Dave's video is about measurement and connection to other electrical appliances, and what can happen.
When Rigol DS2072 is not grounded, it have 115 Volt (or 230 Volt) on chassis and also on probe tip.
Completely without being connected to other equipment.
All my old analog oscilloscopes I have had, do not have 230 V out on Chassis ground, and also on probe tip. And all other electrical instruments I have do not have it.
Rigol DS2072 must be bad isolated from main power(230V).
Are other digital oscilloscope brands also poorly insulated ?
Of course, it is best to ground.
So I just did a few checks. From measureing the mains input socket with an LCR meter, there's a common mode filter with 4.7nf caps between N-G and A-G. There's no blead resistance across the caps and ground (I am not saying there should be.)
So under controlled conditions I removed a ground, powered it up, and got what you described. This is as to be expected, the 4.7nf caps are forming a voltage divider to earth at the input CM filter, and so earth is now half way between neutral and active potentials. In Oz, with a 240V active and neutral at close enough to ground, this gives ~ 120VACrms on the jacks.
Shorting this to ground gives a current of 338uArms, which if you work out 1/(2*pi*f*C) on 4.7nf, and divide 240Vrms by it, you’ll get exactly that.
It’s got nothing at all to do with insulation, it’s designed that way to remove mains line noise (and vice versa.) So just operate it with a ground and you’ll be fine.
When Rigol DS2072 is not grounded, it have 115 Volt (or 230 Volt) on chassis and also on probe tip.
Completely without being connected to other equipment.
All my old analog oscilloscopes I have had, do not have 230 V out on Chassis ground, and also on probe tip. And all other electrical instruments I have do not have it.
I returned the Rigol DS2072, maybe I should buy it again.
When Rigol DS2072 is not grounded, it have 115 Volt (or 230 Volt) on chassis and also on probe tip.
Completely without being connected to other equipment.
All my old analog oscilloscopes I have had, do not have 230 V out on Chassis ground, and also on probe tip. And all other electrical instruments I have do not have it.
Do the other instruments have:
"WARNING: MAINTAIN GROUND TO AVOID ELECTRIC SHOCK"
engraved in large letters on them?
Grounding was in the past for extra protection.
Now, it is obviously necessary.
As I have said before, in Denmark we were first grounding in new houses about 1995 (in wet room before). I would have been happy for a digital oscilloscope, who absolutely not have to be grounded.
I returned the Rigol DS2072, maybe I should buy it again.I hope it didn't cost you anything to return it!
Grounding was in the past for extra protection.
Now, it is obviously necessary.
As I have said before, in Denmark we were first grounding in new houses about 1995 (in wet room before). I would have been happy for a digital oscilloscope, who absolutely not have to be grounded.
Regardless of wiring in Danish houses, any electronics operated from switching power supplies need to be grounded - and always have. I noticed back in 1988 when I ran my PC without a ground connection that there was 110-120V potential on the metal case.
I thought the display is cleared after each trace in normal mode ?
they will appear simultaneously on the display with a minimum decay time (or longer - if you have persistence set higher) - and WAITING for a trigger freezes the 'decay'. You were set to AUTO MemDepth @ 100ns - which means up to 16,790 waveforms per second. This is actually advantageous - and helps spot multiple triggers and glitches.
When on 20 nSec timebase:
and input of a signal of 10 Mhz i get 41.000 WFM/sec
but when change input to 60 Mhz it drops to 22.000 WFM/sec
On 1uS timbase:
and input of 1 Mhz, i get 2.900 WFM/s
but with 10 Mhz it drops to 1.900 WFM/s
On 20 nSec timebase:
and 1 Mhz i get 46.000 WFM/s but change timebase to fine and 20.05 nSec it drops to 5.000 WFM/s
How does that fit in your explanation video about WFM/s, i dont get it.
Or if someone could post just ONE 'before/after' example of it actually 'minimizing' aliasing, I would be happy
I've only seen AA produce an improvement in cases where the scope was displaying low intensity. So if you have dim traces, or a dim swath, turning on AA may add detail. In the first normal acquisition images, you see that the vertical portions of the traces got more intense and easier to follow with the eye. But this isn't a typical aliasing case of undersampling the waveform. I don't know why the trace was so dim to start with. Even at 185us with exactly 4 periods displayed, the wave (in dots) was still pretty dim and wide. At 100us, it looks correct, and with AA turned on in 185us, it looks correct. Is this another kind of aliasing?
The last two images were the only ones I came up with where it looked like AA actually reduced acquisition aliasing. That's a 15.555555MHz signal.
I'm not sure if the DS6000 Demo Board has been mentioned before on EEVBlog or not (a quick search didn't turn up anything), but I found it at Batronix while searching for any possible new UltraVision products - and I hadn't seen it before and thought it was kind of interesting. It lists at €163 / $225 (excl.), and I've attached the user guide below.
"This Demo board is used to illustrate the basic functions of the oscilloscope. It is powered through USB port and can output 25 kinds of signals for the illustration of oscilloscope functions, i.e. sine, video (PAL/NTSC), AM Modulation, Sweeps, many digital signals and lots more. Delivery including Demo Board, USB Cable, CD with manual."
It's got the Instek one beat - Instek demo board only does 10 analog and 5 digital/LA functions for $205 list (so probably about $185 discounted).
I might have to get me one of these to play around with.
Those test point "hoops" on that demo board look neat. Has anyone seen those for sale?
Those test point "hoops" on that demo board look neat. Has anyone seen those for sale?Well, in the original post I made (which you can see in the quoted area above), I mentioned I found the device (and images) at Batronix(.com) in Germany.
Here's the data sheet.
Seriously though, if you want to do any more playing around, I would strongly suggest that you don't use 14M or 56M sample lengths - since traditionally, one of the tools to battle against aliasing is to increase sample length (since that automatically increases sample rates and/or samples being decimated for the display). If anti-aliasing works at all on the Rigol, it should first and foremost be working when you have small sample lengths - so that switching it on might (in the background) automatically force the DSO to capture more samples for random decimation (or change sample speeds) in order to prevent the occurrence of the aliased waveform.
http://www.batronix.com/shop/oscilloscopes/Rigol-DS2202.html
Click accessories!
http://www.batronix.com/shop/oscilloscopes/Rigol-DS4022.html
Click accessories!
Thanks to everyone for the plethora of good information, bugs, comparisons, quirks... It makes purchasing one of these a much more transparent process. Especially to a noob like me considering a first scope.