Rigol's New DHO800 Oscilloscope unbox & teardown

[ozkarah]

Today I received my DHO804 and found a weird problem.

When the vertical range is set to something <=50mV/div and the signal amplitude is more than 1V signal gets distorted.

To test it:
 1- Connect your probe to the test signal generator on the right bottom side of your scope
 2- Set channel coupling to DC
 3- Set vertical sensitivity to 100mV/div. In this case, you should see the bottom of the signal fits to 0 volts correctly. (check first picture)
 4- Now set vertical sensitivity to 50mV/div. In my scope signal is distorted and shows values below 0 volts. (check second picture)


 


 



I also took a video of the problem:

https://youtu.be/2cCnPJAncJQ




Could you please check if the problem also exists in your device?

PS: Installing last firmware and self calibration didn't change anything.
 

[Fungus]

Today I received my DHO804 and found a weird problem.

Could you please check if the problem also exists in your device?

That's just the op-amps recovering after an overload, perfectly normal.

(In fact that's very little distortion compared to some others, but maybe you need to go further off screen, try setting it to 1mV/div and see what happens)

Here it is on a Rigol DS1040Z: https://www.eevblog.com/forum/testgear/ds1054z-distortion-issue/

Here it is on a Siglent: https://www.eevblog.com/forum/testgear/siglent-sds1104x-e-anomaly-on-what-should-be-a-simple-task/

etc.

[Fungus]

Mine arrived!

First impressions:

It feels really solid. I was expecting it to be lightweight but nope, not at all.

I like the color. I think the black one will be worse.

The fan isn't what you'd call loud but it has a definite frequency (150Hz-ish), not white noise.

It definitely smells of "new oscilloscope". Not a lot, but enough that I hope it goes away with time. I'm gonna store it somewhere warm/ventilated when it's not in use, let's see if it fades.

The probes have two springs each in the little accessory bag.

Auto mode is FAST - fast enough that I might actually use it.

The screen is bright. The illusion the the UI is supernaturally high-resolution is real.

Text is small but very readable.

Self cal worked. 

It has a full diagnostics suite to test the screen, all the buttons on the front panel, etc,

There's an option "input lock" in the utility menu that disables all user input until you read the manual to find out the secret.   

Now I'm trying the firmware upgrade... and failing. It recognizes the USB stick but says "No firmware available".

[csuhi17]

do you think there is any chance that the contents of the external display and the internal display will be different?  Software or hardware limitation?

[Fungus]

do you think there is any chance that the contents of the external display and the internal display will be different?

No.

Software or hardware limitation?

It's not hardware - external displays are rendered at the native resolution of whatever screen you connect, it's not just an upscaled image.

[tv84]

Mine arrived!

There goes the neighborhood! 

Eager to read an unbiased hands-on review.

[Fungus]

Eager to read an unbiased hands-on review.

I'm still deciding if I need my own thread. Everybody else seems to have one.

[TK]

Is the AWG output 50ohms?  This is what I get using a direct BNC cable, no 50ohm termination.  Signal gets halved if I add a 50ohm termination.

[tv84]

I'm still deciding if I need my own thread. Everybody else seems to have one.

Since this is at the "singularity event" level, I would suggest creating your own thread. 

[mawyatt]

Mine arrived!

There goes the neighborhood! 

Eager to read an unbiased hands-on review.

We got a DHO814 on 10/12/23, so had a few minutes to play around with it.

First impressions;

Nice shipping packaging, custom fitted.
Nice, small, somewhat heavy, seems like quality build.
Support feet work OK for thin small case.
Nice screen, but dim.
Display looks nice, readable.
Touchscreen works OK considering screen size.
Works with wireless mouse.
Waveform noise levels are good.
General waveform display and triggering seem to work as expected.
UI seems decent, but need much more time to evaluate properly.

Fan is sorta annoying, not too loud tho.
Plastic smell, hopefully will dispense.
FFT implementation is questionable/awkward, altho haven't spent much time, hopefully experience will improve with familiarity.

So 1st impressions are: overall hardware is very well done, UI/software/features yet to be determined (neutral so far, but limited use time).

So far, looks like it will fit our intended specialized purpose.

More later.

Best,

 

[TK]

Fan is sorta annoying, not too loud tho.

I have the DHO914S and fan is not loud at all, I had all DHO914S, DHO4024 and HDO1074 on and the loudest one was the DHO4024. 

[Fungus]

Touchscreen works OK considering screen size.

Yep. UI elements are very small but I haven't had any problems at all hitting the little X to close a window or in dragging things around.

It really seems to figure out what you're trying to do.

[TimFox]

My fingers are a bit fat for the screen, but a normal stylus designed for touchscreens works well for me on the selections from screen.

[Fungus]

Fan is sorta annoying, not too loud tho.

I have the DHO914S and fan is not loud at all

Mine's been on all day and it hasn't annoyed me as much as I thought it would.

