AWG Sig Gen - Agonising over choice! Rigol/Agilent/Siglent (huh???) - Page 1
Forum section: electronics / general

author: LaurenceW
author_rank: Frequent Contributor
timestamp: December 23, 2011, 05:59:10 pm
content: Guys, push me one way or the other, here. I am getting into a number of PIC-based projects, and need to handle incoming signals, mainly digital. Not complex DSP stuff. So I have decided I need a sign Gen, and I might as well go for something which handles arbitrary waveforms, and is good for maybe 10-15 MHz. Some analogue stuff, too, so sine and ramp generators i can see a use for. I've done quite a bit of reading of the specs (only tell you so much), read the manuals (tells you more) and trawled these forums (tells you quite a bit!) but am still undecided.IHADboiled it down to two.The good ole' HP/Agilent 33120Awhich is a solid piece of kit, in my price range, but does not handle pulse signals (I think I may need that). Solid supportOut a couple of years, now, theRigol DG1022, which would compliment my DS1102E 'scope nicely, though feng shui in my "lab" is not such a big deal! Cheap and getting cheaper, but poor support, possibly flakey performance at the edges (but does that matter to me? probably not).But then a THIRD one appears on my radar!Siglent SD1000series (doesn't sound like anyone could confuse that name with Agilent, could they? Of course not, claimed Hugh LePackred, manufacturer of fine clones). Even CHEAPER than Rigol (which seem to be coming down in price on eBay as a direct result), and as plain as anything a rip-off copy of Rigol. Even the product manual hasgreat chunksof the same Chinglish text! what a nerve!.Siglent's angle seems to be "everything the Rigol does, but a bit more, and for a bit le$$". OK, I know well enough that you get what you pay for, and if we judge Rigol suportt poor, I'd assume that Siglent support will be cr@p once they've got your money.I'd love to step up to something like an Agilent 33220, but I just cannot justify the folding to the Finance Committee (she said: "no").Has anyone any experience of Siglent? Am I going to regret purchasing one, the moment I plug it in? Is a colour screen on a sig gen justblingtoo far? Has anyone bought a Rigol and wished they'd gone with Agilent, or vice versa?Oh, agonies!

author: Bored@Work
author_rank: Super Contributor
timestamp: December 23, 2011, 07:11:49 pm
content: Siglent == Atten. And see a previous teradown of an Atten AWG on this site. It ain't pretty.

author: Short Circuit
author_rank: Frequent Contributor
timestamp: December 23, 2011, 07:52:18 pm
content: Are you sure about that? Looking at their website (http://www.siglent.com/en/product_show.asp?articleid=156), their generator is quite different from the Atten models (http://www.atten.eu/function-generators/atten-atf20a-function-generator-54.html). Which are piece of crap indeed, terrible user interface, etc. Luckily, it's cheap crap.

author: LaurenceW
author_rank: Frequent Contributor
timestamp: December 23, 2011, 08:47:51 pm
content: Well thanks, B.A.W, that was the sort of article I was looking for! (Somehow missed it on my first couple of sweeps - other noobies: check outATTEN ATF20B teardownif you want to see it)So ATTEN is so much cr@p, then: jury still out whether Siglent is same but different Cr@p.Hmm - i am leaning back towards the Rigol DG1220 . OK, it is not the full thoroughbred in the Dog's Dangly Bits department, but as long as it does what the manual says - and keeps doing it - I'll be happy. A SERIOUS hike in prices to reach the DG2000 level of sign gens makes it look all the more attractive.I just KNOW there'll be a better, cheaper Rigol model around the corner, but (test equipment) life was ever thus.

