Author Topic: What Oscilloscope buy?  (Read 31579 times)

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Online tautech

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Re: What Oscilloscope buy?
« Reply #50 on: September 25, 2015, 07:08:52 pm »
Take a look at our recently updated App Note on Oscilloscope Vertical Noise.

http://literature.cdn.keysight.com/litweb/pdf/5989-3020EN.pdf

You mean "infomercial"? It has some interesting content but I wonder will we ever see any App Note from Keysight that doesn't include talking about your competition? Especially when you have to compare your current products with in some cases 8yr old competitor scopes.

Yes it is a marketing for our products. I agree with you, I don't like the attack based marketing.........

The reason the scopes are so old is because those happened to be what we had lying around from the competition. When we get some newer scopes in the office, I will update the document again.
If you don't like it, why keep fostering it?  :palm:
These scope manufacturers pissing competitions have been going on for decades, I don't like them much either.
History shows these claims and counter-claims and the selected parameters used to discredit compeditors, like any statistics can be tailored to show the author in a more favourable light.
Many experienced users can see past these novels, so why produce them?
« Last Edit: September 25, 2015, 07:52:51 pm by tautech »
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Offline Howardlong

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Re: What Oscilloscope buy?
« Reply #51 on: September 25, 2015, 07:30:06 pm »
FWIW, these are the measurements on a couple of scopes, sample rate was 4GSa/s in both cases. Connections terminated directly at the scope's BNC. 8mV does seem very high, if that is the Vrms shorted at the scope's BNC. It would explainable if the short was made at the probe end.

TB 100us/div
2mV/div

Agilent/Keysight MSO7104B 1GHz/4GSa/s

1M impedance
BW Lim off
Vrms Open/Short 338uV/354uV

1M impedance
20MHz BW Lim on
Vrms  Open/Short 168uV/204uV

50 ohm impedance
BW Lim off
Vrms  Open/50/Short 310/310/318uV

50 ohm impedance
20MHz BW Lim on
Vrms  Open/50/Short 104/109/123uV

Agilent 54831D 600MHz/4GSa/s

1M impedance
BW Lim off
Vrms Open/Short 450uV/375uV

1M impedance
20MHz BW Lim on
Vrms  Open/Short 361uV/199uV

50 ohm impedance
BW Lim off
Vrms  Open/50/Short 325/324/332uV

50 ohm impedance
20MHz BW Lim on
Vrms  Open/50/Short 132/141/153uV


 

Offline Wuerstchenhund

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Re: What Oscilloscope buy?
« Reply #52 on: September 25, 2015, 08:02:51 pm »
FWIW, these are the measurements on a couple of scopes, sample rate was 4GSa/s in both cases. Connections terminated directly at the scope's BNC. 8mV does seem very high, if that is the Vrms shorted at the scope's BNC. It would explainable if the short was made at the probe end.

Why would anyone do that? If you want to measure the noise level of a scope it would be silly introducing a probe.
 

Offline Berni

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Re: What Oscilloscope buy?
« Reply #53 on: September 25, 2015, 08:05:58 pm »
If you don't like it, why keep fostering it?  :palm:
These scope manufacturers pissing competitions have been going on for decades, I don't like them much either.
History shows these claims and counter-claims and the selected parameters used to discredit compeditors, like any statistics can be tailored to show the author in a more favourable light.
Many experienced users can see past these novels, so why produce them?

That's just how it works in large companies. They have a whole groups of marketing "geniuses" that come to work every day to do nothing else than to try and make the companies products seam superior to everything else. Later on the bosses whip the engineers in to doing there bidding. Its the same thing with how the products are designed. I'm sure most engineers there would agree that they should just slap on a ethernet port on the X3000 scope rather than sell a box with a RJ45 jack and some magnetics. But someone had the idea that they would make more money selling these things so it had to become a module.

Most of the time these fools with business PhDs don't do too much harm but here and there they do cause some facepalm moments to the customers while the engineers that had to execute there "genius plan" bang there heads against the desk.
 

Offline Howardlong

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Re: What Oscilloscope buy?
« Reply #54 on: September 25, 2015, 08:15:40 pm »
FWIW, these are the measurements on a couple of scopes, sample rate was 4GSa/s in both cases. Connections terminated directly at the scope's BNC. 8mV does seem very high, if that is the Vrms shorted at the scope's BNC. It would explainable if the short was made at the probe end.

