EEVblog review missing of Tektronix MDO3000 series scope? - Page 1
Forum section: electronics / testgear

author: taylornate
author_rank: Newbie
timestamp: September 29, 2016, 11:34:32 pm
content: In the teardown video of the MDO3000 (recorded a couple years ago) Dave mentions that he will be doing a review, but I can't find it. I found the one for the Keysight MSOX3000T but not this one. I'm trying to decide which of the two to purchase.

author: nctnico
author_rank: Super Contributor
timestamp: September 29, 2016, 11:38:15 pm
content: Did you look at R&S RTM2000 series? It may be an alternative as well.I recently started a thread about midrange scopes and in there Dave isn't very happy with the Tektronix MDO3000.

author: taylornate
author_rank: Newbie
timestamp: September 29, 2016, 11:42:03 pm
content: Quote from: nctnico on September 29, 2016, 11:38:15 pmI haven't looked at R&S, I'll have to check them out.Would you mind posting a link to the midrange scope thread?

author: nctnico
author_rank: Super Contributor
timestamp: September 29, 2016, 11:52:57 pm
content: This is the thread I started. Your requirements may be different though:https://www.eevblog.com/forum/testgear/is-there-a-good-midrange-($3k-to-$10k)-scope/

author: tautech
author_rank: Super Contributor
timestamp: September 29, 2016, 11:54:57 pm
content: And in that range falls the SDS2000X series despite that some members might like to rubbish it.Check the specs.http://www.siglentamerica.com/pdxx.aspx?id=1488&T=2&tid=1

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 30, 2016, 09:32:58 am
content: Quote from: taylornate on September 29, 2016, 11:34:32 pmWell, I have a Tek MDO3054 here, and I wouldn't recommend it to anyone. It's slow, and I mean really slow, the built-in "SA" is a joke, and the UI comes straight from hell.If I had to chose between the MDO3000 and a MSOX3000T I'd take the Keysight hands down, because it's the much better scope than the Tek. It's disadvantage is that it comes with tiny 4Mpts of sample memory (which depending on what you do can half or quarter), and it's really very expensive.Any reason your choice is just between Keysight and Tektronix? As mentioned there's also R&S (the former Hameg HMOs as well as R&S' own RTM Series), and last but not least LeCroy, who has the WaveSurfer 3000 which is a lot cheaper than the MSOX3000T but still comes with various advantages over the MSOX3000T.However, it very much depends on what you want to do with the scope, which decides what features could be useful to you.

author: Pinkus
author_rank: Frequent Contributor
timestamp: September 30, 2016, 10:32:40 am
content: Quote from: taylornate on September 29, 2016, 11:34:32 pmMartin did compare both.Check his videos:Part 1:Part 2:I was thinking about purchasing a MDO3000 too a while ago. I then checked it out it at the Electronica fair in Munich 2 years ago and played around with it a bit. It was soooo slow and sluggish sometimes, I decided against it and got a Keysight MSOX3000 series instead, which I still love (despite the small memory). But regarding the memory: I rarely need more: if triggering correctly you seldom need lots of other data. For large amounts of digital data you use a logic analyzer anyway.

author: snoopy
author_rank: Frequent Contributor
timestamp: September 30, 2016, 01:32:15 pm
content: Keysight scopes have trouble making measurements because it makes the measurement using the display data whereas the Tektronix uses the acquisition memory. Also from one of those last two videos the Keysight scope has trouble triggering on slow repetitive signals whereas the Tek doesn't.

author: nctnico
author_rank: Super Contributor
timestamp: September 30, 2016, 01:55:25 pm
content: @Snoopy: that video is interesting because it raises the issue on what data to use for a measurement. Appearantly Keysight uses the display data for the measurements and not the acquired data. This is also true on my Agilent DSO7104A so I guess all Keysight scopes measure this way.

author: taylornate
author_rank: Newbie
timestamp: September 30, 2016, 05:22:01 pm
content: Quote from: Wuerstchenhund on September 30, 2016, 09:32:58 amI'll admit, my decision to look at these two was a bit arbitrary--they are two big names that I'm familiar with. This will be a purchase by the company I work for, so it's hard to spend as much time researching as I would for a personal purchase. But, I do want to make sure we get what will work best for us, so I'll have to check out the other options that have been mentioned here.Quote from: Pinkus on September 30, 2016, 10:32:40 amYup, I did watch those videos and they did convince me pretty well that the Keysight would be a better choice. I'd really like to see Dave's review though.Quote from: snoopy on September 30, 2016, 01:32:15 pmThis does concern me, especially the trouble with triggering on slow signals. That's something we may be doing often.

