EEVblog #891 - Siglent SSA3021X vs Rigol DSA815 Spectrum Analyser - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: June 20, 2016, 10:02:47 am
content: Dave compares the new Siglent SSA3021A 2.1GHz spectrum analyser with similar priced Rigol DSA815.Noise floor, clock and PLL phase noise and other performance aspects are measured and compared between the two models.Bugs?, yup, got those too!

author: PsychoBoy
author_rank: Contributor
timestamp: June 20, 2016, 11:33:47 am
content: Hey Dave, you said that 2.1GHz version is software upgradable to 3.2GHz but how did you know that?I did not find an information in datasheet if it is possible to do such upgrade.However I don't own this puppy so I can't check if it's possible.Could you check it in licensing menu?In my opinion the overall look of Siglent SA is very nice. Please do teardown someday too!

author: EEVblog
author_rank: Unknown
timestamp: June 20, 2016, 11:42:05 am
content: Quote from: PsychoBoy on June 20, 2016, 11:33:47 amI think I may have foolishly assumed this. I've been told it's the same hardware. Checking now...QuoteThat's the plan for tomorrow.

author: nctnico
author_rank: Super Contributor
timestamp: June 20, 2016, 01:35:14 pm
content: IMHO things as 'looking cheap... cheap plastic...' are better left out because all test equipment nowadays has a cheap plastic housing. Better stick to things with can be supported by facts.I'm also quite surprised that Siglent followed Rigol as an example. That is kind of the deaf leading the blind. Siglent could have done much better by looking at R&S, Advantest or Keysight spectrum analysers!

author: dr.diesel
author_rank: Super Contributor
timestamp: June 20, 2016, 02:31:47 pm
content: Quote from: nctnico on June 20, 2016, 01:35:14 pmYes Sir, I very much agree.

author: rf-loop
author_rank: Super Contributor
timestamp: June 20, 2016, 02:35:40 pm
content: I can not follow what exatly happend around time 33:00 and bit forward.You perhaps have in this position RBW selection manually forced ti fixed RBW. This used RBW is accepted with this span you have just used. After then you try full span and it do not accept it because your manually forced RBW is out of accepted value in full spand. (minimum RBW for full span is 1kHz. Minimum RBW for TG is 30kHz. There is also some other limits.) If you have set RBW manually and if value is not accepted example in full band and you try full band, it tell you what is wrong but it do not force it to accepted value. It do not overwrite your selection - it tell information and user make decision if he want change his forced parameter.But somehow after this situatuon there come new warning about conflict setting with TG when TG is still off and it is clear bug.

author: senseless
author_rank: Contributor
timestamp: June 20, 2016, 03:14:25 pm
content: Quote from: rf-loop on June 20, 2016, 02:35:40 pmI am pretty sure it has to do with the FFT mode instead of sweep. It has to do sampling at least with 4.2 GSPS for full span.After 'Auto Tune' magic the FFT mode was gone and full span was available.Nevertheless it is a bug, because in the beginning sweep mode was set to auto and hence it should have changed from FFT to sweep automatically.

author: Earendil
author_rank: Regular Contributor
timestamp: June 20, 2016, 07:19:45 pm
content: Dave, I think you should mention SFDR too.Siglent specifies residual response as -90 dBm(yes that's m, not c)typical. So the LO(?) leakage you're seeing at -132 dBm is not that bad compared to spec. Input related spurious is only -65 dBc.Rigol 815's spec is -88 dBm for residual response and -60 dBc for input related spurious. So yeah Siglent has better noisefloor which is a distinct advantage but on paper Siglent doesn't have as significant performance advantage as suggested, imho.Quote from: EEVblog on June 20, 2016, 10:02:47 am

author: tautech
author_rank: Super Contributor
timestamp: June 20, 2016, 07:33:31 pm
content: Quote from: PsychoBoy on June 20, 2016, 11:33:47 amFirst mentioned here:https://www.eevblog.com/forum/testgear/siglent-ssa3000x-spectrum-analyzers/msg938261/#msg938261Thread a few days later:https://www.eevblog.com/forum/testgear/hack-of-sigllent-spectrum-analyzer-ssa3021x/

