Rigol DS1102E Bandwidth problem
Rigol DS1102E іѕ 100MHz bandwidth DSO, bυt wе find wһеח I input tһе 100MHz sinwave bу Fluke 5820A (600MHz Oscilloscope calibrator ) tο check tһаt -3dB bandwidth, іt іѕ very crazy wһеח I turning DS1102E dual channel ON! AƖѕο I find іח dual channel ON wіtһ LONG memory mode tһаt crazy performance іѕ difficult tο identify
Hello
Thank you for your post.
I am trying to decide between 2 brands of oscilloscope:
Owon & Rigol
I think Rigol has the stronger brand and I can’t beat the 1G/sec RTS but . . .
a few features come at a lower price for the Owon – the bigest I’m looking at is the VGA screen.
Since Rigol hasn’t bothered with VGA (QVGA even in their high end) should I care about this feature?
Or is it a gimmick for this type of application?
Thanks! Appreciate anyone’s info that knows!
Checked, when turn on dual channel that sample rate will drop to half by one channel, but still unclear what design to effect bandwidth performance
sorry,command :ACQuire:SAMPlingrate?
And plz check up the actual samplingrate to command through terminal.like :ACQuire*SAMPlingrate?,sometimes your actual sampling rate is 200MHz.Thanks.
Hi.I can’t understand your language,but lookin at your measurement.I think,a bit problem though,maybe at least you cut off DC,and sampling change to Average,and repetitive sampling(Equivalant-Time),and disable CH2.If you do,at least maybe also 100MHz level is within 3dB attenuation.Thanks.
RTFM
Good job. I think we all know now, and you’ve made clear, that the Rigol 1102E and 1052E have the same sampling rates and memory length. The input bandwidth limit is only for the analog front end, but it doesn’t improve the scopes capability near the limit of its sampling capability. When you switched on Channel 2, the 1102E uses 500Ms/s, on long memory, its 250 Ms/s.
rigol made in china
I very much agree with your think, but the ADC is on the internal, who will open the DSO to check when they bought it
I very much agree with your idea, but the internal ADC is on the machine, who will open the view of the machine when he bought the machine
According to the specs for this model, the ADCs are staggered to achieve the 1GSa/s sample rate. This is only available in 1-channel mode. Using two input channels halves the sample rate. I believe long memory also halves it again, due to the memory chip limitations.
@InstrumentVu
Sorry I have difficulty understanding this phrase “however I never forget this terminal from the film you can be seen them.” Could you please elaborate it a bit more?
Thanks for the video btw. It gives a much better insight to the equipment.
The specs are clear. 1G samples/s, half of that in dual channel mode, half of that in long memory mode. If your life or your livelihood depends on a tool, in this case an oscilloscope, why would you buy one not aimed at the pro market? Hell, you could almost buy 3 of these scopes for the price of that function generator!
That’s not (analog) bandwidth problem but sample rate problem. When you set scope in 2 channel mode and turn on long memory, sample rate drops to 250Ms/s.
So you can accept a 100MHz oscilloscope bandwidth drop to 4xMH because the sampling rate issue?Because the relationship of my job, personally I can not accept this kind of specification
Sorry, but this doesn’t prove there is any problem with the DSO. If you set the controls so the internal digitiser is running at a lower speed than 1Ghz (yes, it’s easy to do, read the manual for any DSO) you will get crazy alias problems. Any DSO can be made to show rubbish if you force it to display an aliased waveform. The demonstration may be straight up, but it could also be fudged to make the scope look bad. Without more information we cannot tell.
I’m totally agree with you about samplin speed limitation by ADC performance.
May be DS1000E sampling rate drop to 250MS/s in high speed time/div, cause some siganl peak can not to detect, but I can not acceptable because the impact of sampling rate of decline and than impact that performance of the bandwidth(BW out of spec.)
If you turn on long Memory, it’s 500Ms/s when one Channel is on. I don’t know what’s happening if you switch the second on, maybe it’s only half, 250Ms/s. I have seen on your video, that when you turn off sinx/x, the peaks have a distance of 4ns, seem to be 250Ms/s.
The Digital-Sampling Rate Limitation is caused by the AD-Converters. They have more than one, and they switch theme together, using Phase-shift clocking, to get 1GS/s. If you turn the 2nd Channel on, one half of the ADC’S are used for the 1st Channel, the secound half for 2nd Channel.
Last I just turing OFF that Interpolation function, I’m also very surprised I’m get such a result.
If there are any place I have not noticed, please tell me any time, thanks la.
You are right! It is key issue about 50ohm terminting, 50 Ohm, however I never forget this terminal from the film you can be seen them.
In thehe past, I’ve tested a lot of Oscilloscopes, I know that sampling rate have an some different change in the number of channel turing on on the some oscilloscope, but I have never seen bandwidth will have drop when I turing on that multi-channel, it’s look like very strange.
1)Why are you not Terminating the End with the Riglo-Sycope with 50 Ohm’s? Rigol does not have a switchable Termination, unlike Scopes like the Tek 7xxx Series, etc..
2) In lack of Memory Speed, it seems to switch down to a samplerate, matching the max. Mem. speed. That seem to be 500Ms/s.
3) I NEVER use any digital filter when Measuring. I would never do that, even on a Tek 7xxx Scope. With a filter you can’t see Aliasing effects. If I need a Filter I use scilab afterwards.