Does anyone have any experience with Owon? - Page 1
Forum section: electronics / testgear

author: Armin_Balija
author_rank: Regular Contributor
timestamp: June 27, 2011, 02:36:17 am
content: Hello there EEVBlog forum members,I've been looking around trying to find out what a good entry-mid level quality scope would be for my first purchase. I've been looking at the DS1052E but a recent thread showed me some negative aspects of it ( bad looking noise when just looking at functions ). I don't know too much about scopes in the sense that I don't know what's more important, Sample rate or Bandwidth. I know they're related, but I don't know how a scope with less bandwidth can have a higher sample rate (more on that later.)I saw two oscilloscopes that looked rather good for their price range and was hoping someone had one and could place a review on it. Has Dave ever had any experience with Owon?Here are the two I've been looking at:PDS5022S:http://www.saelig.com/PSBEB100/PSSA002.htm1.The first one I've been looking at is at a good price range which makes it competitive. At $267.00, it could very well be my new scope. However, 25Mhz just seems like itmightbe a bummer in the future if I want to look at higher frequencies. Is it worth it to pick up a cheaper (but more limited) scope if I'm just going to school and working my way towards educating myself? If I'm doing smaller projects at the moment, should I just invest in a better scope in the future?SDS6062:http://www.saelig.com/PSBEB100/PSBEB100003.htm2.The second scope I want to get is priced the same as a DS1052E with a higher bandwidth but lower sample rate (Half of a DS1052E). A DS1052E is 1Gs/s while this one is 500Ms/s and 250Ms/s @ dual channel. This scope has a better rise time, screen resolution, and actually gives you a reliable accuracy on it's measurements; On this one it's 3%(I have not seen the DC accuracy on a DS1052E.)If anyone has either of these scopes what do you think of them?

author: armandas
author_rank: Frequent Contributor
timestamp: June 27, 2011, 08:08:22 am
content: I have had my hands on a PDS6062S and I have to say it's a joke. Sure, if you can get one of these for $100-$150, then go for it, otherwise, look somewhere else.The built quality seemed very low. The STN screen is such a piece of crap, that they had to put a contrast adjustment on the front. Plastics feel cheap and the legends are just printed straight on (which looks like shit). If I had to guess the cost of making these scopes in volume, I'd say $50.The owon also had a triggering issue. The actual trigger level would become different from that shown on the screen as the waveforms were moved up and down (think about fitting two traces on the screen). Don't know if this issue is present across all models/firmware versions.I know next to nothing about the SDS6062. Just don't fall for that "semi-portable" gimmick, PDS series already were overpriced lunch boxes (very little circuitry inside), so it's not like cutting scope's size in half is a big deal.TL;DR: Avoid Owon, get something decent, like a Rigol, GW-Instek, Hantek/Tekway.

author: willd1971
author_rank: Regular Contributor
timestamp: June 27, 2011, 09:52:25 am
content: I advocate Uni-Trend for the budget conscious, I've had some experience selling them in Europe and all my customers are happy. They're confident enough in their product to offer a 3 year warranty, and although they are relatively cheap they feel solid and the screen is fine (although higher resolution would be nice). Also, I find the manufacturer is interactive and interested in aftersales unlike some other people you might deal with in far east. You're welcome to take a look at http:www.labtronix.co.uk to see the kind of offerings they make - I have stock due mid July.As for parameters. Bandwidth needs to be placed in the context of sample rate for a DSO. If the quoted bandwidth is more than half the sample rate then you will only be able to capture periodic signals at the quoted bandwidth when using equivalent sampling. To have any chance of seeing the 'true' shape of an event or a perodic signal the higher the sampling rate the better - essentially you need to take as many individual samples as possible then plot the line between all of them to see the shape, the more points the truer your trace will be. So, 25MHz bandwidth with 2GSPS is a much higher resolution scope in the time domain than 25MHz at 50MSPS which will only just register the presence of a 25MHz signal without giving you any useful shape information. Sample rate is more significant when you are looking at analogue signals or when you are looking at precise timings between digital events. Of course, the higher the frequency content of what you want to look at, the more important parameters such as bandwidth and sample rate become. If you never look at anything over 100KHz (digital or analogue) then 25MHz @ 250MSPS will probably suit you fine.Using scopes for amplitude measurement needs to be done in the knowledge that many factors can affect vertical accuracy. I never use a scope to try and record accurate amplitude levels, but just for indication or relative measurement. If you do want to make accurate recordings you need to set up local calibation first, trim your probe leads, be aware of vertical resolution (ADC) , and compensate for any gain losses considering the frequency content of the signal you're looking at. If you really need to make accurate vertical measurements you need to look for scopes with appropriate ADCs as a starting point, most are 8 bit conversion but you can go higher - at a higher price.All the bestWilliamhttp://www.labtronix.co.uk

author: Armin_Balija
author_rank: Regular Contributor
timestamp: June 27, 2011, 01:45:11 pm
content: Quote from: willd1971 on June 27, 2011, 09:52:25 amI really liked most of the products on that site and the pricing seemed reasonable but it's all out of stock! Seems to be quite the hot item. Around what date in July do you think the next shipment will be in?

