Choosing a four channel Oscilloscope - Page 1
Forum section: electronics / testgear

author: 0xfede
author_rank: Regular Contributor
timestamp: September 07, 2014, 11:06:38 pm
content: Hi all!It's quite a long time that I read this forum and as long that is my first post I've to thanks all for the precious information.As the subject says I'm looking for an oscilloscope with four channel, around 1K€ with a decent wfps, large segmented memory and at least 1GS/S.I'm not interested to have serial decode options (I already have a decent LA) and I don't need high bandwidth (70MHZ is enough) since I already have two good scopes.It would be nice that it is not too heavy because the primary use will be outside my lab.I also find interesting the ability to increase the bandwidth with a software option for future upgrade.The candidates I found:Siglent SDS2074 (a new product with some bugs,but it is heavyand I still don't know if the bandwidth will be upgradable)Rigol DS1074z (Low sampling rate and maybe too low wfps)I'm sure that you may suggest me other valid alternatives too.Thanks in advance,0xfede

author: Fsck
author_rank: Super Contributor
timestamp: September 07, 2014, 11:18:18 pm
content: the specs say they're about the same mass.everything else is either too expensive or older+heavier+tiny memory.the agilent dsox2004 is probably the only other contender but overshoots your price range unless you get one used

author: 0xfede
author_rank: Regular Contributor
timestamp: September 07, 2014, 11:29:54 pm
content: Hi Fsck,thanks for your answer.I've erroneously considered the package mass of the siglent.As you pointed out the agilent is a great contender and I'm considering it (but is 1k6€+taxes).Regards,0xfede

author: nctnico
author_rank: Super Contributor
timestamp: September 07, 2014, 11:41:15 pm
content: If 1Gs/s is a hard requirement then the Rigol 1000Z doesn't qualify because it reduces the maximum samplerate to 250Ms/s with all 4 channels enabled. IMHO Rigol made this oscilloscope under perform in order not to hurt their higher end offerings too much. Siglent's SDS2000 on the other hand can do 1Gs/s with 4 channels enabled.Another option would be a Tektronix TBS1000 series oscilloscope. These are smaller in size and weight but their value for money is extremely low.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 07, 2014, 11:56:23 pm
content: Hi nctnico and thanks for your answer.QuoteThe requirement is met when working in single channel.QuoteI've the same suspect but I still miss a DS2074 like many others in this forum.QuoteI had a TDS224 and I don't want a digital tektronix scope anymore...Regards,0xfede

author: tautech
author_rank: Super Contributor
timestamp: September 08, 2014, 09:31:59 am
content: QuoteGlad you crossed that out. I can pick mine up with one finger.Who knows if the SDS2000 will be cracked?It is still a quite new product and in time as people become more aware of the good hardware within, I'm sure some will try to "improve" it.But just as you are aware, the choice of 4 Ch scopes in this performance class and price range, there is not a great list of models.You also probably know of the recent reviews and the interest in those reviewsSiglenthas taken to iron out the last of the bugs with forthcoming firmware.https://www.eevblog.com/forum/testgear/review-siglent-sds2304-a-comparison-of-features-with-rigol-ds2000-series/https://www.eevblog.com/forum/testgear/siglent-sds2204-mso-review/So with this in mind, would you not purchase knowing 2 important things:1. 2 good videos showing operational features.2. the knowledge that Siglent are actively addressing all the known faults.As you need portability, I presume a carry bag is required?QuoteAlternatively the Siglent SDS 1000CFL Series are 4 Ch and 2Gsa/s with models from 70 MHz andhave a padded carry bag available. SDS1074CFL ~US$500

author: cybertronicify
author_rank: Regular Contributor
timestamp: September 08, 2014, 09:58:08 am
content: Very cheap and good scope for 600 USD!http://www.frys.com/product/4279454;jsessionid=q0G2RL2NtpBeR0RpNEdxNw__.node3?site=sr%3ASEARCH%3AMAIN_RSLT_PG

