New To Oscilloscopes - Page 1
Forum section: electronics / testgear

author: riverrat373
author_rank: Contributor
timestamp: February 28, 2016, 12:04:54 am
content: I have been an electronics buff ever since I built a Knightkit Star Roamer shortwave receiver back in 1969. I have built several electronics projects including a couple of tube integrated amplifiers. I want to continue with DIY audio projects including building more amps and speakers. I also am interested in restoring vintage audio gear and shortwave radios. I have several good digital multimeters, a cheap function generator a good soldering station and three DC power supplies. I would like to add a digital oscilloscope to my bench but see so many conflicting reviews on the same scopes that it is confusing! My questions are: 1. how wide a bandwidth do I need to do what I'm planning on? 2. How deep of memory do I need? Can I get away with 40kpts or do I really need 1M point or more? 3. How fast a sampling rate is needed for my projected projects? 500M Sa/s or 1G Sa/s? 4. I understand the 3db down relating to bandwidth so I know I need approximately 5 times the bandwidth I'm testing to get accurate measurements, so is 100mhz of bandwidth sufficient?My budget for an oscilloscope is around $400 US max. I know that the Rigol DS1052E has been highly recommended but it is only 50mhz. The same with the DS1054S. (I know they can be hacked to higher bandwidth but I won't do that for reasons of my own) Plus I have seen the screen resolution on the Rigol & Siglent entry level scopes and I'm not impressed compared to the Owon and Hantek scopes. Do Owon & Hantek make good entry level scopes? I will say that I'm not interested in buying an analog scope because I don't like buying "a pig in a poke" from Ebay and I may want to do some digital stuff in the future and my research has lead me to believe that the new digital scopes are far more useful in that area. Any thoughts would be greatly appreciated!

author: uncle_bob
author_rank: Unknown
timestamp: February 28, 2016, 12:28:56 am
content: HiThe simple answer is the Rigol DS1054Z. For a max of $400, you are not going to find anything better. There aren't a lot of competitors in that price range. The 1052 is slightly cheaper, but a lot less scope. Essentially the 1054 is the "new improved version" of the 1052. If the 1052 was $200 it would be a reasonable price /performance tradeoff. Unfortunately the 1054 is $399 (with free dinner card) and the 1052 is $329 (with no dinner card). You get 4 channels on one, two channels on the other one. If screen size is an issue, the 1054's screen is bigger and higher resolution.Yes, a nice big screen LeCroy would be better. You haven't even begun to shop for them at 10X the price....Bob

author: tautech
author_rank: Super Contributor
timestamp: February 28, 2016, 12:52:19 am
content: As you're proposing to only do analogue not digital your needs are not so demanding.Complex analysis of captured waveforms is unlikely to be needed therefore memory requirements can be quite small, 40K absolute minimum and 1M adequate.I'd add that for old school valve work and in particular the voltages they use, consider selecting a DSO with 400V rated inputs for an additional safety margin.

author: ez24
author_rank: Super Contributor
timestamp: February 28, 2016, 03:44:59 am
content: Be sure to check this outhttps://www.eevblog.com/forum/testgear/digital-oscilloscope-comparison-chart/

author: ebastler
author_rank: Super Contributor
timestamp: February 28, 2016, 08:12:10 am
content: Quote from: riverrat373 on February 28, 2016, 12:04:54 amIn practice, many scopes are less than 3dB down at their rated bandwidth. (On the other hand, the sensitivity starts to drop off by more than 3dB/octave at some point above the rated bandwidth.) Hence, if "accurate measurements" refers to signal amplitude measurements, e.g. in a shortwave radio, you can still to "nearly quantitative" amplitude measurements for frequencies up to the nominal bandwidth -- as long as you know the signals to be sinusoidal. And you can, of course, always create a calibration table for higher frequencies, say up to ~ 2*rated bandwidth.If, on the other hand, "accurate measurement" means determining the waveform/harmonic spectrum of an unknown signal, then indeed your scope's bandwidth should be at least 5x to 10x the signal's fundamental frequency.It's a pity that Rigol do not offer the bandwidth upgrade as an official software option. If they did, you could upgrade at later point if you encounter a project which does in fact need the 100 MHz bandwidth. As it stands, I would still recommend buying the DS1054Z -- it's an amazing scope at that budget. You can deal with the moral dilemma of hacking it if and when the need for more bandwidth arises...

author: Fungus
author_rank: Super Contributor
timestamp: February 28, 2016, 09:34:11 am
content: Quote from: riverrat373 on February 28, 2016, 12:04:54 amThe DS1054Z is the one to go for in that price range. It's head and shoulders above the rest.Quote from: riverrat373 on February 28, 2016, 12:04:54 amNot compared to the DS1054Z.Quote from: riverrat373 on February 28, 2016, 12:04:54 amBack in 1969 they developed an awful lot of audio and shortwave radio gear with 5-10MHz oscilloscopes. 20MHz would have been a luxury. 50MHz would have been a very expensive/professional piece of kit back then.Quote from: riverrat373 on February 28, 2016, 12:04:54 amI guess that depends on what you mean by "accurate measurements".In practice I don't think you'll need what you're imagining you'll need. Oscilloscopes are more about looking at waveforms than very precise voltage measurements.I don't think the DS1054Z will disappoint.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: February 28, 2016, 10:29:06 am
content: Quote from: riverrat373 on February 28, 2016, 12:04:54 amWell, aside from the fact that digital scopes aren't really a new thing (they exist at least since the '70s, and pretty much replaced analog scopes as general purpose scopes back in the '90s), you're right that buying a digital scope is the more sensible option. Especially since analog scopes have been pretty much a dead end for a long time, and the few that are still made are mostly crap (and due to the low production numbers they're not exactly cheap either).As others already said, if your budget is $400 then there's pretty much only one sensible option, and this is the Rigol DS1064z. The DS1052E was recommended a lot a few years ago but things have changed since then, and today it's dated and no longer the great bargain it once was. With your budget, you will not get much more bang for the buck than with the DS1064z, period.You also have to be aware that $400 is really the bottom-of-the-barrel, and a until a few years ago even a very basic 2ch scope would have been more expensive than that. That means your low beduget will require some compromises. Pretty much all scopes in this price range have low resolution screens, and all are made by B-brands and come with various bugs. The DS1054z is still the best option not only because it's a 4ch scope with decent memory but also because it has been out for a while and lots of bugs have been fixed already.Buying from ebay isn't a risk if you pay a bit of attention (ebay pretty much always sides with the seller), however for $400 you'll mostly find old analog boat anchors and very old (and often broken) DSOs with very poor specs, so you're much better off with a new scope.For what you want to do, the 50MHz of the DS1054z should be more than sufficient. Remember that the scope bandwith is the frequency where a pure since wave (!!!) is shown at -3dB amplitude (~0.707 x U(t), i.e. a 10Vpp sine wave would show with 7.07Vpp). For all sinoid waveforms (i.e. square, pulses, triangles etc), which all are essentially just a mix of multiple sine waves at various frequencies, the useful bandwidth is much lower (i.e. for square waves a 50MHz scope is only really useful for say a 5MHz square wave). Still, for what you want to do, the 50MHz of the DS1054z should be plenty enough.

author: uncle_bob
author_rank: Unknown
timestamp: February 28, 2016, 04:10:36 pm
content: HiThere are a number of things that impact how useful a digital scope is. Most of them drop the sample rate as the frequency goes up. The 1054Z is not quite as wide band (after hack) at 4 channels as it is at one channel. For audio, this is a zero impact issue. If you are at 100 KHz, you are well past the point that even my pet dog would call audio.With the Rigol being out as long as it has been, and having been hackable forever and ever, you are pretty safe hacking the beast. It's easy to do and there does not appear to be any downside. Does that get you a 150 MHz 3db bandwidth or 125 or 175? Is the bandwidth at the front connector? Is it with the included probes? If we still are talking audio ... you don't really care. You will get > 100 MHz and that is way more than you will need. Drop back to a single channel if you have a 200 MHz "something" to look at.Bob

author: riverrat373
author_rank: Contributor
timestamp: February 28, 2016, 05:13:56 pm
content: Lots of good info from those who posted, and I appreciate it all! I will seriously consider the Rigol DS1054Z. I am, however, intrigued by the 200Mhz Hantek DSO5202P for $329.00. I know that it only has 40mpts memory depth but do I need more than that? I have seen one review by Todd Harrison on YouTube that was pretty favorable. Any thoughts?