author: willd1971
author_rank: Regular Contributor
timestamp: June 27, 2011, 02:47:28 pm
content: Thanks Armin_Balija, I have a consignment on the high-seas right now should be landing and ready for sale by mid July. You can never be too certain about the timing of these things because of issues like ocean weather, port congestion, customs clearance, forward shipping etc etc. Some items on the consignment are 'pre-sold' so customers have already reserved an item by placing a deposit. You're welcome to send me a PM for further information.RegardsWilliamhttp://www.labtronix.co.uk

author: JimmyM
author_rank: Regular Contributor
timestamp: July 04, 2011, 06:21:25 pm
content: I have a PDS5022. Had for a couple of years now. I do mostly low frequency stuff 50Hz-10kHz). But have been doing more work with switch mode supplies (100kHz-3MHz) and the PDS is now showing it's bargain basement feature set. Screen resolution is OK for a small screen. Trigger options could be better.If all you do is lower frequency stuff and have no need for things like trigger hold off, it's OK for the money. Don't expect a lot.I'm looking at getting something with a better/larger screen and higher frequency/sample rate. A Rigol is about as cheap as I'd like to go now.

author: gregariz
author_rank: Frequent Contributor
timestamp: July 04, 2011, 07:12:03 pm
content: I have a 6062T along with a Tektronix 2465B at home. The 2465B is a 400MHz Analog scope so if I'm doing any level measurements, worried about transients or basically measuring anything I'm worried about I'd use that. They are pretty cheap on ebay these days so if you need a decent performing scope you could look at a used one. Having said that I did look at the Owon S models and the Rigol.. and a few others. IMO, the Rigol screen is just a bit small for me (5.7" 320x240). The Owon S models were the originals in the series have the nastier STN screen. The screen is ok but the clarity is not as good as the later models. The new SDS models (8" 800x600 500MS/S?) and the PDSxxxxT models (8" 640x480 250MS/S) have the nicer TFT.The Rigol has the clear advantage of the 1GS/S rate so if you want higher frequency/transient type measurements or this is going to be your only scope you may want to look in that direction if you can live with the screen.The Owon is a cheap scope, no doubts about it but if you are just doing general hacking about or trying designs out with low frequency analog or digital circuits it will be just fine. Thats what I use it for and the large colour screen and the ability to be able to forget about the constant analog scope twiddling of the focus/illumination and timebase/volt dials can be a nice motivator to spend some extra time at the bench.I suspect all of the cheap chinese scopes with 250MS/S+ sampling rates will do the basic stuff people want. Otherwise save up and buy a Tektronix with a GS/S sampling rate.