author: 0xfede
author_rank: Regular Contributor
timestamp: September 08, 2014, 10:09:03 am
content: Goodmorning Tautech and thanks for your reply.QuoteI don't want to crack anything, I'm just wondering if there will be buyable options to increase the bandwidth as some other manufacturers provide.QuoteI've already watched those videos (and I need to thanks Marmad and nctnico for their efforts) and those are the reason why I included the scope in my list. Still I'll wait for some improvements.QuoteIt would be nice, as long as a rigid custom flycase.QuoteThe 2Mpts long memory does not fit my requirements but seems a nice scope.Regards,0xfede

author: 0xfede
author_rank: Regular Contributor
timestamp: September 08, 2014, 10:21:21 am
content: Hi cybertronicify.As I said in another post I'll not buy digital tektronix scopes anymore.I've worked for years with all kind of tektronix gear and I was highly satisfied with their scopes until I've buyed a TDS224.Now I'm looking for something else.Thanks and regards,0xfede

author: tautech
author_rank: Super Contributor
timestamp: September 08, 2014, 10:31:44 am
content: QuoteBut you get exactly that with the differing prices through the range of SDS2000 models, do you not?I suppose it is just another way of looking at the same thing, you just have to pay for the additional BW up front instead. But I get what you are driving at.The trend these days seems to be mainly fixed BW models, presumably to protect manufacturers IP, although some have had intense internal bus scrutiny to provide exactly that option you desire. It seems to be the way these days.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 08, 2014, 10:47:58 am
content: I read various post about hacking the scopes and I find them intriguing from a technical perspective.But I'm not a young hobbyst/hacker/DIYer entusiast.As an EE those gears represent my money-maker and I tend to respect the work from my colleagues.QuoteAs I said I don't need high bandwidth right now but who knows?

author: cybertronicify
author_rank: Regular Contributor
timestamp: September 08, 2014, 10:51:06 am
content: Quote from: 0xfede on September 08, 2014, 10:21:21 amOops sry...i should actually read the thread next time huh? But if you after a good 4 channel digital scope. That is the scope you cant beat, for the price.

author: tautech
author_rank: Super Contributor
timestamp: September 08, 2014, 10:55:17 am
content: Quote from: 0xfede on September 08, 2014, 10:47:58 amAcknowledged and respected.QuoteLikewise.

author: nctnico
author_rank: Super Contributor
timestamp: September 08, 2014, 03:32:50 pm
content: It seems there is not much hacking of Siglent scopes going on. I'm also wondering about the bandwidth of the lower end models. The bandwidth on my SDS2204 exceeds the specification pretty far (it says 200MHz on the label but the bandwidth exceeds 300Mhz).

author: lpc32
author_rank: Frequent Contributor
timestamp: September 08, 2014, 03:45:04 pm
content: Quote from: tautech on September 08, 2014, 09:31:59 amMore like $700, no?

author: 0xfede
author_rank: Regular Contributor
timestamp: September 08, 2014, 04:38:53 pm
content: QuoteThat's really nice to hear.I read all your post (https://www.eevblog.com/forum/testgear/siglent-sds2204-mso-review/) and now I have a couple of questions for you:is a good product to work with?is it in a too early development stage?

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 08, 2014, 05:08:17 pm
content: Quote from: 0xfede on September 07, 2014, 11:56:23 pmWhat was bad about that TDS224 scope? Well, it is a basic scope released in 1996. It had limited measurement capabilites and trigger options.Have you ever seen a Tektronix scope released after 2005 or so?

