Lecroy - HDO4034A vs Tektronix - MDO3104

[2N3055]

One thing that is good with fast retrigger is that when you are measuring a parameter and gathering statistics is that with fast rettriger you gather data faster. 
It all depends what you do. For interactive work Keysight concept is king. If you tend to grab data and massage it, LeCroy concept is better.
Also, problem with LeCroy is that cheaper scopes don't have many advanced analysis options that you would use it to make up for lack of speed.
There is no such thing as perfect scope. For instance, little Rigol DS1000Z has some triggers Keysight 3000T doesn't have. But, combined with Zone Trigger, I yet have to find something I can't trigger on..

Best advice is what Nctnico said: get few candidates on a loan and try doing your job.. Showstoppers will reveal themselves.

[nctnico]

To be honest, I'm not a big fan of this anyway. While it's true that you might spot glitches because of fast update rate, a glitch is always very dark due to the intensity grading logic. On a LeCroy, you would rather use advanced measurement/analysis/trigger features to spot issues than to stare at the screen.

I agree that triggering is the best option to capture unexpected events. Staring at a screen is not a good use of time. BTW the R&S RTM3000 has an inverse intensity grading mode. The rare signals stick out like a sore thumb. IMHO having many levels of intensity grading is nice eye candy but there is very little practical value. 16 levels starting at 50% brightness is more than enough. There is only so much visual information you can process.

[Someone]

but the Tek has Fast Acquisition mode or DPO mode as well as a Fast Frame capture mode using segmented memory. Don't think the Lecroys have ever offered fast acquisition  rates.

No?



And as far as I know this intensity mode works with the full sample rate and all scope functions are still available when it's enabled - unlike Tek fastaq

That shows the trigger rate, which can be unrelated to what data is actually arriving at the screen. There are many brands of scope which can be put into configurations where the trigger output shows impressive rates, but the data isn't arriving on the screen. There isn't a simple way to test the waveform update rate in those cases.

The value of those different modes and waveform update rate are entirely down to the user and their applications.

[Someone]

Yes the Teks normally default to slow update rates as usual but the Tek has Fast Acquisition mode or DPO mode as well as a Fast Frame capture mode using segmented memory. Don't think the Lecroys have ever offered fast acquisition  rates. The Intensity graded display of the Tek is useful to display AM waveforms etc or anything that you would use a normal CRO to display.

You have come to the same juncture as many before you, the division between scopes with an emphasis on realtime display, and those with an emphasis on deep memory and analysis of that offline.

Lecroy WaveJet is one of their few realtime designs, and has a really good graded display that works simultaneously with segmented memory so you can also step through the individual waveforms when stopped. A great basic scope but its quite an old platform so may not be as competitive as other options.

[snoopy]

You say that as if intensity graded display was something special - it isn't. Even my old Lecroy LTs have it, in monochrome (analog scope style) and color, and even as a waterfall display And these scopes are over 16 years old

Proper intensity grading ? lets see what it looks like on an AM waveform

btw I have an old Tek TDS784A from the 90's that can capture waveforms at a rate of 390,000 wfs and display rare events. Donlt think any of the competitors had that at the time And a TDS7054 does proper intensity grading with up to 200 K wfs with all measurement ability available. Both scopes have equivalent time sampling of up to 250 Gs/s. Unfortunately they dropped this in the later scopes.

cheers

[Mr Nutts]

You say that as if intensity graded display was something special - it isn't. Even my old Lecroy LTs have it, in monochrome (analog scope style) and color, and even as a waterfall display And these scopes are over 16 years old

Proper intensity grading ? lets see what it looks like on an AM waveform

If you want me to post a screenshot of an AM modulated waveform then you'll have to wait until next week when my lab redecoration is finished 

btw I have an old Tek TDS784A from the 90's that can capture waveforms at a rate of 390,000 wfs and display rare events. Donlt think any of the competitors had that at the time And a TDS7054 does proper intensity grading with up to 200 K wfs with all measurement ability available. Both scopes have equivalent time sampling of up to 250 Gs/s. Unfortunately they dropped this in the later scopes.

I'm no expert (and I think waveform rates are way overvalued) but wasn't there the HP 54600 series with MegaZoom that was even faster and didn't even need a special mode to reach high waveform rates?

