Analog channel: 1 GSa/s (single-channel),
500 MSa/s (dual-channel), 250 MSa/s (three/four-channel)
and simillar goes for memory depth. more channels=less bandw. and memory depth.https://www.eevblog.com/forum/testgear/new-rigol-ds1054z-oscilloscope/?action=dlattach;attach=112665
in img tags)Has anyone here actually proof that the DS1104Z can not do 100 MHz on all 4 channels at same time?
For me the analog frontend should just limit the max. frequency to make sure that there is no conflict with the corresponding ADC specs
and that it can sample at it's highest rate (without fear of aliasing) that XX MHz with all N channels ON. The DS1104Z can not - period.
But with all 4 channels on, 250MSa/s, Nyquist is still 125 MHz, right? Am I missing something?
Has anyone here actually proof that the DS1104Z can not do 100 MHz on all 4 channels at same time?
Or are the speculations just that it can not, because it is supposed to have no fancy anti-aliasing filter or whatever it might be called?
For me the analog frontend should just limit the max. frequency to make sure that there is no conflict with the corresponding ADC specs (sample rate) in the path beyond,
and my understanding is that a 100 MHz scope has proper filtering by default to take care of this requirement in combination with > 200 MS/s ADC.
100 MHz scope == proper filter in the analog frontend to limit max. frequency to 100 MHz, period.
Isn't the anti-aliasing filter just a band pass filter?
How complex can that be?
Mark_O: can't one just turn off the other channels to check how the signal looks in one channel mode if you get a feeling something might be off? Then if you have confirmed it, you can safely turn on the rest of the channels knowing that what you see is the accual signal. Of course, this assmums that one is triggering off the channel in question.
Would there be any accual problems going about it this way?
P.S. I know that that would be a hassel and I'm not saying it's convenient. Nor am I saying I understand this stuff all that well, it's just an idea I got while reading the previous comments.
What about the other Rigol series, and their reliable bandwidth?
For the Rigol DS1104Z: ALL 4 channels, 25 MHz is reliable bandwidth.
For the Rigol DS2302A: ALL 2 channels, what is the reliable bandwidth?
But even when you are only debugging 25 MHz designs with this scope, you will still have the risk of higher frequencies right? I mean, even if you use it as a 25 MHz scope, there could be higher frequencies that give false readings? Or do I miss understand here?
For the Rigol DS2302A: ALL 2 channels, what is the reliable bandwidth?
But even when you are only debugging 25 MHz designs with this scope, you will still have the risk of higher frequencies right? I mean, even if you use it as a 25 MHz scope, there could be higher frequencies that give false readings? Or do I miss understand here?No, you are correct - but in general, you shouldn't be attempting to measure signals that contain such high frequncy components (just as, for example, you wouldn't want to be measuring the same signals with only 1 channel on, but a sampling rate of 250MSa/s due to your time base/memory depth settings).
Another option would be to enable the 20MHz bandwidth limiter of each channel when using 3 or 4 channels. The DS1000Z appears to be using AD5207s for gain adjustment of the amplifiers in the front end - and I'm assuming that they apply the bandwidth limiting there.
sorry .. I just had to chuckle. I own several Tektronix 2465B's that will do 4-channel and 400 Mhz acquisitions in their sleep!
With four channels on the DS1054Z might be a better scope than the DS1104Z because it has a much harder cutoff filter (above 50MHz).
as far as the screen size, it's amazing how much great engineering was accomplished with the eye-strain and mental anguish caused by staring at a small CRT.
rehashing the analog versus digital oscilloscope comparison is ... sophomoric at best.
I was reacting to what $400 can buy if you need high-bandwidth and multiple channels, and relaxed triggering requirements.
perhaps I simply felt that after 23 pages, this thread could use an injection of analog humor.
as far as the screen size, it's amazing how much great engineering was accomplished with the eye-strain and mental anguish caused by staring at a small CRT.
I seem to remember having no problems at all staring at my Tek 465 all day and night.
W7NGA, can you do a single shot 400MHz on 4 channels with your Tektronix 2465B? The answer is no.
This is comparing apples and pears.
As my aim was to free it from its chains i thought I should test it's performance before and after applying the upgrade. The result surprised me!
To me it seems that at least my sample of the DS1054Z was not bandwidth limited to 50 MHZ out of the box.
...that implies that it's BW frequency response is at least XX at -3db - and that it can sample at it's highest rate (without fear of aliasing) that XX MHz with all N channels ON. The DS1104Z can not - period. Since it does not adhere to these normal expectations, this would be no different than breaking one of the other implied specifications: e.g. that a 300MHz DSO has a 450MHz BW (even though that BW is at -9db).
Does anybody know if the DS1104Z supports ETS (Equivalent Time Sampling)?