Why would anyone do that? If you want to measure the noise level of a scope it would be silly introducing a probe.

I don't know, I was trying to explain the apparent aberration.

Relaaaaaax..... just a thought, you may not realise it but did you know that you do frequently come over rather abruptly and patronisingly? Just sayin'...
 

Online nctnico

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Re: What Oscilloscope buy?
« Reply #55 on: September 25, 2015, 08:19:08 pm »
I guess the days are gettings shorter...
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Online tautech

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Re: What Oscilloscope buy?
« Reply #56 on: September 25, 2015, 08:23:27 pm »
I guess the days are gettings shorter...
Ours are getting longer, daylight saving 1 hr timeshift soon.
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Online tautech

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Re: What Oscilloscope buy?
« Reply #57 on: September 26, 2015, 09:24:58 am »
I already decided to buy oscilloscope.
Keysight DSOX3024T all free licenses, and also 12h free training for Keysight to learn this oscilloscope, as I said the first time will have one digital, the payment facilities
that normally no one gives, as most is cash payment.

Congratulation, that's a good decision. I'm sure you won't regret it.




Excellent! Your first positive comment about a Keysight product ever! :-DD

And we agree, it is a very good decision indeed, not just for today but for the long haul. Keysight's support is second to none. I speak from first hand knowledge.
Well hunting for threads on a request about Siglents today I came across positive comments too.  :o
https://www.eevblog.com/forum/testgear/siglent-ds1102cnl-dso/
Post #2    :)
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Offline Wuerstchenhund

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Re: What Oscilloscope buy?
« Reply #58 on: September 26, 2015, 09:59:23 am »
I already decided to buy oscilloscope.
Keysight DSOX3024T all free licenses, and also 12h free training for Keysight to learn this oscilloscope, as I said the first time will have one digital, the payment facilities
that normally no one gives, as most is cash payment.

Congratulation, that's a good decision. I'm sure you won't regret it.




Excellent! Your first positive comment about a Keysight product ever! :-DD

And we agree, it is a very good decision indeed, not just for today but for the long haul. Keysight's support is second to none. I speak from first hand knowledge.
Well hunting for threads on a request about Siglents today I came across positive comments too.  :o
https://www.eevblog.com/forum/testgear/siglent-ds1102cnl-dso/
Post #2    :)

Well, it shows that at least you know how to use this forum's search function, but then I guess the results wouldn't fit some people's "only bashed other brands" BS agenda.

At the end of the day, the truth is out there (my recommendation for Siglent, Agilent/Keysight, R&S, even Tek, plus all the links and references), easy to find if you're truly interested in the truth and have some time to spare. Nothing is hidden. And the gullible that may be interested but can't be arsed to check some unsubstantiated claims fully deserve being spoon-fed crap. At the end of the day, it's them who are potentially missing out, not me.

Now I suggest we return to the actual topic.
 

Offline Wuerstchenhund

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Re: What Oscilloscope buy?
« Reply #59 on: September 26, 2015, 10:05:20 am »
FWIW, these are the measurements on a couple of scopes, sample rate was 4GSa/s in both cases. Connections terminated directly at the scope's BNC. 8mV does seem very high, if that is the Vrms shorted at the scope's BNC. It would explainable if the short was made at the probe end.

Why would anyone do that? If you want to measure the noise level of a scope it would be silly introducing a probe.

I don't know, I was trying to explain the apparent aberration.

Relaaaaaax..... just a thought, you may not realise it but did you know that you do frequently come over rather abruptly and patronisingly? Just sayin'...

Geez, Seriously? What's patronizing on a simple question? Maybe spend a little less time being oversensitive and more time reading more carefully as I already stated that this noise was with open connectors, so it should have been clear that there wasn't a probe connected (and no cable, and no antenna, or anything else). Plus it should be very obvious why connecting a probe would be a pretty stupid thing to do if the aim is to measure the internal noise of a test instrument.