But that doesn't matter because no matter how fast your scope is you still never know if there's that very rare anomaly because it most of the time it's still completely blind

My old LT will capture rare anomalies every time because of its sophisticated set of triggers

TDS7000 are ancient, and as far as I know they run the code of early TDS scopes on a separate computer inside the scope and wrapped a Windows GUI around it which is why all these scopes are so horribly slow. My college had Tek  DPO3000 and MDO3000 (which were the standard scopes), a few MDO4000, I think two TDS6000 and a DPO7000 (and maybe others I can't remember), and all of them were slow as wading through molasses

And ETS at 250GSps, who cares? It's not giving you any advantage over the 200 GSps in ETS as on the Waveruner xi, or even the 20GSps I could get from my LT. And who cares about ETS anyways?

I'd rather use an Agilent Infinum or Lecroy X-Stream scope over any Tek scope - no matter if TDS, DPO or MDO. Less frustrating and better performance

[Mr Nutts]

Lecroy WaveJet is one of their few realtime designs

Lecroy Wavejet is not Lecroy design. It's a rebadged Iwatsu scope (was mentioned often enough in this forum)

[Someone]

Lecroy WaveJet is one of their few realtime designs

Lecroy Wavejet is not Lecroy design. It's a rebadged Iwatsu scope (was mentioned often enough in this forum)

Didn't say it was, Lecroy offer and still sell a scope of the realtime design even if it is rebadged or co-designed.

[JPortici]

Proper intensity grading ? lets see what it looks like on an AM waveform

who cares? unless all you need to do is look at AM sine waves
Color temperature intensity grading is much more useful IMHO. I may be wrong but in the lecroy WS3K i could also decide the colours for hot/cold so i could also achieve the inverted colour grade. For my experience i have to agree with nico, 16 levels have been plenty in the real world for me.

Even better, launching an histogram of that area shows me much more than what intensity grading tells me.

[snoopy]

You say that as if intensity graded display was something special - it isn't. Even my old Lecroy LTs have it, in monochrome (analog scope style) and color, and even as a waterfall display And these scopes are over 16 years old

Proper intensity grading ? lets see what it looks like on an AM waveform

If you want me to post a screenshot of an AM modulated waveform then you'll have to wait until next week when my lab redecoration is finished 

btw I have an old Tek TDS784A from the 90's that can capture waveforms at a rate of 390,000 wfs and display rare events. Donlt think any of the competitors had that at the time And a TDS7054 does proper intensity grading with up to 200 K wfs with all measurement ability available. Both scopes have equivalent time sampling of up to 250 Gs/s. Unfortunately they dropped this in the later scopes.

I'm no expert (and I think waveform rates are way overvalued) but wasn't there the HP 54600 series with MegaZoom that was even faster and didn't even need a special mode to reach high waveform rates?

But that doesn't matter because no matter how fast your scope is you still never know if there's that very rare anomaly because it most of the time it's still completely blind

My old LT will capture rare anomalies every time because of its sophisticated set of triggers

TDS7000 are ancient, and as far as I know they run the code of early TDS scopes on a separate computer inside the scope and wrapped a Windows GUI around it which is why all these scopes are so horribly slow. My college had Tek  DPO3000 and MDO3000 (which were the standard scopes), a few MDO4000, I think two TDS6000 and a DPO7000 (and maybe others I can't remember), and all of them were slow as wading through molasses

And ETS at 250GSps, who cares? It's not giving you any advantage over the 200 GSps in ETS as on the Waveruner xi, or even the 20GSps I could get from my LT. And who cares about ETS anyways?

I'd rather use an Agilent Infinum or Lecroy X-Stream scope over any Tek scope - no matter if TDS, DPO or MDO. Less frustrating and better performance

By all means show us then ! And that HP scope scope you quoted is a sub-sampling scope with a 20 msps max sampling rate for a quoted bandwidth of 100MHz. I very much doubt that claim you made about it because I used one of these scopes once and its single shot performance was terrible showing a sparse collection of dots or jagged lines on the screen which made it pretty much useless for single events !

And there is no point in trying to capture an anomaly using triggering if you don't know what kind of anomaly it is ! Once you characterize the anomaly then you can setup your trigger to capture it That's why Tek brought out Instavu on some of its early scopes, one of which I have. And it does capture rare anomalies that other scopes completely miss.

Also ETS scopes display information much more accurately approaching the nyquist frequency compared to scopes that use interpolation

And your description of the TDS7000 scopes is way off too. You can sse in this video differences in performances of scopes with different WUR !

https://youtu.be/2465uN-qpIY?t=1316