Does the DS2072 have a bandwidth filter? - Page 1
Forum section: electronics / testgear

author: alank2
author_rank: Super Contributor
timestamp: March 31, 2014, 12:13:18 am
content: Hi,I remember another Rigol scope I have that had an electronic filter so you could pass a certain frequency or block based on your own settings. Does the DS2072 have this too? I'm not talking about the channel 20M/100M filter, but another one where you could say the type of filter such as above, below, notch, and then set parameters for it...Thanks,Alan

author: Mark_O
author_rank: Frequent Contributor
timestamp: March 31, 2014, 12:56:24 am
content: Quote from: alank2 on March 31, 2014, 12:13:18 amNo. The 4 parametric digital filters on the older 1000C/D/E/CD scopes: LPF, HPF, BPF, BRF, are not available on the next-gen flagship DS6000 scopes, or any of the models it spawned: 4000, 2000, or 1000Z.That went away, along with ET sampling, and dual, independent time-bases.

author: tom66
author_rank: Super Contributor
timestamp: March 31, 2014, 01:18:30 am
content: The DS1000Z has dual timebases and equivalent time sampling.... but no digital filter. I don't particularly miss it, but it was useful now and then; I expect it didn't work well with the FPGA driven phosphor engine (as the CPU would have to step in for each of the ~30,000 wfm/s.)

author: Mark_O
author_rank: Frequent Contributor
timestamp: March 31, 2014, 04:36:15 am
content: Quote from: tom66 on March 31, 2014, 01:18:30 amFascinating!Since you have a DS1074Z and I don't, I'd appreciate it if you could direct me to the section of the manual that describes these functions. From my reading, there is no alternate time-base capability, nor can it sample any higher than it's real-time sampling rate allows. I must have missed something, or Rigol failed to document it.

author: tom66
author_rank: Super Contributor
timestamp: March 31, 2014, 01:07:52 pm
content: Quote from: Mark_O on March 31, 2014, 04:36:15 amAlternate - no. Delayed/Dual - yes: press to zoom on the horizontal knob, and you do get two separate timebases. Not used it much though. The dual appear to be sampled separately (one after another.)Equivalent time sampling is easily visible in this image. You can see that the waveform is sampling faster than 1GSa/s for repetitive signals. (Or in this example 500MSa/s over two channels.) Each dot is every real time sample, you can see if persistence is on, the equ-sampling is visible.I have not read the manual in detail. It's pretty intuitive to use.

author: Mark_O
author_rank: Frequent Contributor
timestamp: April 01, 2014, 11:08:11 pm
content: Quote from: tom66 on March 31, 2014, 01:07:52 pmNot really. The Delayed Sweep you're referring to is nothing more than a second zoomed segment of the original trace. And it's not sampled separately, as you think. That's not what I was originally talking about, which the DS1xxxE has, but the new scopes lack.QuoteI disagree. That's not ET sampling at all. Clearly there is just one sample every 2 ns. The cluster (blur) around dots you're seeing has nothing to do with multisampling with an offset sample time (as is done in ET mode), but simply reflects the instability (or jitter) in the source and the sampler in the Rigol.And BTW, real ET mode doesn't require persistence to be turned on. Persistence will always make it look like the sample rate is higher than it is, because it's accumulating samples from many passes. And if the sync was solid, with no jitter, what you'd see would be small dots, increasing in intensity (and perhaps blooming a bit), but still,no dots in betweenthose 2 ns sample points.