author: nctnico
author_rank: Super Contributor
timestamp: September 08, 2014, 05:28:55 pm
content: Quote from: 0xfede on September 08, 2014, 04:38:53 pmIt is good enough for everyday work if you have used an oscilloscope before. I'm using it as my everyday scope (and logic analyser) now.@Hydrawerk: I have used a DPO2024 today at a customer. Except for the low display resolution it is a nice oscilloscope which works well. However, the biggest problem with modern Tektronix oscilloscopes is that Rigol and Siglent are 3 times cheaper for the same functionality. If a similar oscilloscope from Tektronix was €300 more expensive than the Siglent I just bought I might have considered the Tektronix. The choice between €6000 and €2000 is pretty easy. There is no justification to spend that kind of extra money.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 08, 2014, 05:35:04 pm
content: Hi Hydrawerk.QuoteWhen I bought it in 2001 it was my first DSO and my third oscilloscope.It has the ability to trigger of a turned off VIC20 (at least IMHO).Every day I had to restart it several times for fw bugs.Tek asked me to pay for fw update.I sent it to tek for fixing channel 3 offset two times.After two years I got rid of it.QuoteAs a consultant I work for various companies so yes. I'm not impressed at all though.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 08, 2014, 05:47:23 pm
content: QuoteThanks for the answerQuoteTotally agree

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 09, 2014, 01:05:26 am
content: Quote from: 0xfede on September 08, 2014, 05:35:04 pmWell, 2001, it is just too many years ago. At that time I doubt there was any competitor for TDS200 very compact series. Agilent produced 56000 series scopes with CRT screens in that years.Nowadays, things changed and Tektronix still has virtually no competitor for Agilent DSOX2000 at its price range. Only that DPO2000 with slow waveform update rate and no Trig Out...But both brands do not offer much bang per buck.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 09, 2014, 08:00:38 am
content: @HydrawerkQuoteOh dear, that is tough to admit but I don't have many oscillosopes leftQuoteThat was the reason that drove me when I bought it.QuoteNot considering the mass it was way better than TDS224 IMHO.QuoteAgreeQuoteDSOX2000 series performance/price ratio is more interesting than tektronix one and I'm considering the DSOX2004a@nctnicoI read in the manual that roll mode could be activated until 100mS/div. Could you confirm?Thanks!

author: tautech
author_rank: Super Contributor
timestamp: September 09, 2014, 08:18:40 am
content: I can confirm thefastesttimebase setting the Roll Mode will operate at is 100 mS/div.Just powered up my SDS2304 for a little job and double checked.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 09, 2014, 08:44:22 am
content: QuoteThank you tautech!That's for me a nice feature to have and I was a little disappointed by the Rigol 200mS/div.But the Agilent here performs better displaying roll mode up to 50mS/div.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 09, 2014, 03:44:02 pm
content: Quote from: 0xfede on September 09, 2014, 08:00:38 amBuy it if 1Mpoints per each channel memory is enough for you. Well, If you need a huge memory,you might consider Rigol DS2000, that also has that well-known well-implemented segmented memory (called record & playback function).Oh shit, yes, it has only two channels.

author: Fsck
author_rank: Super Contributor
timestamp: September 09, 2014, 03:45:27 pm
content: Quote from: Hydrawerk on September 09, 2014, 03:44:02 pmexcept the ds2000 doesn't come in a 4-channel version.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 09, 2014, 05:04:30 pm
content: @HydrawerkQuoteIt's a gap in Rigol scope range.I'm still favourable to both SIGLENT and DS1074z.I know that the later is a bit underpowered for my needs but is so cheap that I may buy it and see what happens.And worst, I'm finishing the time for a decision.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 09, 2014, 07:35:50 pm
content: Quote from: 0xfede on September 08, 2014, 04:38:53 pmHey, it was released in November 2013.http://www.siglent.com/en/news/detail.aspx?id=100000065214624&nodecode=119002004It should be well developed today. But it is not. It is rather embarrassing.

author: nctnico
author_rank: Super Contributor
timestamp: September 09, 2014, 08:30:47 pm
content: That's more like announced. The SDS2000 wasn't for sale until early this year and the MSO option was not available since a month of two.No matter how you try to twist it: every competing oscilloscope with similar features is at least more than twice as expensive.

