Rigol Rubbish DG800 - An expensive piece of Junk - Page 1
Forum section: electronics / testgear

author: eTobey
author_rank: Super Contributor
timestamp: May 10, 2024, 05:40:37 pm
content: Warning:Fanboys should not keep reading this!I got the Rigol DG812, and i am really dissapointed... say furious. It has some nice features, but some dont work at all, and other issues make the work with it rather challenging. It feels like i bought a chines 100$ wavegen. I just had trouble debugging my code, but it wasnt the code, it was the rigol.Here is a list i made, hope some might find it useful (Yes, its only negative feedback):- Socket protrude on the back, almost set it on the back while unwrapping- The knob works as good as a button. Turning it faster does not speed it up! It does spin wobbly... Its a disgrace!- Keypad closes unintentionally while seemingly hitting between the buttons.- Cursor jumps on different place when reached lower limit on setting up amplitude/Frequency.- Sometimes putting in numbers in the numberpad will replace old value (as it should behave), and sometimes not.- Ramp wave only 200kHz? WTF? This thing says 10MHz on the case...- Menu for choosing modulation wave jumps back up or chooses an item after scrolling down.- No color guidance on the display. The only color is printed at the sockets.- Text on top sometimes stays the same (Modulation/Continous)- Square highlevel 1.5V and lowlevel 0V is a 0-3V level!- Highlevel limit not working on hamonics -> 4.9V with 3V limit. Negative limit is also exceeded.- Longer dialog messages can not be read, as they appear only for about 1-2 seconds.- No option to have signals constantly aligned. You have to hit button align over and over again, after settings are changed.- Activating the counter, and then the generator again: Settings gone!- USB on backside- USB sticks are hardly working.- Major GUI bugs: Menu switches when activating DSSC- Not possible to set up negative or above 360° phase shift. No rollover either.- Burst and sweep does not work with ext trigger (only FM mod, or other)- High or low level limit in general settings can not be set, if the current waveform has conflicting settings.- Changing PWM period causes pulses to be smaller or bigger than set up values from before or after.Limits were in place, and one would not know were the conflict were:- Low level limit only to -1.5V not 0Dont bother asking me about details, its just not worth it, just buy something else.

author: shabaz
author_rank: Frequent Contributor
timestamp: May 10, 2024, 06:51:27 pm
content: Hi,A few of the items on the list sound like they may be related to a 50 ohm setting, specifically the comment about the square wave high level, and the mention about the harmonics limit. I don't own this instrument so I'm making a guess based on experience with other signal generators.The 200 kHz ramp is mentioned in the datasheet (it is very normal for such waveforms to be spec'd to a far lower frequency for AWGs, so that needs to be examined closely in the datasheet when buying any AWG, even expensive ones).

author: eTobey
author_rank: Super Contributor
timestamp: May 10, 2024, 07:23:30 pm
content: Quote from: shabaz on May 10, 2024, 06:51:27 pmWhatever setting there may be behind: If i set a limit, then it should not be exceeded by setting 50Ohm. Someone else here on the forum fried his 150$ FPGA when it went negative.200kHz is very poor, no matter what the datasheet says.

author: Sensorcat
author_rank: Regular Contributor
timestamp: May 10, 2024, 08:55:38 pm
content: Quote from: eTobey on May 10, 2024, 07:23:30 pmSo you are unhappy with what you got, even if it is in accordance with the data sheet.You could:Do some research on what the reason might be. Hint: There is one.Ask someone for the reason.Look at data sheets of generators in the same price category, or one higher, to find out that their specs are all 'poor'.These choices would result in a learning effect.You could also:Return the unit and replace it with one with higher spec.Use the hardware you already have in a clever way to get a ramp with higher frequencies. Hint: It is possible.Build something better on your own, perhaps only for the ramp function.These choices have the potential that your problem gets solved.Why do you choose an option that is less likely to result in any improvement for you?