author: scopeman
author_rank: Frequent Contributor
timestamp: July 05, 2011, 04:01:25 am
content: I have just received a Owon SDS6062 (60 MHz) that I bought from their dealer, Saelig, for my company. I picked this scope because of its trigger out feature (more details on that below). I needed to be able to trigger a B&K 4079 dual channel arb (a great arb by the way) from an analog signal. I could use the scope as the trigger source and also verify that the arb output was synchronized with the analog trigger source. It seems that low cost arbs with a analog trigger function are rare.Back to the scope:I can say that overall I amveryimpressed with the product. It is a much better scope than the Owon PDS series (really there is no comparison) and a better buy than the 25MHz PDS series (I have one of the PDS5022S units). Definitely worth the $132.00 difference in cost. The variable record length (1K,10K,100K,1M,10M) is quite useful. Very nice large/sharp evenly back lit SVGA screen (way better than the PDS series). I plan to put a review up for it at some point (unless Dave does one).At the moment I would say it is also a better buy for 399.00 than the Rigol 1052E (I have one of those as well) and you can add the battery power option for the Owon later if you would like. No battery option exists for the Rigol DS1052E.There is a 100MHz version of the Owon SDS scope for 599.00 as well. Next I would like to see a 4 channel version (with individual vertical attenuator and position controls and separate cursor controls - please!).More nice SDS6062 features:Rear Mask Pass/Fail output that can be configured to trigger on a mask pass or fail or just when the scope triggers if the mask test feature is not enabled. This is a very handy feature that can be used to trigger an external device (like a logic analyzer). It is delayed by about 2uS from the actual trigger but very useful nonetheless. As far as I know this is the only low cost scope that has the trigger out feature.This trigger output works differently than the Rigol which only works on a mask pass fail. The difference is that a mask/fail test trigger takes at least the time of a full sweep before the trigger occurs so setting the limits of the mask very tightly still does not give you a fast trigger. I suggested the Rigol that they look into adding this feature to the firmware but their only suggestion was to look into their 5000.00 scope.Some points that could/should be improved, most if not all would be firmware changes as all of the basic hardware is already present : (I have more but this is a start!).When making measurements and zooming waveforms the display could be managed more effectively by making better use of the space below the screen and placing some data on the right side of the screen. The show all measurements mode could be placed in the bottom area and could be hidden when pressing any of the H buttons if access to those features are needed.If you want a maximum display mode everything on the lower half of the screen could be hidden. Maximizing the display for waveforms (the LeCroy LC and LT series do a great job of this).Get rid of that difficult to use "window" zoom mode and instead intensify the area to be zoomed and show that area in a different color for the zoomed trace on the screen and add the ability to split the screen into two areas zoomed and un-zoomed. All of the controls on the instrument have a pushbutton mode so I think that could be used with the timebase control to switch between the "A" and "B" time bases.Add a cursor selection mode so that you can select the cursors to be up and down pointing arrows and use the multipurpose knob to select between cursor types.Alternately the position knobs could be use to move the cursors as they are presently and the pressing the respective vertical position knob changes the mode from cursor mode to vertical position mode.The cursor data should be presented in both absolute and relative form. Both time and voltage data can be reported.There should be an option to allow the both cursors to track the reference cursor position.When using single-shot mode the scope should be able to capture up to the maximum of the acquisition memory size. The SDS6062 does that but it is difficult to figure out where you are in the record (after stopping a single shot or hitting Run/Stop) and the display looks like it shows aliased data until you expand the time base. I believe that this is due to the way they display the data and not in the way that the data is captured as it appears the data is complete.I have started a Owon_Owners_Group on Yahoo Groups so look there for future info and feel free to post if you have any information to share.Perhaps later I'll have some screen captures to share!SamP.S. I have no association with any of the brands or companies mentioned in my post other than I use and like their products. I can say that I have been very impressed with the Saelig company in all respects.

author: JimmyM
author_rank: Regular Contributor
timestamp: July 05, 2011, 01:57:06 pm
content: Excellent post, scopeman. I will give the SDS6202 and their higher frequency brothers SDS7102/8102.AT $400, the SDS6202 seems like a bargain. Especially given the improvement over the PDS series. I like the 800x600 screen and VGA output.

author: Armin_Balija
author_rank: Regular Contributor
timestamp: July 05, 2011, 03:54:31 pm
content: Do you think the SDS6062 has enough features and is good enough even after changing the firmware on a DS1052E to the 100Mhz model?

author: scopeman
author_rank: Frequent Contributor
timestamp: July 05, 2011, 08:59:41 pm
content: Jimmy,The SDS6062 doesnothave theexternalVGA output or the LAN capability. I think that those options are reserved for the higher bandwidth (100MHz+) models. It does have USB I/O and RS-232 I/O and USB Memory Stick. Also I should mention that the screen update rate (waveforms per second seem very fast for what is a bargain scope. I don't know numerically what the update rate is but when I feed it a very fast swept wave from a sweep generator it is very snappy even when set to the maximum acquisition memory rate. Even faster (of course) when I set the memory to one of the lower signal rates. Soon I want to check how it does with real video.See the attached data sheet for the Owon Series. I just noticed that Saelig just put the 100MHz SDS7102 up on their web site (599.00) so for an additional 200 bucks you get 100MHz, VGA out, and LAN. 2nS and 1Gs/S sample rate and a pair of 100MHz bandwidth probes. Probably worth the difference if you need the extra bandwidth. They also put the SDS8102 2GS/s unit on the site as well (its is 729.00).Note that the battery adds 60.00 to the instrument cost. Still a good buy and I like the bench form factor for my line of work better than the hand held form factor.I did a test the other night on it with the backlight set to 10% and got at least 4 hours of use out of it. I need to run it down to see how far it will really go. The instrument also has a main power switch that can be used to cut off all power when the battery is charged, leaving the top switch to turn the instrument on and off.Now I can't wait to see if they really do a 4 channel deep memory scope. No one has done that as an entry level product.Sam

author: scopeman
author_rank: Frequent Contributor
timestamp: July 05, 2011, 09:31:22 pm
content: Quote from: Armin_Balija on July 05, 2011, 03:54:31 pmArmin,Yes. After having both units at this point I would opt for the Owon for most uses assuming that you do not really need the extra bandwidth. You could always save up another 200.00 and buy the 100MHz version. At some point they will probably come down in cost once the product volume picks up or if Owon gets in a price war with Rigol. Who knows.One more thing that I forgot to mention in my previous post. The Owon has individual vertical attenuator knobs and position controls for each channel. This is a feature I really think is a must have for any scope. These days the encoders are so cheap anyway so there is really no reason why you should multiplex often used functions on a scope. I would certainly pay a little more for good ergonomics. Little things like that make a scope a joy to use!Remember the first HP DSO's? What a PITA they were to use!Sam