author: tautech
author_rank: Super Contributor
timestamp: September 09, 2014, 08:32:22 pm
content: Quote from: Hydrawerk on September 09, 2014, 07:35:50 pmAccurateWestern Markethistory of product development and release in below post:https://www.eevblog.com/forum/testgear/review-siglent-sds2304-a-comparison-of-features-with-rigol-ds2000-series/msg501479/#msg501479

author: don
author_rank: Regular Contributor
timestamp: September 09, 2014, 09:28:02 pm
content: Quote from: nctnico on September 09, 2014, 08:30:47 pmI would choose the Siglent over Rigol because I found the Rigol DS4000 quite buggy for its age and price. However, both were too buggy for me (very subjective). When looking at value (features vs cost for example), consider that many of the "features" simply do no not work. I think this is a big reason price is so low. They save on SW development cost. Maybe a perfect tradeoff for your needs but understand paper specs might not work as expected.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 09, 2014, 09:49:54 pm
content: QuoteThanks don for your answer.I have to admit that this is my first look at a chinese instrument after a couple of decades of work with the same brands.I saw some video reviews both of Rigol and Siglent and I was so impressed that I found useful giving those gears a try.And I need an instrument for the field of course. I don't want to move anymore my calibrated (and pricey) scope from my lab bench.0xfede

author: don
author_rank: Regular Contributor
timestamp: September 09, 2014, 10:38:19 pm
content: Set expectations accordingly and hopefully you'll be fine. After sds2074 I thought the Rigol Ds4014 was the way to go. But I found the 140M memory unuseable in zoom (I'd make an adjustment and machine would take minutes to cycle through queue of zoom adjustments), I found i2C decode only worked on 100ms/div or faster even though sample rate was very fast (so why have 140M memory) and i2c decode did not work with segmented memory. That and unit locked up twice in 2 hrs. I had an issue with cursors in roll mode, no zoom in roll mode. Maybe my unit was bad, but it drove me crazy for a $2500 USD instrument. So to me, the 140M, segmented memory and i2c decode did not meet expectations. I use pretty high end scopes daily so I have fairly high expectations..i'm probably not their target market. Coming out of school years ago I'd take either of these scopes in a heartbeat and just grind through the issues.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 09, 2014, 10:56:57 pm
content: QuoteThis is very common in many scopes including Agilent DSOX2000 series.I suppose you mean this zoom, do you?

author: nctnico
author_rank: Super Contributor
timestamp: September 09, 2014, 11:17:15 pm
content: Changing the timebase on my SDS2204 works just fine to zoom in on a stopped trace in roll mode. The only thing zoom does is display which part of a signal is on screen.

author: marmad
author_rank: Super Contributor
timestamp: September 09, 2014, 11:18:37 pm
content: Quote from: nctnico on September 09, 2014, 11:17:15 pmExcept he means while running in Roll mode.

author: marmad
author_rank: Super Contributor
timestamp: September 09, 2014, 11:28:16 pm
content: Quote from: don on September 09, 2014, 10:38:19 pmIf you're going to mention specs from a DSO that the OP wasn't actually considering, it might make more sense to compare them to the DSOs he actually asked about:Slowest speed for decode / Decode segmented memory? / Zoom in Roll mode / Cursors in Roll modeSiglent SDS2000 50ms/div Not currently No YesRigol DS1000z 100ms/div? Not currently? No? ?Maybe a DS1000Z owner can fill in the details which I don't know/am not sure about?

author: nctnico
author_rank: Super Contributor
timestamp: September 09, 2014, 11:53:38 pm
content: Does it make sense to have zoom in roll mode? I think roll mode is incompatible with zoom by definition. Zoom works like a delayed timebase; in roll mode there is no trigger event so there is no time reference to point a zoom window to.

