Rigol's New DHO800 Oscilloscope unbox & teardown

[Howardlong]

When I get mine I will do a teardown and schematic for the PSU make sure it's built right and help people fault finding in the future.

What's the point of it, if they are using an off-she-shelf PSU? They can always switch to the new supplier, equally if user doesn't like it, he can easily use whatever USB-C PSU he likes, of which there are thousands on a market. PSU is one thing I don't really care about in this scope due to it being so easily replaceable.

LiteOn do have a good reputation, they're often shipped with Intel NUCs for example.

One caveat about using your own third party PSU is that often the multi-outlet PD PSUs re-negotiate all ports whenever anything is plugged or unplugged. For a battery powered laptop or phone, this behaviour is relatively benign, but for a scope without battery backup the bahaviour will be a shutdown or restart.

[Martin72]

Great, my posts from yesterday went with in the split thread....
So again:
I want to see the signal quality of the LiteON power supply (ripple) without having to open the power supply.
So I ordered usb-c breakout boards, which I will put between the power supply and the scope and can then measure.
And implement the suggestion of TimFox and supply the rigol scope with a linear power supply (and see what happens in terms of noise on the reference signal for the probe alignment).
Nice side effect, I can then also check the accuracy of my usb-c powermeter.
Today the boards arrived, tomorrow will be tinkered.

[Serg65536]

TimFox and supply the rigol scope with a linear power supply

I'm using linear PS with my scope now. On a good old iron transformer. I can confirm 40-50 kHz switching spikes are gone.
It's important to get rid of switching power source completely, because of EMI and strong introduction of noise from the mains line.

[chris178]

Does anyone know if for cursor measurements one set of cursors can  be disabled?

I don't think so. You have to have all four enabled at once.

No X or Y, just both ?
 

I checked both the scope and the manual, it looks like only both.  But if it can handle, why not?  You can move the axis you don't want out of the screen until delta is 0, if it bothers you.  What I don't like is that there is no knob that can move both X1 and X2 or Y1 and Y2 at the same time once you have the delta fixed

Once you enable the cursors on the screen, the "cursor" measurement item shows in RHS "Result" pane.
If you tap on the "Cursors" item there a pop-up menu will show next to it with top option "settings".

You can select here with cursors are manual or tracking, etc. Also AX BX fixed reference can be locked here.
Press on knob 1 or 2 with toggle between active axis.

Hope this helps... this is not so obvious.

[chris178]

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.

Compared to our Siglent SDS2000X+, KS34465A and other instruments, the DHO814 screen is much dimmer, even in this image it shows, and it actual visual use much dimmer than on the image displayed. Trace brightness is not even close to Siglent trace brightness, which is set to just 52%.

The reflective screen makes this even more difficult for viewing. Just barely acceptable IMO, and will be a tad more difficult in a bright environment.

Best,

There is a way to change brightness with ADB. Current setting on mine out of factory was 209 over 255 (max).
However there isn't big difference between 209 and 255.. minor increase.

[asmi]

I used 16 MHz deliberately to illustrate point of very common signal (Arduino clock), being square wave, will have much larger frequency content of 16 MHz. This is common mistake with beginners, they buy 100 MHz BW scope to look at 50 MHz square wave because it is only 50 MHz, right.

Beginners buy 100 MHz scope to watch 50 MHz square waves because that's all they can afford. There is no mistake here. I would gladly buy a 9000 GHz scope if I could afford it, and so would vast majority of "beginners" (and non-beginners too).

[Fungus]

More realistically:

Beginners buy 100 MHz scope because that's all they can afford.

[Fungus]

There is a way to change brightness with ADB. Current setting on mine out of factory was 209 over 255 (max).
However there isn't big difference between 209 and 255.. minor increase.

Nope. That setting is only the brightness during boot. The system changes it to 255 when the main app starts.

[Fungus]

If you tap on the "Cursors" item there a pop-up menu will show next to it with top option "settings".

I hadn't seen that one yet... 

Measurements can also have visual "indicators" to show you where the measurements come from. Tap a measurement and select "indicator" to enable it.

eg. Vpp shows min/max.

[2N3055]

If you tap on the "Cursors" item there a pop-up menu will show next to it with top option "settings".

I hadn't seen that one yet... 

Measurements can also have visual "indicators" to show you where the measurements come from. Tap a measurement and select "indicator" to enable it.

eg. Vpp shows min/max.

Just a comment. Those are called measurements cursor's in other brands. Rigol has amusing policy to call same things differently than the rest of industry.  That is also sometimes a reason for confusion when we are asking "does it have this or that ?" questions.