author: Armin_Balija
author_rank: Regular Contributor
timestamp: July 05, 2011, 10:18:48 pm
content: Quote from: scopeman on July 05, 2011, 09:31:22 pmI'm mostly doing analog electronics at the moment because of my education. I'm a 2nd year undergrad student in electrical/electronic engineering. I don't yet know of things that will be oscillating at speeds faster than 50Mhz. If it's called upon, maybe a function generator will be used in a project, but at the moment I'm not quite sure what field or what have you would be oscillating that fast.I'm going to be learning digital electronics next semester so is there anything that will be needing a 100MHz bandwidth? I seek advice because I lack the experience. I need a scope that I can use at home to work on projects or homework that was left unfinished in class. If I have reliable tools at my disposable it'll make my academic career that much more enjoyable. I'm leaning towards the SDS6062 now. I don't have the money to go over $450.00.Thanks for all the replies!

author: gregariz
author_rank: Frequent Contributor
timestamp: July 05, 2011, 11:57:36 pm
content: The digital scopes look nice and have some nice features ie colour TFT's etc. But I recommend new users who will only have one scope look seriously at analog/DSO scopes. There's a reason that they are still making and selling them. The signal performance of an anolog scope is generally better than even a high end digital scope. When it says 60MHz performance on an analog scope that exactly what you get.

author: JimmyM
author_rank: Regular Contributor
timestamp: July 06, 2011, 10:43:20 am
content: Quote from: scopeman on July 05, 2011, 08:59:41 pmI see that they have thePDS7102 (640x480) screen. I don't see theSDS7102Oops. Found it. My bad.

author: Unknown
author_rank: Unknown
timestamp: July 06, 2011, 08:10:45 pm
content: Quote from: gregariz on July 05, 2011, 11:57:36 pmSure, if you're on a tight budget. A (used) $100 analog scope will perform infinitely better than any DSO that sells for $100. For $400, it depends on the application. A used analog scope will give you more bandwidth and a higher update rate, but a DSO has features like storage, pre-trigger view and FFT.Quote from: gregariz on July 05, 2011, 11:57:36 pmOnly the low-end ones, which basically compete on costs. None of the high-end brands make them anymore. I believe the Iwatsu 470MHz scope (also re-badged by Lecroy) was discontinued a number of years ago. Is there any 400MHz or 1GHz analog scope still in production? This was the top end twenty years ago, and far from high end these days.Quote from: gregariz on July 05, 2011, 11:57:36 pmCould you elaborate? Are you talking about aliasing? Aliasing is much less of a problem today than in the early days of the DSO due to deeper memory and better software. The update rate also exceeds analog scopes these days. Analog front-end is similar. An analog scope is better in several ways than a cheap Rigol or Instek scope. Not so sure compared to a mid-end scope like the Agilent X3000 series. Not sure how a cheap analog scope will even compete with today's high-end scopes. How's the frequency response at 20GHz?Quote from: gregariz on July 05, 2011, 11:57:36 pmYep, a good 60MHz scope will display a 60MHz sine wave at at least 0.707 times the amplitude. Are you implying that a DSO does not?