author: uncle_bob
author_rank: Unknown
timestamp: February 28, 2016, 05:53:41 pm
content: Quote from: riverrat373 on February 28, 2016, 05:13:56 pmHiThat's a two channel competitor to the old 1052. I would not pay major attention to the bandwidth number. It's about as reliable / useful / important as the "175 MHz" numbers you see for the 1054Z. The per channel sample rate of 500 MS/s on two channels will get you before the bandwidth does with real troubleshooting waveforms. It's "big large high resolution" display the same size and resolution as the 1054. No idea if the contrast is as good or not.For audio, you will find large(r) memory depth to be nice(r). Triggering on something and then being able to zoom into this that part of the waveform is indeed something you do a lot. Searching a monster record ... ugg. Splitting the memory between 4 channels , scanning to find the point on one and then looking at the others ... yes that's not to bad.The other thing I notice is that you get ethernet connectivity with the 1054 but not with the older 5202. That may not sound important now. When your new computer does not recognize the USB drivers for your scope ... it's mighty important.Bob

author: vince53
author_rank: Contributor
timestamp: February 28, 2016, 05:56:19 pm
content: riverrat373I just read your description in the first paragraph and it all sounds familiar. I also built a Knightkit Star Roamer in the 60's and have roughly your complement of test gear. I also have an old B&K 3" single channel scope. I'm recently retired and am starting to play with electronics again. The old scope quits working when it warms up and I'm looking at a Siglent 2000E series 4 channel. I didn't bother to mention to my wife that I could get a cheaper one!I play around with radio control stuff and have a Radio Amateur license. I just got my Analog Devices ADALP2000 parts kit and will start experimenting with op amps soon. Dave's videos have really energized me to get back to experimenting with electronics. Thanks Dave.Don't forget to look for the thread for the eevblog discount at Tequipment.netVince

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: February 28, 2016, 06:27:26 pm
content: Quote from: uncle_bob on February 28, 2016, 04:10:36 pmNo, they don't. The sample rate does not change with the frequency. It changes with the time base depending on the size of the sample memory.QuoteScope analog bandwidth is always specified at the connector, and never includes any probes.Quote from: uncle_bob on February 28, 2016, 05:53:41 pmNo, it doesn't. 500MSa/s is perfectly adequate to sample a 200MHz sine wave in real time.

author: uncle_bob
author_rank: Unknown
timestamp: February 28, 2016, 07:04:11 pm
content: Quote from: Wuerstchenhund on February 28, 2016, 06:27:26 pmHiOk typo on the sample rate .. .s.b. channels go up.Always at the connector ....no not at all. There are a lot of Tek "portable" scopes that specified it at the Tek supplied probe tip.Now for the major item .... please do a little research on sampling theory. You can get amplitude but not phase at 500 MS/s on a 250 MHz waveform. How do I know this? Well sampling theory actually was around back when I was in school. I repeated the 250 number to a prof as "known correct" and spent the next hour going through math (until I got it right) to demonstrate you did need the other two samples to get the phase. That's why you have I/Q in the first place. If you have 500 MS/s of I and in addition 500 MS/s of Q then you have what you need. That's 1 GS/s total samples.Bob

author: ebastler
author_rank: Super Contributor
timestamp: February 28, 2016, 07:20:42 pm
content: Quote from: uncle_bob on February 28, 2016, 07:04:11 pmWell, sampling at exactly twice the signal frequency is obviously borderline. You could end up always sampling the zero crossings, for example, and miss the signal entirely. I'm pretty sure Nyquist's theorem says you need to sample at > 2* signal frequency, not equal.But youcanget the amplitude and the phase if you sample a200 MHzsignal with 500 MS/s, as in Wuerstchenhund's example, right? Or a 249 MHz signal, for that matter...

author: Fungus
author_rank: Super Contributor
timestamp: February 28, 2016, 08:09:47 pm
content: Quote from: ebastler on February 28, 2016, 07:20:42 pm2.5x is usually quoted as the limit for oscilloscopes with sin(x)/x interpolation.(and that's exactly what a DS1054Z has at 100MHz with all 4 channels turned on)

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: February 28, 2016, 08:19:03 pm
content: Quote from: riverrat373 on February 28, 2016, 05:13:56 pmI would avoid the Hantek at all costs. First scope I got was a Hantek MSO5102 (same as the DSO5102 except it had the extra digital channels). There are plenty of threads on here talking about bugs in Rigol's firmware but Hantek's firmware is much much worse. The scope would fully lock up multiple times per day and would have to be completely reset. I ended up returning the Hantek and getting a Rigol and have been very happy with it.

author: riverrat373
author_rank: Contributor
timestamp: February 28, 2016, 08:43:03 pm
content: Yikes!!!

author: nctnico
author_rank: Super Contributor
timestamp: February 28, 2016, 09:32:14 pm
content: Quote from: riverrat373 on February 28, 2016, 12:04:54 amFor audio work 100MHz is more than sufficient for audio. Even 50MHz would do fine. However an oscilloscope and accurate measurements don't go hand in hand. You have to assume the amplitude an oscilloscope shows is accurate to about 3% for signals below 1MHz without fancy probes and calibration. An oscilloscope's primary purpose is to look at the shape of a signal. FFT will be very handy to hunt for distortions (unfortunately Rigol's FFT is very short) but for accurate amplitude measurements you are better off with a true-RMS voltmeter.

author: riverrat373
author_rank: Contributor
timestamp: February 28, 2016, 09:33:15 pm
content: Another question: A friend gave me a brand new pair of 100mhz oscilloscope probes. Could I use those with the 50mhz Rigol DS1054Z?

author: riverrat373
author_rank: Contributor
timestamp: February 28, 2016, 09:35:34 pm
content: Quote from: nctnico on February 28, 2016, 09:32:14 pm

author: tautech
author_rank: Super Contributor
timestamp: February 28, 2016, 09:46:16 pm
content: Quote from: riverrat373 on February 28, 2016, 09:33:15 pmOf course, they might even be better quality than those supplied with a 1054Z.The only thing with probe suitability is the compensation range adjustment, most scopes are in the 10 -25 pF range and if the probes can be adjusted to suit you'll be fine.

author: Fungus
author_rank: Super Contributor
timestamp: February 28, 2016, 10:01:54 pm
content: Quote from: riverrat373 on February 28, 2016, 09:33:15 pmYes.(you can always use higher-rated probes, no problem)

author: uncle_bob
author_rank: Unknown
timestamp: February 28, 2016, 10:02:10 pm
content: Quote from: ebastler on February 28, 2016, 07:20:42 pmHiTo get both phase and amplitude you need the I and the Q samples. The zero crossing example is a good one. Consider the case of just below Nyquist. You will need a very long set of samples to get an idea of what is going on. If the waveform changes in that time period (phase modulation) you are toast. The modulation need not take the signal out of bandwidth to quickly mess up the re-construction.How does this matter:I have a 4 channel scope (a 1054Z). I trigger on one channel. It gets the phase of that channel correct. The other three 250 MS/s channels may or may not get the phase right. Having the signal randomly invert is sort of a dis-advantage. This can happen inside the bandwidth of the scope.Does it mater for audio? Nope, you have plenty of samples and the sin(x)/x stuff makes the display look very nice. It's only at the extreme where you run out of information that the "guess" comes in. Sometimes the magic works, sometimes it doesn't . As long as you stay out of that region .... not a problem at all. My Tek gear does 4 samples per sine wave at max bandwidth for that reason....Bob

author: riverrat373
author_rank: Contributor
timestamp: February 29, 2016, 02:16:21 am
content: Any thoughts or experience with the GW Instek GDS-1072B or GDS-1102B oscilloscopes?

author: ebastler
author_rank: Super Contributor
timestamp: February 29, 2016, 05:55:29 am
content: Quote from: uncle_bob on February 28, 2016, 10:02:10 pmI think you are mixing up two (related) topics here -- or I am not getting your point:To properly reconstruct amplitude and phase, it is sufficient to sample "slightly" above twice the signal frequency. What "slightly" means will depend on the length of the sample sequence one takes and uses to reconstruct the signal. In theory, 1% margin should be enough if you take 100 samples; in practice, 25% margin (sampling at 2.5 x the signal frequency) seems to be a common rule of thumb for robust reconstruction. Certainly no need to taketwicethe number of samples via I and Q sampling.Acquiring I and Q samples, in my understanding, provides a "real time" way to reconstruct amplitude and phase, without looking at a sequence of sampled data. Commonly used in heterodyning (frequency conversion by multiplicative mixing). But to interpolate and display data in an oscilloscope, the scope has at least a screenful of samples, and can reconstruct the signal with just a bit of oversampling and without I and Q samples.

