Looking for a new scope. - Page 1
Forum section: electronics / testgear

author: Davy
author_rank: Regular Contributor
timestamp: June 26, 2020, 01:48:11 pm
content: I'm looking for a new 2 ch scope, must be at least 100Mhz and 2GSa/s..... 1GSa/s per channel at least.I've been looking at the Rigol DS2302A and the Siglent SDS2352X.... if you was buying, which one would it be? Would I be right going for the Siglent in view it being more modern than the Rigol?I get suspicious when Rigol starts offering free upgrades, either they want to rid their stocks or they are losing trade to their competitors.... no new Rigol scopes on the horizon is there by chance.Which one is the most preferred and reliable?The HP1744A is getting outdated and taking far too much space these day's and not being exactly portable, the flood control seems to be getting critical to adjust these day's.... aging high value resistors I guess, one of these day's I'll get the 'tin opener' out, I do have all the servicing documents.Thanks, Dave

author: tv84
author_rank: Super Contributor
timestamp: June 26, 2020, 02:12:34 pm
content: Don't start another thread. Just browse through the latest 2 pages of threads.There are plenty in these last days with the same theme.Read this one starting here:https://www.eevblog.com/forum/testgear/rigol-ds1202z-e-entry-level-scope-(200mhz-2-channel)/msg3100589/#msg3100589

author: Davy
author_rank: Regular Contributor
timestamp: June 26, 2020, 02:50:22 pm
content: Thanks tv84.... I should've looked first.I found better and exact match here.https://www.eevblog.com/forum/testgear/help-with-decision-siglent-sds2352x-e-vs-rigol-ds2302a/msg2702100/#msg2702100Dave.

author: kripton2035
author_rank: Super Contributor
timestamp: June 26, 2020, 02:55:13 pm
content: I think Rigol offers free upgrades because they know the scope can be hackedand they prefer to offer it instead of having some scopes bricked after a bad hacking.also the scopes are getting older and the rentability level must have been reached.

author: tautech
author_rank: Super Contributor
timestamp: June 26, 2020, 09:45:53 pm
content: Quote from: tv84 on June 26, 2020, 02:12:34 pmIn a totally different class.OP asked for 2 GSa/s.Quote from: Davy on June 26, 2020, 01:48:11 pmThe 200 MHz SDS2202X-E is a good bit cheaper than the SDS2352X-E 350 MHz model however it comes with 200 MHz rated switchable probes. Those 350 MHz probes are nice and although still switchable type might sway your decision if seeking better quality probes.Anyways, the standard features like Decode, Bode plot and webserver might be of interest to you.Thread if you haven't yet found it:https://www.eevblog.com/forum/testgear/siglent-sds2000x-e/

author: tv84
author_rank: Super Contributor
timestamp: June 26, 2020, 09:50:55 pm
content: tautech, the OP is a beginner...He also mentioned 100 MHz and was looking at 300 MHz scopes.

author: tautech
author_rank: Super Contributor
timestamp: June 26, 2020, 10:25:26 pm
content: Quote from: tv84 on June 26, 2020, 09:50:55 pmReally, I don't see that considering he's been a member for at least 5 years and been down the looking for a scope road before:https://www.eevblog.com/forum/testgear/looking-for-a-scope-50458/Davy has a fairly good idea of what he needs but just needs gaps of knowledge filled in about particular models.

author: Davy
author_rank: Regular Contributor
timestamp: June 27, 2020, 12:17:26 am
content: Thanks tautech, you are quite right I do have an idea of what I need..... certainly not a 4 channel job.The link tv84 gave was of no use to me, I did say-:I'm looking for a new 2 ch scope, must be at least 100Mhz and 2GSa/s..... 1GSa/s per channel at least.then went on to askWhich one is the most preferred and reliable?the link had nothing to do with that had it tv84?Sounded like he replied just to be grumpy... did 'he' ever do anything in error?Dave

author: tautech
author_rank: Super Contributor
timestamp: June 27, 2020, 12:20:43 am
content: Quote from: Davy on June 27, 2020, 12:17:26 amNo mate he just saw 1 GSa/s and tried to help. We all make mistakes.I well know where you're coming from.

