something when the edge rate is limited by scope BW by more than the setup time.Your PS is just taking my comment totally out of context. Where do I mention a "single stage RC low pass", I don't!I wanted to find somewhere on line that would validate my thought process independently. National Instruments has a document online discussing just this. (Turns out my memory on the calculations was correct. Remembered this from working on oscilloscopes back at Heathkit in the early 80's.) The link even uses the same 100ns rise time.http://digital.ni.com/public.nsf/allkb/A4530BE56775FB2C86257282005EAB58

author: Bored@Work
author_rank: Super Contributor
timestamp: December 18, 2011, 08:01:59 am
content: Quote from: Zodiac on December 17, 2011, 04:49:52 amAnd I question the credibilities of individuals who can't get their prefixes right and write millihertz when they mean megahertz or vice versa. While I would, and have read, publications containing Rigol screenshots, although I don't like the company, I immediately stop when someone doesn't get his units of measurement right. And that includes the prefixes. Chances are I won't miss the lyrical waxing of the next Einstein.

author: slateraptor
author_rank: Frequent Contributor
timestamp: December 18, 2011, 08:17:18 am
content: I'm going to exercise self-restraint and firmly object to playing bad cop.

author: slateraptor
author_rank: Frequent Contributor
timestamp: December 18, 2011, 08:22:02 am
content: Quote from: BoredAtWork on December 18, 2011, 08:01:59 amLMFAO!So do you write kilo as k or K? Because every time I see KHz, I always seem to ask myself, "WTF is a Kelvin-Hertz?!"

author: IanB
author_rank: Super Contributor
timestamp: December 18, 2011, 08:25:53 am
content: Quote from: slateraptor on December 18, 2011, 08:22:02 am1 KHz = 1024 Hz

author: EEVblog
author_rank: Unknown
timestamp: December 18, 2011, 08:27:34 am
content: Quote from: bfritz on December 18, 2011, 02:36:53 amI agree. If you are actually trying to measure and characterise a 25MHz digital signal, then a 50MHz bandwidth scope isn't going to serve you all that well. Heck, a 50MHz bandwidth scope can't even accurately measure a 50MHz sine wave amplitude, it's going to measure almost 30% low (unless you happen to know roll off figures and compensate manually).But in general, yes, a 50MHz scope is usually enough for a hobbyist to get stuff done.Dave.

author: EEVblog
author_rank: Unknown
timestamp: December 18, 2011, 08:33:42 am
content: Quote from: slateraptor on December 18, 2011, 08:22:02 amMany use "K" in protest, because that's what it should damn well be!Dave.

author: slateraptor
author_rank: Frequent Contributor
timestamp: December 18, 2011, 09:18:27 am
content: Quote from: IanB on December 18, 2011, 08:25:53 amBRILLIANT!!Quote from: EEVblog on December 18, 2011, 08:27:34 amRemember all that fancy stuff with numbers that everyone seems to deplore?

author: Unknown
author_rank: Unknown
timestamp: December 18, 2011, 01:59:07 pm
content: bfritz appears to be confusing bandwidth and sampling rate. The point that edge rate is an important parameter that determines the required bandwidth is valid, however. If you send an 1 MHz signal through a 74HC gate, the output signal might have a rise time of 5 ns. To get a reasonable representation of this signal with 10% timing uncertainty, you would need a 130 MHz scope according to the figures from Agilent AN 1420. Faster logic families and FPGA's will have even faster edge rates.

author: Bored@Work
author_rank: Super Contributor
timestamp: December 18, 2011, 02:08:32 pm
content: Quote from: IanB on December 18, 2011, 08:25:53 amThat is 1 KiHz - ignored and neglected since 1998, and soon on the list of endangered species.

author: Keith
author_rank: Contributor
timestamp: December 18, 2011, 02:57:52 pm
content: I don't give a crap about what my scope says about me. Also, for the record, I don't care about what I absolutely need for my hobby its about what I want and can afford. I'm planning on spending $2,000-$3,000 for my next scope. I work my ass off every day for my money and I'm getting some cool and possibly expensive shit that I may or may not use all of the features. Maybe I'm getting older but you go around once so getting what I want. Chances are it will be more than what I need so I'll have to up my game.