« Last Edit: September 26, 2015, 10:08:45 am by Wuerstchenhund »
 

Offline Howardlong

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Re: What Oscilloscope buy?
« Reply #60 on: September 26, 2015, 01:50:31 pm »
FWIW, these are the measurements on a couple of scopes, sample rate was 4GSa/s in both cases. Connections terminated directly at the scope's BNC. 8mV does seem very high, if that is the Vrms shorted at the scope's BNC. It would explainable if the short was made at the probe end.

Why would anyone do that? If you want to measure the noise level of a scope it would be silly introducing a probe.

I don't know, I was trying to explain the apparent aberration.

Relaaaaaax..... just a thought, you may not realise it but did you know that you do frequently come over rather abruptly and patronisingly? Just sayin'...

Geez, Seriously? What's patronizing on a simple question? Maybe spend a little less time being oversensitive

I was trying to point out in as reasonable way as I could that your responses are frequently abrupt and patronising, just like the one you've just given in fact. Maybe you should think about the way you're coming across a bit more? I'm sorry if you don't think you come over like that, I was trying to help you. There's just no need to bite peoples' heads off. A bit of consideration, humility and respect doesn't cost anything you know, just a bit of thought before you say things.

It wasn't clear to me that the termination was at the scope by the way. I am sorry if I missed something where that was stated, or misinterpreted what was said. In your world that may be stupid, but I did actually look to see if the tests were done terminated at the scope and I couldn't see that explicitly stated when I looked across threads. I was trying to offer a suggestion.

I am sure you have plenty of knowledge and experience to share, it would just be appreciated if it came over with a bit less arrogance and condescension please, you'll find people will accept and understand things when delivered that way. Again, I'm just sayin', I'm trying to help you here.
 

Offline Wuerstchenhund

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Re: What Oscilloscope buy?
« Reply #61 on: September 26, 2015, 03:43:07 pm »
I was trying to point out in as reasonable way as I could that your responses are frequently abrupt and patronising, just like the one you've just given in fact.  Maybe you should think about the way you're coming across a bit more? I'm sorry if you don't think you come over like that, I was trying to help you. There's just no need to bite peoples' heads off. A bit of consideration, humility and respect doesn't cost anything you know, just a bit of thought before you say things.

Man, come down! All I did was asking why anyone would test scope noise with a probe. That's "biting your head off"?

Seriously, if you're that sensitive then maybe a web forum isn't the right place for you.

Quote
It wasn't clear to me that the termination was at the scope by the way. I am sorry if I missed something where that was stated, or misinterpreted what was said. In your world that may be stupid, but I did actually look to see if the tests were done terminated at the scope and I couldn't see that explicitly stated when I looked across threads. I was trying to offer a suggestion.

That's fine, but again, all I asked is why anyone would do that. Because it doesn't make much sense. If you don't know why, no problem, but just say so. I don't have a cristal ball, and can't possibly see why this simple question was so troubling to you.

I really feel like Adam Sandler in Anger Management:


After all, this form of communcation is text-only, you can't see your commincation partner, and you therefore can't see any emotive expressions aside from a few ugly emoticons. That means just because its limitations its prone to misunderstandings, and probably the worst form of communication for oversensitive people. That's just how it is.

Quote
I am sure you have plenty of knowledge and experience to share, it would just be appreciated if it came over with a bit less arrogance and condescension please, you'll find people will accept and understand things when delivered that way. Again, I'm just sayin', I'm trying to help you here.

This has nothing to do with experience, it's simple common sense and basic engineering. If you want to test the properties of an object then the #1 rule is to minimize all external influences that skew the test results. Using a probe when measuring a scope's internal noise is the complete opposite, it's the equivalent of trying to test the acoustic noise of a low noise fan inmidst a horde of screaming kids. You'll never get reliable results. Again, common sense and basic engineering.

Now, if you wanted to know the systemic noise (i.e. internal scope noise + noise caused by the probe) then that's a different story, and then you need to have a probe connected as its part of the UUT (Unit Under Test).

Again, even if you didn't know all this, fine. But then just say so!
« Last Edit: September 26, 2015, 03:45:25 pm by Wuerstchenhund »
 

Offline joeqsmith

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Re: What Oscilloscope buy?
« Reply #62 on: September 26, 2015, 04:25:29 pm »
Hey Wuerstchenhund,  you know the SSD in the old 64Xi has been in there since April 13th without a single issue, even without any changes to any of the OS settings?   Just a mirror of the drive.   That's not just sitting on a bench but using it.   The one in the 8500A has been in there longer but it has seen much less use.   Again, no problems (same for the 1G Ethernet card).    Even channel 3 (which was the problem channel of the 64Xi) continues to work just fine.   The only issue has been the button battery failed in the 8500A.     