author: alm
author_rank: Super Contributor
timestamp: May 10, 2024, 08:59:50 pm
content: Quote from: eTobey on May 10, 2024, 05:40:37 pmIs this the first generator you've used? The bandwidth number on the case is always just for sinusoidal signals. You need to consult the datasheet for anything else. For square waves some generators will have dedicated hardware, but ramps are not so easy and will probably be done using the arbitrary waveform generator which needs a lot of samples per cycle.Quote from: eTobey on May 10, 2024, 05:40:37 pmThis sounds a lot like having the generator set for a 50 Ohm output but running it with a high-impedance load. The way the output impedance setting works (it's not actually switching a resistor but just doubling the figures) this is bound to happen. Have you used any other generator with a selectable 50 Ohm / hi-Z "output impedance"? Because any other generator you buy will likely have the same issue.

author: Martin72
author_rank: Super Contributor
timestamp: May 10, 2024, 09:25:14 pm
content: QuotePlus take a look at the specsbeforebuying, instead of complaining about it afterwards in the now familiar way.

author: thm_w
author_rank: Super Contributor
timestamp: May 10, 2024, 09:45:26 pm
content: Ah yes, super "expensive" at the princely sum of $300... DG800 is a low end generator, I'd say its fine for what you pay, and fine for average student or hobbyist working on basic designs. And with a few minutes of hacking you can unlock 100MHz.The DG800 Pro can be had for the same price and resolves *some* of your complaints (like USB on the front). Has other issues like loud fan, etc. Still, if I had a choice I'd pick the dg800 pro for the larger UI.Previous threads:https://www.eevblog.com/forum/testgear/rigol-dg800-combining-arbitrary-waveform/https://www.eevblog.com/forum/testgear/new-rigol-16-bit-function-generators-dg800900-series/msg5268007/#newI feel really bad for any retailer that has to deal with people like OP.

author: xrunner
author_rank: Super Contributor
timestamp: May 11, 2024, 12:19:19 am
content: Quote from: eTobey on May 10, 2024, 05:40:37 pmBoth of these are clearly seen in pictures you could have easily known about before buying.

author: DaneLaw
author_rank: Frequent Contributor
timestamp: May 11, 2024, 01:41:24 am
content: Quote from: eTobey on May 10, 2024, 05:40:37 pmYou sound like the pedicle of a fanboy.You see a well-known brand "Rigol" and expect the moon while purchasing the cheapest from this specific brand, without any incentive to do basic due diligence' and then you hurry on the internet and generalize the whole DG800 series as "rubbish & junk" primarily from your own lack of knowledge.Quote- if you wanted a DG800 unit that could do more than 200kHz ramp, then why not purchase a DG800 with higher ramp tolerances.Did you even look in the datasheet before purchasing your new Rigol waveform generator.?

author: eTobey
author_rank: Super Contributor
timestamp: May 12, 2024, 05:34:31 am
content: "could have looked at the datasheet / pictures"I would not expect the fuel tank of a car with 160HP to be only like 15 litersI couldnt care less about your input, as this information is only intented to help others decide.

author: beatman
author_rank: Regular Contributor
timestamp: May 12, 2024, 07:57:39 am
content: All manufactures have different series and platforms start with basic model with optional upgrade packages or locked futures.In most of times the hardware stay the same except the inputs outputs.

author: tautech
author_rank: Super Contributor
timestamp: May 12, 2024, 08:15:40 am
content: Quote from: beatman on May 12, 2024, 07:57:39 amDespite this quite valid fact, it is a valuable skill to be able to read and properly understand datasheets.

author: Aldo22
author_rank: Super Contributor
timestamp: May 12, 2024, 03:02:42 pm
content: What leaves me somewhat perplexed about signal generators are the different "specialties" in the specifications.I think that better in one discipline does not automatically mean better in other/all disciplines.For example, my AWG built into the $130 Hanktek scope has a 1MHz ramp.It can also do 25MHz AWF. A 50MHz square wave is possible with an AWF.But then the vertical resolution is probably only 12bit and the maximum amplitude is 7Volt.Cheap FY3234s has a sampling rate of 250MSa/s etc.Accuracy and noise etc. would have to be compared separately.What I want to say: At least in the lower price range, there is no simple "better" or "worse", but you always have to compare the individual features.Is that correct? What is most important?