author: Kire Pûdsje
author_rank: Regular Contributor
timestamp: June 20, 2016, 08:47:17 pm
content: Just a remark about the delta markers. When you take a 'difference' in dB's between two values (ie a ratio) the unit disappears. Eg the 'difference' between 23 dBm and 13 dBm is 10 dB. Likewise the difference between -100 dBm/Hz and -120 dBm/Hz is 20 dB.It seems the Rigol takes the ratio of the powers and then divides by the RBW. For example at 24:23 I read 0 dBm and -67 dBm. the ratio would be -67 dB. Dividing by the RBW results in -87 dB/Hz.However in my view the only point where this would make sense is when the reference marker is at the peak (as in your case). For any other point except that special case the Siglent way (just dB) is more generic. For example if I would want to compare the noise floor at two points, supposing there is a -10 dB ratio between the two powers, I would rather read -10 dB, than -30 dB/Hz. This latter value would not make any sense to me.

author: KenGaler
author_rank: Contributor
timestamp: June 20, 2016, 09:30:31 pm
content: Seems to me that it's not a coincidence that the base model doesn't quite make it up to the 2.4GHz ISM band. You have to spend twice that to upgrade.Ken

author: EEVblog
author_rank: Unknown
timestamp: June 20, 2016, 09:50:46 pm
content: Quote from: nctnico on June 20, 2016, 01:35:14 pmBut those companies don't make a competing scope in the price/performance bracket. Siglent only care about taking sales away from the Rigol DSA815.

author: EEVblog
author_rank: Unknown
timestamp: June 20, 2016, 09:51:17 pm
content: Quote from: KenGaler on June 20, 2016, 09:30:31 pmAlmost certainly not a coincidence!

author: EEVblog
author_rank: Unknown
timestamp: June 20, 2016, 09:53:29 pm
content: Quote from: Kire Pûdsje on June 20, 2016, 08:47:17 pmThat makes sense. But if you put the marker in noise mode it should know this and give you the correct units of measurement you expect IMO.

author: nctnico
author_rank: Super Contributor
timestamp: June 20, 2016, 10:02:14 pm
content: Quote from: EEVblog on June 20, 2016, 09:50:46 pmIMHO that is causing 2 problems for Siglent: Firstly: they can eat into R&S, Advantest or Keysight's lower end market if their spectrum analysers operate similar to those brands. Secondly: Rigol is a very poor example to copy from.For example: I have an older Advantest spectrum analyser and the SSA3000 would definitely be a step up from that. So even if Siglent can't match the specifications of current models they can get a piece of the market which would otherwise be fullfiled with used equipment from R&S, Advantest or Keysight.

author: tautech
author_rank: Super Contributor
timestamp: June 20, 2016, 10:19:38 pm
content: Quote from: nctnico on June 20, 2016, 10:02:14 pmWe like these types of problems ^^^.

author: EEVblog
author_rank: Unknown
timestamp: June 20, 2016, 11:09:33 pm
content: Quote from: nctnico on June 20, 2016, 10:02:14 pmIt doesn't matter, it's clever marketing.If someone is looking to buy at this price point, the Rigol is the only other option. So if someone demo's both, it's easy for them to make operational feature comparisons.

author: nctnico
author_rank: Super Contributor
timestamp: June 20, 2016, 11:46:49 pm
content: Quote from: EEVblog on June 20, 2016, 11:09:33 pmIf you insist on buying new but the way I see it the choice usually is between used A-brand (with warranty) or new B-brand if you are on a budget. And then the story is completely different. If I take my Advantest SA as an example (again): the Rigol and Siglent are in the same price range of what I paid for my Advantest SA including a 1 year warranty.

author: nixfu
author_rank: Unknown
timestamp: June 20, 2016, 11:54:52 pm
content: Finally.....someone smacks Rigol in the face to challenge them to update the(long in the tooth) DS-815 and see they can do even better.Rigol have been sitting with no competition for the DS815 for too long. Maybe this will convince them to make something with even better $/performance than their now several years old model.