author: marmad
author_rank: Super Contributor
timestamp: September 10, 2014, 12:00:23 am
content: Quote from: nctnico on September 09, 2014, 11:53:38 pmWe already had this whole discussion once already (since it seems to be a big deal for Don) - over in the "Siglent's new product- MSO/SDS2000 Series" - with me making exactly the same point that you're making now. But apparently, there are some DSOs that do it - andWuerstchenhund posted images from his LeCroy WaveRunner 64Xi managing to do it.I have to say, it's not a function that I would need often - but it would come in very handy from time to time.

author: don
author_rank: Regular Contributor
timestamp: September 10, 2014, 12:45:04 am
content: The reason I mentioned the issues I had was because nctnico said you had to pay 3x the price of Rigol or Siglent to get equivalent function. This may be the case on paper. And I tried the two scopes thinking that was the case, but found out it wasn't entirely true. Reason being the scopes were very buggy or lacked features I have come to know as standard (yes, like zoom in roll mode! ). I didn't even know there were scopes that didn't zoom in roll mode...and it's one of my favorite features. Anyway, since Oxfede is not a newcomer to scopes I wanted to share my experiences. Some people don't mind bugs and happily work around them. I'm generally like that but when bugs are unpredictable and numerous I don't trust the equipment and get frustrated.

author: marmad
author_rank: Super Contributor
timestamp: September 10, 2014, 12:59:21 am
content: Quote from: don on September 10, 2014, 12:45:04 amWhat is odd is that the Rigol DS2000 seems, in many ways, more advanced - and bug-free - than the DS4000, even though it costs much less (and shares much of the same firmware). It does decode segmented memory - and it doesn't seem slow when zooming around the 56M (although, granted, it's not as big as 140M). I guess it got more attention from Rigol because it was their big seller - at least for awhile.

author: don
author_rank: Regular Contributor
timestamp: September 10, 2014, 01:21:46 am
content: Quote from: marmad on September 10, 2014, 12:59:21 amAgreed, and equally as strange - you can spend almost $9k on a 4000 series at high bandwidth. Not sure how they can compete at that price point with their current firmware (going on 2yrs?)

author: 0xfede
author_rank: Regular Contributor
timestamp: September 10, 2014, 07:35:08 am
content: @donQuoteThank you for that. I appreciate your experiences and is exactly what I'm looking for on these fora.QuoteMe too. And of course the researh for huge marketing/advertisement driven feature stop the research for the most basic and fundamental.But as I said it happened to me on a well known high end brand.@nctnicoQuoteIt makes perfectly sense to me since I use roll mode lot of times. But IMHO is not a big problem to stop the scope and zoom.@marmadThanks for your reviews. I found them very interestingQuoteI agree here. And IMHO this is an example of an easy to implement feature dropped for more exotic ones.0xfede

author: 0xfede
author_rank: Regular Contributor
timestamp: September 11, 2014, 08:32:34 am
content: Last evening I finished reading the three scopes manual (Agilent, Rigol and Siglent).As far as I can see all of three have their own limitations:Agilenthas small memory and the higher price.Rigolis just sampling @.25 GS/S when all four channels are enabled and with 30kwfps max is the slowest.Siglentis still too new and has some bugs and is unclear if its bandwidth will be (buying an option) upgradable.I've a quote for the first two and I'm awaiting the third.The weekend is coming and I've two days left to decide.

author: tautech
author_rank: Super Contributor
timestamp: September 11, 2014, 09:08:01 am
content: QuoteThe BW upgrade option has not been offered by Siglent, however I have sent them an email for clarification.I am unaware if BW is set by code or HW. Obviously if set by HW....return to base if upgrade is available or offered, IMO unlikely.Hopefully we have a prompt reply.As you have been doing some homework and see the engagement from Siglent re the latest bugs, are they such a concern knowing Siglent is addressing them?