author: Sensorcat
author_rank: Regular Contributor
timestamp: May 12, 2024, 03:36:44 pm
content: Quote from: eTobey on May 12, 2024, 05:34:31 amIt's just that you did not buy a car with 160 hp, the DG800 is the equivalent of a chinese scooter designed with little more than budget in mind. The 15 litres tank you got is huge for this class of vehicle.Let's take a look at two serious AWGs for comparison, both roughly 10 times the price of the DG800, both primarily designed to solve problems, not to match pocket money:Keysight 33500B Series, max. ramp frequency 200kHz, non-upgradable, Non-linearity (typ) < 0.05% from 5% to 95% of the signal amplitudeTektronix AFG31021, max. ramp frequency 500kHz, higher limits available in series, Linearity, typical (1 kHz, 1 Vpp, 100% symmetry) ≤ 0.1% of peak outputYou have (from DaneLaw's post above): 200kHz, Linearity, typical (1 kHz, 1 Vpp, 100% symmetry) ≤ 1% of peak output. Which means that the frequency limit has been pushed in order to impress people who do not look careful, to the point where the non-linearity rises to frightening levels.The frequency limit, especially for the ramp function, is not a hard barrier defining what the system is capable to provide, it's a decision to set a limit at a point where the signal otherwise becomes useless. In general, linearity degrades with increasing frequency. Since linearity is the number one criteria for a ramp, naturally the decisions vary depending on the intended customer type. Rigol plays the game here of showing heavy limitations only in the datasheet, while the shorter fact sheets will be quiet about 1% linearity, typical, at 1 (!) kHz. Tek uses the same set of lame conditions, but offers 10 times better linearity, and resists the temptation to push to the point where their hardware reaches 1%. Keysight delivers 0.05% for an extreme wide range of conditions, but restricts the frequency instead.Does that mean you can't get ramps with frequencies above the respective limit? Of course not, the only thing you cannot get is a ramp function above the respective limitwith a specified linearity. If you need something ramp-ish with higher frequency, just use yourAWGas anAWG: Enter a ramp as an arb function and check how far you can get. The Keysight 33522B, for example, has no problem to create a 10MHz unspecified ramp-ish function that way.

author: 2N3055
author_rank: Super Contributor
timestamp: May 12, 2024, 06:04:40 pm
content: Quote from: Aldo22 on May 12, 2024, 03:02:42 pmYoualwayshave to read specifications carefully and decide if they are useful to you.For high end expensive equipment even more so because stakes are higher.There are many details to pay attention to.For instance that Hantek 1MHz ramp, does it specify linearity error?Triangle wave is hard to do linear at high frequencies.At highest square wave frequency, what are rise/fall times of edges? Are they so slow that it is trapezoidal wave instead? Are rise/fall times guaranteed at highest output amplitude?

author: Aldo22
author_rank: Super Contributor
timestamp: May 12, 2024, 06:52:11 pm
content: Quote from: 2N3055 on May 12, 2024, 06:04:40 pmDon't get me wrong, I'm not trying to talk up my cheap Hantek. It's just an example that I know.I just find it very difficult to orientate myself with the specifications of a signal generator because they vary so much.It would be easy if the specifications went in the same direction.e.g. 16bit vert. res., 300Msa/s, square rise time 3ns etc.But it's not like that.It's 12bit, 250MSa/s, 3ns RTOR16bit, 125MSa/s, 16ns RT etc.A beginner doesn't know which spec is more important.I think this is also eTobey's problem. He thought he had a "good" signal generator. But apparently he is not happy with some of the specs.Apparently "good" and "better" is not so easy to determine here.P.S. Attached is a 50MHz Hantek square wave (AWF 2*square, 50Ohm load 2V->1V), clearly at the limits of the scope and the signal generator, but quite stable and no sine wave.And a 1MHz ramp @7Vpp.

author: Martin72
author_rank: Super Contributor
timestamp: May 12, 2024, 11:17:45 pm
content: QuoteIt is about time that this title was changed, even if it would ultimately serve the purpose of self-protection.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 13, 2024, 12:09:09 am
content: Quote from: Martin72 on May 12, 2024, 11:17:45 pmYeah, it's redundant anyway. 😉😉

author: jonpaul
author_rank: Super Contributor
timestamp: May 13, 2024, 05:08:09 am
content: Just usual junk from China, suggest for the $300, get a used 1980s or 1990s HP FG AWGj

author: ebastler
author_rank: Super Contributor
timestamp: May 13, 2024, 10:35:00 am
content: Quote from: jonpaul on May 13, 2024, 05:08:09 amWhat would be your recommendation for a dual-channel HP AWG in that price range? The HP 33120A looks plausible but is single-channel only. Did they make a comparable model with two channels?

