Products > Test Equipment
REVIEW - Rigol DS2072 - First Impressions of the DS2000 series from Rigol
marmad:
--- Quote from: PA0PBZ on January 07, 2014, 06:35:15 pm ---
--- Quote from: marmad on January 07, 2014, 06:31:03 pm ---Sorry, but I'm not sure I buy this BW chart.
--- End quote ---
Atttached Excel sheet with the measurements.
--- End quote ---
Well, I believe you made measurements and a chart - but that doesn't mean it's accurate. ;) Hell, you had HighRes mode on - which is an averaging technique, and thus a filter - which would normally be the last thing you should do if trying to accurately measure bandwidth.
But, IMO, if your measurements ARE correct, I'd say Rigol made a mistake in redesigning their filter - and it makes me feel better about owning a HW v.1 ;D
PA0PBZ:
I just had hi res on for the other screenshots because I figured that EV had it on too (too many dots) in his original posting and I switched it off after taking the shots. Not sure what is going on, going to test my sig gen now ;)
EV:
I got explanation to this from TEK Forum:
"When at 400ns/div or faster horizontal time base, the sample rate is maxed at 2.5GS/s. To overcome the max sample rate, the instrument goes into real time interpolate mode and mathematically adds points depending upon the horizontal time/div setting. What you are seeing are the interpolated points, not actual samples."
--- Quote from: marmad on December 26, 2013, 01:56:24 pm ---
--- Quote from: EV on December 26, 2013, 11:43:29 am ---My old TEK TDS3032 has 2.5 GS/s and 5 samples per division with 1 ns time base. It is so regardlss whether both or only one channel is on.
--- End quote ---
But that doesn't make sense mathematically. If 2.5GSa/s is the maximum rate, 400ps is the smallest sample period. That would be 2.5 samples per div @ 1ns. 5 samples per div would require a 5GSa/s rate (200ps sample).
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marmad:
--- Quote from: PA0PBZ on January 07, 2014, 06:45:29 pm ---I just had hi res on for the other screenshots because I figured that EV had it on too (too many dots) in his original posting and I switched it off after taking the shots.
--- End quote ---
Ok, sorry, my mistake. :)
Again, I have no problem if the -3dB BW is up around 350MHz - but the rolloff according to your chart is so slow I think problems could arise with signal reconstruction.
Compare it to the rolloffs in the two bandwidth charts posted on this page.
--- Quote from: EV on January 07, 2014, 06:48:36 pm ---"...and mathematically adds points depending upon the horizontal time/div setting. What you are seeing are the interpolated points, not actual samples."
--- End quote ---
Which is basically what the Rigol is doing in HighRes mode below a certain time base.
Carrington:
--- Quote from: EV on January 07, 2014, 06:48:36 pm ---I got explanation to this from TEK Forum:
"When at 400ns/div or faster horizontal time base, the sample rate is maxed at 2.5GS/s. To overcome the max sample rate, the instrument goes into real time interpolate mode and mathematically adds points depending upon the horizontal time/div setting. What you are seeing are the interpolated points, not actual samples."
--- End quote ---
--- Quote from: Carrington on December 28, 2013, 07:25:18 pm ---A few days ago someone mention something about a Tek oscilloscope that in dots mode showed more samples than should be.
It's not magic, are interpolated (maths).
--- End quote ---
https://www.eevblog.com/forum/testgear/sniffing-the-rigol%27s-internal-i2c-bus/msg355318/#msg355318
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