author: 0xfede
author_rank: Regular Contributor
timestamp: September 11, 2014, 09:28:37 am
content: QuoteThanks for your time tautech.QuoteI'm certainly pleased by the fact that Siglent is actively present on this forum and is addressing the concerns of the SDS2000 owners.However I can't see the future and the time is running low.Next week I'll restart working at full thrust.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 11, 2014, 10:29:25 am
content: QuoteWell, I'm adding this info to the valutation.And I'm awaiting for the final price from Italian distributor.Again thanks for your time tautech.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 11, 2014, 11:02:13 am
content: Quote from: marmad on September 10, 2014, 12:59:21 amhttps://www.eevblog.com/forum/testgear/rigol-mso4000-and-ds4000-tests-bugs-firmware-questions-etc/

author: 0xfede
author_rank: Regular Contributor
timestamp: September 11, 2014, 06:34:51 pm
content: Now I have all three prices and three days left to decide.This will be an hard decision.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 11, 2014, 06:43:14 pm
content: Agilent (oh, Keysight) scopes just do what you expect them to do according to the user manual, especially when DSOX2000 and DSOX3000 are three years old so almost all bugs are fixed now, but there have never been many of them.

author: marmad
author_rank: Super Contributor
timestamp: September 11, 2014, 09:54:21 pm
content: Quote from: 0xfede on September 11, 2014, 06:34:51 pmThere is also theGW-Instek GDS-2000A series. Although it only has 2M of memory and appears to only do 16 levels of intensity grading, it has a number of nice features which are lacking on all of the other three DSOs - such as an 800x600 display, Equivalent Time Sampling, SVGA-out option (possible on Agilent?), Alternate trigger, Waveform Search and Mark functions for segmented or zoomed memory with dedicated Play/Pause/Search hardware controls - among other features.If I absolutely had to have a 4-channel DSO in this price range, I would certainly check out the GDS-2000A as well (I hear the offered prices can be very low, too).

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 11, 2014, 10:07:38 pm
content: https://www.eevblog.com/forum/testgear/gds-2000a-new-economic-oscilloscope-by-gw-instek-comes-to-market/msg421614/#msg421614https://www.eevblog.com/forum/blog/eevblog-474-gw-instek-gds-2000a-series-oscilloscope-unboxing-fi/msg245984/#msg245984Well, Dave was not very impressed. Me too.There is no serial decoding onanalog channels.The built-in function generator is really poor.http://www.gwinstek.com/en/product/productdetail.aspx?pid=3&mid=7&id=1349https://plus.google.com/photos/106264218831814439783/albums/5857196858625060337

author: 0xfede
author_rank: Regular Contributor
timestamp: September 11, 2014, 10:10:40 pm
content: Thank you marmad for this info.I've read about the GDS-2000a series various post in this forum but I felt it unreliable.If you consider it worth a look maybe I will search for a quotation and read its manual.I'm not sure that the remaining time will be enough.0xfede

author: marmad
author_rank: Super Contributor
timestamp: September 11, 2014, 10:22:46 pm
content: Quote from: Hydrawerk on September 11, 2014, 10:07:38 pmDo you really need to continually post videos from other pages on this very forum? Anybody with half a brain can find them.Dave's simple (by his own admission) un-boxing and first impression video (not a review) was done 16 months ago - and he didn't examine any of the advanced features.QuoteI'm not sure what your link is pointing at... from what I can read, it says:"*Standard model provides I2C, UART, SPI serial bus trigger and decoding functionalities"Standard model is non-MSO model.QuoteWho cares? I would never get a limited function generator inside a DSO anyway - they're overpriced.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 11, 2014, 10:22:59 pm
content: Thank you Hydrawerk.I've already seen this review and I noticed that its firmware lacks improvement.QuoteI prefer to use real AWG and LA because they are tipically faster and more optimized than the built in ones.I never use a screwdriver to hammer in a nail.

author: marmad
author_rank: Super Contributor
timestamp: September 11, 2014, 10:29:32 pm
content: Quote from: 0xfede on September 11, 2014, 10:10:40 pmI never got the idea that it was unreliable - I think Instek is probably more reliable (and more experienced in terms of building DSOs) than either Rigol or Siglent. The problem was that Instek made some important mistakes/omissions in the data sheet when the DSO was first released (they should have just stated clearly that it does 16-level intensity grading), and so that, coupled with Dave's dislike of it (plus some FW bugs) when he first tried it, gave it a bad reputation that it's struggled to get past. But from what I read, Instek made many fixes/firmware improvements - so 16 months later, it must be a mature product and, IMO, worth a look.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 11, 2014, 10:52:54 pm
content: QuoteIts a shame that I haven't included it in the list from the beginning.QuoteThat was cutting edge technology 15 years ago... Today it left me disappointedQuoteAnd of course I'll give it a shot. But I'm in hurry...