author: scopeman
author_rank: Frequent Contributor
timestamp: July 08, 2011, 12:34:10 am
content: Hello,Well I have to admit, (at least as my wife says) I have too many scopes. I always advocate that one own at least one good analog scope in addition to a digital one, but of I was a EE student once and I would have loved to have had a scope as good as the SDS6062.In fact no common digital scopes existed back in the late 60's and early 70's.As a student you can't ignore the data capture ability of a good DSO for making records of your experiments and triggering on events that the analog scope just can't do.Additionally, as a student you should be able to gain access to a high bandwidth scope should you really need one.Comments on analog scopes:If you really want a analog scope you can always pick up a Tek 453/454/454A or a Tek 465 for about 100.00 or even less if you want to fix one (a great education there) or maybe even for free if you find a company that is upgrading their scopes.My personal favorite is the Tek 454A (150MHz) as they are easy to keep running (as long as the CRT is good) and they will last for decades. The 454 is the older version with the 454 being all solid state. The 453 (50MHz) and 453A (60MHz) are great scopes. Look for a serial number >=20,000 in the case of the 453 (again FET inputs verses tubes (Nuvistors) Stay away from the HP models (unless someone gives you a HP1740A, HP CRTs are not as good and long lived as Tek). The Tek 465/A/B/475A are great scopes as well but do have some IC's in them that are a little hard to find. But they go cheap. Newer Tek 2465 scopes are okay as well but they will cost more as well. I don't recommend the 2465A or B models as beginner scopes as they can have some repair issues with bad caps, etc. But if you get one cheap I can help you fix it.You could also look for a Tek 7000 series plug in scope. You can probably pick one of those up at a hamfest including a set of plug-ins for about 100.00 to 200.00 with bandwidths from 100 to 250MHz. The 4 slot mainframes are the better ones. However these scopes are not much fun to fix and you need an extender cable set to trouble-shoot and calibrate the plug in modules. The 7603 frame goes to 100MHz, the 7704A goes to 250MHz (there is a high writing rate CRT OPT9 I think), The 7904A is either 400 or 500MHz if I remember correctly. If you are considering any of these I would suggest that you pick it up in person as the frames are prone to get damaged if the shipper does not take care with proper packing. I have worked on a few of these that were dropped by UPS or Fed-X that ended up as scrap because the CRT's were damaged internally.One last point on the above mentioned analog scopes. You can find service manuals for all of them either free on the web or as a low cost download from manual dealers like Artek Media. That is one thing that you will not find on any of the low cost (or any currently produced digital scope).Back to digital scopes:I can tell you that the screen update rate and performance of the SDS6062 is very impressive. The 10Mpts acquisition memory makes for a very good digital scope. I doubt that as a student you will need much more than that.I am sure that even more improvements will happen as time goes on and you will want to upgrade to an even faster scope with more features, etc.I could go on and mention that if you really need the bandwidth and extended math and measurement capabilities of a high performance professional digital scope you could look at a used LeCroy scopes like the 9354AL 500MHz scope. I have seen them (rarely) for 500.00 to 800.00 on ebay. Not bad for a scope that was nearly $40,000.00. However you need to make sure that you get one that is 100% guaranteed to be operational and in otherwise perfect condition as parts are very hard to find. I still use these excellent scopes and their newer derivatives and I highly recommend LeCroy but as new they are way out of the range of most students/hobbyists. You can find out more on my Yahoo group LeCroy_Owners_Group if you are interested. You can find manuals for the scopes on the group site as well. Service manuals are available as well but keep in mind that these advanced scopes have custom IC's in them and the PCB's are very difficult to repair.Well I believe that I have taken enough of you time. So little time, so many oscilloscopes.Here is a Tek 454 on ebay. The current bid is 16.50http://cgi.ebay.com/Tektronix-Type-454-Oscilloscope-150-MHz-/300574055402?pt=BI_Oscilloscopes&hash=item45fb9c1beaHere is a 453A with the rare front cover (currently no bids)http://cgi.ebay.com/Tektronix-453A-Oscilloscope-/260813919284?pt=BI_Oscilloscopes&hash=item3cb9b89434Here is a 200MHz Tek 475 for a buy it now of 150.00. May be the best bargain of all.http://cgi.ebay.com/TEKTRONIX-475-OSCILLOSCOPE-2577-/160615892040?pt=BI_Oscilloscopes&hash=item2565740448Got to go,Sam

author: gregariz
author_rank: Frequent Contributor
timestamp: July 08, 2011, 01:43:51 am
content: Quote from: alm on July 06, 2011, 08:10:45 pmWhen I mentioned DSO, I did not imply a modern digital scope. A DSO may essentially be an analog scope with a storage mechanism as was common 20 odd years ago ie. Captures on trigger. Thats what we called them years ago to differentiate between scopes that could hold on trigger. Typically you would turn the DSO off and leave it free running if you didnt need that function.Thats a different beast to the current crop of Digital DSP Scopes. Their signal performance is essentially based on their sampling rates. Whilst a sine wave may be captured at double the sampling rate, transients etc may be many times that frequency and if they appear between the sampling 'blind spots' will not be captured. For example if you are going to capture a 10MHz waveform at 1GS/S on a current digital scope how many 'points' on the waveform do you capture?, and what do you miss? What you miss depends on the complexity of the waveform. If its a sine wave then the answer is essentially nothing. Which is why I think for general hacking about even lower 250MS/S digital scopes are ok. An analog scope essentially has your probe connected to the vertical deflection on the CRT so its has a much higher 'sampling rate' that is essentially determined by the response time of the input circuitry.Thats the only point I was attempting to make, is that for a scope that doesn't lie, albeit it with less sexy 'save' features, an analog scope could be a good choice. The Tek 2000 series I mentioned doesnt have a great USB save mechanism (ie a photo) but it does have the same digital markers and the math functions you'll find today of the digital scopes. Not to mention 4 channels and a trigger that does what its told to. Not bad for a scope series that was made from the early 80's to the mid 90's.Now you shouldnt think I dont like digital scopes.. I love them.. I'd easily take one of these, for which I'm sure the high frequency performance is great..

