Author Topic: RIGOL DS1054Z Offset Range limits  (Read 14154 times)

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Online rstofer

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Re: RIGOL DS1054Z Offset Range limits
« Reply #25 on: June 02, 2016, 02:59:41 am »
They were probably thinking something like, "If we use a non-standard aspect ratio then we'll have to use custom-made screens instead of off-the-shelf. That will increase the price of everybody's 'scope just to make a tiny percentage of people a bit more happy. This means we won't be so competitive and we might go out of business."You've got four channels. What was preventing you from looking at the drift on one channel of the 'scope and the noise on another?

How about the fact that the screen is wildly rectangular and, by convention, reticle grids are square?  The reticle is 8x12 because of the widescreen display.  They could have gone 10x15 but 15 isn't an even number and the squares would be much smaller.  They could have solved the x15 problem by just using larger menus.  Heck, we could have had that stylish 10x10 reticle with a lot more room for menus.

BTW, the square reticle is required for XY mode.

All in, I can live with it the way it is.
 

Offline wraper

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Re: RIGOL DS1054Z Offset Range limits
« Reply #26 on: June 02, 2016, 07:33:36 am »
If you are looking for your 2Hz 200mV p-p voltage drops on the Rigol, would you perhaps use AC coupling and a vertical resolution of 100 mV/div, say, and a timebase setting of 500 ms/div? While simultaneously looking at the nominal DC voltage on another channel, DC coupled? Of course to see the higher frequency noise/ripple that I showed above you could use a third channel at even greater vertical sensitivity but you'd have to manually change the timebase, or use the horizontal zoom function.
AC coupling, really? Don't you know that AC coupling does not work well at low frequencies? The fact is, low offset range is a serious shortcoming in certain (real) situations where another scopes would perform perfectly well.
Lets think about such situation, there is some load which have high current consumption a few times per second, say some heater, motor or power hungry relay connected to the power rail. You want to see what's going on on the power rail. As you can see from the following pictures, even at 10 Hz scope will be unable to properly display the waveform in AC mode. And even at 50 Hz there is noticeable waveform distortion.



« Last Edit: June 02, 2016, 07:45:11 am by wraper »
 

Offline wraper

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Re: RIGOL DS1054Z Offset Range limits
« Reply #27 on: June 02, 2016, 07:42:47 am »
As far as I know, only keysight has a probe to measure this properly and directly,  the N2070A. If anybody knows a similar probe for a sensible price I'd love to know.
C'mon, you need to buy very expensive probe to make a such simple measurement? I guess you mean N7020A:
Quote
Low noise: 1:1 attenuation ratio probe adds only 10% to the baseline noise of the oscilloscope it is attached to
Large offset range: Has a large +/-24 V offset range, enabling users to set their oscilloscope at maximum sensitivity and have the signal centered on the screen
Low DC loading: 50 k? DC input impedance will not significantly load DC power rails
Large active signal range: Has a +/-850 mV active signal range in addition to its large offset range so users can measure large transitions of their power rails
High bandwidth: 2-GHz bandwidth makes it very useful for finding high-speed transients that can have detrimental effects on clocks and digital data
 

Offline D3f1ant

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Re: RIGOL DS1054Z Offset Range limits
« Reply #28 on: June 02, 2016, 07:43:11 am »
Yeah sorry N7020A.http://thesignalpath.com/blogs/2016/03/11/keysight-n7020a-2-0ghz-power-rail-probe-review-teardown-and-experiments/

This will of course only work on a keysight scope with appropriate software support, not much help for you here sorry but I guess at some point other manufacturers will do something similar.
« Last Edit: June 02, 2016, 07:58:50 am by D3f1ant »
 

Offline wraper

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Re: RIGOL DS1054Z Offset Range limits
« Reply #29 on: June 02, 2016, 08:10:05 am »
Yeah sorry N7020A.http://thesignalpath.com/blogs/2016/03/11/keysight-n7020a-2-0ghz-power-rail-probe-review-teardown-and-experiments/

This will of course only work on a keysight scope with appropriate software support, not much help for you here sorry but I guess at some point other manufacturers will do something similar.
For 2 GHZ probe you need 2 GHz scope first of all. BTW Keysight makes also lower bandwidth version N7023A. But why would you need it anyway unless you are in serious business and have tons of money to blow. Main advantage of those probes is 1x 1:1 attenuation ratio which allows you to see very tiny noise.
 

Offline D3f1ant

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Re: RIGOL DS1054Z Offset Range limits
« Reply #30 on: June 02, 2016, 08:16:22 am »
You can use any BW probe on any scope and vice versa, but your only going to actually get whatever the lowest bandwidth part is.
The N7023A is just the 'prober' part, its included with N7020A.
« Last Edit: June 02, 2016, 08:21:01 am by D3f1ant »
 

Offline wraper

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Re: RIGOL DS1054Z Offset Range limits
« Reply #31 on: June 02, 2016, 08:23:33 am »
You can use any BW probe on any scope and vice versa, but your only going to actually get whatever the lowest bandwidth part is.
Yes you can, but why would you blow a huge money away for the probe from which you cannot get an advantage from. That particular probe is certainly not for 99% of the oscilloscope users.
 