author: Aldo22
author_rank: Super Contributor
timestamp: May 13, 2024, 10:52:19 am
content: Quote from: ebastler on May 13, 2024, 10:35:00 amCould you explain to me what is better about the 33120A than a modern AWG?That's an honest, naive question. I would like to understand it.When I look at the specs, I don't see much that sounds particularly great.Amplitude resolution 12 bitsSample rate 40 MSa/sSine 100 μHz - 15 MHzSquare 100 μHz - 15 MHzTriangle 100 μHz - 100 kHzRamp 100 μHz - 100 kHzRise/Fall time < 20 nsetc.So how do I know that this device is good/better, other than by hearsay?

author: ebastler
author_rank: Super Contributor
timestamp: May 13, 2024, 11:15:10 am
content: I don't think I claimed that it is better.Some specs are a tad better than the low-end Rigol discussed in this thread (e.g. total sine distortion in the audio range), others are a tad worse. Overall, both punch in a similar class, I'd say. The modern devices have more features, e.g. dual-tone and harmonic generation, a touch screen, and USB instead of RS-232 & GPIB. They might also have a few unexpected software bugs, which are less likely in mature HP and comparable gear. A comprehensive service manual is available for the 33120A, but not for the Rigol to my knowledge.I think it's largely a matter of preference whether one likes "solid feel and established brand" or "made in China, more features". In the specific case at hand, I am not aware of a (roughly) comparable HP dual-channel generator in this class, so the vintage route might not offer a real alternative.

author: Aldo22
author_rank: Super Contributor
timestamp: May 13, 2024, 11:35:11 am
content: Quote from: ebastler on May 13, 2024, 11:15:10 amThat's right, you didn't say that, but Jean-Paul did.I was referring to your post because you mentioned a specific model.My question to@jonpaulremains: Why is a 40 year old HP FG AWG better than "junk from China" when the "junk from China" is better in almost every specification?How can I tell?I mean, I know that some people say that aMercedes-Benz /8is the best car ever.But would you really buy one today?

author: Berni
author_rank: Super Contributor
timestamp: May 13, 2024, 11:42:01 am
content: The OP should try one of the cheap Hantek signal generators, those are a buggy mess of a cheap chinese product.Not saying the Rigol DG800 series is perfect, but it is a damn good deal for the price. It is very feature packed for its price class and it does work reliably without any major UI problems (even if the UI is not the best out there).Feel free to purchase a more expensive signal generator if you have more advanced needs. But in this price range you will be hard pressed to find something better.

author: Aldo22
author_rank: Super Contributor
timestamp: May 13, 2024, 12:12:28 pm
content: Quote from: Berni on May 13, 2024, 11:42:01 amTo whichspecific modeldoes your statement refer?HDG3000B SeriesHDG3000C SeriesHDG6000B SeriesCan you share your experience with us?Information on these is relatively scarce.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 13, 2024, 01:11:07 pm
content: The incessant need to call junk "cheap Chinese products" is unnecessary bigotry. China makes great products, and shite products. China itself doesn't determine the quality of the product, and pretending the source of manufacture has an effect on that is ignorant. Pay for something good, get something good. Pay for shite, get shite.

author: coppice
author_rank: Super Contributor
timestamp: May 13, 2024, 01:16:11 pm
content: Quote from: KungFuJosh on May 13, 2024, 01:11:07 pmWhen I look back over the last 50 years, the worst crap I've bought was German. Germans also made some of the best stuff I've seen. Most countries are capable of making both good and bad stuff, and do so. A lot of the best stuff China makes you just don't see in the west, as few people abroad want to pay a decent price for them, and they mostly sell to the domestic market.