author: bdunham7
author_rank: Super Contributor
timestamp: June 27, 2020, 12:25:27 am
content: I would note that the humble SDS1104X-E is 100MHz (unhacked) and has the requested 1GSa/S per channel on two channels as long as you use Channels 1 and 3.

author: tautech
author_rank: Super Contributor
timestamp: June 27, 2020, 12:27:05 am
content: Quote from: bdunham7 on June 27, 2020, 12:25:27 amNo 50 ohm inputs though.

author: rf-loop
author_rank: Super Contributor
timestamp: June 27, 2020, 02:51:38 am
content: Quote from: bdunham7 on June 27, 2020, 12:25:27 amBit more perfectlyBelow table red channel is on. (Independent of if it is displayed or not - in case when one want use one main channel as "better" Ext Trig without trace visible):Bolded all cases when max is 1GSa/s per channel and 14Mpoints max limit per channelCh1Ch2 Ch3 Ch4 |(1GSa/s 14M)Ch1Ch2Ch3 Ch4 |(1GSa/s 14M)Ch1 Ch2Ch3 Ch4 | (500MSa/s 7M) + (500MSa/s 7M)Ch1 Ch2Ch3Ch4 |(1GSa/s 14M)Ch1Ch2Ch3Ch4 |(1GSa/s 14M) + (1GSa/s 14M)Ch1Ch2Ch3Ch4 |(1GSa/s 14M) + (1GSa/s 14M)Ch1 Ch2 Ch3Ch4 | (500MSa/s 7M) + (500MSa/s 7M) + (500MSa/s 7M)Ch1 Ch2 Ch3Ch4|(1GSa/s 14M)Ch1Ch2 Ch3Ch4|(1GSa/s 14M) + (1GSa/s 14M)Ch1Ch2Ch3Ch4|(1GSa/s 14M) + (1GSa/s 14M)Ch1 Ch2Ch3Ch4| (500MSa/s 7M) + (500MSa/s 7M) + (500MSa/s 7M)Ch1 Ch2Ch3Ch4| (500MSa/s 7M) + (500MSa/s 7M)Ch1Ch2Ch3Ch4| (500MSa/s 7M) + (500MSa/s 7M) + (500MSa/s 7M)Ch1Ch2Ch3Ch4| (500MSa/s 7M) + (500MSa/s 7M) + (500MSa/s 7M)Ch1 Ch2 Ch3 Ch4| (500MSa/s 7M) + (500MSa/s 7M) + (500MSa/s 7M) + (500MSa/s 7M)About frequency response SDS1104X-E and (front panel model plate SDS1104X-E but working las 200MHz model,)When SDS1204X-E USER need understand that unknown signal under inspection may have so high frequency components that it produce aliasing in ADC specially when ADC is non interleaving mode (Max 500MSa/s)This is common problem when oscilloscope do not have sampling speed dependent filtering BEFORE ADC. Of course some can do using DSP filters after ADC but it can not know if its input is down conversion from ADC what works also as frequency converter.eevblog.com/forum/testgear/siglent-sds1204x-e... some tests with unmod and mod versionFor OP.This meet minimum needs: 2 channel least with 1GSa/s both and also true BW goes far over 200MHz.For some note about 50 ohm inputs.Many, most of, this kind of scopes do not have real 50 ohm impedance inputs for full BW.Mostly 50 ohm inputs are 50ohm DC resistance inputs. Just relay switched 50ohm resistor parallel with normal 1M/20pF pathway including also PCB traces and relay parasitic C's and L's network.It works somehow up to perhaps 50-100MHz but after then start more or less troubles. Most easy it can see with known fast edges where is lot of higher frequency components what then may make totall mess and peoples looks scope screen and "believe" more or less they see and then talking here how miraculous things they see in "caleidoscope" window....All what can see is sum of errors mixed with bended truth. Why bended truth... bended because you touch signal and change it in curcuit, more or less......wise can estimate and make his own decision how much he can tolerate these all errors.Because he have experience with HP1740 or what ever other nice professional class analog scope I will recommend 2GSa/s scope with enough long max acquisition memory length what can keep maximum or high sample speed even with more slow t/div settings. Analog scope have always full BW with what ever t/div, even slowest possible, without any aliasing with what ever signal. This do not never happen with normal usual this class of digital oscilloscopes and if think really tight, it do not happen even with most expensive most modern "rolls royce" class digital scopes.One nice scope is SDS2202X-E/SDS2352X-E both are 2 channel models max 2GSa/s but thuis speed is only if one channel is in use.Also it is good to keep in mind that 2 channels and EXT trig... well, EXT trig do not have at all same features and performance as is main channel trigger. EXT Trig pathway is totally very different. And THIS is not any Siglent special... I do not know any scope what have full speed ADC and front end in EXT trig pathway. These modern scopes mostly today have full digital side trigger engine in main channels but then EXT trig is cheap version of analog trigger where trigger jitter is high and many other ways quite poor performance.But, SDS2000X Plus version, 4 channel models. They have 2GSa/s for two channels (same logic as above, afaik)Also there is EXT trig but if usually need 2 main channels then there is 2 channels what can use as EXT trigger also but now with full main channel trigger functions and performance. All know that trigger make scope and Siglent digital side trigger engine performance is least very good. Rumors tell that some models can also "improve" quite nicely.