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: December 24, 2011, 05:51:19 am
content: Go for the Rigol DG1022! I have the Rigol And Atten and did the teardown of the Atten. Any manufacturer that will make a FAKE usb port on the device does not deserve to be incorporated on benches.

author: saturation
author_rank: Super Contributor
timestamp: December 24, 2011, 12:37:28 pm
content: Atten are on a lower class its own, but Siglent is even lower than Atten even if both have the same parent company, based on samples of their wares within eevblog; see tear downs you can find on the archives. That the parent company resorts to sneaky things [ such as selling the same hardware with 2 different brand names] to make sales suggests dubious management practices, they would always be last in any list of possible vendors, if there at all.https://www.eevblog.com/forum/index.php?topic=4660.30Not a good way to make a brand name, IMHO.Rigol is better rated, but if the number of bits needed in the AWG aren't crucial, have you looked at the thread done on the Hantek 3x25, as it does useful output to 100 MHz? With the money saved, I'd look for a used quality pulse generator from eBay.

author: Short Circuit
author_rank: Frequent Contributor
timestamp: December 24, 2011, 12:58:20 pm
content: Quote from: hacklordsniper on December 24, 2011, 05:51:19 amThat's a bit harsh statement. It's not good of course, but even my (rather expensive) Agilent DSO6034A has a connector and buttons that are not in use (for the optional $$$ logic inputs). And I'm quite happy to have that one on my bench, yessirThe problem with the Atten is more about the counter-intuitive user interface.On the other hand, it's an absolute bargain to get two signal sources in a fancy looking case. So it's not bad to have as an extra. For me it's actually the only generator that gives me signals between 2MHz and 20MHz with some amplitude. I have a 'real' signal generator (2.4GHz Marconi) as well, but that one does only 2Vrms.

author: robrenz
author_rank: Super Contributor
timestamp: December 24, 2011, 03:39:52 pm
content: I love my Rigol 1022 so far. It has done everything i wanted it to do and AFAIAC the user interface is super. I dont care about computer interface so I cant comment on that aspect. I especialy like the ability to set the actual load impedance to match your actual load. That makes your set voltage output actualy match the voltage across your load.

author: LaurenceW
author_rank: Frequent Contributor
timestamp: December 24, 2011, 05:13:10 pm
content: Thanks for your replies, everyone. With minor variations, I am clearly reading that "you get what you pay for", although what you get seems to be going UP with each passing year - nice.I've thought hard about my (present) NEEDS, and I think I want a "pulse" option in my generator, so that has already ruled out a good old HP 33120A, I believeThe Rigol DG1220 price seems to be coming down under pressure from latest clone offerings, so I think I will go for that, and not be TOO precious if some of the specs are more wish-list than verified measurements! I would like to step up to a DX2xxx or DG4xxx but the price hike is extreme (for me). I am sure the entry level product is going to do 95% of what I really need, which is 95% more that my current equipment...And "hey", Saturation - ITRUMPyour NPN transistor with my old collection of Germanium (I thought that was a FLOWER?) PNP transistors! OC71, anybody?

author: Chet T16
author_rank: Frequent Contributor
timestamp: December 24, 2011, 05:35:07 pm
content: I have a DG1022 although i've only had it a short while and it arrived during my university study/exam period so my experimentation time has been very limited.The glincher for me was being able to use it with the Rigol scope capturing and replaying waveforms which seems to work very wellMaking waves in ultrawave hasn't been as successful but given the limited amount of time i've had i wouldn't like to discount this being a user error just yet

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: December 24, 2011, 10:53:27 pm
content: Quote from: Short Circuit on December 24, 2011, 12:58:20 pmOh well Atten, Siglent or Agilent is all same piece of errr instruments. The Rigol should be chosen any day over the Atten, Siglent

author: Unknown
author_rank: Unknown
timestamp: December 25, 2011, 04:14:36 am
content: Quote from: LaurenceW on December 24, 2011, 05:13:10 pmA pulse is just a single period of a square wave with a DC offset. A pulse train is a square wave with a DC offset. Square wave can produce pulses assuming it's within the duty cycle range, though control is less convenient. You can of course use the arbitrary ability to produce pulses of any shape. A dedicated pulse function is only available on the newer series (eg. 332xxA) I think.Quote from: robrenz on December 24, 2011, 03:39:52 pmDo you like programming arbitrary signals from the front panel, or did you spend the $$$ on an arbitrary/function generator without using the most expensive part?Quote from: hacklordsniper on December 24, 2011, 10:53:27 pmWhat's wrong with the Agilent function gens?