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: June 21, 2016, 12:26:21 am
content: At about 25:24, talking about the phase noise of the internal clock of the Rigol, "Likely an issue with the PLL response" pops up on the screen. I'd say thats pretty unlikely. I'm pretty sure Rigol understands how to do a PLL correctly. I would be shocked if they ever had a problem with a PLL in anything they've built.

author: egonotto
author_rank: Super Contributor
timestamp: June 21, 2016, 01:20:16 am
content: Hello,in about 10:33 Dave compare the noise floor. He said the same detector.But it seams to me the in the Rigol is the Pos Peak and in the Siglent is a average detector. So the real difference of noise floor is lower than 20dB.Best Regardsegonotto

author: EEVblog
author_rank: Unknown
timestamp: June 21, 2016, 01:33:25 am
content: Quote from: nctnico on June 20, 2016, 11:46:49 pmUsed spectrum analyser in Australia cost a fortune. Shipping is a killer as you almost always have to import them.

author: AlfBaz
author_rank: Super Contributor
timestamp: June 21, 2016, 02:24:15 am
content: Speaking of prices in Australia, I was wondering about the prices you were talking about in the video. You mentioned 1700 (I presume US) with the TG for the 2.1GHz.It appears TRIO are selling it for closer to 1800US without TG and EX GST. By the time you add the TG and gst it would be closer to 2.5k (which is still good, I might add)Is there anywhere I can get it nearer the prices mentioned, as at that price I would still be tempted to shell out a bit extra and go with a 2nd hand "A brand"

author: bitseeker
author_rank: Super Contributor
timestamp: June 21, 2016, 02:31:43 am
content: Quote from: CustomEngineerer on June 21, 2016, 12:26:21 amYeah, that only happens with Yaigol devices.

author: EEVblog
author_rank: Unknown
timestamp: June 21, 2016, 02:46:56 am
content: Quote from: AlfBaz on June 21, 2016, 02:24:15 amNot in Australia officially, you'd have to import it yourself.Also, you wouldn't get local warranty support.

author: rf-loop
author_rank: Super Contributor
timestamp: June 21, 2016, 07:20:35 am
content: Quote from: EEVblog on June 20, 2016, 09:53:29 pmErrr....This is good that there read: IMO.7 points wink: User need know whhat he is doing. Equipment can not know.Is it better that you do some day one "teaching hour" Video where you explain Normalization to 1Hz, dBc/Hz and then NOISE dBm/Hz and importantly if you use noise cursors for look noise level dBm normalised to 1Hz noise BW.It is not at all simple game. If we take (sinusoidal type) peak dBm level what we look with 100Hz RBWa filter. We can normalize it to 1Hz RBWb same kind of signal using same kind of RBW shape factor just using 20dB subtract. (10 * log (RBWaHz/RBWbHz)With random noise situation is bit different.Random wideband noise have Gaussian distribution, but here with RBW filter noise have Rayleigh distribution.Also just sidenote: Many times VideoAverage Detector can not measure signal peak level so using example two (noise mode) markers for different kind of signal comparing drops user to trap very easy.How machine can know what signal is under your marker position. This is what user need know. And USER NEED do Right selections/settings. But this need knowledge.Proper using SA's for measurements need knowledge about basic fundamentals -- and also user need know his equipment. Tjis is why old times you buy expensive tool HP give also free teaching and training courses some time times and in lab, only peoples who have get training for equipment have access to use it. Also there was available quite deep explanation about theory of operation.In other way we need every day wonder what hell results user get and are these results valid or total bullshits what we then discuss about why my equipment display so strange things. But, of course this we need also and this is (mostly) useful for lot of peoples who are curious and always willing to learn more - and this is least one reason why I have been hobbyist with electronics over 50 years and never get enough.Out from box and then wondering this and that and oh my god this value or that figure is strange or wrong or is my equipment broken.We have seen it with all equipments, here and there and everywhere.For todays SA's this AN-150 is nearly as Mandatory reading. (It also tell how Siglent works in principle)And very importantly if you are bit new with SA's and/or worked lot of with analog sweeping SA's and fulldigital IF Sweep/FFTSA is new for user.Btw: Chapter 5 pages 46 - 54 explain these noise things.