author: gf
author_rank: Super Contributor
timestamp: June 27, 2020, 08:12:53 am
content: Quote from: rf-loop on June 27, 2020, 02:51:38 amDo I interpret this correctly? Does the unmod frequency response really have a just a notch @250 MHz, while ~350 MHz can pass again with an atttenuation of only ~10dB? Crazy. I do not really understand the intentionMay I ask how these tests were executed? Just capture a single sweep and display the FFT of the whole sweep? Sweeping each alias region separately (and letting the ADC act as digital down-converter) is a good idea too in order to measure the frequency response beyond Nyqist.

author: Fungus
author_rank: Super Contributor
timestamp: June 27, 2020, 08:38:48 am
content: Quote from: Davy on June 26, 2020, 01:48:11 pmThe Rigol upgrades are ridiculously expensive. A fully optioned DS1054Z was over 1000 bucks. Siglent had the options as standard. I'm guessing somebody at Rigol marketing lost a few contracts so they changed it.None of this has ever affected us because we generate the unlock codes ourselves and get all the options for free (also part of Rigol's marketing plan, BTW - they don't want to keep hobbyists away).None of this has any effect on the hardware or what it can do. Look at the specs of the best model in the range, look at the prices of the cheapest model. That's what you're getting.

author: nctnico
author_rank: Super Contributor
timestamp: June 27, 2020, 09:02:35 am
content: Quote from: Davy on June 26, 2020, 01:48:11 pmWhat is your use case? Based on your current 2 channel CRO I would guess you are mostly into analog circuits and don't need protocol decoding. So I wonder why aren't the Keysight DSOX1202, R&S RTB2002 (10 bit ADC!) and Tektronix TBS2102 on your list? With a bandwidth of 100MHz 1Gs/s is more than enough (1Gs/s is enough to support 400MHz of bandwidth); 2Gs/s is just sheer overkill.

author: tv84
author_rank: Super Contributor
timestamp: June 27, 2020, 09:44:18 am
content: Quote from: tautech on June 26, 2020, 10:25:26 pmMy bad, sorry, I just looked at the #posts. But, with 5 years membership and not beginning by looking around for some answers (at least the last 2 pages of threads)... no excuse.Quote from: Davy on June 26, 2020, 02:50:22 pm"Grumpy" ?? For someone who first thanked me...Quote from: Davy on June 27, 2020, 12:17:26 amThat link wasan exampleof a thread where the discussions go around 200MHz 2-ch 1 GSa/s scopes choices and then evolve to the latest 2 GSa/s (even suggested by tautech), which are better bang-for-bucks than the old models you were "preferring"...Quote from: Davy on June 27, 2020, 12:17:26 amSure, many things. One of the latest was trying to help you.