author: Aldo22
author_rank: Super Contributor
timestamp: May 13, 2024, 01:46:40 pm
content: Quote from: KungFuJosh on May 13, 2024, 01:11:07 pmI almost agree.But I would add a distinction:Whether something is "shite" depends very much on whether you feel you have paid too much for it.Some devices are OK for $50.But if you pay $500 for the same device, then it's probably "shite" because you can get much better for that money.Especially in the low-cost segment, every yuan counts and if there is a market for a $50 thing, then it will be produced for that.You just can't expect the quality of a $500 product.But I think that's OK and no reason to use bad language. Just don't buy it if it's not for you.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 13, 2024, 01:52:10 pm
content: Quote from: Aldo22 on May 13, 2024, 01:46:40 pmThe distinction is irrelevant since the country of manufacture had no impact on any of that.

author: mawyatt
author_rank: Super Contributor
timestamp: May 13, 2024, 02:45:24 pm
content: Let's not forget that much of the upper tier OEM TE suppliers utilize many "off shore" resources to design and build various subassemblies or end products. The highly regarded HP/AG/KS often had such products, the Keysight/Rigolpossibleconnection, or the LeCroy/Siglentpossiblerelationship, or thepossiblesimilarity between some R&S and Tonghui instruments and so on.The fundamental design, attention to detail, components, final assembly/test and after market support determines the overall quality and value of an instrument, not its origin!!Best

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 13, 2024, 02:53:59 pm
content: Exactly. Tonghui's build quality is exceptional in our LCR meters. I think their support is abysmal, and people should buy the rebadged SourceTronic versions of those LCR meters, but that doesn't take away at all from the build quality.

author: Aldo22
author_rank: Super Contributor
timestamp: May 13, 2024, 02:59:04 pm
content: Quote from: KungFuJosh on May 13, 2024, 01:52:10 pmYes, I wasn't talking about Chinese products at all.I meant something else.A cheap product can be very welcome and you don't necessarily have to call it a bad name, even if it doesn't match the quality of more expensive models.For example, I have an FY3224s signal generator.Is it crap or "shite"? Yes, there are many aspects that seem cheap, starting with the appearance and the lack of a 3-wire power cable.Would I buy it again or recommend it to others?If you can get it for $50: yes!It's simply the cheapest, usable 2-channel, 20Vpp, 24MHz AWG available.And it works. Everything else is details in the specs.Sufficient for hobbyists and you can be thankful that something like this exists.If you know that you need a better device, you can get it elsewhere, but you don't have to insult the cheap one.It's better to complain about expensive goods that don't meet your expectations.And here we are "on-topic" again.The topic starter pays € 300 and rightly expects more than the $50 model offers.

author: Berni
author_rank: Super Contributor
timestamp: May 13, 2024, 03:20:48 pm
content: Quote from: Aldo22 on May 13, 2024, 12:12:28 pmIt was a HDG2000B series.I was pretty impressed with the hardware of it, but the software was so horribly buggy that it made it unusable. Tried a firmware update or two but then gave up on it and sold it. Later on when the Rigol DG1032 was released for a good price i bought it and was much happier with it.It is possible the newer Hantek HDG models are better, but after the awful experience with it, i didn't even look at any other models.

author: mawyatt
author_rank: Super Contributor
timestamp: May 13, 2024, 03:25:31 pm
content: Quote from: KungFuJosh on May 13, 2024, 02:53:59 pmI would give Tonghui a 10 on the TH2832, but a 3~4 on support (they did help with an issue early on), and for Hioki 10 on the IM3536, and maybe a 4~5 on support. Of course Tonghui is China origin and Hioki is Japan origin, both exceptionally good OEM TE suppliers in their respective product lines IMO.Rigol and Siglent are much broader OEM suppliers tho, and both have demonstrated good value in most of their respective equipment offerings.Personally think we should all thankRigol,Siglent, andGWfor thinking of us on the low end of the equipment totem pole, and quit bitching/nitpicked about features/performance/comparisons and so onEverything we've seen from these OEMs is quite good in overall value and performance, and thankful we have these selections at this low totem pole positionBest,

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 13, 2024, 04:19:32 pm
content: Quote from: Aldo22 on May 13, 2024, 02:59:04 pmI totally agree with that. I have a TC3 that I think is great for what it is. I don't expect it to compare with serious TE, but it is a useful toy.