author: robrenz
author_rank: Super Contributor
timestamp: December 25, 2011, 05:09:01 am
content: Quote from: alm on December 25, 2011, 04:14:36 amI bought it on sale combined with the 1052E. had no current need for the arbitrary gen. Just needed dc offset capability and decent voltage range, liked the looks of the unit and the manual was understandable and I could afford it even if it is currently overkill for my needs.

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: December 25, 2011, 08:19:12 am
content: I can confirm that, the DG1022 useable without even reading the manual, its intuitive and only bad side is the software does not work always.However the Atten ATF20B is retarded and i would expect a few 10 year old kids to design much better UI

author: saturation
author_rank: Super Contributor
timestamp: December 25, 2011, 03:57:32 pm
content: Happy holidays! The last time I saw a Germanium transistor was in 'transistor' radios that used either 9V or D 1.5V batteries.One consideration for your lab is looking for repairable or working metrology grade lab equipment. These devices still have impressive specs by today. For example, a Tek SG505 still beats many audio generators today, and when they are made available are eBay sold ~< $200, working.Quote from: LaurenceW on December 24, 2011, 05:13:10 pm

author: LaurenceW
author_rank: Frequent Contributor
timestamp: December 25, 2011, 06:07:31 pm
content: Saturation, that TEK looks like a nice piece of kit, almost tempted to add one to the list "for old times' sake"I am looking for something which will see me right for maybe another ten years (then who knows what kit will be available??) without costing the earth. I guess i know what my needs are NOW, but not what they might be in a few years! The Rigol is looking like fitting the bill - as i currently see it.....But Wait! What's thisRigol DG4062for under 500 bucks:http://www.aliexpress.com/product-gs/519276071-adopting-the-DDS-technology-two-channels-a-multifunctional-generator-DG4062-free-shipping-wholesalers.htmlohoh! Scope creep setting in....

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: December 25, 2011, 07:23:55 pm
content: That is nice price with free shipping!

author: LaurenceW
author_rank: Frequent Contributor
timestamp: December 26, 2011, 12:41:07 pm
content: ... or it would have been a nice price! On asking our Chinese friends to confirm the advertised figure, i am told it is "now" USD $749. Hmm may pass on that one!Slightly off topic - any good/bad experience of buying through AliExpress? It feels a bit like eBay without the safety net! I love jumpin' out of aeroplanes without a parachute, me

author: Bored@Work
author_rank: Super Contributor
timestamp: December 26, 2011, 02:28:59 pm
content: Quote from: LaurenceW on December 26, 2011, 12:41:07 pmThey are a subsidiary of Alibaba, who also run Taobao.At the beginning of this year it turned out that 2% of Alibaba's own sales force were in cohorts with scammers, letting scammers onto Alibaba, resulting in something like 1% of newly signed up "verified gold suppliers" actually being scammers. That smells like organized crime to me.http://www.time.com/time/world/article/0,8599,2052971,00.htmlhttp://www.economist.com/node/21016214But you know something is really going south when one notorious scammer (Paypal) refuses to deal with a fellow scammer (Aliexpress) any morehttps://www.thepaypalblog.com/2011/06/update-on-aliexpress/Alibaba/Aliexpress/Taobao are also known for a lot of bait and switch going on. Sellers offer some brand product, but actually ship a clone or a mediocre domestic product as a "substitute". Complaining is difficult and sending the wrong item back is expensive, so often it is not worth it to complain and try to get the item replaced. The Alibaba escrow service is notorious for not responding to complaints and only considering a complaint, if at all, if no item was received, not if the wrong or broken item was received.You decide if you want to risk that gamble.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 26, 2011, 03:08:46 pm
content: Quote from: BoredAtWork on December 26, 2011, 02:28:59 pmthanx to them. who refunded my money twice for item not received, and the 2nd item i got for free after it did arrived 2 months after the refund.