I suspect that the older SSDs you were using had problems.  You may want to try using a modern SSD and see if you run into any problems.   

Offline Wuerstchenhund

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Re: What Oscilloscope buy?
« Reply #63 on: September 26, 2015, 04:41:26 pm »
Hey Wuerstchenhund,  you know the SSD in the old 64Xi has been in there since April 13th without a single issue, even without any changes to any of the OS settings?   Just a mirror of the drive.   That's not just sitting on a bench but using it.   The one in the 8500A has been in there longer but it has seen much less use.   Again, no problems (same for the 1G Ethernet card).    Even channel 3 (which was the problem channel of the 64Xi) continues to work just fine.   The only issue has been the button battery failed in the 8500A.     

I suspect that the older SSDs you were using had problems.  You may want to try using a modern SSD and see if you run into any problems.

Yes, I know. The Transcend SSD you used is a newer model than the one I used, to my surprise Transcend has actually fixed (or better, worked around through the drive's firmware) the UDMA issues in these newer drives which is great. However, they seem to be the only ones who fixed the issue of higher UDMA modes and the lack of 80 conductor cables for the high density (44pin) EIDE interface.

I now got one of the newer SSDs myself for my WR64Xi, but at first I have to have the connectors on the acquisition board replaced, which isn't easy (don't have the tools myself, nor a source for the connectors, and can't take it to work, so I have to outsource). Probably have to send the boards to LeCroy.

My WavePro 7300A still has the intel SSD 320 I gave it after I bought it, and its still going strong, too, but that's not surprising given that this is connected via SATA.

Now that you had your WRXi for a while, how do you like it?
« Last Edit: September 26, 2015, 04:47:44 pm by Wuerstchenhund »
 

Offline Howardlong

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Re: What Oscilloscope buy?
« Reply #64 on: September 26, 2015, 04:59:36 pm »
Wuerstchenhund: That's a bit better.

The reason I mention your way of responding is to help you, so you can avoid some of those negative responses you've been getting. If this is the way you want to behave on an internet forum the so be it, but please don't be surprised when you get the responses you do. I somehow doubt you behave in this way with your colleagues at work or with family or friends, or even someone face to face at a check out for example, so why would you do it here?

You might think that something's obvious, when in fact, it might not be to someone else. Stating something is simply good or bad engineering practice, or common sense or basic engineering, as a justification and leaving it at that adds little if any value, that is like learning by rote instead of by understanding. There's really no need to say something's stupid or silly, that is just condescending. Instead you could suggest why something might or might not be a good idea, and how better it might be done and why, now that would be constructive and helpful.

I am sure at some point in your life things weren't all so obvious. Try to think back to those days and how you'd feel if someone called your lack of understanding silly or stupid. Again, I think you have much to offer, but it's just lost sometimes I'm afraid. I'm trying to help you here.

The positive aspect of this is that the test with the probe in and out is a good test for someone to do if they want to see how much difference it makes to the scope's noise floor. All part of learning about the limitations of their equipment and how to use it.
 

Offline joeqsmith

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Re: What Oscilloscope buy?
« Reply #65 on: September 26, 2015, 05:46:34 pm »
Hey Wuerstchenhund,  you know the SSD in the old 64Xi has been in there since April 13th without a single issue, even without any changes to any of the OS settings?   Just a mirror of the drive.   That's not just sitting on a bench but using it.   The one in the 8500A has been in there longer but it has seen much less use.   Again, no problems (same for the 1G Ethernet card).    Even channel 3 (which was the problem channel of the 64Xi) continues to work just fine.   The only issue has been the button battery failed in the 8500A.     

I suspect that the older SSDs you were using had problems.  You may want to try using a modern SSD and see if you run into any problems.

Yes, I know. The Transcend SSD you used is a newer model than the one I used, to my surprise Transcend has actually fixed (or better, worked around through the drive's firmware) the UDMA issues in these newer drives which is great. However, they seem to be the only ones who fixed the issue of higher UDMA modes and the lack of 80 conductor cables for the high density (44pin) EIDE interface.