author: scopeman
author_rank: Frequent Contributor
timestamp: July 08, 2011, 04:36:40 am
content: The RTO by R&S in the video/picture is an excellent scope, I had some time to actually use one recently, however at $22,000.00 it is hardly in the league of the low cost digital scopes we have been talking about.And even at $22K the maximum sample point for an FFT is limited by the R&S hardware. The scope depicted has a very fast FFT update rate since the FFT is done in hardware thus it is limited to 100K points. LeCroy has been able to do FFT's on very large records since the early 90's as they do the FFT processing in software. The screen update rate can be slower but it depends on what you want to do. Also unlike the Tek the LeCroy scopes do the math processing based on every sample point in the record, not based on some statistical or other sampling method. That is why the processing can be slower on some of the math functions based on the internal method used to do the calculations.Most of the original Tek DSO's like the TDS2000 series only have 2.5K record lengths anyway so that is why the screen update rate is so fast. If you reduce the record length on a LeCroy (or the SDS6062 for that matter) the update rate will increase accordingly but the ability to look back in a record and have good fidelity of the signal is reduced accordingly.You can easily see the results of this by inputting a fast train of pulse and setting your trigger point so that most of the recorded record is before the trigger point. Set the scope to the shortest record length (can't do this on earlier scopes as they have a fixed record length, but stay with me on this). Reduce the sweep speed and take a single shot record. When the scope stops, expand the record. Look at the fidelity of the signal (use dots mode so you can see how many points you are capturing on the rising and falling edges). As you capture more for a longer period of time you will come to a point where the pulses no longer look like pulses as the record length is shortened, the same as the effects of under-sampling. Increase the record length and do the experiment again. You will find that having a longer record length greatly increases the fidelity when you need to capture an event for a longer time.For example, assume that we have two scopes, running in single shot mode, both have 500Ms/S digitizers, one has a 2.5K record length, the other has a 10 megapoint record length.Both scopes will have a time resolution of 2ns (since 1/500 X 10E6 is 2ns)The 2.5K record length scope will capture 5uS worth of data (2nS X 2500 =5000ns = 5uS).The 10 megapoint record length scope will capture 20mS worth of data (2nS X 10 million =20 million nS = 20mS). So you have a 20mS record with 2nS per point resolution.I have attached a simple spread sheet where you can enter a scope sample rate and see the effects of maximum record capture time verses record length.Even in repetitive mode you can see the effects of too short of a record length at a given sweep speed. If you feed in a pulse signal that has high speed over-shoot you can see a "picket fence" effect (what looks like amplitude modulation of the over-shoot spikes) on the over-shoot as you reduce the record length. You can see a similar effect if you reduce the sweep speed on a fixed record length scope.One might conclude from this that you might want to fix the record length at the maximum that the scope has and just leave it at that. There are some very good reasons not to do that. One is screen update rate. Sometime you just want to have a fast update rate and fast computation. In that case you want to use the smallest record possible that still give you the fidelity you need. Other times you may need to look at data over a longer time period or run a FFT on a larger record.It could be that you want to run trend analysis on the data, or plot a histogram, for that you probably would want a large amount of data. The LeCroy scopes have software options for extended record FFT as well is trending and histograms. These are features the lower cost scopes like the Owon and the lower costs Teks do not have. I believe that one could implement an external software package that could us the Owon scope to collect data to provide histogram and trending functions. That would be useful.All for now,Sam

author: gregariz
author_rank: Frequent Contributor
timestamp: July 08, 2011, 05:39:25 am
content: Quote from: scopeman on July 08, 2011, 04:36:40 amThanks Sam, I don't really have much experience with the FFT functions on Scopes. I have used it on occasions when I am probing a circuit, it seems to give a an indication, but as an RF engineer I have always deferred back to a Spectrum Analyzer for spectrum measurements - I guess thats my safety zone of something I know and trust. I must be a bit old fashioned in the way I approach a scope. I guess that it was a bit unfair to identify the RTO and I guess a Spectrum Analyzer is not really a hobby device either, although there a bunch of cheap CRT based ones coming out of china for about 500-800.

author: Unknown
author_rank: Unknown
timestamp: July 08, 2011, 11:17:00 am
content: Quote from: gregariz on July 08, 2011, 01:43:51 amQuote from: gregariz on July 08, 2011, 01:43:51 amThose are not high end DSO's. Those are not even low end ones. They are ancient history as far as DSO's are concerned.Quote from: gregariz on July 08, 2011, 01:43:51 amTrue, sampling rate is as important as bandwidth.Quote from: gregariz on July 08, 2011, 01:43:51 amThat's the difference between bandwidth and fundamental frequency. Bandwidth depends on the highest frequency component (of interest) in the signal. A 60MHz scope is not suitable for looking at a 60MHz signal unless you only care about the fundamental and tolerate the 30% error, whether it's digital or analog.Quote from: gregariz on July 08, 2011, 01:43:51 amAnd the slew rate of the vertical amplifier and CRT. And the spot size. And the response of the phosphor. Unless you're talking about an MCP CRT, you'll have a hard time spotting a fast peak due to the extremely low intensity. Don't fool yourself into thinking a CRT has infinite bandwidth and resolution. The main difference is that the roll-off may be more gradual. The sampling rate of course induces a hard limit.Quote from: gregariz on July 08, 2011, 01:43:51 amEvery piece of equipment gives a distorted result, the only difference is the type of distortion. An analog scope will hide rare transients for example. Performance near the edges is also a lot worse than in the center, which is why it's often only specified for the center X divs.Quote from: gregariz on July 08, 2011, 05:39:25 amFFT is useless compared to a spectrum analyzer IMO. Imagine a spectrum analyzer with 8 bits (less than 50dB) of vertical range. Then subtract the fairly high noise floor. Maybe this can be improved with tricks like averaging, but I wouldn't expect them to replace the spectrum analyzers anytime soon.