Offline D3f1ant

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Re: RIGOL DS1054Z Offset Range limits
« Reply #32 on: June 02, 2016, 08:29:53 am »
Your quite right, definitely in a niche, for people trying to accurately measure power rails with oscilloscopes. All niche products are expensive...and niche Keysight gear even more so :(
The advantage from the probe is it allows you measure exactly what your wanting to do, and no other probe I know of let's you do that.
« Last Edit: June 02, 2016, 08:35:49 am by D3f1ant »
 

Offline wraper

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Re: RIGOL DS1054Z Offset Range limits
« Reply #33 on: June 02, 2016, 12:28:37 pm »
Your quite right, definitely in a niche, for people trying to accurately measure power rails with oscilloscopes. All niche products are expensive...and niche Keysight gear even more so :(
The advantage from the probe is it allows you measure exactly what your wanting to do, and no other probe I know of let's you do that.
It is really useful only if you wan't to measure some very high frequency stuff, like FPGA power rail. For usual power supply measurements there is no value in it.
Quote
As far as I know, only keysight has a probe to measure this properly and directly,  the N7020A.
About this again. This is completely wrong. That probe is for very detailed measurements with high bandwidth. For what OP wanted to measure, usual scope with decent offset range is completely adequate. 1x measurement without attenuation or fancy probes can be completely adequate as well if hundreds of MHz is not what you are looking for.
 

Offline D3f1ant

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Re: RIGOL DS1054Z Offset Range limits
« Reply #34 on: June 02, 2016, 02:27:18 pm »
Haha, yes a big electromagnetic load certainly doesn't sound like a very sensitive load so the offset and range available on most scopes should be adequate.
« Last Edit: June 02, 2016, 02:47:48 pm by D3f1ant »
 

Offline StillTrying

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Re: RIGOL DS1054Z Offset Range limits
« Reply #35 on: June 02, 2016, 02:31:15 pm »
If you need a much lower AC bandwidth, use your own capacitor, with the scope on DC coupled of course. :)
CML+  That took much longer than I thought it would.
 

Offline metrologist

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Re: RIGOL DS1054Z Offset Range limits
« Reply #36 on: June 02, 2016, 04:00:06 pm »
Sorry to butt in, but I'm not seeing what the Rigol is incapable of measuring here? The scope shots above show ~500 mv DC on both DC and AC couplings.
 

Offline wraper

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Re: RIGOL DS1054Z Offset Range limits
« Reply #37 on: June 02, 2016, 04:57:30 pm »
Sorry to butt in, but I'm not seeing what the Rigol is incapable of measuring here? The scope shots above show ~500 mv DC on both DC and AC couplings.
Those are from DS2000, not 1000Z. And DC voltage level is below what OP wanted to measure (limit of the signal gen). They are only for a reason to show that AC is not really a replacement for DC offset.
 

Offline David Hess

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Re: RIGOL DS1054Z Offset Range limits
« Reply #38 on: June 08, 2016, 02:22:02 am »
The offset range is multiplied by the attenuation before the offset signal is added.  In the Rigol 1000Z series, there is only one switchable x100 attenuation stage yielding two offset ranges.  Further, the dynamic range of the 1000Z input amplifiers is small limiting the range of the offset signal.

Some old analog oscilloscopes have huge offset ranges.  A Tektronix 100 MHz 7A13 supports +/- 10 volts of offset at 1mV/div and +/- 100 volts of offset at 10mV/div.  It is like having a position control with 10,000 vertical divisions of range but these were not primarily designed for this reason.  What they allow is "slideback" precision DC voltage measurements at any point of a waveform using an analog oscilloscope.  This is why the 7A13 is called a differential comparator and not a differential amplifier although it does that as well.

The modern implementation of the Tektronix 7A13 is the Preamble Instruments 1855 and from what I remember, the same designer worked on both.  Preamble was bought by LeCroy but still produce this stand alone differential probe amplifier.  If you have to ask the price, then you cannot afford it.

As far as the x1 versus x10 passive probe, the output impedance of a power supply or regulator is so low that the added capacitance of the x1 probe is insignificant but its relatively low bandwidth limitations still apply.
 
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Offline hgjdwx

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Re: RIGOL DS1054Z Offset Range limits
« Reply #39 on: January 19, 2017, 02:24:14 am »



« Last Edit: January 19, 2017, 02:51:32 am by hgjdwx »
 

Offline alsetalokin4017

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Re: RIGOL DS1054Z Offset Range limits
« Reply #40 on: January 19, 2017, 03:07:47 am »
What, are you telling me there are better oscilloscopes than the Rigol DS1054z?    Who knew?      :horse:
The easiest person to fool is yourself. -- Richard Feynman
 
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Offline tautech

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Re: RIGOL DS1054Z Offset Range limits
« Reply #41 on: January 19, 2017, 04:59:03 am »
What, are you telling me there are better oscilloscopes than the Rigol DS1054z?    Who knew?      :horse:
Micsig didn't do a very good job on this one:
https://www.eevblog.com/forum/testgear/dc-offset-wander/
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