author: coppice
author_rank: Super Contributor
timestamp: June 21, 2016, 01:52:46 pm
content: In China Siglent list 1.5GHz models - SSSA3015X and SSA3015X-TG - but western sites selling Siglent don't seem to be offering these.

author: SeanB
author_rank: Super Contributor
timestamp: June 21, 2016, 07:37:27 pm
content: I was laughing so much with the "Come on, while I'm still young" with the booting. Had to take a 5 minute break just to get over that..........

author: AF6LJ
author_rank: Unknown
timestamp: June 21, 2016, 08:41:13 pm
content: Quote from: SeanB on June 21, 2016, 07:37:27 pmThat was funny as hell, made me wonder if that thing had a 80286-16 under the hood

author: BobC
author_rank: Unknown
timestamp: June 21, 2016, 10:02:20 pm
content: +1 for rf-loop's recommendation for a Fundamentals Friday video on spectrum analysis in general, and reference measurements in particular.Perhaps 2 videos: First one for the what these measurements are and how to make them (theory + how implemented in test equipment). Second one for which is needed when and why (application and mis-application).AN-150 is truly excellent, but may be a bit advanced for some. Perhaps a primer to get folks ready to plow through AN-150 on their own?

author: ElectricGuy
author_rank: Regular Contributor
timestamp: June 21, 2016, 11:48:17 pm
content: Quote from: BobC on June 21, 2016, 10:02:20 pm+1

author: f4eru
author_rank: Super Contributor
timestamp: June 22, 2016, 08:36:38 pm
content: hmm. 2.1 GHz ? Seriously, Siglent?why not 2.5 GHz ? coz, you know, 2.4 is a very very common band, and people actually do want to measure it. Go figure...Concerning the menu : it is the same because every specan is the same since 15 Years. Or they all copied R&S and Agilent, since 15 Years, if you prefer.

author: bitseeker
author_rank: Super Contributor
timestamp: June 23, 2016, 03:02:23 am
content: Quote from: f4eru on June 22, 2016, 08:36:38 pmBecause they want those people to buy the 3.2 GHz model, of course.

author: Smokey
author_rank: Super Contributor
timestamp: June 23, 2016, 05:06:05 am
content: All of your reference signals need to be at 1.21GHz

author: EEVblog
author_rank: Unknown
timestamp: June 23, 2016, 05:23:43 am
content: Quote from: Smokey on June 23, 2016, 05:06:05 amDamn, yes!

author: DL5TOR
author_rank: Contributor
timestamp: June 23, 2016, 02:08:30 pm
content: Quote from: EEVblog on June 23, 2016, 05:23:43 amBut then please with 121 dBm (do the Math)

author: altaic
author_rank: Unknown
timestamp: June 23, 2016, 07:05:00 pm
content: Quote from: EEVblog on June 23, 2016, 05:23:43 amCorrectly pronounced "one point twenty-one jigahertz!"Also, you should make a version of O0 with white hair for the Doc.

author: bitseeker
author_rank: Super Contributor
timestamp: June 23, 2016, 07:43:08 pm
content: Quote from: altaic on June 23, 2016, 07:05:00 pm+1

author: Brumby
author_rank: Unknown
timestamp: June 24, 2016, 12:07:33 am
content: Quote from: DL5TOR on June 23, 2016, 02:08:30 pmI did wonder about the power level. Thank you for that detail.

author: Smokey
author_rank: Super Contributor
timestamp: June 24, 2016, 12:42:21 am
content: Quote from: DL5TOR on June 23, 2016, 02:08:30 pm88dBm!!!!!! You'll see some serious shit!