author: nctnico
author_rank: Super Contributor
timestamp: September 30, 2016, 05:47:01 pm
content: There is no issue with triggering! What Tektronix does (unlike any other DSO manufacturer) is freeze the screen for a while when it has triggered but no new trigger event is there. This makes it easy to show infrequent signals even with auto-trigger enabled. The downside is that Tektronix DSOs have a lag because of it. If you put your probe on a signal with a fixed DC level (check a power rail for noise) you'll likely have the event of putting the probe on the signal on the screen for half a second before auto-trigger kicks in and shows the DC level. In some cases it is handy in some cases it is annoying but JL Morton is definitely wrong about Keysight not being able to trigger on an infrequent signal. BTW I have owned a few Tektronix DSOs as 'daily use' scopes as well.

author: taylornate
author_rank: Newbie
timestamp: September 30, 2016, 06:24:42 pm
content: Quote from: nctnico on September 30, 2016, 05:47:01 pmI get what you are saying about the Tek freezing the screen, but aside from that, it does appear to be clear that the Tek is triggering while the Keysight is not.Here's a link that will jump to the part of the video in question:http://tinyurl.com/jx2jcjkWhat am I missing? Why is Morton wrong?edit: tinyurl because video embedding broke the special link

author: nctnico
author_rank: Super Contributor
timestamp: September 30, 2016, 06:34:43 pm
content: This issue has been debated here at length already (perhaps someone with a better memory than me can link to the thread) but Morton is wrong. What he shows is a side effect of Tektronix' delay after trigger which in his case makes it appear as if the Tektronix is triggering properly. However if you make the signal slower the Tektronix scope will show the same effect as the Keysight scope. The bottom line is that in auto trigger mode you can't expect a scope to trigger properly on an infrequent signal. You can spot something is there but that's it.

author: taylornate
author_rank: Newbie
timestamp: September 30, 2016, 07:40:12 pm
content: After reading this thread, my concerns have been alleviated:https://www.eevblog.com/forum/testgear/keysight-4000-x-6000-x-2000-x-3000-x/

author: taylornate
author_rank: Newbie
timestamp: September 30, 2016, 10:04:10 pm
content: Thanks for the help everyone, we've decided to go with the Keysight. The Wavesurfer looked interesting until the quote came back higher than the other two. Can't wait to get it!I'm still curious about what happened to Dave's review of the Tektronix. If it was negative, I wonder if he got pressure to take it down or something.

author: EEVblog
author_rank: Unknown
timestamp: September 30, 2016, 11:05:57 pm
content: Quote from: Wuerstchenhund on September 30, 2016, 09:32:58 amI've shown how slow and frustrating it can be in a couple of videos I think, so I agree on those fronts.i wouldn't want to use it as an everyday use scope, it would frustrate me too much.I don't think the SA is a joke though, I think it's pretty useful, and if it's effectively free then it can be good value in that respect.No I haven't done a formal review of it.

author: EEVblog
author_rank: Unknown
timestamp: September 30, 2016, 11:08:21 pm
content: Quote from: taylornate on September 30, 2016, 10:04:10 pmI don't take down videos because of pressure, especially from a manufacturer.If any manufacturer ever pressured me to do so, rather than take it down I'd press the record button and rip them a new one publicly. I'm not the least bit afraid to burn bridges.

author: taylornate
author_rank: Newbie
timestamp: September 30, 2016, 11:09:53 pm
content: Quote from: EEVblog on September 30, 2016, 11:08:21 pmReally glad to hear thatIn your teardown video you mentioned that you planned to do a review. Did you change your mind specifically or did you just not get to it?

author: EEVblog
author_rank: Unknown
timestamp: October 01, 2016, 02:01:28 am
content: Quote from: taylornate on September 30, 2016, 11:09:53 pmBTW, I've only ever taken down one video by request.That was a soldering lecture I got permission to film provided I didn't release "the whole thing".I put one 20min part or something that I thought was interesting of the 4 hour lecture and the organiser went feral calling me up frantically saying I was ruining his business and he was watching the view counter go up saying he was losing hundreds of dollars forevery viewSo I just took it down, I didn't want to deal with such a clueless person.QuoteJust didn't get around to it and lost the enthusiasm for it (and scope reviews are a huge job)

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: October 01, 2016, 11:15:07 am
content: Quote from: taylornate on September 30, 2016, 10:04:10 pmDid you go through the manufacturer or through a distributor/reseller? Because seriously, if you've been quoted more for a WaveSurfer 3000 than for the Keysight or Tek equivalent then someone clearly tried to pull a fast one on you because the WS3000 is notably cheaper - several hundreds for the 200MHz base version up to a few grand for the 500+Mhz variants.Quote from: EEVblog on September 30, 2016, 11:05:57 pmIt's a joke because Tek markets it as a replacement for a real standalone SA, which it clearly isn't.I'm not saying it can't be useful in cases where 8bit FFT over 1Mpts with the resulting poor dynamic range is good enough, but then on the basic MDO3K scope you pretty much get the same as on every other scope - FFT over the analog BW. If you want the full 3GHz, unless you get a special deal or "hack" your scope, you're paying a premium for it (the MDO3SA option is roughly $2600, not exactly a bargain when a real SA like the Rigol DSA832 is $2900)