I now got one of the newer SSDs myself for my WR64Xi, but at first I have to have the connectors on the acquisition board replaced, which isn't easy (don't have the tools myself, nor a source for the connectors, and can't take it to work, so I have to outsource). Probably have to send the boards to LeCroy.

My WavePro 7300A still has the intel SSD 320 I gave it after I bought it, and its still going strong, too, but that's not surprising given that this is connected via SATA.

Now that you had your WRXi for a while, how do you like it?

You may remember I was using an adapter on my 8500A to use a SATA drive with it.   I actually figured this one would have a problem but it was a newer drive as well. 

After using that 64Xi for almost 6 months now as basically my main scope I have to admit, I like it!  Really, for a general purpose scope I like it a lot!  I am glad I took the time to up the RAM and add the SSD.   The new knobs they sent for it stay put.   Sure it's old, not the fastest thing out there, throws out a fair bit of heat, fairly loud but this is all stuff I am used to and it covers 99.9% of my home projects.  :-+   

The only thing that I don't care for is their calibration routine.   If you turn them on from a cold start and use them (fully expecting them to cal often) and select normal trigger.   The DSO will sit there and not run an auto cal.   Minutes go by, no auto cal.   Then you put in a signal, bang the auto cal starts and you may loose your signal.    Of course, you can turn off the cal or just let the thing warm up.    Maybe there is a work around so the thing will cal no matter if there is a trigger or not.   I have not asked.

 

Offline Wuerstchenhund

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Re: What Oscilloscope buy?
« Reply #66 on: September 26, 2015, 06:34:15 pm »
You may remember I was using an adapter on my 8500A to use a SATA drive with it.   I actually figured this one would have a problem but it was a newer drive as well. 

This data corruption issue only affects 44pin UDMA interfaces, not the 40-pin variant for which there is an 80-conductor cable suitable for the higher UDMA modes.

Quote
After using that 64Xi for almost 6 months now as basically my main scope I have to admit, I like it!  Really, for a general purpose scope I like it a lot!  I am glad I took the time to up the RAM and add the SSD.   The new knobs they sent for it stay put.   Sure it's old, not the fastest thing out there, throws out a fair bit of heat, fairly loud but this is all stuff I am used to and it covers 99.9% of my home projects.  :-+   

Yes, it'a good scope, although the build quality could really have been a bit be better, and LeCroy could have put in a bit more memory and a faster processor right from the start. But the scope performance is still very good, after all this is the first scope with a max update rate of 1.25M waveforms/s, long before Agilent made waveform rates their key argument for selling their scopes.

Quote
The only thing that I don't care for is their calibration routine.   If you turn them on from a cold start and use them (fully expecting them to cal often) and select normal trigger.   The DSO will sit there and not run an auto cal.   Minutes go by, no auto cal.   Then you put in a signal, bang the auto cal starts and you may loose your signal.    Of course, you can turn off the cal or just let the thing warm up.    Maybe there is a work around so the thing will cal no matter if there is a trigger or not.   I have not asked.

That's a bit strange, mine does a calibration run after the scope app starts and the channels become active, and if its cold and the auto-cal setting is enabled it does re-cals pretty often. Once it has temperature stabilized the auto-cals come up less often.

The annoying thing is that on some older LeCroy X-Stream scopes (i.e. WP7kA and WM8kA before production of late 2008) auto-cal can only be reduced but not disabled completely (even though the setting suggests that it does disable it). I can't remember if the WRXi is one of them (mine is currently disassembled because of the connectors) but I'm pretty sure it is (it's better with the successor WRXi-A). Funny enough, on the older non-Windows scopes, auto-cal could be disabled completely.
« Last Edit: September 26, 2015, 07:17:25 pm by Wuerstchenhund »
 

Offline Wuerstchenhund

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Re: What Oscilloscope buy?
« Reply #67 on: September 26, 2015, 07:14:59 pm »
The reason I mention your way of responding is to help you, so you can avoid some of those negative responses you've been getting. If this is the way you want to behave on an internet forum the so be it, but please don't be surprised when you get the responses you do. I somehow doubt you behave in this way with your colleagues at work or with family or friends, or even someone face to face at a check out for example, so why would you do it here?