author: EEVblog
author_rank: Unknown
timestamp: June 24, 2016, 02:10:33 am
content: Quote from: Smokey on June 24, 2016, 12:42:21 amSome serious shit is about to happen!

author: Smokey
author_rank: Super Contributor
timestamp: June 24, 2016, 04:41:55 am
content: Actually we must be in the future... because it appears Siglent made a piece of gear that isn't total crap.

author: bitseeker
author_rank: Super Contributor
timestamp: June 24, 2016, 05:40:31 am
content: Wow, you just about got to 88!

author: kalleboo
author_rank: Regular Contributor
timestamp: June 24, 2016, 10:07:21 am
content: Quote from: EEVblog on June 24, 2016, 02:10:33 amWell you *did* go back in time 16 years!

author: IshtarTor
author_rank: Newbie
timestamp: June 25, 2016, 06:30:00 am
content: Quote from: EEVblog on June 21, 2016, 01:33:25 amInterestingly, Tektornix and R&S have interesting entry level analyzers.http://www.testequity.com/products/5286/http://www.testequity.com/products/5286/Still twice as expensive as the chinese brands, but the Tek has a 6GHz BW.Quote from: Smokey on June 24, 2016, 04:41:55 amTheir sig gen is not bad at all. And the chinese brands fill a price market that simply didn't exist before. Spectrum analyzers were simply a dream for many very small companies and individuals.

author: PartialDischarge
author_rank: Super Contributor
timestamp: June 25, 2016, 11:07:07 am
content: Quote from: nctnico on June 20, 2016, 11:46:49 pmDoes your Advantest have TG? If so please post the response of it, I hope its not as 'good' as the R3361A:http://www.fatpigdog.com/Advantest_R3361A/R3361A.htm

author: rf-loop
author_rank: Super Contributor
timestamp: June 25, 2016, 11:22:48 am
content: Quote from: MasterTech on June 25, 2016, 11:07:07 amDo it have function: "Normalize" ?

author: smarteebit
author_rank: Contributor
timestamp: July 02, 2016, 07:20:23 am
content: Quote from: EEVblog on June 24, 2016, 02:10:33 amCannot understand it. Is it an intrinsic spur? Or there is some story in it?

author: tautech
author_rank: Super Contributor
timestamp: July 02, 2016, 08:02:16 am
content: Quote from: smarteebit on July 02, 2016, 07:20:23 amYes and yes.For very detailed technical explanation go to your local video store and hire/by "Back to the Future" movie.Study in great detail for mentions of GHz.

author: rf-loop
author_rank: Super Contributor
timestamp: July 02, 2016, 08:20:18 am
content: Quote from: smarteebit on July 02, 2016, 07:20:23 am88 dBm power is over 630kWBut also if you see DL5TOR comment:Quote

author: bitseeker
author_rank: Super Contributor
timestamp: July 02, 2016, 06:28:49 pm
content: Yep, many such goodies around Dave's lab and sometimes on Dave.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: May 01, 2017, 03:48:40 pm
content: I been reading through the threads all morning.I am going to buy a spectrum analyzer very soon. This week maybe.Now after all the reading I may be a bit more confused than ever.So which one to buy....Siglent SSA3021X or Rigol DSA815?Perhaps I should go with the Rigol DSA832E-TGEither unit must have TG installed.Will mostly be for RF work in ham and commercial radio.Duplexer tuning ect.Anyone using one of these mentioned for radio work? I do not think there is any other options on the market at these prices.

author: AF6LJ
author_rank: Unknown
timestamp: May 01, 2017, 05:43:37 pm
content: I wonder if Rigol fixed the weird glitch the TG generated around 10MHZ..

author: tautech
author_rank: Super Contributor
timestamp: May 02, 2017, 12:42:25 am
content: Quote from: Radio Tech on May 01, 2017, 03:48:40 pmThis new vid on SSA3032X might be worth watching:https://youtu.be/uA4SvTBCAXU

author: Radio Tech
author_rank: Frequent Contributor
timestamp: May 02, 2017, 03:46:54 pm
content: Not sure if they fixed that or not. Will be interesting to find out.That Siglent is a really nice looking piece of gear.And has me thinking about it.At the moment I am really thinking about this package:DSA815-TG SA/TGDSG815 Signal generatorDS1054Z scope.I think anything else would be a bit over kill.