Doesn't mean I'm not going to try and make it quieter though...

Nice screen, but dim.

Mine seems plenty bright enough but I guess it depends on your ambient lighting.

I haven't found a brightness control anywhere.

[Fungus]

The front panel has some nice-but-impossible-to-photograph lighting.

I think the blue of button 4 is outside the sRGB spectrum, ie. no monitor will display it. You can sort of see it projected on the panel in the dark insert, but... not really.

The pink/magenta of button 3 doesn't really come out either. You'll just have to get your own DHO to see them in person. 



The trigger slope has cute LED indicators for slope which are a bit pointless (it's shown on screen). The TWO twisty knobs have LED indicators to show if they're currently adjusting horizontal or vertical things (eg. cursors) - very nice!

[ebastler]

The front panel has some nice-but-impossible-to-photograph lighting.

When photographed like that, it does remind me a bit of gaming keyboards. Can you select different color and animation patterns? 

Given Dave's review comment that he struggled to see the indicators on the function knobs and trigger mode (under his rather bright studio lights) I assume the button illumination is bright enough to be seen, but not so bright as to become obtrusive, in typical room lighting?

[Serg65536]

Rigol DHO800 waveform update freezing bug
This bug occurs at a horizontal scale of 200 ms per division and above, when you set the trigger position to the time before the capture starts.
Setting the trigger some time before the capture is used widely to debug large signal sequences. By moving the trigger position, you can study the whole signal in small portions.
Firmware version 1.00
https://youtu.be/FyM5jibkgfE

[Serg65536]

Today I received my DHO804 and found a weird problem.

There are a lot of problems with the oscilloscope. Please, check out my channel to be aware of the major ones:
https://www.youtube.com/@sergivaschenko

[mawyatt]

This puppy gets kinda warm after awhile!!

Anyone know how to change the HDMI resolution for external monitor? Also, if an external HDMI touch screen works (touch part)?

Best,

[Fungus]

The front panel has some nice-but-impossible-to-photograph lighting.

When photographed like that, it does remind me a bit of gaming keyboards. Can you select different color and animation patterns? 

I can animate the big green one to red by pressing it. See below.

Given Dave's review comment that he struggled to see the indicators on the function knobs and trigger mode (under his rather bright studio lights) I assume the button illumination is bright enough to be seen, but not so bright as to become obtrusive, in typical room lighting?

The function indicator lights aren't very bright but they're not much dimmer than the screen. If you can see the screen you should be able to see them.


The buttons are much brighter than the screen, especially the big RUN/STOP button (which must have two or three LEDs underneath it). 

I haven't found them obtrusive though because they're soft, diffused colors. Not shining in your eyes.

YMMV.

Maybe they might be obtrusive if you fixate on them after reading this post...   

[UK]

This puppy gets kinda warm after awhile!!

Anyone know how to change the HDMI resolution for external monitor? Also, if an external HDMI touch screen works (touch part)?

Best,

Try this

"Test Mode" (by pressing 3 times the Utility->About menu item)

--------

This puppy gets kinda warm after awhile!!

Anyone know how to change the HDMI resolution for external monitor? Also, if an external HDMI touch screen works (touch part)?

Best,

Yep, David demonstrated that on its second channel.

[Fungus]

Also, if an external HDMI touch screen works (touch part)?

Most touch screens have a USB output that emulates a mouse when you touch them.

If yours does that then you just connect it to the USB port on the 'scope and it'll work.

[Fungus]

This puppy gets kinda warm after awhile!!

Anyone know how to change the HDMI resolution for external monitor?

Try this

"Test Mode" (by pressing 3 times the Utility->About menu item)

--------

Then go to "other":


It might not be very usable at 640x480 but give it a go and see what happens. 

nb. I think it detected/used the monitor's native resolution in Dave's video when he didn't set it explicitly.

[Mechatrommer]

The front panel has some nice-but-impossible-to-photograph lighting.
I think the blue of button 4 is outside the sRGB spectrum, ie. no monitor will display it. You can sort of see it projected on the panel in the dark insert, but... not really.
The pink/magenta of button 3 doesn't really come out either. You'll just have to get your own DHO to see them in person. 

what nonsense are you talking about? how do you know its not in sRGB spectrum? monitor gamut alone (differ between brands) is already different from camera sensor's or human eye's gamut. how do you measure? do you have speculumeter? https://en.wikipedia.org/wiki/SRGB my dho804's lighting is good, nothing to complaint about, its relativistic actually...

btw, trying to compare FFT output between DS1054Z and DHO804, there is hope for lower SNR on 12bit scope ymmv...

[JOSM]

Does anyone know if for cursor measurements one set of cursors can  be disabled?
For example I want to measure timing and don't want to see the vertical cursors. I know that I could move them to the window borders but then they are still visible.
If I am not overlooking something, the manual does not mention an option to do so. If I am not proven wrong then I could post this as a feature request to Rigol.