I'm the same person at work, or in any other way of life.

Quote
You might think that something's obvious, when in fact, it might not be to someone else. Stating something is simply good or bad engineering practice, or common sense or basic engineering, as a justification and leaving it at that adds little if any value, that is like learning by rote instead of by understanding. There's really no need to say something's stupid or silly, that is just condescending. Instead you could suggest why something might or might not be a good idea, and how better it might be done and why, now that would be constructive and helpful.

That's appreciated, but you really should develop a thicker skin. This is an international forum, which means there are many people from different cultures around, so what you might consider condescending isn't necessarily seen the same by others.

I guess it's cultural, I see you, too, have listed UK as country, so I guess you're a Brit. I occasionally see similar sensitivities here in real-life (and they don't necessarily involve me, but it often involves American colleagues), something that for me as a German (as well as my European and especially my American colleagues) pretty much comes across as hypersensitivity. Sometimes it drives my American colleagues crazy  ;)

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I am sure at some point in your life things weren't all so obvious.

That's true but the difference is that if I don't know or understand something I ask for clarification and don't feel embarrassed or humiliated. Life's a path of constant learning so why not make the most of it?

For example, at the moment I'm in the process of buying a soldering station, something which I don't have much experience in (I use the Pace rework stations at work but I don't buy hand tools or have much experience with other brands), which turned out to be much more complex than I initially thought. So I just opened up a question thread in another section of this forum and asked, which gave me a lot of valuable information. Had I not asked then I would have missed out. So if you don't know anything, just ask. Simples.  ;)  (btw, Dave, we need a Meerkat emoticon!)

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Try to think back to those days and how you'd feel if someone called your lack of understanding silly or stupid.

Believe me, I've done my fair share of stupid things in my life, even in the lab, and have been called out for that many times. So what, I suck it up, learn and move on. What would be the point of victimizing? After all, I wouldn't have been called "stupid" if I hadn't done something stupid, so it was well deserved. What's the point making it into a drama? Learn and move on.

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Again, I think you have much to offer, but it's just lost sometimes I'm afraid. I'm trying to help you here.

That's appreciated of course. But again, relax, and don't take everything here so personal. If you think I'm rough then you haven't seen some of the other people I met here. I really don't care if some of them swear like a sailor (I'm not a saint, either), what's important for me is the information and knowledge that's exchanged. Which I believe is the main point of this forum.

Quote
The positive aspect of this is that the test with the probe in and out is a good test for someone to do if they want to see how much difference it makes to the scope's noise floor. All part of learning about the limitations of their equipment and how to use it.

The problem with the probe is that amongst other things it also acts as a kind of antenna, so how much it impacts the noise level on the scop's display very much depends on where you are and what the RF environment is.
 

Offline joeqsmith

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Re: What Oscilloscope buy?
« Reply #68 on: September 26, 2015, 10:15:39 pm »
You are going to have your 64Xi repaired then?   I am surprised mine had not had any more problems after I had it apart.   

The whole setup is the same as my original post when you suggested there would be problems using the SSDs.   These were the 3.5" drives and am pretty sure they were using mode 2. 

The 64Xi's plastic case has a few chips in the corners and the internal chassis does flex a bit.  On the bright side, at least the knobs don't fall off anymore!  The CPU speed has not been a problem for me but adding the RAM helped it out a lot.   

I have never seen the auto calibration problem in auto mode, only normal.   It doesn't always do it.  I made a short video using the 64Xi to better help explain.   It works the same with the 8500A.     I bring it up from a cold start.   You can see it triggers and displays just fine the first few times.  Then after a while it gets into this mode.   I show this part in actual time so you can see how long I am letting it sit for.   As soon as it gets that last transient at the end of the video, it starts the cal and losses the next transient.   All that dead time with nothing to do but autocal but instead it waits for the signal, then runs the cal.   

I assume it was done this way for a reason.  For me, loosing the data I want to see is more important than any gains they think they gained by making it work this   
 
1.27 if you want to skip to where it all starts.....
https://www.youtube.com/watch?v=EK3I55MHiGg









Offline GlowingGhoul

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Re: What Oscilloscope buy?
« Reply #69 on: September 26, 2015, 10:25:35 pm »
Wuerstchenhund: That's a bit better.