author: vk6zgo
author_rank: Super Contributor
timestamp: February 29, 2016, 06:13:15 am
content: Quote from: nctnico on February 28, 2016, 09:32:14 pmIn fairness,3% is about 0.26 dB.The instrument of choice for much RF work,a Spectrum Analyser,is battling to do better than around 0.5dB.

author: tggzzz
author_rank: Super Contributor
timestamp: February 29, 2016, 08:19:58 am
content: Quote from: vk6zgo on February 29, 2016, 06:13:15 amBut a spectrum analyser should belineardown tomuchlower levels. Try looking at a 2GHz -100dBm signal on a scope

author: nctnico
author_rank: Super Contributor
timestamp: February 29, 2016, 10:24:01 am
content: Quote from: riverrat373 on February 29, 2016, 02:16:21 amI have a GDS-2204E. The major difference between the GW Instek 2000E and 1000B series seems to be protocol decoding (not available on the 1000B series). There still are a lot of issues with the Rigol 1000Z series so the GW Instek may be a better buy than the Rigol.

author: Fungus
author_rank: Super Contributor
timestamp: February 29, 2016, 11:17:00 am
content: Quote from: nctnico on February 29, 2016, 10:24:01 amNo there aren't. There's, like, three.In functions you may never even use.(...and one of them is just a spelling mistake in a menu)DS1000Z gets regular firmware updates, I expect the next one will sort out pretty much everything.

author: vk6zgo
author_rank: Super Contributor
timestamp: February 29, 2016, 12:19:52 pm
content: Quote from: tggzzz on February 29, 2016, 08:19:58 amIndeed,but my point was that 3% sounds a lot worse than it is.The maximum sensitivity of the 'scope was not commented upon in the posting I replied to.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: March 01, 2016, 06:36:15 am
content: Quote from: uncle_bob on February 28, 2016, 07:04:11 pmAnd even this is only true on some scopes, not all.QuoteYou're right, I forgot about them (well, it's Tek, they're easy to forget these days). But even they now declare the bandwidth of their bench scopes at the connector, not with probes. Which is the only way it makes sense.QuoteNot sure what you're on about, or that you really understand the the basics behind it or even what a scope does.For a start, I/Q is one way to express voltage and phase of a signal (I is the momentary amplitude, Q is the momentary amplitude of the quadrature component, i.e. 90deg phase shifted). The important part here ismomentary, which is important for certain modulation schemes.This however is completely irrelevant for a scope, which is an instrument that simply captures amplitude over a time period and plots it in sync with a trigger event (time domain). That's it. A scope does not split (demodulate) a signal in I and Q components (modulation domain, although some can do that as well), all it shows is voltage variation over time (I). Since a scope is a time domain instrument and not a modulation domain instrument there is no separate sampling of the quadrature component. All that matters is I. And as Nyquist & Shannon found out a long time ago, as long as the sampling frequency is higher than 2x the input signal then you have captures sufficient data for a valid reproduction of the input signal. That's not just theory, it works.Don't believe me?Here's a 20MHz sine wave sampled at 1GS/s (which is 50x the input frequency):Looks nice, right? So lets test Nyquist-Shannon and see what happens when the sampling rate drops to 50MSa/s (2.5x the input frequency), which according to you would be completely insufficient:But look, it's still a sine waveWhat is now missing are the imperfections (i.e. frequency components other than the basic sine wave) that can be seen in the the 1GSa/s screenshot, however the basic 20MHz sine wave is still there. Which clearly demonstrates that Nyquist & Shannon were absolutely right.So next time you lecture someone about sampling theory try to get the basics right first.

author: ebastler
author_rank: Super Contributor
timestamp: March 01, 2016, 07:16:26 am
content: Wuerstchenhund, I'm with you regarding the need for sampling rates just slightly above 2x signal frequency, and the irrelevance of I/Q sampling to the present discussion. (As explained in my post #24 above.)However, I'm confused by your second screenshot: What are all those dots on the curve, 25 of them over a full signal period? Those are not the samples taken by the scope, are they? Either the scope is sampling 10x faster than indicated, or it shows those dots which mean something else? In either case, I find the screenshot misleading as a visual demonstration how a sampling rate of 2.5x the signal frequency is sufficient to reconstruct the signal. Could you explain please, or add a screenshot which more clearly represents the 2.5x sampling rate?

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: March 01, 2016, 07:55:22 am
content: Quote from: ebastler on March 01, 2016, 07:16:26 amNo, these are screen data points of the sin(x)/x interpolation that is used to reconstruct the waveform on the screen.The sample rate is the one shown in the lower left corner and on the Timebase tag on the right-hand side below the graticule.QuoteThis was just a quick demonstration, but in hindsight, you're right, they are confusing, and I should really have disabled the data point indicators.If I don't forget I'll re-do the demo tonight with the indicators off.

author: nctnico
author_rank: Super Contributor
timestamp: March 01, 2016, 10:47:32 am
content: Quote from: uncle_bob on February 28, 2016, 07:04:11 pmAs Wuerstchenhund already wrote I/Q sampling has absolutely nothing to do with oscilloscopes. What you are describing is using two ADCs interleaved. Also Nyquist says that signal UP TO half the sampling rate can be reconstructed. So 500Ms/s is enough to get all the information from a 249.999999999999999999999MHz sine wave but not from a 250MHz sine wave.

author: riverrat373
author_rank: Contributor
timestamp: March 01, 2016, 07:07:32 pm
content: Hey guys, arguing about the technical details on my query isn't helping me to chose a scope!

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: March 01, 2016, 07:33:14 pm
content: Quote from: riverrat373 on March 01, 2016, 07:07:32 pmThese "technical details" are pretty much a detailed answer of a part of your original question (re sample rate), so maybe it would be worth being a bit less dismissive.This aside, this thread may very well be read by other beginners, so it's useful to stomp out any half-truths and myths right at their roots or they'll end up being taken as facts (which happens just too often).And if the "technical details" bore you then you should already have your answer anyways: Rigol DS1054z.

author: riverrat373
author_rank: Contributor
timestamp: March 01, 2016, 11:59:40 pm
content: Quote from: Wuerstchenhund on March 01, 2016, 07:33:14 pmI see what you are saying, but I am a novice when it comes the technical aspects of oscilloscopes and the answer that I'm looking for lies in what scope would be reliable and work for my uses.

author: tautech
author_rank: Super Contributor
timestamp: March 02, 2016, 12:07:24 am
content: Quote from: riverrat373 on March 01, 2016, 11:59:40 pmAny of the cheaper 70-100 MHz Siglents will do what you need for a good amount less than a 1054Z, the advantages being no hacks required and 400V inputs for your tube work.Trouble free and reliable they are too.

author: riverrat373
author_rank: Contributor
timestamp: March 02, 2016, 12:37:28 am
content: Any of the cheaper 70-100 MHz Siglents will do what you need for a good amount less than a 1054Z, the advantages being no hacks required and 400V inputs for your tube work.Trouble free and reliable they are too.Thank you! That's the kind of answer I'm looking for!

author: riverrat373
author_rank: Contributor
timestamp: March 02, 2016, 12:39:05 am
content: I guess that asking for opinions is like asking to see someone's butt! Everyone has one!

author: tautech
author_rank: Super Contributor
timestamp: March 02, 2016, 01:18:22 am
content: Quote from: riverrat373 on March 02, 2016, 12:39:05 amYep, and there'll be several contrary to my advice.Stick to a SDS1072, 1102, CNL(40K) or CML(2M Memory)My best seller is the SDS1102CML, there's something magical about a 100 MHz scope, lower BW's just don't seem to sell the same in my market and the 2M memory the CML's have allows quite reasonable examination of captured waveforms. As I offered in an earlier post, your requirements are not at all demanding and you could get away with less than 100 MHz BW.Back in "the day" techs only had 20-50 MHz BW or less and managed fine for audio work.

author: nctnico
author_rank: Super Contributor
timestamp: March 02, 2016, 01:30:46 am
content: But those are all 2 channels scopes aren't they? I'd pick a 4 channel scope over a 2 channel scope especially if it costs -more or less- the same. The day you need more than two channels is the day you realise you where wrong in thinking two channels should be enough

author: riverrat373
author_rank: Contributor
timestamp: March 03, 2016, 03:37:46 pm
content: Well, I was going to buy the Rigol DS1054Z at Tequipment but decided to look one more time at Circuit Specialists offerings before I did. They have the 200mhz Hantek DS5202P on special for $200.00 plus free shipping. At that price I just had to try it! It's on it's way!