author: scopeman
author_rank: Frequent Contributor
timestamp: July 08, 2011, 03:10:36 pm
content: "FFT is useless compared to a spectrum analyzer IMO. Imagine a spectrum analyzer with 8 bits (less than 50dB) of vertical range. Then subtract the fairly high noise floor. Maybe this can be improved with tricks like averaging, but I wouldn't expect them to replace the spectrum analyzers anytime soon."I basically agree with that assessment, but we were talking about low cost digital scopes, many of which throw in the FFT feature. I would not totally discount the FFT feature of DSO's I have found it to be quite useful for low bandwidth work, but like you I dig out my HP8566B for serious RF work. It took me many years of serious trading before I could get such a tool. But even now they are outside the cost range for most home labs.I would apply the following rule "Never substitute a tool, even a good one, for knowledge".Improper application always yields inaccurate results.One thing is almost sure. You can pick up a decent analog scope for about the cost of dinner for 12 at McDonalds. Certainly for 100.00. I once bought a Tek 422 at a local flea market for $15.00. That is 1.00 per megahertz! A good rule of thumb for a bargain priced analog scope. The 422 is now my loaner scope. Only a few very select people are allowed to borrow my Tek 2465.Sam

author: gregariz
author_rank: Frequent Contributor
timestamp: July 08, 2011, 05:52:48 pm
content: Quote from: alm on July 08, 2011, 11:17:00 amIts typically been my experience that whilst you can't rely on a scopes performance beyond the specified analog bandwidth, that an analog scope generally rolls off slowly to the extent that you can see the high frequency components at least, even if their levels are unreliable. Simply seeing the spikes/shapes on the rising or falling edge, I find to be a useful piece of information. The phosphor limits are actually pretty reasonably. In the old days when scopes were extremely expensive beyond a few MHz, people used to modify their scopes to take the input directly to the deflection plates. Although levels were very low, this did work sufficiently for people to do something like tune transmitter modulation. But each to their own, I expect Analog's will be completely replaced in the next few years as the digital scopes get a little bit better, but I would also expect people to hang on to their analog scopes that they have.I've used the FFT on a scope on occasions simply due to the high impedance of the scope probe. A high impedance probe for a spectrum analyser on the other hand is typically an expensive add-on. But they are an available and valuable add-on.

author: Unknown
author_rank: Unknown
timestamp: July 08, 2011, 07:20:13 pm
content: Quote from: scopeman on July 08, 2011, 03:10:36 pmAgreed, it's not useless, but it is useless compared to a specan. I wouldn't recommend gregariz to give up his spectrum analyzer in exchange for a DSO with FFT. They're just not in the same league.Quote from: gregariz on July 08, 2011, 05:52:48 pmIt rolls off with about -6dB/decade, just like a low-end DSO (sort-of). But the roll-off of the DSO tends to get steeper once you go well beyond the rated bandwidth, and of course hits a brick wall at sample rate / 2. An analog scope will present a severely distorted picture instead of none at all. But since digital scopes can have much more bandwidth than analog scopes, this isn't a major issue. I wouldn't call this lying, it's just that the unspecified behavior beyond the rated bandwidth is not what you expect. If you expect a reasonable representation of a signal with 60MHz bandwidth on a 60MHz scope, you deserve to be lied to.Quote from: scopeman on July 08, 2011, 03:10:36 pmNo argument that analog scopes have some advantages over cheap DSO's like Rigol makes, I'm certainly not against analog scopes, but the time that they were superior to the high-end DSO's is long gone. Analog scopes are already completely replaced by digital scopes in the market place as far as I know, none of the big three manufacturers make them anymore, and the analog scopes still in production are fairly low spec ones that compete purely on price.Quote from: scopeman on July 08, 2011, 03:10:36 pmAn analog scope with a signal output may be used as a heavy buffer amplifier.

author: gregariz
author_rank: Frequent Contributor
timestamp: July 08, 2011, 10:38:44 pm
content: Quote from: alm on July 08, 2011, 07:20:13 pmThis discussion reminds me a bit of the one we had years ago regarding Analog Multimeters. Everyone thought they would become extinct but they are still being made and people still swear by them.

