Products > Test Equipment
New Tektronix 3 Series MDO
james_s:
Hm I've never encountered a use for mask testing, I suppose it must be the sort of thing that is very useful in certain situations. Haven't found FFT on scopes to be all that useful either, it's kind of a cool toy but since getting my hands on a real spectrum analyzer I haven't used the FFT on any of my scopes since.
Triggering is extremely useful and I set up various trigger conditions all the time. Waveform update rate is nice when I'm just poking around and don't really know what I expect to find, or when I'm using the scope to get a quick visual of a power rail or something. If I'm looking for intermittent glitches I'll set up a trigger.
It really depends on what you're trying to do. I used analog scopes for years and feel very comfortable driving one so perhaps that's why the older Tek DSOs appeal to me. I'm not a fanboy though, there are lots of nice scopes out there and given infinite budget and space I'd have at least one of every brand I could get my hands on.
snoopy:
--- Quote from: Wuerstchenhund on April 30, 2020, 01:12:11 pm ---
--- Quote from: Someone on April 29, 2020, 11:56:12 pm ---
--- Quote from: Wuerstchenhund on April 29, 2020, 10:53:52 am ---
--- Quote from: james_s on April 28, 2020, 05:05:02 pm ---I don't really grasp what you mean by it being slow. I have a TDS3054 and a TDS784C and the only time I've ever noticed any kind of slowness in either one is using deep memory on the TDS784. The TDS3000 feels very snappy to me, what do I need to do to see this "painfully slow" lag you refer to? I'm genuinely curious and don't know what you're talking about.
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It's not about 'lag' or general controls. There isn't any input lag when operating the scope. But unfortunately the user interface isn't everything.
For example, try mask testing on the TDS3000. Or FFT. The TDS3000 is also slow when it comes to waveform rates, as in normal mode it's trigger rate is some 450 wfms/sec. This raises to 3k wfms/s or so in Fast trigger mode but then the sample memory (with 10kpts not exactly large) is limited to a measly 500pts. It's not a big problem if you can make it with the available trigger suite (which is quite good if the advanced trigger option is installed) but that doesn't change the fact that the scope *is* slow, and when used in an 'analog scope' manner (like searching for glitches through trace persistence) then it will perform poorly.
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Slow waveform update rates make it bad, got it...
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You clearly didn't 'get' it. I didn't say that the low update rate in normal operation was a problem, I actually said it isn't (and, just for you, I highlighted above where I did that so you can easily find it ;) ).
The point I was making is that the scope might feel OK if you twidle the knobs, it's still a very slow scope. And while the waveform rate isn't really a problem, the slow architecture is for tasks like mask testing, math or FFT.
It should also be remembered that the TDS3000, while looking a lot like the entry-level scopes of today, wasn't a an entry level or even particularly cheap scope (the 500MHz version without any options ran some $18k+, even the 100MHz 2ch base model was over $7k!). Back then in 1999 it's competitors were not common bench scopes like the Agilent 54622A (which was around $4k back then if I remember right) but other expensive scopes like the Agilent Infiniium 54800 Series or the LeCroy WaveRunner LT (and for the 500MHz models even the LC Series). Just to put this into some context.
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Waveform update rate on that Agilent ?? I think Dave did a review on a similar scope once and he could only clock in about 400 wfs/s !! Just saying ;)
Wuerstchenhund:
--- Quote from: james_s on April 30, 2020, 11:27:43 pm ---Hm I've never encountered a use for mask testing, I suppose it must be the sort of thing that is very useful in certain situations. Haven't found FFT on scopes to be all that useful either, it's kind of a cool toy but since getting my hands on a real spectrum analyzer I haven't used the FFT on any of my scopes since.
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Well, FFT is often seen as a cheap spectrum analyzer replacement but on a good scope you can apply it to other data (i.e. maths functions) as well, and quite often can give helpful information as to the properties of interference sources.
Mask testing is useful, for example for testing spec compliance of certain signals, but as persistence mode it's also limited by the update rate. It works best for signals where all events happen within the acquisition time.
--- Quote ---Triggering is extremely useful and I set up various trigger conditions all the time. Waveform update rate is nice when I'm just poking around and don't really know what I expect to find, or when I'm using the scope to get a quick visual of a power rail or something. If I'm looking for intermittent glitches I'll set up a trigger.
--- End quote ---
Sounds like a good strategy.
--- Quote ---It really depends on what you're trying to do. I used analog scopes for years and feel very comfortable driving one so perhaps that's why the older Tek DSOs appeal to me. I'm not a fanboy though, there are lots of nice scopes out there and given infinite budget and space I'd have at least one of every brand I could get my hands on.
--- End quote ---
At the end of the day it's down to whatever suits you best anyways.
But yes, if I had the budget and especially the space then I'd try to get one exemplar of every scope series, too. Thinking about it, maybe not having the money and space for that isn't such a bad thing after all ;)
snoopy:
--- Quote from: Sighound36 on April 24, 2020, 11:18:06 am ---I have to agree having had both the 5 & 6 series scopes I can confirm they are under performers, clunky,very average UI way over priced for both software and probes. Ridiculous boot up time of around 6 minutes 12 bit dubious performance unless around 1Ghz on the 6 series probe prices like raw graphene costs!
Also our units crashed quite consistently.
Not having a downer on Tek here, have purchased two pieces of quality Tek test equipment very recently its just the scopes are way off the mark in many areas plus the silly pricing.
Look at LeCroy or Keysight equivalent offers much better all round imho
Some observations below
https://www.eevblog.com/forum/testgear/rd-oscilloscope-acquisition-now-settled/msg3000760/#msg3000760
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A 1 GHz scope that can't measure 1GHz and 12 bit ADC that can't really do 12 bits !! Are you sure that was a Tek scope ?
0xdeadbeef:
Hm, the typical marketing nonsense, selecting two products from different price classes with totally different sample rates and assuming that anybody will fall for this.
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