author: Sighound36
author_rank: Frequent Contributor
timestamp: June 27, 2020, 11:26:04 am
content: Tv84 is an immensely helpful and decent chap with the patience of a saint, may I suggest the issue lies elsewhere

author: rf-loop
author_rank: Super Contributor
timestamp: June 27, 2020, 12:25:15 pm
content: Quote from: gf on June 27, 2020, 08:12:53 am"Do I interpret this correctly? Does the unmod frequency response really have a just a notch..."Yes. If you do not understand I can not help.Btw, thewre is only one model, SDS1204X-E. (SDS1104X-E is just simple way BW rejected and equipped with 100M probes."May I ask how these tests were executed? Just capture a single sweep and display the FFT of the whole sweep?"Perhaps you have not even looked these test images? Yes there is not all perhaps over hundred images what come out from this test but there is least some where is just what you tell. Need only look and read and also understand images and said things. /Also you need note different samplerates in different images or part of images and also different sweeped bands.

author: gf
author_rank: Super Contributor
timestamp: June 28, 2020, 05:42:58 pm
content: Quote from: rf-loop on June 27, 2020, 12:25:15 pmIs the apparent notch filter in reality adigitallow-pass filter, applied after sampling?If yes, then I would at least understand why its frequency response appears mirrored across Nyquist.Btw, yes, I did well notice the different sweep ranges, different sampling rates, and the stitched frequency response images.

author: Davy
author_rank: Regular Contributor
timestamp: June 29, 2020, 01:02:42 pm
content: @nctnicoMainly RF up to appx. 50Mhz and general purpose usage, fault finding, signal tracing and so on mainly RF, I'm taken the 3db roll off generously any more b/w would be a 'plus' and don't mind paying the extra, a 4ch. scope would be OTT I feel.... the most I've ever used is two channels and that would be once every blue moon.The more I read the more confusing it gets.... you read this or that has this fault and that quirk and so on... time Rigol had a rethink and updated their models.Dave

author: nctnico
author_rank: Super Contributor
timestamp: June 29, 2020, 01:40:30 pm
content: Quote from: Davy on June 29, 2020, 01:02:42 pmI think the A-brands will give you a better balanced user experience. Dave (Mr EEVblog) is extremely fond of using Keysight oscilloscopes and I have the feeling his usage might be similar to yours. In the end the best way forward is to make a short list with 3 to 4 models, make a test plan and then just test the models you selected to see which one suits you best.

author: rf-loop
author_rank: Super Contributor
timestamp: June 29, 2020, 02:55:58 pm
content: Quote from: gf on June 28, 2020, 05:42:58 pmIt looks like... It is what I mostly "believe"... until any other real evidences..

author: martinot
author_rank: Regular Contributor
timestamp: July 02, 2020, 04:17:23 pm
content: Quote from: nctnico on June 29, 2020, 01:40:30 pmI am also looking at different basic copes around $1000, including the Siglent discussed in this thread, but I get very worried with Chinse brands when I read reviews like this (https://www.batronix.com/shop/oscilloscopes/Siglent-SDS2352X-E.html):"This unit is unfinished, very very bad.It should not be for sale, it's impossible to work with.It has serious hardware and firmware problems.I bought one on 12-02-2019, and I'm out of use.Neither Batronix nor Siglent solve the problem."Currently I am leaning a little more for US (Keysight) or European (Rhode & Schwarz) made scopes.Listening to the comments by EEvblog Dave in his videos it also seems that generally his experience often leans a little bit more to those western designed scopes. Especially with regards to the firmware and software side (even if he do sees the low price of Asian designed scopes as a plus).One of the favorite daily scopes by Dave seems to be the basic 1000-series from KS (https://www.keysight.com/en/pcx-2759552/infiniivision-1000-x-series-oscilloscopes?nid=-32110.0&cc=GB&lc=eng).Looking at one myself as one of the possible options to consider (I also hate buggy or slow responsive devices), but very open for other suggestions.

author: nctnico
author_rank: Super Contributor
timestamp: July 02, 2020, 04:49:25 pm
content: @martinotYou have to carefully consider your use case. Not every scope is a good fit for a particular use case; the perfect oscilloscope which can serve all purposes doesn't exist (no matter what price you pay!).