author: ebastler
author_rank: Super Contributor
timestamp: March 03, 2016, 07:58:26 pm
content: Quote from: riverrat373 on March 03, 2016, 03:37:46 pmRight, and with all the glowing recommendations the Hantek received here, you can't go wrong with it! Glad you asked the forum for advice...

author: tautech
author_rank: Super Contributor
timestamp: March 03, 2016, 08:24:56 pm
content: Quote from: ebastler on March 03, 2016, 07:58:26 pmHe'll be back.

author: riverrat373
author_rank: Contributor
timestamp: March 03, 2016, 11:13:56 pm
content: Quote from: ebastler on March 03, 2016, 07:58:26 pmWell, some of us have to economize.

author: nctnico
author_rank: Super Contributor
timestamp: March 03, 2016, 11:30:00 pm
content: True but sometimes going cheap means wasting money. Just be sure you can return it and test it very thouroughly before the grace period for hassle-free returns is over.

author: uncle_bob
author_rank: Unknown
timestamp: March 04, 2016, 12:26:22 am
content: Quote from: riverrat373 on March 03, 2016, 11:13:56 pmHiIf it is a "use once every 5 years" piece of gear, sure. As a matter of fact - for every 5 years rent something. For daily use, don't buy solely on price and nothing else. In 6 months or a year, you will be back spending even more money on a replacement.Bob

author: kcbrown
author_rank: Frequent Contributor
timestamp: March 04, 2016, 12:58:16 am
content: Quote from: riverrat373 on March 03, 2016, 03:37:46 pm$300 is what their site is quoting right now. If you managed to get it for $200, then that's quite excellent.It'll be interesting to see what your impressions are of it once you have it and have used it a bit.

author: ebastler
author_rank: Super Contributor
timestamp: March 04, 2016, 06:54:38 am
content: Quote from: riverrat373 on March 03, 2016, 11:13:56 pmIf you indeed got the Hantek for $200, then at least you got a good price. At $300, which is the "special" I see advertised on the circuitspecialists.com front page, I am not convinced at all.As pointed out earlier in this thread, the DSO5000 is an older series of scopes. Witnessed e.g. by the small memory (40k), slow waveform update rate (2k wfrm/s?), and lack of an intensity-graded display, I believe. Looking a complex signals or detecting rare events will be quite ineffective with this scope.For audio work these limitations will not matter that much; the scope will certainly be useful to you. But neither will the 200 MHz bandwidth do you any good for the "core" application you have in mind at the moment. And in order to have a somewhat future-proof, flexible scope, I think your focus on the extra bandwidth was not a smart choice. Usability, robustness, responsiveness, ... are more important; my bet would still be on the Rigol DS1054Z in this entry-level price range.

author: Karel
author_rank: Super Contributor
timestamp: March 04, 2016, 07:28:30 am
content: Quote from: tautech on March 02, 2016, 12:07:24 amDon't buy anything from Siglent if you are not sure you don't want to sell it on Ebay later...https://www.eevblog.com/forum/testgear/siglent-they-filed-a-'wrongful-trademark-claim'/

author: riverrat373
author_rank: Contributor
timestamp: March 04, 2016, 04:04:08 pm
content: My mistake! Hantek is $299.00!

author: riverrat373
author_rank: Contributor
timestamp: March 04, 2016, 07:04:27 pm
content: You guys have scared me so much about the Hantek scope that I am returning it and I have not even received it yet!I am now looking at the Instek GDS-1054B and the Rigol DS1054Z.

author: tautech
author_rank: Super Contributor
timestamp: March 04, 2016, 07:25:57 pm
content: Quote from: riverrat373 on March 04, 2016, 07:04:27 pmDo either have 400V inputs?

author: ebastler
author_rank: Super Contributor
timestamp: March 04, 2016, 07:37:37 pm
content: Sorry if we caused you a sleepless night! But I think you will be happy you changed your mind once you have selected and started using your new scope.Both, the GW Instek and the Rigol, are good entry-level choices in my view. Quite similar in concept and many specs, but the GW Instek is a tad above the Rigol in some respects. It has more computing power under the hood, resulting in somewhat faster waveform update rate (50k wfrms/s vs. 30k for the Rigol) and a significantly more powerful FFT (although you may not use that often for auio work, since both scopes use only 8 bit sampling).Other notable differences: Rigol has a smaller form factor, GW Instek has separate knobs for each of the vertical sections. Rigol is hackable to enable 100 MHz bandwidth, serial decoders, advanced triggers, which turns it from a "very good value" to an "extremely good value" scope.The GW Instek is also more expensive, about 60% more than the Rigol in my part of the world. Whether its worth the difference is a matter of personal opinion. I am still very happy with my Rigol DS1054Z after more than a year and would definitely buy it again today. I don't have first-hand opinions on the GW Instek and will leave those to others. Whichever model you chose, I am confident you will not regret it!

author: riverrat373
author_rank: Contributor
timestamp: March 04, 2016, 07:43:17 pm
content: Quote from: ebastler on March 04, 2016, 07:37:37 pmThe Instek GDS-1054B is $381.81 U.S. plus a small discount from Tequipment here in the U.S. so it's actually a little cheaper than the Rigol.

author: ebastler
author_rank: Super Contributor
timestamp: March 04, 2016, 07:44:16 pm
content: Quote from: tautech on March 04, 2016, 07:25:57 pm... asked the Siglent dealerSorry, couldn't resist... I'm not sure whether 400V inputs are critical for audio work, or for a general purpose scope. Maybe for tube amps? I can't recall ever finding 300V rated inputs limiting in my scopes during the past 35 years.

author: tautech
author_rank: Super Contributor
timestamp: March 04, 2016, 07:52:19 pm
content: Quote from: ebastler on March 04, 2016, 07:44:16 pmAnd it won't for an experienced user like yourself.As most new DSO's come with switchable probes it's too easy for the inexperienced to inadvertantly connect @ 1:1 and fry an input stage.As the OP in this thread has said he'll be doing tube work, sound advice would be to ensure he gets a scope with 400V inputs, nothing more.I don't care what scope he buys, he won't be getting one from me as I won't supply internationally, I just don't want him starting a thread with this:

author: ebastler
author_rank: Super Contributor
timestamp: March 04, 2016, 07:55:01 pm
content: Quote from: riverrat373 on March 04, 2016, 07:43:17 pmThat makes the GW Instek look quite attractive indeed! The option to upgrade the Rigol for free is probably its main advantage over the GW Instek. If you are sure that you will never want to make use of that (which I believe you mentioned early on in this thread?), the GW Instek may be the way to go!

author: riverrat373
author_rank: Contributor
timestamp: March 04, 2016, 11:31:38 pm
content: Quote from: tautech on March 04, 2016, 07:52:19 pmAre you saying that 300vrms isn't enough for doing tube work?

author: riverrat373
author_rank: Contributor
timestamp: March 05, 2016, 04:01:11 pm
content: I purchased the Rigol DS1054Z for Tequipment.NET last night and do feel much better on my decision! I don't know if I'm going to get back into tube amps but I certainly plan to experiment with chip amps and speakers so I think this scope will do everything that I need. I appreciate all the advice given here and I will certainly will be back with more questions!

author: Karel
author_rank: Super Contributor
timestamp: March 05, 2016, 04:34:19 pm
content: Quote from: riverrat373 on March 05, 2016, 04:01:11 pmCongrats. I'm sure you'll not regret it. The DS1054Z is still king in this priceclass.Make sure you download the latest version of the manual:http://beyondmeasure.rigoltech.com/acton/attachment/1579/f-050a/1/-/-/-/-/MSO1000Z%26DS1000Z_UserGuide.pdf

author: alsetalokin4017
author_rank: Super Contributor
timestamp: March 05, 2016, 05:17:00 pm
content: Does the latest version of the manual mention that the RMS voltage measurements sometimes can't be trusted?https://www.eevblog.com/forum/testgear/ds1054z-issue/

author: riverrat373
author_rank: Contributor
timestamp: March 05, 2016, 06:19:27 pm
content: Quote from: alsetalokin4017 on March 05, 2016, 05:17:00 pmLet's face it, unless you spend about a zillion dollars, most all scopes are going to have some bugs. Probably even the zillion dollar scopes have their problems!