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 12, 2014, 12:22:34 am
content: Quote from: marmad on September 11, 2014, 10:22:46 pmWell, I am not sure but I think that I2C, UART, SPI serial bus trigger and decoding functionalities are only present at digital channels. But maybe things have changed. Then it must be a newly added feature. For more info go through these user manuals at their website.http://www.gwinstek.com/en/product/productdetail.aspx?pid=3&mid=7&id=1349But it seems that they made some kind of a new plug-in 25MHz generator.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 12, 2014, 12:25:38 am
content: Here is the new generator. Under that scope!http://www.gwinstek.com/en/product/productdetail.aspx?pid=5&mid=305&id=1390

author: nctnico
author_rank: Super Contributor
timestamp: September 12, 2014, 07:33:41 am
content: Quote from: marmad on September 11, 2014, 10:29:32 pmI looked at their scopes but even on the 500MHz model it seems there is no 50 Ohm input mode. They can't be serious

author: tggzzz
author_rank: Super Contributor
timestamp: September 12, 2014, 08:56:09 am
content: Quote from: nctnico on September 12, 2014, 07:33:41 amThat is indeed, er, suboptimal. But it is also something that can be easily, cheaply and accurately synthesised with an external 50 ohm terminator. Hence if everythign else is right I wouldn't regard it as a deal-breaker.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 12, 2014, 10:37:43 am
content: QuoteOf course it can be solved, but I hope that is the only oversight by GW-Instek.In general I don't like the GDS-2000a series user interface and this will be the deal-breaker.

author: tggzzz
author_rank: Super Contributor
timestamp: September 12, 2014, 12:00:28 pm
content: Quote from: 0xfede on September 12, 2014, 10:37:43 amThat's a far more cogent reason for rejection - and, unfortunately, one that won't be apparent in reviews. It is bloody difficult to improve on the usability of old analogue scopes.

author: nctnico
author_rank: Super Contributor
timestamp: September 12, 2014, 02:47:09 pm
content: Quote from: tggzzz on September 12, 2014, 08:56:09 amThat won't work at all. You'll still have the input capacitance (16pf) of the oscilloscope parallel to a 50 Ohm terminator causing all kinds of problems. Rule of thumb: If a scope goes over 100 MHz it must have a 50 Ohm input mode otherwise the extra bandwidth is just useless.@0xfede: I wouldn't dismiss a oscilloscope because the user interface looks clunky at first sight. Every piece of test equipment has a different idea on how the user interface should be. You'll get the logic soon enough.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 12, 2014, 03:21:13 pm
content: QuoteThanks for your advice.But the more I'm seeing it, the more I dislike.And there is no time left for a price inquiry.

author: tggzzz
author_rank: Super Contributor
timestamp: September 12, 2014, 05:29:25 pm
content: Quote from: nctnico on September 12, 2014, 02:47:09 pmPoint taken and (since my "normal" probe is a 10:1 Z0 probe) I would always insist on a 50ohm input. Fortunately the scopes I've used have all had a 50ohm input.However, the scope specification ought to include a definition of how (in)accurate the 50ohm load is - often expressed in the form of SWR or VSWR. My ancient-but-lovable 100MHz/1Mohm/20pF HP1704 merely puts a 50ohm resistor in parallel with the DC input stage. It states SWR<=1.4. I ought to go and examine the input stage schematics of more modern scopes.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 13, 2014, 12:05:52 am
content: Quote from: nctnico on September 12, 2014, 07:33:41 amI think the GDS-2000A series is 300MHz maximum. Did you mean the GDS-3000 series?http://www.gwinstek.com/en/product/productdetail.aspx?pid=3&mid=7&id=1290