author: Martin72
author_rank: Super Contributor
timestamp: May 13, 2024, 05:04:29 pm
content: Quote from: KungFuJosh on May 13, 2024, 01:11:07 pmOr in short, the Chinese can't do magic either.But this is a very interesting phenomenon of our time and applies to all products:People don't want to spend money, then buy cheap things and are sorely disappointed when the quality isn't right....The Amazon reviews are full of such tirades.You can only say, buy something better.If you can't afford it, then save up for it.If you don't want that, then buy something good second-hand.If you don't, then it's your own fault and stop complaining.

author: Aldo22
author_rank: Super Contributor
timestamp: May 13, 2024, 05:31:08 pm
content: Quote from: Martin72 on May 13, 2024, 05:04:29 pmAlmost. I would only rephrase the last sentence:"If you don't, then it's your own decision."Buying something cheap is a decision (see KungFuJosh's TC3) and not necessarily a fault.It's only a fault if you expect your $50 thing to be as good as a $500 product.

author: Martin72
author_rank: Super Contributor
timestamp: May 13, 2024, 06:02:55 pm
content: Yes, a true word.

author: DaneLaw
author_rank: Frequent Contributor
timestamp: May 13, 2024, 06:15:26 pm
content: Its worth noting that Rigol do have a newer line of waveform-generators with the loaded label "PRO" with significantly better specs across the plate.Datasheet specifications are posted below between the 2018 entry-line DG800 versus this new 2023/24 DG800PRO-line, which also is an entry/budget-seriesTook the plunge on one back in November 2023 (DG821PRO) under the Singles-day-sale after a non-official Chinese Fluke/Rigol seller on Aliexpress to my surprise was willing to make up a new listing for one, though under the promise I extended the shipping-time to a handful of weeks, as it wasn't released yet in China, but it was only a matter of days.It arrived in mid/late-December, quite an early unit 0000013, the final price was a tad under 300 euros (incl. both 25%EUVAT & delivery)That specific seller (Fluke & Rigol store) all his listings' became invalid after 1-1-2024 with a sitemessage, "saying not available to your region".. it seems to be down to Aliexpress implementing new regional restrictions for EU from 1_1 2024 for certain brands.Went for this unit, as I tried to speculate on the fact that there wouldn't be any actual hardware differences between the cheapest DG800PRO and the higher-end line of DG900PRO, and that the community down the line would be able to liberate this new line, as it wouldn't be a bad deal' if these specs were up for grabs for under 300 bucks [ 1.25GSa/s - 200MHz - 32M - 16-bits ] in a modern signal gen.My biggest complaint so far, are the anoying fan.. it's a temp-regulated fan, that got a will of its own, and will cycle with minute differences up and down' that are far from pleasant,.. it can likely be optimised in firmware updates down the line, but then again, Rigol certainly dont have a curriculum that inspires any confidence for optimizing products after the fact.It's more or less constantly on after around a +5-minute use-case and stays on... Looks like its the same noisy-fan as in Rigols DHO800/900-scope line, so in that regard the older series DG800 / DG900 and DG2000 do have an advantage, as they were all fan-less, if I recall correct, but also a lot slower. 125MSa/250MSa vs 625MSa/1.25GSaDoes get quite hothttps://i.imgur.com/Cr5RSoD.mp4Two things I do value a lot on Rigol's DGXXXPRO signal-gens, are the big high-res screen (7" 1024x600) that makes it way more enjoyable to explore & adjust features [UIhttps://tinyurl.com/2z87bkzy]Also, appreciate the ability to run it from power banks, and the mobility it gives.The specs & tolerances DG800PRO (out of the box) versus the previous DG800 datasheet.Quite a jump across the plate.

author: bateau020
author_rank: Frequent Contributor
timestamp: May 13, 2024, 06:29:28 pm
content: Yes, the UI can be improved, Yes, the sync does not work reliably (and sometimes not at all), but I have the impression that the OP does not have the latest FW, nor has opened up the device to the max of its capabilities:* make sure you have the latest FW (from 2021), as the original firmware was really bad.* please know that "liberating" it to a DG992 is possible. That will at least get you up to 2MHz on the ramp, and 100MHz on sine wave (although, if you do not get it recalibrated, the amplitude will start to drop off at the higher frequencies. But hey, what do you expect?)