author: tggzzz
author_rank: Super Contributor
timestamp: March 05, 2016, 06:55:23 pm
content: Quote from: riverrat373 on March 05, 2016, 06:19:27 pmIndeed, but you need totrustyour instrument. Let's face it, all scopes (and other instruments) can be misleading in one way or another.If you know that an instrument is "faulty" in some way, it is often possible to work around the imperfections or to take them into account. But, and it is a big but, if you discover "random" unexpected "surprises", you can lose trust and continually wonder what other problems are lurking undetected.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: March 05, 2016, 08:00:18 pm
content: Exactly. And if you've purchased a scope with the idea in mind that you can do, for example, RMS voltage measurements, power computations using Math, or similar functions, and then you discover that the scope will report tens of volts RMS on a channel that isn't connected to anything and is even GND-input-coupled... your confidence in the instrument may indeed be shaken. Especially if this "feature" came along with a firmware update, as this one seems to have done. And then when you discover that you can't even roll back the "update" to a previously functioning version... well, you might just want to.I think if I had a zillion-dollar scope that did this particular thing, I'd have to ask for my money back.

author: tggzzz
author_rank: Super Contributor
timestamp: March 05, 2016, 08:17:22 pm
content: Quote from: alsetalokin4017 on March 05, 2016, 08:00:18 pmWell, HP made its name by delivering on its promised specification. The first time they failed at that (HP3000) , Dave sent a famous two sentence memo to the effect that "we should ensure that equipment meets the specification before shipping it".The manager framed it and hung it on his wall, and all new employees everywhere got to hear another Bill and Dave story.(And then Fiorina explicitly and deliberately killed the HPWay)

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: March 05, 2016, 09:26:49 pm
content: Quote from: riverrat373 on March 05, 2016, 06:19:27 pmYes, all scopes have bugs, but the difference is that the big brands tend to do extensive testing to make sure most bugs are found and squashed and that all functions work as advertised before a product is on the market, plus if any bugs are discovered after release they generally make sure a fix is available in very short time, i.e. in some cases (critical bugs) even within days. You also know how long the manufacturer will support the scope, which includes bug fixes.B-brands like Rigol or Siglent don't do much pre-release testing and pretty much rely on user feedback for finding bugs, and often not all advertised functionality works correctly or at all. But even when bugs are reported it's no gurantee they'll ever get fixed, or when. Some bugs may get fixed quickly, some can take considerable time, others may never be fixed. And because there's very little pre-release testing it happens that a new firmware update fixes a few bugs but introduces a set of new ones (or re-introduces problems that had been fixed before). And because B-brands have no real support strategies for the end user you never know if there even will be another firmware update.There's also the matter what kind of bugs are in the scope. Say a certain functionality clearly doesn't work, the scope crashes or you get some error message. While this is inconvenient, at least the user is aware that there is a problem. The real issue are bugs where the user can't immediately see that something is wrong, like measurement functions showing erroneous values. Any good test instrument might have some of the former type, but should not exhibit any of the latter.Having said all that, we should remember that in regard to this thread we're talking about $400 scopes, which for a scope is really bottom-of-the-barrel. And it's only the cheap B-Brands that can even offer anything in that price range, and yes, all their products come with bugs. The reality is that quality control and support cost money, and a comparable big brand scope will cost you a lot more than just $400. And even the 2nd hand market, usually a viable alternative to new gear, rarely offers anything better in the $400 class. At $400, the Rigol DS1054z is incredible value for money, despite the bugs. It's a good basic scope, as long as the user is aware of its limitations and its bugs, and can live with the shortcomings. If not, well then the only real option is to increase the budget. A lot!

author: alsetalokin4017
author_rank: Super Contributor
timestamp: March 06, 2016, 12:11:02 am
content: Well... at least reporting 40 or 60 VRMS on a channel that is grounded and receiving zero volts is waay better than reporting zero volts on a channel that is actually receiving 40 or 60 VRMS !But I'm really tired of hearing this "Well what do you expect, it's only 400 dollars" thing every time a new bug shows up. What I expect is a product that works according to the specifications on the data sheet. How much the manufacturer wants to sell it for is entirely another issue. If it's too much for me I won't be buying it, no matter whether it works or not. But if I buy it, for whatever cost, I expect it to work properly, as designed and specified. Call me old fashioned....The fan is noisy? What do you expect, it's only 400 dollars.You can't push a knob without turning it? What do you expect, it's only 400 dollars.It miscounts pulses? What do you expect, it's only 400 dollars.All Measurements stop working at random times when Math is in use? What do you expect, it's only 400 dollars.At 500 ns/div, the Math trace is not synched with the input traces? What do you expect, it's only 400 dollars.It has a speling eror? What do you expect, it's only 400 dollars.You can't roll back to earlier firmware? What do you expect, it's only 400 dollars.RMS voltage measurements show up on channels with no input? What do you expect, it's only 400 dollars..... and so on./

author: tggzzz
author_rank: Super Contributor
timestamp: March 06, 2016, 01:42:09 am
content: Quote from: riverrat373 on March 05, 2016, 06:19:27 pmThat's a poor argument. To see why, look at it "from the other end"...I could develop and sell a scope with the DS1045's specification for1%of the DS1054's price -providedthat it is acceptable for there be "bugs" in my implementation of the specification.Would you buy such a scope, without knowing the bugs? Now, would you buy a DS1054 without knowing its bugs?

author: riverrat373
author_rank: Contributor
timestamp: March 06, 2016, 01:43:48 am
content: Quote from: alsetalokin4017 on March 06, 2016, 12:11:02 am

author: riverrat373
author_rank: Contributor
timestamp: March 06, 2016, 01:45:17 am
content: Quote from: tggzzz on March 06, 2016, 01:42:09 amYou really know how to bring a person down, don't you.

author: tggzzz
author_rank: Super Contributor
timestamp: March 06, 2016, 01:46:52 am
content: Quote from: riverrat373 on March 06, 2016, 01:45:17 amNot at all. I'm "taking theargumentdown".

author: uncle_bob
author_rank: Unknown
timestamp: March 06, 2016, 02:16:13 am
content: Quote from: tggzzz on March 06, 2016, 01:46:52 amHiEither extreme:1) that there must be absolutely noting that anyone can ever look at as a bug under any circumstances2) that a product can be simply one massive bug with no function at allis equally flawed.It is a rare case that does not look ridiculous when taken to the extreme.Bob

author: markone
author_rank: Frequent Contributor
timestamp: March 06, 2016, 02:22:42 am
content: Quote from: alsetalokin4017 on March 06, 2016, 12:11:02 amWell, almost every DS1054Z's buyer expects that it works well beyond its data sheet specs ...This is the current game with this scope, on one side we have who buys it and hack it right after, on the other side we have Rigol that does know that very well and recovers the profit loss not providing prompt FW service support.You have to put this on the balance pan and if the reading is still negative for you, then put it on sale and prepare some grands for a professional scope, this one is mainly targeted at amateurs for unsalaried hobby activities, where within some extent this kind of things are not a deal breaker.

author: tggzzz
author_rank: Super Contributor
timestamp: March 06, 2016, 10:02:36 am
content: Quote from: uncle_bob on March 06, 2016, 02:16:13 amJust so. But it can be a useful technique for directly or indirectly drawing attention to the limitations of an argument. In effect, making it clear that the world isn't black and white, and that gray areas exist.It is a matter of personal choice where to draw a boundary within the gray area.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: March 06, 2016, 10:34:57 am
content: Quote from: alsetalokin4017 on March 06, 2016, 12:11:02 amThen don't buy something made by a Chinese B-brand. Simple as that.Buying B-brand but expecting big brand quality control and support is idiotic, really. The saying "you get what you pay for" remains valid, even more so for test instruments. Producing a mature, stable and well supported product costs much more than what the B-brands sell their stuff for (while still making a profit). It's simply not possible.I have made my fair share experience with Rigol and Siglent kit (both my own and devices in my environment), and because of that it's extremely unlikely I'll ever touch any of their devices again. I've decided I can't live with half-working functionality, idiotic bugs or (in case of Siglent) the clear display of utter incompetence to write proper firmware for their products. Therefore for me it's still pretty much 2nd hand big brand all the way, which has served me well for a very long time already.But that's me. On the other side, for a starter with a tight $400 budget and modest requirements, what is he gonna do? A mature big brand scope, even a used one, is simply not available for that price, unless you consider some antique analog boat anchor a good starter scope in 2016 (I don't). Something like a Rigol DS1054z however, despite its bugs, is still better than no scope at all. And it can still be incredible useful if the user is aware of its bugs and limitations.