The reason I mention your way of responding is to help you, so you can avoid some of those negative responses you've been getting. If this is the way you want to behave on an internet forum the so be it, but please don't be surprised when you get the responses you do. I somehow doubt you behave in this way with your colleagues at work or with family or friends, or even someone face to face at a check out for example, so why would you do it here?

You might think that something's obvious, when in fact, it might not be to someone else. Stating something is simply good or bad engineering practice, or common sense or basic engineering, as a justification and leaving it at that adds little if any value, that is like learning by rote instead of by understanding. There's really no need to say something's stupid or silly, that is just condescending. Instead you could suggest why something might or might not be a good idea, and how better it might be done and why, now that would be constructive and helpful.

I am sure at some point in your life things weren't all so obvious. Try to think back to those days and how you'd feel if someone called your lack of understanding silly or stupid. Again, I think you have much to offer, but it's just lost sometimes I'm afraid. I'm trying to help you here.

The positive aspect of this is that the test with the probe in and out is a good test for someone to do if they want to see how much difference it makes to the scope's noise floor. All part of learning about the limitations of their equipment and how to use it.

Please don't bother. It doesn't matter how many people tell this guy he's abrasive and rude. His arrogance has him convinced everyone else is wrong. He clearly thinks very, very highly of himself and not so much of the rest of us. In my experience, this kind of behavior is compensation for an otherwise disappointing life.
 

Offline Wuerstchenhund

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Re: What Oscilloscope buy?
« Reply #70 on: September 27, 2015, 01:19:46 pm »
You are going to have your 64Xi repaired then?

Yes, because aside from it being a great scope it's still pretty valuable (used ones still sell somewhere between $3500 and $4000, and the ones with the MSO option for even more). And even if I have it repaired by LeCroy this shouldn't cost me more than say $1200 or so (just a guess, wouldn't be surprised if its a lot lower).

Quote
I am surprised mine had not had any more problems after I had it apart.

I vaguely remember you mentioned that yours had been in repair before, so maybe that makes a difference. The connector problem is mostly an manufacturing/assembly issue (the tight bolts leave no room for the PCB to expand when warming up), and when a scope is sent in for repair this should be mitigated by using nylon spacers and less torque. The upgraded fans also help to keep temperatures low (although this makes the scope a bit louder).

How's the touchscreen of your scope doing? The protective sheet on it tends to delaminate after a few years, but that's not too difficult to fix.

Quote
The 64Xi's plastic case has a few chips in the corners and the internal chassis does flex a bit.  On the bright side, at least the knobs don't fall off anymore!
 

Hey, that's a LeCroy trademark! It ain't no LeCroy if you don't leave behind a trail of knobs when moving it!  ;)

You're right with the chassis, but on mine (which is one of the early models, don't know if they changed it on later models) the press-in nuts that are pressed into the alloy chassis are pressed in from the outside, which means that the bolts pull the nut out of the chassis  :palm: Thankfully that's easy to fix as the nuts can just be taken out and pressed in from the other side, but still that's pretty stupid.

Quote
The CPU speed has not been a problem for me but adding the RAM helped it out a lot.
   

Yes, RAM makes some difference, but when I upgraded mine from the standard 1.3GHz Celeron-M  (400MHz FSB, 512k cache) to a Pentium-M 1.8GHz with 533MHz(?) FSB and 2M cache the scope became noticably faster. Not that it was slow before, but the slighly sluggish feel when changing settings is gone, plus FFT and math are noticably faster (it also increases the performance of WaveScan). The main benefit will be the bigger L2 cache (LeCroy X-Stream does all calculations in the CPU's L2 cache due to its speed). It now feels as snappy as most embedded scopes.

Considering that these CPUs now go for a few bucks it's an upgrade worth doing. The other benefit is that unlike the Celeron-M the Pentium-M supports SpeedStep powermanagement, which keeps CPU temps lower than for the Celeron.

Quote
I have never seen the auto calibration problem in auto mode, only normal.
   

What auto mode do you mean? There's a setting that allows you to disable automatic calibration, is it this one?

