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REVIEW - Rigol DS2072 - First Impressions of the DS2000 series from Rigol
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Teneyes:
A Tip for Math function  Intg() and Coupling
In order to check if pulse train average duty cycle is positive or negative, use Intg()
see displays
 1  60% duty cycle, the trace drifts up
 2  40% duty cycle, the trace drifts down
 3  20% duty cycle, But AC coupled drifts???
marmad:

--- Quote from: Galaxyrise on July 12, 2013, 05:10:15 am ---With you up to here.  I thought "at some point the memory wouldn't be large enough" is every time sample rate is reduced. Going back and looking at one of the examples you posted, the scope is sampling at 200kSa/s because the memory depth is set to 14kpt and the timebase is 5ms. There's no room to increase the sample rate there, so that couldn't be a fix to that particular aliasing.
--- End quote ---
Huh?  ???  No room to increase the sample rate? It's sampling at 200kSa/s because the memory depth is FIXED at 14k - that's the only reason. If the sample size wasn't fixed there (if it used all 56M), it could be sampling at 500MSa/s; plenty fast enough to fix that aliasing.


--- Quote ---What's an example where it could still sample at 2GSa/s into sample memory that it isn't doing that already?

--- End quote ---
ANYTIME up to 2ms/div it's not sampling at 2GSa/s, it could be - if it didn't use FIXED sample sizes.


marmad:
From Rigol Engineering (thanks to jsykes):


"Every fixed scale, from 1mV/div to 10V/div with 1-2-5 steps (assuming probe attenuation is set to 1X, other probe attenuation settings are math based), is physically amplified or attenuated.
 
The 500uV/div and any vernier scales (those between ranges) are math based. They do not have a fixed range resistor implementation, but instead rely on a variable gain attenuator."
ve7xen:

--- Quote from: Teneyes on July 12, 2013, 09:07:19 am ---A little Tip for Math function  Intg()
When using an input from a Chan and the Scan rate is in mSec, then multiply the input by 1000, that way the Units calculated will be in U,  see the display
For a square wave input of -1.0  to 1.0 Vdc at 4mSec period
So integrating (+1.0 *1000) for 2 mSec = +2 Units
So integrating (-1.0 *1000) for 2 mSec  =  -2 Units

--- End quote ---
Nice work! It's useful after all!

Thanks :D

I would consider this a bug though.
Teneyes:
Tips for FFT
When using the FFT Math feature, it is good to know that the 'SCALE' and 'POSITION' knobs change functions,
After selecting 'CH'
        the   Scale  Knob adjusts the Time Base
        the Position Knob adjusts the Trigger postions

After selecting 'Math'
        the   Scale  Knob adjusts the Frequency Span
        the Position Knob adjusts the Center Frequency

There are 4 frequency scales at each time base setting, see display 4

Here are some FFT Displays
  1. 500KHz Carrier
  2. 500KHz Carrier with 25Khz Modulation
  3. 500KHz Carrier with 25Khz Modulation at 1st Bessel Carrier Null

  4  Table of available frequency Scales at each Timebase setting,(scales per) + Max.Freq.

EDIT added Max Freq. to Table
EDIT added Anti-Aliasing comment to table
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