author: Eheran
author_rank: Regular Contributor
timestamp: March 06, 2016, 10:47:54 am
content: Quote from: tggzzz on March 06, 2016, 01:42:09 amWell go ahead then. There are always bugs in everything that is remotely more complex as a hand mixer.I gues its clear that "a few bugs" is not "not fullfilling the spec at all".QuoteThose are all of the issues with the scope? Even something like a loud fan? Which you can find in every price range...?5/6 of these 8 problems can be solved in a new firmware. So far they did solve problems in their firmwares, didnt they?What will be left after fixing all of that in <12 Month? A loud fan and knobs that are not superb. Jeeeez!For me: Only the RMS could be a real problem. The fan is replaced. Never had any of the other bugs and/or dont use that.400$/€ for that scope is just a awesome price.

author: tggzzz
author_rank: Super Contributor
timestamp: March 06, 2016, 11:03:47 am
content: Quote from: Eheran on March 06, 2016, 10:47:54 amPlease do not misattribute quotes.I doubt anyone would buy "my" scope after it became apparent that, despite its specifications, the implementation consisted of a random number generator. But I'm sure you realised that.

author: forrestc
author_rank: Unknown
timestamp: March 06, 2016, 11:38:52 am
content: Quote from: riverrat373 on March 04, 2016, 11:31:38 pmI'm pretty certain what he's saying is that you're less likely to accidentally blow up a 400Vrms scope than a 300Vrms scope. Remember with a 10X probe, you're not going to end up with the raw voltage you're reading on that input. If you have a typical 1x/10x switchable scope and you hook it to a 350V source and the probe is accidentally switched to 1X, you'll cook your scope. As long as you never do that you'll probably be ok. (But .. don't come yell at me if you cook your scope).Personally I've moved toward fixed 10X probes. The switchable ones are fine, but most of the time, you should just set your probe to 10X and leave it there. In 1x mode, you'll be loading your circuit with the scope impedance directly - probably 1Mohm. With a 10X probe, the impedance will increase to 10Mohm which will load your circuit even less. A 100X probe would reduce the loading even further. More importantly, the 10X probe has significantly lower capacitive loading than the 1X would, and of course a 100X probe would have even less. All of this adds up to the fact that a 10X probe seems to be the sweet spot between voltage into the scope and loading - a 1X has so much resistive and capacitive loading that you're just asking for the performance of your circuit to be changed by the addition of the probe, and the 100X tends to attenuate too much voltage, at least for lower-voltaged circuits.Because of this, when I purchased my newest scope, I put the expensive supplied probes away for special uses (let's just say that replacement probes from the scope manufacturer cost around what you are going to pay for your entire scope with four probes). I then picked up some decent quality fixed 10X probes from probemaster which is what I use for every day use.In reality, for you, the 1X/10X switched probes should be fine, just be careful around high voltages. I would, however, strongly consider purchasing a fixed 100X probe (or maybe switchable 10/100x) for the high voltages. I don't have a 100X probe, but if I needed one I'd buy one from probemaster. They have a Fixed 100X probe for $76 which is rated for 1200VDC and 200Mhz.Hope this helps.Oh, and I'll add into everyone else's opinions.... For your budget, just buy the Rigol DS1054Z. You'll be happy with it. And, by the time you're not happy with it, you'll know very specifically why you're not happy with it.One more note: tequipment.net is really good at giving discounts to eevblog members. I'd ask for a quote with the 'eevblog discount'. You should be able to get this at an even lower price.

author: nctnico
author_rank: Super Contributor
timestamp: March 06, 2016, 11:58:04 am
content: Quote from: forrestc on March 06, 2016, 11:38:52 amThere is a caveat here: the voltage rating of a probe gets lower when the frequency gets higher so you have to take that into account as well.

author: tggzzz
author_rank: Super Contributor
timestamp: March 06, 2016, 12:46:39 pm
content: Quote from: forrestc on March 06, 2016, 11:38:52 amOnly at audio frequencies, of course. At 100MHz its impedance will be around 100ohms (i.e. 0.1kohm).And, as nctnico reminded us, check the probe's voltage-vs-frequency rating - youwillbe surprised.QuoteI strongly agree with the "use it to learn what you really want/need" concept. You might never want/need anything else. One way or another youwillpay for your learning experience

author: Fungus
author_rank: Super Contributor
timestamp: March 07, 2016, 11:39:31 am
content: Quote from: Eheran on March 06, 2016, 10:47:54 amThis. Rigol has already shown they can fix issues. What's left on that tiny list could easily all be fixed in the next update. I guess the people endlessly posting here about spelling mistakes will have to find a new hobby when that happens.

author: Fungus
author_rank: Super Contributor
timestamp: March 07, 2016, 11:47:20 am
content: Quote from: forrestc on March 06, 2016, 11:38:52 amGood idea.One or two fixed 10x probes is a very wise investment if you regularly work with high voltages. 100MHz probes are still in the "very cheap" category - you can get reasonably good ones for about $20.Quote from: forrestc on March 06, 2016, 11:38:52 amYep.

author: riverrat373
author_rank: Contributor
timestamp: March 07, 2016, 04:37:58 pm
content: Quote from: Fungus on March 07, 2016, 11:39:31 am

author: alsetalokin4017
author_rank: Super Contributor
timestamp: March 07, 2016, 06:05:04 pm
content: Errors that were evidently _introduced_ by the latest firmware "fix" that didn't happen before:The Pluses spelling errorThe miscounting of pulsesThe Measurements that stop working at random times when Math is in use, requiring a power-cycle restartThe RMS errorThe severe slowing down of response to controlsand who knows what else.Errors that have not been fixed through several firmware updates:The 500ns/div Math horizontal errorThe fact that Boot Version isn't changed by updates, leaving many scopes with the older Boot Version 0.0.1.2 subject to the Freeze bugThe fact that new firmware cannot be rolled back to previous versionsThe very slow saves of screenshots to USB flash drivesThe crazy bad pc softwareThe tiny font choice for the measurementsand who knows what else.At least we now know how to fix the flaky switches on the probes, by cutting away bits of plastic flash. And you can make the yellow insulation caps stay in place by a few bits of tape. And who cares if replacing the fan voids the factory warranty.But what do you expect, it's only 400 dollars. Why, a decent set of probes alone from a "real" manufacturer will cost you more than that. And a new firmware update will fix these problems.... won't it? And you can avoid _all_ these bugs and errors, simply by "don't use that".... just leave the scope turned off!!(Hey, leave my hobby alone, it provides me with great amusement. You want a scope that makes pretty coloured lines when it's connected to a FG -- well we got that, and it's only 400 dollars, what do you expect!!! )

author: riverrat373
author_rank: Contributor
timestamp: March 07, 2016, 08:34:42 pm
content: After reading all the negative posts about "bargain" scopes I'm inclined to believe that there are a bunch of "scope snobs" on this forum! If these "bargain" scopes are so bad there must be 10's of thousands of unhappy "bargain" scope buyers around the world. It must be by some unknown miracle that those "bargain"scope builders stay in business! I see here what I see on a lot of audio forums. If it didn't cost thousands it's no good.

author: nctnico
author_rank: Super Contributor
timestamp: March 07, 2016, 08:46:05 pm
content: Quote from: riverrat373 on March 07, 2016, 08:34:42 pmIt depends on what you want. Any oscilloscope can display signals so if that is your usage scenario then any oscilloscope will be fine. The problem is that the cheaper scopes have a lot of features which are implemented poorly & buggy and bug fixes are slow or non existent.