author: LaurenceW
author_rank: Frequent Contributor
timestamp: December 26, 2011, 07:34:48 pm
content: Yes, am further I am learning that their so-called Escrow agreement isn't all that it's cracked up to be - in other words, not independent of AliBaba & co, at all. Not enough Chinese walls and too many Chinese whispers?Reading deeper into some of these "companies", and the "facts" just don't stack up, with a lot of them. I imagine sole traders, pitching popular items on AliExpress, with no stock to offer. When they land an order, THEN they run around looking for something close.A good trawl through their feedback often reveals a most diverse range of previous sales, and often precious few (like, NONE) previous sales of the specific item of interest. Go figure.I should add that I have made several small (sub $50) purchases from AliExpress over the last year or two, with no problems and decent savings. But big ticket items are the ones that are going to attract the crooks, of course.Suddenly, eBay looks like the "safe(er)" place to do business!

author: Bored@Work
author_rank: Super Contributor
timestamp: December 26, 2011, 08:51:04 pm
content: They can even screw you with small orders. The order system has a feature allowing a seller to adjust the price after you ordered. Officially this is intended so the seller can give you a discount. Now the funny thing is if the seller enters a negative number in the price adjustment/discount field it is added to the price. You order something for $50, the seller gives you a "discount" of -$100 and you end up with an order of $150.Officially this is a software error, but isn't fixed for whatever reasons ...

author: grenert
author_rank: Frequent Contributor
timestamp: December 26, 2011, 09:04:08 pm
content: Quote from: LaurenceW on December 26, 2011, 07:34:48 pmWell, probably the truly safer place to do business would be a local authorized dealer, or at least one in your own country. If you're in the UK, MCS Test Equipment has offered Rigol equipment for sale on this forum. Do a search.

author: LaurenceW
author_rank: Frequent Contributor
timestamp: December 27, 2011, 03:42:22 pm
content: Yes, I know of MCS (hello Joy, if you are following this!) and indeed bought my DS1102E 'scope through them in the early days. But I did pay a bit of a premium. Example: Rigol DG1022 SigGen - August price quote was GBP £325 + 20% VAT, delivered. Current "best" Ebay price GBP £266 delivered, but there is the RISK that customs will take an interest to the tune of a further 20%, of course.The DG4000 series is still pretty new, so maybe prices are all over the place. The DG1022, on the other hand, is now widely available. And yet, on BOTH occasions, when I asked an ALiExpress reseller to confirm what looked to be very aggressive initial pricing, suddenly the price had gone up! (even though the original offer was still "up" on their site). OK, I get the picture.I can easily see, B.A.W, how I might place an order for USD $300, only to find my credit card debited to the tune of $450 ("Solly sir this is new plice), and me without a proverbial leg to stand on!Like my mother always said, "If something looks too good to be true, put it down and come and finish your dinner, or it goes in the dog." At least, I think that was it.

author: DaveW
author_rank: Frequent Contributor
timestamp: December 27, 2011, 06:44:34 pm
content: Try Batronix-they can be cheaper than MCS, free shipping to the UK from Germany and they do support what they sell; or at least when I had broken knobs on a couple of Rigols they replaced them for me. Pretty cheap for the DG1022