author: thm_w
author_rank: Super Contributor
timestamp: May 13, 2024, 10:34:14 pm
content: Quote from: DaneLaw on May 13, 2024, 06:15:26 pmIt is quite a jump for roughly the same price, assuming the full hack is eventually made public. Comparing DG992 to DG900 pro:- 625Ms/s vs 250MS/s- 200MHz vs 100MHz- Maybe 5dB better harmonic/spurious distortion- Though 5dB worse phase noise, seems to not have the same wave combining features, and probably other small details I missed.Quote from: bateau020 on May 13, 2024, 06:29:28 pmOP is running 00.02.06.00.01 which should be the latest. I mentioned hack above but don't know if they'd be interested, presumably they returned it already or are trying to return it.

author: Sensorcat
author_rank: Regular Contributor
timestamp: May 13, 2024, 11:30:24 pm
content: It seems that this question is still unanswered, so I give it a try.Quote from: Aldo22 on May 13, 2024, 10:52:19 am'Better' usually means 'better for me' and a lot of avoidable debate and trouble comes from omitting these two words. This means 'better' is subjective and everybody must decide on his own what specs are most important. It is interesting to compare the classic, now obsolete, HP/Agilent 33120A with the Rigol DG800, because you can probably buy them now at a similar price. Availability of a used 33120A may vary depending on your location, though.I don't think that comparing the key signal specs is most important for a comparison. What makes the difference then?DG800 advantages:2 channel option, very important if you need 2 signals with fixed phase relationa large LCD, shows a lot of information at oncemuch more memory for arbcounter includedmuch more functions for modulation/burst/sweepUSB33120A advantages:better build qualityschematics and service manual availableusing a milestone design (the 33120A made DDS affordable) feels like driving a VW beetleEEs 40+ might know it already from workmanufacturer has/had the reputation of providing elaborate, sophisticated, well-thought-out designsmanufacturer has/had the reputation of not 'cheating' in specs/fineprintmature firmwareGPIBQuote from: Aldo22 on May 13, 2024, 10:52:19 amIf you don't deep-dive yourself into this stuff, there is nothing better than hearsay, with the challenge that there are as many opinons as experts, or more...

author: DaneLaw
author_rank: Frequent Contributor
timestamp: May 14, 2024, 12:10:12 am
content: Quote from: thm_w on May 13, 2024, 10:34:14 pmWasn't the phase-noise values on the older units taken at merely 10MHz, while on the PRO its 20MHz and double the value? (another -3dBc to the PRO's value?)- Took a look at the datasheets for different models, it seems to be uniform.Phase Noise DG800 / DG900 / DG2000 series.Typical (0 dBm, 10 kHz offset) 10 MHz: <-105 dBc/Hzhttps://www.batronix.com/files/Rigol/Funktionsgeneratoren/DG900/DG900-Datasheet-EN.pdfPhase Noise DG800PRO & DG900PROTypical (1 Vpp, 10 kHz) 20 MHz: <-110 dBc/Hzhttps://www.batronix.com/files/Rigol/Funktionsgeneratoren/DG800Pro/DG800Pro_DataSheet_EN.pdfOn paper - the Rigol PRO-line of 2023/24 signal gens is a significant step up, but then again Im not sure how much confidence you can put into these specs.I recall UNI-T UT962E claimed a very impressive (-125dBc at 10Mhz / 10kHz) which seemed to be a straight-out lie pulled from the air.It performed even worse on phase noise than the cheapest entry Juntek JDS2900 DDS signal-gen and also significantly worse than a TTI (TG2511A) that merely claimed -115dBc 10MHz / 10kHz.Testhttps://youtu.be/hBDGztAnfI4?si=oOIr9gMOI6Bu2H5J

author: Aldo22
author_rank: Super Contributor
timestamp: May 14, 2024, 08:58:47 am
content: @SensorcatThank you for your answer.Yes, that's probably very subjective.I don't actually see any advantages with the 33120A that would be convincing for me.In my opinion, the device is simply outdated, if only because of its size (374mm depth, 4kg) and I'm not particularly interested in whether it can still be repaired in 20 years' time.I don't own a museumBut I do think that you have to compare specifications.It certainly has advantages in terms of accuracy, harmonic distortion etc. but also some values that are no longer convincing.Look, I have a new $130 oscilloscope (I won't name the brand because that's not the point) which has a built-in AWG (would cost $20 extra).The prototypical "usual junk from China".For example, I can use it to generate a single 20ns pulse that looks reasonable (Image). Rise time is approx. 3.6 ns.Can the great 33120A do this too? Haven't found anything about this.There are certainly areas where the 33120A is far superior, but these devices are not cheap even used (in Switzerland), if you can find them.But above all, it's too clunky for me.