author: Marcos
author_rank: Contributor
timestamp: March 07, 2016, 08:59:40 pm
content: Quote from: nctnico on March 07, 2016, 08:46:05 pmThen don't advertise them as full of options to trick peoples believe that they get the best "fancy" scope in the world for 400 bucks.Oooh, and also up-gradable to 100Mhz for free.Everything for 400 dollars.Wait!That's not all!You'll get a Free Dinner too and a Movie Gift Card if you'll buy it from tequipment.net.http://www.tequipment.net/Rigol/DS1054Z/Digital-Oscilloscopes/?b=y&v=7906

author: uncle_bob
author_rank: Unknown
timestamp: March 08, 2016, 12:24:06 am
content: Quote from: riverrat373 on March 07, 2016, 08:34:42 pmHiThere are also an amazing number of people who buy a bargain scope and then pick their purchase apart. It rapidly becomes apparent that the specs they were after are only available on a $5,000 device. Somehow they just didn't notice that their $200 scope did not include those features before buying it. The process then forks, either it becomes a rant about the manufacturer not doing firmware upgrades to add the features or it becomes a *poof* $200 scope vanishes, replaced by the $5,000 one.BobBob

author: tggzzz
author_rank: Super Contributor
timestamp: March 08, 2016, 12:49:51 am
content: Quote from: uncle_bob on March 08, 2016, 12:24:06 amMaybe. But the point at question here is whether or not the manufacturer's implementation matches the manufacturer's specification.What other manufacturers charge for the same specification is a completely different question. Cfhttp://www.windowsnetworking.com/j_helmig/gotohell.htm

author: uncle_bob
author_rank: Unknown
timestamp: March 08, 2016, 12:54:17 am
content: Quote from: tggzzz on March 08, 2016, 12:49:51 amHiIt is rare to find a $200 device that "matches specifications" to the same degree as a $5,000 device. That's true no matter what you are buying. It is also rare to find a $5,000 device that is "fully spec compliant" no matter who looks at the spec's in which and what way. What is true is that the higher price gizmo is a lot more likely to come closer than the $200 item. Quality assurance costs money, it is one of the things you get "more of" on the higher price device.Bob

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: March 08, 2016, 06:22:01 am
content: Quote from: uncle_bob on March 08, 2016, 12:54:17 amThat's nonsense, money has nothing to do with compliance with the mfgr spec. I can agree that $200 does not give you the same performance as a $5k device but that is no excuse for the $200 device to not match its promised specifications, which after all have been put together by the manufacturer.And if you really believe price is a differentiator then I guess you've never used a Rigol DS6000, a scope which costs in the region of $6k to $9k, and guess what, it pretty much suffers from similar problems as its $400 brother.Now go and compare that with any big brand device. Even a $200 Keysight DMM will fully comply with its specifications.QuoteYes, if it's made by Chinese B-brands like Rigol. I've yet to see a big brand device that does not conform to it's mfgr specs, unless it's defective (and I've seen a lot of T&M gear in my life). In fact, most big brand devices pretty much exceed the stated specs by some margin. If a big brand device fails its specs then it's defective, simple as that. And if its defective it goes back to the mfgr who will fix it so that it conforms to its specs again.Any reputable T&M manufacturer will make sure that its devices comply with the listed specs, especially as specs can become part of contractual obligations.QuoteYes, QC costs money, and so do proper software development processes, and both is pretty much absent from B-brands. There's a reason why a company like Rigol can push out a 1GSa/s 4ch scope at $400 and still make a profit, which is only possible if corners are cut.

author: tggzzz
author_rank: Super Contributor
timestamp: March 08, 2016, 07:59:49 am
content: Quote from: uncle_bob on March 08, 2016, 12:54:17 amIt is unacceptable that the manufacturers lie to their customers in such a way. Doubly so since their product is probably useful and good value for money even without the, ahem, "enhanced" advanced specs.I usually prefer something that does one thing well rather than two things badly. I loathe things and people that promise more than they can deliver.

author: nctnico
author_rank: Super Contributor
timestamp: March 08, 2016, 09:46:39 am
content: Quote from: Marcos on March 07, 2016, 08:59:40 pmThose free dinners are usually only free if someone else comes along and doesn't include the drinks (and guess what restaurants make the most profit from). Actually very much like the Rigol and Siglent offering; it looks nice on paper but the actual device is performing nowhere near of what is promised.

author: Fungus
author_rank: Super Contributor
timestamp: March 08, 2016, 10:25:49 am
content: Quote from: uncle_bob on March 08, 2016, 12:24:06 amRubbish.The DS1054Z (for example) easily meets its bandwidth specs, etc. At a hardware level there's no possible criticism that it doesn't do what it says in the advert.Are there a couple of hardly-ever-used functions that don't quite work? Yes. Is there a spelling mistake in a menu? Yes.But ... any person with a bit of common sense will forgive those becauseyou're getting a 4-channel, 100MHz oscilloscope with decent memory, bandwidth, waveform update rate and a whole bunch of useful featuresfor $400. That's about a quarter of the price that the snobs paid for oscilloscopes that are only a tiny bit better in real terms (and often worse in features like memory size).You'd have to be head-slappingly stupid to not see the DS1054Z as abargainthat should be grabbed, especially if you don't own another oscilloscope.PS: If Rigol ever does fix the last couple of problems with a firmware update then you can come back here and laugh at them. Me? I'm ready to go. I'll create that thread myself!

author: Fungus
author_rank: Super Contributor
timestamp: March 08, 2016, 10:40:15 am
content: Quote from: uncle_bob on March 08, 2016, 12:54:17 amThat's nonsense.If I sell a million devices for $200 I'll have alotmore money for development and QA than somebody who sold a thousand devices for $5000.

author: Fungus
author_rank: Super Contributor
timestamp: March 08, 2016, 10:47:28 am
content: Quote from: tggzzz on March 08, 2016, 07:59:49 amWhat about a product that does 99 things well and 1 thing badly.Is the product that does 100 things well worth four times more money?Me? I'd say you should look at how often you'rereallygoing to use that particular feature. Perfection is a nice concept but in real life having four times more things can be nicer.What's better? a) An oscilloscope scope that doesn't have any spelling mistakes in the menus, or b) An oscilloscope that has a spelling mistake + a signal generator + a power supply + a high end multimeter + a decent soldering iron?

author: tggzzz
author_rank: Super Contributor
timestamp: March 08, 2016, 02:19:02 pm
content: Quote from: Fungus on March 08, 2016, 10:47:28 amObviously it depends on what the things are. If a car had perfect automatic sunroofs and similar, but occasionally misreported the speed or the throttle jammed open, then I would avoid it like the plague.QuoteMeasuring values correctly is pretty fundamental to a measurement instrument. Or don't you agree?Other things might be tolerable, but they reduce confidence.

author: Fungus
author_rank: Super Contributor
timestamp: March 08, 2016, 02:53:04 pm
content: Quote from: tggzzz on March 08, 2016, 02:19:02 pmYes, but itisn'tanything fundamental like that. Stop pretending that it is.Let's look at the massive list of bugs being posted here:QuoteThere's only three things on there that can really be classed as "bugs". The rest are only whines.OK, they exist. Now let's assume Rigol is incapable of fixing (eg.) the 'math' bugs, that they simply disable that menu in the next firmware release.Even so, even without the math menu, the DS1054Z would still bemonstrousvalue for money. You'd be an idiot not to buy one for general purpose work just because that menu is greyed out. You wouldn't doing anybody a favor by going on the Internet and telling other people to avoid it, that they should be spending $2000 instead to get a 'real' oscilloscope.Newbie note: The 'math' functions are where you take two input signals, do some math with them and display the result, eg. Channel A minus Channel B. It's not usually a function you use every day.

author: tggzzz
author_rank: Super Contributor
timestamp: March 08, 2016, 04:46:06 pm
content: Quote from: Fungus on March 08, 2016, 02:53:04 pm2+2 = 5 is a significant bug. Intel did the right thing with the Pentium FDIV bug.Standard anecdote about how small "gui" issues can hide fundamental problems... When bringing up a version of an early Smalltalk interpreter, everything (GUI/windows/compiler/VM) was working except that the windows scrolled in the wrong direction. It was traced to being an incorrect implementation of the subtraction of negative numbers. (I've never known whether to think Smalltalk is therefore wonderfully robust in the presence of errors, or impossible to assure that it is working correctly.)So yes, getting the details right does matter. "If they can't get the easy things right, what chance have they of getting the difficult things right?"QuoteNo. By my count there are 5 serious errors plus 6 infelicities.QuoteI agree it would still be good valueifthe menu was greyed out until fixed.But it isverybad value if you spend a significant amount of your remaining life chasing bugs in the scope. In a similar way, any suspect cable/probe should be binned - not stuck back on the shelf to waste the next person's time.QuoteBut when you do, it is critical functionality. For example, I've unavoidably been doing that all week, while faultfinding another scope.

author: kcbrown
author_rank: Frequent Contributor
timestamp: March 09, 2016, 04:15:56 am
content: Quote from: tggzzz on March 08, 2016, 04:46:06 pmWhile that is surely true, only one person really has to do that, and then publish his results. Then anyone who sees the published results will know the limitations of the math functionality, and thus the value will be even greater to him than it would be if the menu were grayed out.I think the lesson here is that one should test functionality that one is going to depend on before actually depending on it, particularly with such an inexpensive instrument.QuoteThe main problem is that oftentimes, one does not know in advance all the functionality that will be required. So it then becomes a question of how responsive the manufacturer is with respect to fixing bugs (Agilent, for instance, is truly excellent. See the Agilent 34665A thread starting withthis messagefor a great example), along with the probability of encountering a significant bug in the functionality you need (which should generally be quite a bit less for the reputable manufacturers).