author: saturation
author_rank: Super Contributor
timestamp: January 04, 2012, 02:49:41 pm
content: Hi LaurenceW,Its a matter of your intent for your gear. If you are using gear mostly to design, high fidelity is more important than convenience. DDS is famous for stability but higher distortion, analog generators give low distortion, but more prone to frequency drift. arbs need to be specified by the number of bit resolution, to improve its resolution and reduce distortion. If the arb need is fairly low or uncertain, used pulse generators, etc., from eBay sell for far less than a new Rigol, and made by more reputable makers. If you choose one from 1990s technology they are fairly easy to repair and, likely, made of parts from the golden days of USA, Japan, EU and Taiwan sources with far better quality than today.There is strong suggestion than cheapo arb or DDS generators can produce high quality and spending more won't get you more, it depends on manufacturer [ see a thread on eevblog on the Velleman USB signal generator versus Hantek 3x25 regarding harmonic distortion content of its sine wave output.] So you can get such a device separately, and get a separate pulse and function generator, all geared to be as best bang for buck, over say the Rigol.I recent got this reference pulse generator capable of < 70ps for $70. You can build the Jim Williams version for about the same money, but its designed only to go to 300ps-1ns range.http://webpages.charter.net/dawill/tmoranwms/Elec_Pulse.htmlAs Bored suggests, I am too am very leery about buying from alibaba and most large China based vendors; if I do I would consider the purchase a complete gamble and know before hand I will lose all my money, or receive damaged goods.Alibaba is a strange name for a web business, he was in league with the '40 thieves.' The story goes " ...popular perception of Ali Baba, and the way he is treated in popular media, sometimes implies that he was the leader of the "Forty Thieves": in the story he is actually an "honest man" whom fortune enables to take advantage of the thieves' robberies."http://en.wikipedia.org/wiki/Ali_BabaSo maybe the website is trying to make an honest living by hosting thieves?I think it safer to buy direct from eBay based Chinese vendors as the 'small guy' is less likely to screw you given he wants business, and you can more easily chat with them via email to determine how honest they will deal with you. eBay also tracks their history of successful transactions and, being based in the USA, you have some redress for complaints.Quote from: LaurenceW on December 25, 2011, 06:07:31 pm

author: Unknown
author_rank: Unknown
timestamp: January 04, 2012, 06:18:57 pm
content: Quote from: saturation on January 04, 2012, 02:49:41 pmAnalog function generators suck as far as distortion of their sine output is concerned. The sine is usually generated by shaping a triangle wave until it looks approximately like a sine, a good one might do < 0.5% THD on a good day. A good DDS generator will be an order of magnitude better. There's a reason why the big brands like Agilent make (almost?) no analog function generators anymore.

author: hazzer
author_rank: Regular Contributor
timestamp: January 04, 2012, 06:42:26 pm
content: I bought the Siglent SDG 1020 back in Oct 2011....I choice it over Atten range as the Siglent range has 14bit vertical resolution vrs the 8bit resolution of the Atten.I though the Rigol were just a tad too expensive for my needs.I'm very happy with the Siglent - the PC software is a bit clunky but it does do all its supposed to do.(it runs on windows7 64bit as well)....It comes with a useful range of pre loaded arbitrary waveforms ... so all in all I think it was good value.Build quality is good - nice solid construction.If you want any more info lets know.Harry

author: wkb
author_rank: Super Contributor
timestamp: January 04, 2012, 07:47:13 pm
content: Quote from: hazzer on January 04, 2012, 06:42:26 pmAs a matter of curiosity: does anyone know if there are vendors of AWG that have software that runs on MacOSX? [I can dream, can I?]

author: Bored@Work
author_rank: Super Contributor
timestamp: January 04, 2012, 08:04:33 pm
content: Quote from: wkb on January 04, 2012, 07:47:13 pmYour best bet would be an AWG that uses a well standardized USB class for communication, one by default implemented on the Mac, and where the vendor has properly documented the commands to be exchanged over USB. Alternatively, instead of USB a device supporting the LXI LAN interface, again with good documentation from the vendor.Then "all" you need is a programmer writing some interface software and an AWG editor for you.Interestingly, there is no real free / open source alternative for LabView, and there are only proprietary ,but no free implementations of VISA, LXI, IVI drivers etc. for Linux, Unix, Mac and the like. There are only fragments. A driver here, a GPIB library there, some VXI-11 tools, etc. But not a consistent, standardized (or setting the defacto standard) instrumentation framework.If someone wants to make a name for himself in open source, here is the niche that is waiting to be filled.