author: wkb
author_rank: Super Contributor
timestamp: December 18, 2011, 03:34:30 pm
content: Quote from: Keith on December 18, 2011, 02:57:52 pmAmen to that perspective!I for one have a bunch of cameras that have absorbed more money than makes sense for an amateurphotographer. But at least one of them has satisfied my boyhood desires for that particular camera brand. Using it makes me happy every timeAnd given that our various glorious governments / banks etc seem to be intent on stealing our savings... better make sure you use the money you worked for so hard!

author: Unknown
author_rank: Unknown
timestamp: December 18, 2011, 03:45:15 pm
content: I wonder if you could make a scope by attaching pads across your muscles on your arm and stimulating them.Similar to that guy who was implementing a 3D system by electrically forcing the eye-lids to open and close quickly.The smaller you arm, the higher the bandwidthOh, and you can choose the style and thickness of your trace by visiting your local stationary shop. Is that right...Franky?

author: ivan747
author_rank: Super Contributor
timestamp: December 18, 2011, 04:06:16 pm
content: Quote from: wkb on December 18, 2011, 03:34:30 pmAt least you are a photographer. I know people with $700+ cameras and they just use them to take horrible photos of their friends. I mean, I could do better with my 2008 Nokia 5610. The same applies for scopes: you may have something better than what you need, but if you don't care about learning to use all the features and exploit all its potential, the scope is a waste of money. wkb is on the other side of the coin: he gets the advanced stuff to learn how to use it and exploit all its potential, even knowing he could use all the features a cheaper scope from day one. If he didn't care about learning to use the advanced stuff, I could do better with a 50MHz Rigol scope.

author: chrome
author_rank: Regular Contributor
timestamp: December 18, 2011, 04:09:59 pm
content: Quote from: Alex on December 18, 2011, 03:45:15 pmI do hope you know that was fake...

author: Unknown
author_rank: Unknown
timestamp: December 18, 2011, 04:15:58 pm
content: Yes, but give him some credit.The led next to his eye is in perfect sync with his blinking. And can anyone blink this fast?!

author: don.r
author_rank: Frequent Contributor
timestamp: December 18, 2011, 04:19:00 pm
content: I have an old Tek 2225 and recently acquired a 2245A. Both are overkill for my needs but they are well built scopes that have worked well for 20 years and probably will for another 20. If they break,Ican fix them (probably). I don't give a toss what other people think of me, I gave that mug's game up when I retired.Kelvin-Hertz at certain values only.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 18, 2011, 04:57:14 pm
content: Quote from: wkb on December 18, 2011, 03:34:30 pmonce i owned Canon 1D, you know what it is? you know what happened? i sold it out, it didnt make my skill better! it didnt get back my money better! and i feel miserable using it time by time. what i learnt?pro people buy pro gear because they know they need to, because they can get good return/result out of it, not because to gain good impression from other people. i saw one guy, he's a world class asian photographer, went to shoot wedding to western side every week, and you know whats his gear? a diy "book selofane taped" remote control strapped to his flash unit, not some robotics (expensive) instrument. he's still one of my idol in photography.and i know one guy here in eevblog, he never... never! AFAIK mentioned about any brand name, all his words are sound technical, he seldomly post his dso shoot, but when he do (even though he got super expensive dso) his technical expertise is more prominent than his screenshoot. when he made a post/reply (and the screen shot) it took me only 1 sec to think how good the dso brand he's using, but took me many minutes and hours to digest what he actually meant/answered and how long and effort to take to get to that (his) conclusion. he's my idol hereand believe me, if i buy the same dso as him, i will still dont know what a "gaussian respond is", not in a day, and not by luck. experience matters!you want to impress other people? want to become a proffesional wannabe? go for it! buy a porche, and learn how to "stand next to it". all dom toretto needs is his farther's old car to win a race.ps: and i will never, never! be able to comprehend why 1K = 1024, because my good teacher taught me 1K = 1000! no matter what you want to say