author: PartialDischarge
author_rank: Super Contributor
timestamp: May 02, 2017, 07:56:24 pm
content: Quote from: Radio Tech on May 02, 2017, 03:46:54 pmWhat I'd do:-DSA815-TG SA/TGI'd definitively get the SSA3021X after seeing Daves comparison between the two.-DSG815 Signal generatorNice unit, but given that you live in the US I'm sure you can get a good deal on an old (but better speced) HP RF generator or a Rohde and save some bucks.-DS1054Z scope.ok, no complaints here if 4 channels are needed. If you can live with 2 I'd buy the new siglent 200Mhz model, can't beat that price/performance.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: May 02, 2017, 08:21:02 pm
content: Quote from: MasterTech on May 02, 2017, 07:56:24 pmThat Siglent is very tempting.QuoteI already have several older units.HP 8640B signal generator fully restored.IFR (AeroFlex) 1200 with spectrum analyzer.IFR (AeroFlex) 1200 Super S with Spectrum and tracking gen.QuoteI really love to have a four channel scope. Since 90 percent of my work and repairs are in the low band RF (0 to 30 MHz) repair/restore I believe this scope would do the job. Since it can be hacked to 100 MHz. I been using two Tektronix 2335 two channel 100 MHz scopes for years. Even with V/UHF I have been able to get by with 100 MHz scopes. I did buy a Owon PDS6062S a few years ago. Big mistake BTW.I will say I like the looks of the Siglent. But the reason I like the Rigol is they have all three pieces same brand. Don't get me wrong my mind can change and I am always open to ideas. Appreciate the comment.

author: tautech
author_rank: Super Contributor
timestamp: May 02, 2017, 08:36:32 pm
content: Quote from: Radio Tech on May 02, 2017, 08:21:02 pmDo I say this or not ?Beware brand snobbery........but I know exactly where you are coming from and I used to be a little that way too, but if you want/need the best equipment for your particular price band it seems common these days to cherry pick products from amongst the brands available. The industry these days is truly fast moving and it takes a lot of my time trying to keep up with what's going on so I imagine it'd be harder for those that only venture into the marketplace "once in a blue moon".The RF gen ? Do the available AWG's not produce the frequencies you need ?Requirements ?

author: Radio Tech
author_rank: Frequent Contributor
timestamp: May 02, 2017, 09:29:31 pm
content: Quote from: tautech on May 02, 2017, 08:36:32 pmCompletely fine by me to say that. No problems at all.I am one of those that NEVER venture out to look new equipment. I have only bought two pieces of new est gear in the last 3 years. The Owon and a DMM. Most of my equipment is old but works great. Guess I am just so old school. I buy used non working test gear and repair it to use here in the shop. But I have now ventured out in other electronic repairs and setting up different benches in the shop. Currently have four benches and going to add two more this summer.As far as brands? That does not really matter. As long as they function and get the job done.QuoteMy equipment serves me well and does what I want as far as the SG goes. But none of them cover over 999 MHz. So at the moment I have nothing in the shop that covers the 23CM (1.2 Ghz) ham band.Thanks

author: Sidlinger
author_rank: Newbie
timestamp: July 18, 2017, 12:18:42 am
content: Hello Dave, this is Bruce from Arizona (long time listener / first time caller).Would you happen to know if the DSA815 used in this comparison was main board version 00.04 or main board version 00.05? I am told by Rigol that 00.05 improves performance (noise, etc.)Thank you.

author: EEVblog
author_rank: Unknown
timestamp: November 15, 2017, 07:31:51 am
content: Not sure if this is old news, but just been informed that the RBW is now 1Hz instead of 10Hz, just update the firmware to get it.