Segmented memory -> Recording
Indicators -> Measurement cursors

We could make an dictionary for non Rigolians...

[ebastler]

Just a comment. Those are called measurements cursor's in other brands.
[...]
Indicators -> Measurement cursors

Is that so? Seems to me that the term "measurement cursor" is (also?) used to designate the cursors which you move interactively to take a measurement manually. I quite like the clearly different term "indicator" for the automatically positioned lines which show you where the scope has taken its automatic measurements.

[2N3055]

Just a comment. Those are called measurements cursor's in other brands.
[...]
Indicators -> Measurement cursors

Is that so? Seems to me that the term "measurement cursor" is (also?) used to designate the cursors which you move interactively to take a measurement manually. I quite like the clearly different term "indicator" for the automatically positioned lines which show you where the scope has taken its automatic measurements.

Usually: Manual / Tracking / Measurement

I'm not saying it is wrong. That is why I said just a comment...
It is not illogical. Just different...

[tautech]

KISS = Cursors.
Then menus provide what types.

[Serg65536]

Just a comment. Those are called measurements cursor's in other brands. Rigol has amusing policy to call same things differently than the rest of industry.

In the save window there is the "overlay" toggle. That should be "OVERWRITE", as common sense suggests! 

[2N3055]

Just a comment. Those are called measurements cursor's in other brands. Rigol has amusing policy to call same things differently than the rest of industry.

In the save window there is the "overlay" toggle. That should be "OVERWRITE", as common sense suggests! 

Yes thank you. That is what I was saying. Logically it makes sense, it is going to overlay file on top of existing one.
But that is not how it is usual to say it in English for that operation.

This also might be the language barrier.  Like when Chinese sellers on Ebay use word welding for soldering and welding.
Which is because in Chinese that is how they say it.

[chris178]

There is a way to change brightness with ADB. Current setting on mine out of factory was 209 over 255 (max).
However there isn't big difference between 209 and 255.. minor increase.

Nope. That setting is only the brightness during boot. The system changes it to 255 when the main app starts.

In my case ADB setting (settings put system screen_brightness 120) absolutely survives full device power cycle, including removing power source at the back.

I can confirm app's brightness adjustment during boot time in the sequence of high, lower then high again, but then finally it sets to what is configured with above command.
My preferred is 120.

[Martin72]

And implement the suggestion of TimFox and supply the rigol scope with a linear power supply (and see what happens in terms of noise on the reference signal for the probe alignment).

Not much...
The rigol supplied with a linear supply has not changed much regarding the ripple on "my" reference signal.
But at least I could look at the currents with a multimeter, the comparison with the usb powermeter will follow soon.

Voltage: 15.04V Current : 14mA (Scope in standby)
Voltage: 15.06V Current : 2.49A +/-60mA (Scope on)

[Fungus]

Also worth mentioning is that these things just don't seem to slow down.

Here I turned on three different FFTs (each one with a different window function), a math function and some tables and it was perfectly happy:

[iMo]

[Fungus]

Just a comment. Those are called measurements cursor's in other brands. Rigol has amusing policy to call same things differently than the rest of industry.  That is also sometimes a reason for confusion when we are asking "does it have this or that ?" questions.

No... these aren't cursor measurements. Cursors are things you turn on and move around by hand to measure things on screen.

These "indicators" move around automatically to show you where the measurement functions are getting their numbers from.

[tautech]

Just a comment. Those are called measurements cursor's in other brands. Rigol has amusing policy to call same things differently than the rest of industry.  That is also sometimes a reason for confusion when we are asking "does it have this or that ?" questions.

No... these aren't cursor measurements. Cursors are things you turn on and move around by hand to measure things on screen.

These "indicators" move around automatically to show you where the measurement functions are getting their numbers from.

Known in the industry as Tracking Cursors.

[kirill_maker]

Is there possibility to show freq like 4.43361875 Mhz, my dho804 only shows like rounded to 4.4444 - only 4 digits after dot

[ebastler]

Is there possibility to show freq like 4.43361875 Mhz, my dho804 only shows like rounded to 4.4444 - only 4 digits after dot

You can change the "resolution" in the Counter settings. The limit is 6 digits though.

[dmulligan]

Is there possibility to show freq like 4.43361875 Mhz, my dho804 only shows like rounded to 4.4444 - only 4 digits after dot

I don't have a signal source to test this.  Is the accuracy 4 decimal places or 100s of Hz?

Shouldn't it round 4.43361874 to 4.4336 using the round half up rounding method?

[Martin72]

Three pics, 3-digits(min), 4-digits(def)and 6-digits(max).
The adjusted frequency is 4.545672 Mhz...