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 18, 2011, 05:33:50 pm
content: i guess why this kind of thread usually appear is because people misunderstood what a "professional" term means, they thought it is a "joy", "skilled person", "expert" and all that. well... if you've never felt the term like "pressure", "full dedication", "responsibility", "hardwork", or even "anger" in your work, i dont think you deserve as a "professional" (a person who know what you are doing). my 2cnts.

author: wkb
author_rank: Super Contributor
timestamp: December 18, 2011, 07:41:32 pm
content: Tools without the know-how to use them properly are a waste indeed. No debate there.On theotherhand, don't underestimate the fact that some people simply enjoy using top quality kit just for the heck of it.Only you can decide if something is worth your $ and/or if owning it makes sense for you.

author: IanB
author_rank: Super Contributor
timestamp: December 18, 2011, 10:20:12 pm
content: Having now had the opportunity to try out the Rigol first hand, I am sure I would like an Agilent scope better. However the Rigol is functional, the user interface is clean, and it is nicely compact. The truth is that a Rigol DS1000 series scope is infinitely better than no scope at all, whereas an Agilent would only be marginally better than the Rigol when used for any job the Rigol can do.In fact, when I see home users and hobbyists buying Flukes and Agilents, I tend to wonder how much such equipment actually improves the results of their efforts. There's nothing wrong of course in spending money on expensive toys if you can afford it, and I fall into the temptation myself. But let's be honest, the outcome of your endeavours usually depends more on the wet stuff behind the eyes than on the price of the equipment on the bench.

author: EEVblog
author_rank: Unknown
timestamp: December 18, 2011, 10:28:40 pm
content: Quote from: IanB on December 18, 2011, 10:20:12 pmDepends entirely on the measurement situation.I can certainly envisage situations where the slow update rate on the Rigol will not capture a fault, but the fast Agilent will.That could save many hours of troubleshooting.So some things may not be just "marginally" better, it could be a case of the lesser tool not really being capable of doing the job at all, making the better tool "infinitely" better again.As always, YMMV.I think the whole point is rather moot though, as they are two different price and performance class instruments.Dave.

author: IanB
author_rank: Super Contributor
timestamp: December 18, 2011, 10:33:01 pm
content: Quote from: EEVblog on December 18, 2011, 10:28:40 pmTrue. That's why I qualified the statement with "any job the Rigol can do". If the Rigol is not up to the job at hand, then obviously the difference is night and day. Part of the value of the wet stuff behind the eyes is understanding the measurement situation and recognizing the limitations of whatever tools you are using.

author: ejeffrey
author_rank: Super Contributor
timestamp: December 18, 2011, 11:15:04 pm
content: Quote from: IanB on December 18, 2011, 10:33:01 pmThe other factor is that we are talking about electronics as a hobby and you are supposed to enjoy it. If you enjoy using the agilent more even if it isn't a make-or-break difference that can mean a lot. If you can afford a better scope and it translates into you spending more time on your hobby and enjoying it better, by all means go for it. The fact is there are orders of magnitude variation in how much money people are able to comfortably spend on an electronics hobby. Some people can't afford the rigol, others have no problem justifying an agilent or even something fancier. Other people love finding great ebay deals on old analog scopes that spank both of them in bandwidth. Personally, I like to freeload off the scopes at work.So when I see a video where some hobbyist uses an agilent scope, I assume they have a bit more money to spend on test gear than the average guy. There just isn't much more to read into it than that.Some people certainly make foolish buying decisions: they save up every penny to blow on a fancy scope and can't afford a soldering iron -- or their rent. There are also people who waste money buying cheap equipment that won't do the job -- but that doesn't really have anything to do with the equipment.

author: Rufus
author_rank: Super Contributor
timestamp: December 18, 2011, 11:57:17 pm
content: Quote from: bfritz on December 18, 2011, 07:11:50 amThe typical 15pF loading of a x10 probe and the typical 1k pull up on I2C lines is going to be 3db down at 10MHz so you better add a pair of active probes to your requirement for viewing I2C signals.