Quote
It doesn't always do it.  I made a short video using the 64Xi to better help explain.   It works the same with the 8500A.     I bring it up from a cold start.   You can see it triggers and displays just fine the first few times.  Then after a while it gets into this mode.   I show this part in actual time so you can see how long I am letting it sit for.   As soon as it gets that last transient at the end of the video, it starts the cal and losses the next transient.   All that dead time with nothing to do but autocal but instead it waits for the signal, then runs the cal.

I see. Do you have Automatic Calibration enabled or disabled? It shouldn't do that if its disabled unless there's a larger temperature change.   

Quote
I assume it was done this way for a reason.  For me, loosing the data I want to see is more important than any gains they think they gained by making it work this
   
 
The reason for this auto cal functionality is to make sure the scope maintains its specs in the whole operating range and not just at the temperature it was calibrated at (as it is the case with scopes from other manufacturers). Unfortunately on the older X-Stream scopes auto-cal got a bit overzealous, but if you disable it then it should stop calibrating unless the temperature changes significantly.

Also, make sure you have the latest firmware installed, as there were some improvements re. calibration as well.
« Last Edit: September 27, 2015, 01:23:37 pm by Wuerstchenhund »
 

Offline joeqsmith

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Re: What Oscilloscope buy?
« Reply #71 on: September 27, 2015, 11:06:10 pm »
I have not seen any delamination problems with my two touch screens and these are fairly old scopes.    Maybe its a climate problem.  Do you see air pockets in it?     


What auto mode do you mean? There's a setting that allows you to disable automatic calibration, is it this one?

I see. Do you have Automatic Calibration enabled or disabled? It shouldn't do that if its disabled unless there's a larger temperature change.   

The reason for this auto cal functionality is to make sure the scope maintains its specs in the whole operating range and not just at the temperature it was calibrated at (as it is the case with scopes from other manufacturers). Unfortunately on the older X-Stream scopes auto-cal got a bit overzealous, but if you disable it then it should stop calibrating unless the temperature changes significantly.

Also, make sure you have the latest firmware installed, as there were some improvements re. calibration as well.

Auto vs Normal trigger mode.  Surely you have heard of them?   :-DD 

I have the autocal enabled and let it do its thing.      I understand why they autocal and can't see why I would want to disable it but I also don't understand why if the trigger is set to normal that they would wait for a trigger event to start the cal instead of just running it.     

Offline Muxr

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Re: What Oscilloscope buy?
« Reply #72 on: September 28, 2015, 02:22:33 am »
I really feel like Adam Sandler in Anger Management:


I sometimes feel like this, when I am involved in online discussions:

 

Offline Wuerstchenhund

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Re: What Oscilloscope buy?
« Reply #73 on: September 28, 2015, 05:04:19 am »
I sometimes feel like this, when I am involved in online discussions:



 :-DD
 

Offline Wuerstchenhund

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Re: What Oscilloscope buy?
« Reply #74 on: September 28, 2015, 05:23:37 am »
I have not seen any delamination problems with my two touch screens and these are fairly old scopes.    Maybe its a climate problem.  Do you see air pockets in it?   

No air pockets, the protective sheet just becomes comes loose and eventually falls off. It's a common problem with the particular touch panel used in the WRXi (it does not affect the WM or other LeCroy scopes, or the successor WRXi-A).

It may well be that yours has been fixed in the past and no longer suffers from the problem.

Auto vs Normal trigger mode.  Surely you have heard of them?   :-DD 

Ah, OK. Yes, I think I heard of them  ;) But the trigger mode shouldn't affect the calibration cycle.

Quote
I have the autocal enabled and let it do its thing.      I understand why they autocal and can't see why I would want to disable it but I also don't understand why if the trigger is set to normal that they would wait for a trigger event to start the cal instead of just running it.

Auto-cal can be disabled to avoid the problem in your video - to avoid the scope calibrating when you need it to capture a signal. If you disable auto-cal then the WRXi performs the same as any other non-LeCroy scope that doesn't have a similar auto-cal feature, and unless the temperature variations in your place are extreme (i.e. your lab was a garden shed in Alaska) then disabling it won't give you any problems (plus it will still occasionally calibrate i.e. if the temperature changes a lot, just less often). I'd give it a try.
« Last Edit: September 28, 2015, 05:26:58 am by Wuerstchenhund »
 


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