author: Njk
author_rank: Frequent Contributor
timestamp: May 14, 2024, 09:32:32 am
content: Quote from: Aldo22 on May 14, 2024, 08:58:47 amSure. But keep in mind that typical modern generator has its waveform output connector internally grounded. That's not the case with the obsolete instrument.

author: m k
author_rank: Super Contributor
timestamp: May 14, 2024, 12:54:21 pm
content: Quote from: eTobey on May 10, 2024, 05:40:37 pmI'd say that your expectations were out of the region.Commercial rule of thumb is that lost customer is too expensive to get back.Would it be better to sell it with some loss than keep it and feel the endless pain.I'd say former.Amount of money is not significant, its value is.

author: thm_w
author_rank: Super Contributor
timestamp: May 14, 2024, 10:54:52 pm
content: Quote from: Njk on May 14, 2024, 09:32:32 amOh good feature. 33120A is spec to float 42V from earth.DG800 Pro has both output grounds tied, but, isolated from earth via the USB power supply. Though I'm not sure how far you can really safely float them, as its not an advertised feature... But I would hope 42V is fine. Same with the DHO800, you are supposed to tie the chassis to earth, how many people actually do though..

author: Martin72
author_rank: Super Contributor
timestamp: May 14, 2024, 11:09:43 pm
content: So many people will do this who don't know why the scope should actually be grounded.At some point they will realize that it might have been a good idea after all.

author: 2N3055
author_rank: Super Contributor
timestamp: May 15, 2024, 04:36:15 am
content: Quote from: thm_w on May 14, 2024, 10:54:52 pm33120A isolated ground is just that. It serves the purpose to prevent DC/low frequency current ground loops while measuring.It is not to be used as a fully floating signal source.Other thing is that signal output to protective ground leakage and capacity is not specified in D.S. so for AC you might have much less isolation than you think...

author: tautech
author_rank: Super Contributor
timestamp: May 15, 2024, 04:58:00 am
content: For some reason it seems industry std is+42V but not clear to me.The discontinued SDG5000 range offered this as does the current USB AWG module SAG1021I.P5https://int.siglent.com/upload_file/user/SDG5000/SDG5000_DataSheet_DS02050-E03C.pdfhttps://siglentna.com/product/external-arbitrary-waveform-generator-2/

author: Aldo22
author_rank: Super Contributor
timestamp: May 15, 2024, 07:21:33 am
content: Quote from: Njk on May 14, 2024, 09:32:32 amMy cheap FY3224S also came without grounding, with a two-core mains cable.Is that the same?Of course, I then pulled in a 3-core cable and connected PE to the BNC connectors (switchable).

author: Njk
author_rank: Frequent Contributor
timestamp: May 15, 2024, 01:37:20 pm
content: Quote from: Aldo22 on May 15, 2024, 07:21:33 amThat does not count. I meant "grounded" is connected to the chassis, no matter if the chassis is grounded or not.IMHO a 3-core electrical arrangement brings more harm to T&M equipment than good. It's not a CE equipment, it's for professional use and that's normal. It was a common practice (at least here) that every instrument has a 2-core mains connection and it's the user's responsibility to connect the chassis of every instrument on the bench with PE in single point, using a dedicated wire. To avoid ground loops. Electrical safety of 3-core arrangement seems more a marketing/legal point that makes the instrument fool-proof but frequently results in inconvenience for all the others.

author: Aldo22
author_rank: Super Contributor
timestamp: May 16, 2024, 12:00:24 pm
content: @Njk:Thanks for the explanation. Interesting.The FY3224S does not actually have a chassis in that sense.The BNCs are soldered directly to the PCB and the housing is made of plastic.I put in a three core wire because otherwise the BNC have 94VAC against earth, which made me a bit worried.But as I said, I installed a switch so that it can be disconnected again.