author: scopeman
author_rank: Frequent Contributor
timestamp: July 09, 2011, 03:10:09 am
content: Just for kicks I ran a test to check the delay of the trigger out jack between the Owon SDS6062 and a LeCroy LT584L 1GHz scope.I connected a cable from the the trigger out jack into channel 2 of the scope under test. Channel 1 was triggered from a fast rise pulse, the delay was measured from channel 1 to 2. The LeCroy showed 62nS of delay. The Owon showed 2uS of delay.Sam

author: Armin_Balija
author_rank: Regular Contributor
timestamp: July 09, 2011, 05:42:46 am
content: Many thanks to ALL of you who have replied to my thread. The amount of knowledge, feedback, and friendliness is, in my opinion, without equal across boards all over the internet. Thanks for the video, it was great.I've also decided to go with the SDS6062 around Sept. 1. I hope it will go down in price by then but if it doesn't so be it. It seems like you have all made your case. I was kind of against getting the Rigol just because of the number of topics that have cropped up about it that were negative. It seems as though the scope itself is not that bad and even though the Rigol can be updated to a higher bandwidth, it seems that the resolution is lower than the Owon.Thanks for all the information, advice, and replies. I appreciate all of it more than you know!

author: tinhead
author_rank: Super Contributor
timestamp: July 13, 2011, 12:58:19 pm
content: Quote from: scopeman on July 08, 2011, 04:36:40 amright, this scope have max sampling rate of 500MSs...Quote from: scopeman on July 08, 2011, 04:36:40 am... but others might have different max. sampling rate while in long memory mode than in short memory.In principle all low budget scopes sampling max. 500MSs within long mem and max sampling rate in short mem.,even for the new "low budget" Hameg DSOs i didn't got ANY answer on the sampling rate while in long mem.How the SDS7xxx/SDS8xxx are handling these 10M memory and on what sampling rate we don't know yet,we have to wait for an review.

author: ChrisH
author_rank: Newbie
timestamp: July 24, 2011, 03:31:34 am
content: Found a review on the SDS6202 here:https://www.mortoncontrols.com/blog/files/category-oscilloscopes.htmlHe also reviews several other of the competing scopes, well worth a read. In the photo, below, the Owon is the scope in the upper left hand side of the group.EDIT: His review also shows that the ATTEN ADS1042CML scope can do a single channel split screen display of both a regular waveform and FFT, does anyone know if the HanTek DSO5202B can also do this?

author: saturation
author_rank: Super Contributor
timestamp: July 24, 2011, 12:59:53 pm
content: The 'review' is not very good, it also about the usability and appearance, it has not one comparison of how good they are as measuring instruments, which is really what you want.That the review spends some time explaining what FFT is suggests he is not a technically versed person, and he even uses a Mac!.

author: Unknown
author_rank: Unknown
timestamp: July 24, 2011, 03:20:44 pm
content: Quote from: saturation on July 24, 2011, 12:59:53 pmLOL. I've seen some people use Windows and still manage to have some technical skills, so I guess a Mac user with a clue is possible.

author: ChrisH
author_rank: Newbie
timestamp: July 24, 2011, 04:23:11 pm
content: I should not have written review, he only stated "first impressions". For me, that page is very good because I'm a novice to this subject and it does provide information, at my level, I am interested in.

author: saturation
author_rank: Super Contributor
timestamp: July 25, 2011, 04:53:33 pm
content: Yes, I understand. But, you'd really want to know the scope works as a scope you pay for, before anything else. Its an important first impression of any test gear. A technically minded person would immediate jump at the core functionality, just as with new PCs or mobos, tech folks would appreciate a system benchmark test to determine overall speed. What good is ergonomics if the scope measures unreliably or poorly? Since the reviewer has all those models available, its a unique opportunity to compare if they are all functionally similar, or not. A rise time or single 10MHz square wave response is all that's needed, and if all the scopes pass then what makes a difference between one scope and the next is mostly ergonomics, and that's what the extra costs are all about.Quote from: ChrisH on July 24, 2011, 04:23:11 pmSorry for the stereotype, I couldn't resist, and its not good to stereotype anyway. You're right of course. After all Labview was first designed for Macs only and Mac OS-X is pretty much Mac favor of Unix.Quote from: alm on July 24, 2011, 03:20:44 pm

author: Bren
author_rank: Contributor
timestamp: July 28, 2011, 07:48:47 pm
content: Sorry to Hijack this forum, but my question is somewhat related to what was discussed earlier.Do the OWON SDS scopes use the full 10M when displaying FFT?andCan FFT be displayed with the signal?(all the screenshots I've seen show the FFT by itself awkwardly in the middle of the screen).Bren.