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 13, 2014, 12:24:07 am
content: Quote from: marmad link=topic=36158.msg511410#msg511410Well, I have read thenewuser manual. There is no information about serial decoding on analog channels. I could only find some info on digital channels (MSO) decoding.I think this scope cannot do serial decoding or trigger on analog channels. But if you think that I am wrong, try to bring some pdf manual with additional information. I did not find it.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 13, 2014, 12:30:37 am
content: 0xfede, you probably know about Hameg scopes.http://www.hameg.com/720.0.html?&L=0There is also a weird 4-channel Owon TDS7104.http://www.batronix.com/shop/oscilloscopes/Owon-TDS7104.html

author: 0xfede
author_rank: Regular Contributor
timestamp: September 13, 2014, 04:19:14 pm
content: QuoteI don't think that this is good for me but I can't believe the price of the OWON TDS8204...QuoteYes I know it. And I received a better price for an Agilent DSOx2204a plus some options.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 14, 2014, 10:06:19 am
content: It's late Sunday morning and a bright sunny day here. I'm in the garden and I'm thinking about the scope.My wife has now resigned to my absence and doesn't question anymoreI've about ten hours left to decide but its not a big issue because probably I already know the winner.I wish to thank all people who kindly share their infos and opinions on this forum as long as our host, Dave.Best,0xfede

author: marmad
author_rank: Super Contributor
timestamp: September 14, 2014, 06:23:28 pm
content: Quote from: 0xfede on September 14, 2014, 10:06:19 amAlthough I don't think the following information is necessarily important in your particular case (since you own other oscilloscopes), it might be relevant for others following this thread who are looking to buy their first scope - and so I think it needs to be stated:Although I like the fast hardware platform that the Siglent SDS2000 series is built around, I think the firmware is still seriously undercooked - for example, at least 2 of the 4 main Y-T acquisition modes are not working properly (I actually think 3 of the 4 is not working exactly properly, because I don't think Averages is performing as it should either - but that's a whole other discussion).You might argue that all of these Chinese T&M equipment manufacturers release half-baked products and then fix the bugs later - and to some extent, that seems to be true. But I bought my Rigol DS2000 almost precisely the same length of time (or shorter) after it's Western markets debut as was the length time between Siglent's SDS2000 debut and when I received the unit for review - and let me tell you, the Rigol firmware - even though it had bugs - wasWAYmore finished and bug-free than Siglent's firmware - no contest whatsoever. All acquisition modes worked correctly, etc, etc.Obviously, Siglent appears (based on their comments and responses in this forum) to be working on solving these problems - but one never knows how long these things might take. As I've mentioned before, it appears at least some of the wfrm/s speed of the DSO seems to be built around the fact that they downsample before doing averaging, intensity grading, etc - so I'll be curious to see how their implementations (when correct) of Peak Detect, High Res, Averaging, etc. will affect update speed (and grading).So because of these current problems, I couldn't personally recommend itat the momentfor someoneif it's the only oscilloscope they're going to own. Better to wait for one (or two) more firmware updates.

author: 0xfede
author_rank: Regular Contributor
timestamp: September 14, 2014, 10:18:04 pm
content: QuoteI'll go for the Agilent. I was waiting tomorrow morning to reveal that, when I'll place the order.QuoteThat's the major issue (along with the navigation between an high number of frames) that slowed down my choice. And that's a shame, because the HW seems rock solid.QuoteAnd if they will be ever addressed... Probably they'll do, but who knows?A personal note:It's hard to say (especially while writing in another language) the feeling for your comments and reviews. Your experience and skill makes your words believable at thousands kilometers of distance. And generally I don't trust who I don't know personally.Again, thank you.