author: wkb
author_rank: Super Contributor
timestamp: January 04, 2012, 08:14:38 pm
content: Quote from: BoredAtWork on January 04, 2012, 08:04:33 pmThank you. Done quite a bit of programming in the past, but writing something like this is more than a small time sink... It is more a black hole of a time sinkOne would indeed like a FOS version of LabView, in a similar fashion like SciLab offers a FOS MathLab-like clone.

author: Bored@Work
author_rank: Super Contributor
timestamp: January 04, 2012, 08:59:55 pm
content: Quote from: wkb on January 04, 2012, 08:14:38 pmSure it is. I am always surprised that people do start large open source projects, knowing in advance that it will take them ages.QuoteI think the biggest issue would be to get access to all the instruments for testing protocol and driver implementations. You can't afford to buy all those instruments. Even renting them for a short time would be insanely expensive. So you have to do such a project with the help of some company, university, research facility or the like, where they have a access to a lot of instruments. A fearless student might be the right one to get such a project started.

author: Unknown
author_rank: Unknown
timestamp: January 04, 2012, 09:26:58 pm
content: Quote from: BoredAtWork on January 04, 2012, 08:04:33 pmIs there an USBTMC driver for Mac? Even though this is a horrible standard, it is kind of a standard for interfacing T&M equipment via USB. RS-232 would be another option, assuming the protocol is documented.Quote from: BoredAtWork on January 04, 2012, 08:04:33 pmOr you could do like Rigol and use free Agilent/Tektronix software to generate the signals and import them in your program.Quote from: BoredAtWork on January 04, 2012, 08:04:33 pmThere are some incomplete attempts likepylt, but nothing mature. I wouldn't be aiming for a Labview equivalent, just a standardized framework like VISA and bindings for popular programming languages.Quote from: BoredAtWork on January 04, 2012, 08:59:55 pmYou don't have to support everything. As long as you support the common interfaces (eg. USBTMC, RS-232, LXI, GPIB) and most types of instruments (eg. function gen, AWG, scope, DMM, counter, power supply), and make it easy to write instrument drivers, interested users can do the rest. Assuming the programming protocol was documented by the manufacturer. Those cheap disposable instruments without any documentation will always be an issue unless someone is motivated enough to reverse-engineer the protocol.

author: saturation
author_rank: Super Contributor
timestamp: January 04, 2012, 09:46:49 pm
content: We don't see much of this brand here on eevblog, would be good if you could review it and place it on a separate thread if you can.Quote from: hazzer on January 04, 2012, 06:42:26 pm

author: saturation
author_rank: Super Contributor
timestamp: January 04, 2012, 09:58:48 pm
content: Yes, concur but I was thinking of dedicatedaudiogenerators, so my bad. The generic analogfunctiongenerator is both distortion rich and unstable compared to most DDS based FG.In the audio domain for example, you can eBay this old model for < $200, still sold, with sine wave distortion 0.004%, or~ -88dBhttp://www.tequipment.net/KenwoodAG-253.htmlCompared to a reference DDS based audio generator at - 100dB THDhttp://www.thinksrs.com/products/DS360.htmList price of $2800.Quote from: alm on January 04, 2012, 06:18:57 pm

author: wkb
author_rank: Super Contributor
timestamp: January 04, 2012, 11:10:28 pm
content: Quote from: BoredAtWork on January 04, 2012, 08:59:55 pmHehe...Been there, or rather, still am there. Check outhttp://www.freebsd.orgfor my time sink of the last decade or so.

author: grenert
author_rank: Frequent Contributor
timestamp: January 05, 2012, 02:58:29 am
content: Quote from: hazzer on January 04, 2012, 06:42:26 pmI'm surprised by the Siglent's sine wave distortion numbers in the audio spectrum (from the manual):Total harmonic waveform distortion DC ~ 20 kHz?1 Vpp <0.2%Those are rather high for a 14 bit DAC. The old HP 33120A (12 bits) is specified to:DC to 20 kHz <0.04%Maybe in practice the Siglent performance is actually much better than specified.