author: tggzzz
author_rank: Super Contributor
timestamp: March 09, 2016, 08:13:14 am
content: Quote from: kcbrown on March 09, 2016, 04:15:56 amIn an ideal world, yes. In the real world people rarely read the instructions, let alone errata. And as for things discovered after initial purchase use, not a chanceQuoteVery true, but it is also beneficial with expensive perfect equipment - to assure yourself that you understand the instrument and everything related to the measurement technique. The obvious example w.r.t. scopes is to understand the probes!Or, as I am doing a the moment, with old equipment such as a Tek485 - which (now) works perfectly except that the gain is marginally low.QuoteYes, and that kind of attitude was baked into all HP employees via the HP Way and numeroud "Bill and Dave" anecdotes. Fiorina explicitly and deliberately discarded the HP Way, much to the employees disgust.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: March 09, 2016, 12:06:57 pm
content: Quote from: tggzzz on March 09, 2016, 08:13:14 amTrue, and now she's offering to do the same for America!

author: kcbrown
author_rank: Frequent Contributor
timestamp: March 11, 2016, 03:19:13 am
content: Quote from: tggzzz on March 09, 2016, 08:13:14 amNobody reads electronics forums?QuoteRight.But then, if that's the case, then someone who gets "bitten" by a bug in functionality they depend on either didn't do their due diligence before making the measurements, or they didn't do their due diligence before making the purchase, with the only differentiating factor being whether or not they knew in advance that they'd need the capability in question.Don't get me wrong -- that doesn't excuse a manufacturer like Siglent or Rigol from fixing issues when they are discovered. But in the end, the only time it'sreallyegregiously unforgivable for a showstopper bug in available functionality to exist is when that functionality is basic to the main function of the instrument (here, that would mean things like failing to properly display a waveform), or when the nature and/or frequency of bugs in the instrument is way out of proportion to the price of the instrument.Put another way, there is an inverse relationship between the price of the instrument and the nature/frequency of the bugs that are reasonably "acceptable" in terms of their initial existence or time to fix. The higher the price of the instrument, the smaller the nature/frequency of the bugs that one would reasonably allow. A bug in the math functionality of a 20K LeCroy would be unacceptable, probably warranting return of the product if the manufacturer doesn't fix itRight Now, while that same bug in a $400 Rigol is, while annoying, at least something that one can live with (and if it's something that cannot be lived with, then clearly a different instrument is appropriate).Quality costs money, period. Whether it is in software or in hardware is irrelevant. If you insist on paying for the lowest end equipment, and that equipment has software/firmware that drives it, then you should expect it to have bugs. Conversely, if you pay a large sum for your equipment, then you have every right to expect it to be essentially bug-free, and for the manufacturer to fix any bugs immediately.Honestly, it's somewhat astonishing that thehardwareissues with the Rigol/Siglent/etc. are as rare and unobtrusive as they are.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: March 11, 2016, 06:54:04 pm
content: QuoteWhat about if someone searches, finds and sees a couple of long video reviews and teardowns of the instrument in question, and decides to purchase the thing based on what he/she sees in those videos? In other words, "due diligence" was done by looking at all available information that the purchaser could find... But the videos somehow missed coverage of the actual bugs-that-bite ... and then on top of that, a new firmware update actually _introduces_ new biting bugs? What's the "differentiating factor" in that case? Who could have guessed in advance that a (only 400 dollar) DSO might be used, say, to make RMS voltage measurements?Personally, I expect a product to perform as advertised, no matter how much the manufacturer decides to sell it for. Either that, or the product's advertising should clearly state that "Not all advertised functions may work exactly as specified or as you expect".....

author: Marcos
author_rank: Contributor
timestamp: March 11, 2016, 07:16:22 pm
content: Quote from: alsetalokin4017 on March 11, 2016, 06:54:04 pmThe best way to fix this scope is to completely remove faulty features, delete those from their advertising, and staying focused on the available (still good) features to make them working as specified.Anyway, their price is dropping so fast so, very soon, we will say "What do you expect for a 100 bucks scope?"

author: tggzzz
author_rank: Super Contributor
timestamp: March 11, 2016, 07:27:42 pm
content: Quote from: Marcos on March 11, 2016, 07:16:22 pmPrecisely. Rigol would still have a winner on their hands, and people wouldn't have anything to criticise - which would be good for people and good for the company.QuoteWhich won't change anything, of course."It is only a $5 1000V DVM, what do people expect for £5?" is the subject of different threads

author: kcbrown
author_rank: Frequent Contributor
timestamp: March 12, 2016, 10:50:52 am
content: Quote from: alsetalokin4017 on March 11, 2016, 06:54:04 pmIf youreallyneed RMS voltage measurements so much that whether or not the feature works is a make-or-break thing, and you know this in advance, then you get on a forum like this one and ask people who already own one if the RMS voltage measurement feature works. That is the "due diligence" I speak of.Due diligence isn't merely a question of whether or not you've acquired as much information as you reasonably can about the general capabilities of the instrument. It also encompasses gathering information about the mission-critical aspects of the instrument you're considering. If you insist on purchasing the lowest priced instrument in the market, there is that much greater reason for you to ensure ahead of time, through whatever means you can, that the instrument will do what you need it to do.TANSTAAFL. Period. Either you pay in terms of money or you pay in terms of sweat equity.QuoteBelieve me, I agree with you in principle. But the reality on the ground is that the ROI of quality is generally a lot lower than the ROI of advertising (do you think software quality would be in such a shoddy state in general if it weren't expensive to achieve?). Quality not only costs more in terms of development man-hours, it costs more in terms oftime, and that means it costs more in terms of market opportunity. Rigol is cleaning up over Siglent in the lowest end of the market with their DS1054Z becausethey got there first.Advertising to the world that "not all functions may work exactly as specified or as you expect" is a sure way to kill your market prospects dead. No sane company wouldeverdo that. So, what, you expect these companies to commit suicide? Remember that they compete with theentiremarket, not just against the established players, which means they compete with each other. If their edge isn't quality, then it has to be either features or price. It can't be features because the established players already have that covered, too, so that leaves only price. And if it has to be price, thensomething has to give. What exactly do you expect to give if it isn't quality? If you expect it to be features then, well, that experiment has already been performed. There already exist scopes with greater quality but fewer features at roughly the same price point: the previous generation scopes (e.g., the Siglent SDS1102CML), which are mature and can still be purchased new. How well do you think they are selling relative to scopes like the DS-1054Z? Do you think most customers would opt for the older but more mature scopes over the newer and more feature-rich ones? The sheer amount of discussion about the latter makes the answer to that question clear: most opt for the newer scope because it ismore capable, even if it does have more bugs.And finally, software is probably the most complicated thing about just about any product. And with something like an oscilloscope, it's even further complicated by very strict real-time requirements that are absent in most software. That a company like Rigol is able to produce an oscilloscope with the amount ofworkingfunctionality that the DS1054Z has at the pricepoint they're targeting is, frankly, astonishing. It's not like an oscilloscope is a heavily mass-produced item like a smart phone. That the pricepoint is what it is despite the relatively low economies of scale is quite incredible.Could Rigol do it better? Most definitely. Could they do it better while maintaining their current pricepoint? Well, that's the real question, isn't it? I'd say they probably could, but that's just a guess. Would I prefer that they did it better if it meant increasing the price by a significant amount (like, say, doubling it)? Actuallyno. Why? Simple: becausethatmarket is already filled by other players like GW Instek.I'd rather that the market have greater variety, even if that comes at the expense of quality at the lowest end. As long as the remaining market is not adversely affected, then it's better for everyone.

author: Dave Atom
author_rank: Contributor
timestamp: March 17, 2016, 09:03:45 am
content: I was going to start a new thread about whether or not to buy the DS1054Z, but as the forum states, they answer may already exist if you lookThanks for those that contributed to this particular thread, I think the decision is made, now I just need to persuade the other half that it's a wise investment

author: uncle_bob
author_rank: Unknown
timestamp: March 17, 2016, 12:38:18 pm
content: Quote from: Dave Atom on March 17, 2016, 09:03:45 amHi..... I find that during the "spring re-plant the garden" season, it's often best to slip the scope purchase in with the discussion of how many (hundred) bags of this and that we "really need" to get the garden going.Bob