Search found 14 matches

by vernarim
Fri May 13, 2011 8:01 pm
Forum: DSO
Topic: DSO Quad bandwidth
Replies: 117
Views: 129322

Re: DSO Quad bandwidth

The worst part of this situation is the almost total silence about the Company. It's a silence making lot of rumor... HugeMan, would you explain what will be the future of (our) Quads (at least of mine)? For anyone is reading at this message: I'll sell my Quad for a discounted price (having few week...
by vernarim
Thu May 12, 2011 8:13 pm
Forum: DSO
Topic: DSO Quad bandwidth
Replies: 117
Views: 129322

Re: DSO Quad bandwidth

Thanks everybody. About the opamp instability, I could agree but the enhancement is not so great. It reach about +6dB, so... I don't agree the digital filtering equalization. The ADC is 8bit, so its dynamics is about 46dB. Also the sampling rate is 72Ms/s, so -to avoid aliasing- we should be able to...
by vernarim
Wed May 11, 2011 8:52 pm
Forum: DSO
Topic: DSO Quad bandwidth
Replies: 117
Views: 129322

Re: DSO Quad bandwidth

The story is always funnier than expected. I have done some measurements right now. As HugeMan/lygra suggested, I feed the ch-A input (without any probe) directly with the signal generator. BTW: the instrumentation is still exactly the same. I checked the signal either on the Quad display and with t...
by vernarim
Mon May 09, 2011 8:09 pm
Forum: DSO
Topic: DSO Quad bandwidth
Replies: 117
Views: 129322

Re: DSO Quad bandwidth

@HugeMan: I will check the analog bandwidth by open my Quad, as soon I have spare time to do it. @lygra: I appreciate your effort to demonstrate (better: trying to do it) with tons of theories, but I guess that you are mixing many concepts together. A square wave is yes composed by odd harmonics (I ...
by vernarim
Sat May 07, 2011 2:37 am
Forum: DSO
Topic: DSO Quad bandwidth
Replies: 117
Views: 129322

Re: DSO Quad bandwidth

Have you measured your bandwidth at U5 and U15 pin-3? HugeMan is not referring to displayed results. He is referring to the inputs to the unity gain op-amps that directly feed the ADC. No, I didn't open my Quad yet. Anyway it makes to me almost a nonsense by saying about the "analog BW to pin 13......
by vernarim
Fri May 06, 2011 8:12 pm
Forum: DSO
Topic: DSO Quad bandwidth
Replies: 117
Views: 129322

Re: DSO Quad bandwidth

HugeMan, I don't know whether your Quad has the same hardware as the mine, but *of sure* the mine has a -3dB cutoff around 2-3MHz. Please, specify whether the probe could be so relevant in the test, because I have considered it always in my tests. I don't understand what you stated also: at the very...
by vernarim
Mon May 02, 2011 1:37 am
Forum: DSO
Topic: DSO Quad bandwidth
Replies: 117
Views: 129322

Re: DSO Quad bandwidth

Hi lygra. I read the latest posts right now, but I am not sure to understand everything well..Okay, I am actually tired too. I was not able to perform any other test because I am very busy at the moment. The instrumentation is in the lab, while at home I can only try with simple circuits. Anyway, I ...
by vernarim
Wed Apr 27, 2011 10:27 pm
Forum: DSO
Topic: DSO Quad bandwidth
Replies: 117
Views: 129322

Re: DSO Quad bandwidth

I have done some other test. I am sorry but I can't made any picture, so you should believe what I write... Generator: HP33120A Reference scope: LeCroy LC358 1GHz I have placed a 50 Ohms load on the generator output, then a 2-feet coaxial cable toward a T-plug. One side is for the LeCroy scope (with...
by vernarim
Sat Apr 23, 2011 8:16 pm
Forum: DSO
Topic: DSO Quad bandwidth
Replies: 117
Views: 129322

Re: DSO Quad bandwidth

@lygra: I never would have hurt you!...I really apologize if you feel that! I was only asking you in which way did you measured/show a good shaped 3.5M square wave, nothing all. Could you post any DSO snapshot of that wave? I have explained what in the lab I have tried, which instrumentation and how...
by vernarim
Fri Apr 22, 2011 1:32 pm
Forum: DSO
Topic: DSO Quad bandwidth
Replies: 117
Views: 129322

Re: DSO Quad bandwidth

You apparently haven't learned how to maximize the DSO Quad which has a small capture buffer (4-Kbytes per channel) and sample rate limitations. That's probably true: I'd love if you explain me how to display a 3.5MHz well-shaped square wave. Let me know what and how to connect the Quad and I will ...