New toy(?) scope Fnirsi DPOX180H, claimed 180MHz/500MSps (May 2023)

[rhb]

The Owon HDS272S delivers the promised 70 MHz -3 dB point, but is usable much higher.  And the FW is much better than the analogous Hantek.  UI is everything when you make it small.

[RAPo]

I cannot replicate the measurement, even with probe attenuation=100x 

[Aldo22]

[RAPo]

Hi RAPo

And what is the bandwidth according to your measurement?
Just the point where Pk-Pk falls below -3 dB (0.707) compared to, say, 100kHz?

I'm a bit busy. I will need to get my TinySA Ultra for reliable testing. See PSG908/FY6900 testing.xlsx for preliminary results. 

[RAPo]

Mailed Fnirsi and asked for a firmware update regarding the cursors.

Fnirsi responded within one day: results are sen d to their engineers. They will respond back within a few days.

While on the topic, I asked for some "enhancements":

Could a long press CH1/CH2 button enable/disable the signal?
Could a double click on CH1/CH2 button enable/disable the bandwidth filter?
Could a long press on the trigger button cycle through the trigger modes?
Could a long press on the orig-button cycle through the coupling mode of the active channel?

[IconicPCB]

Is the signal generator ground independent of scope ground? ( galvanically isolated)?

[Aldo22]

Some people complain that you don't see vertical lines with square waves.
What do you think?
Bug or feature?

[RAPo]

I've just finished some discussion with Fnirsi. On the good side: they respond quickly, and are really looking into things.
But the cursor problem took a strange turn.
On my question the V1 and V2 measure, I got as the answer:

V1 and V2 are the voltage cursors of channel 1 and channel 2, respectively to distinguish

Presenting evidence that this cannot be right (see images), the response was:

The measurement principle of the cursor is to measure according to the vertical sensitivity of the channel.
Therefore, when measuring, it is necessary to measure the voltage cursor of the channel separately to obtain an accurate value.
V1V2 is the vertical sensitivity set according to channel one and channel two; to measure the voltage value of the range selected by the cursor

.

I'm giving up on this scope and bought a Zeeweii DSO2512G.

[RAPo]

Some people complain that you don't see vertical lines with square waves.
What do you think?
Bug or feature?

I consider it a bug implemented as a feature

[Aldo22]

I'm giving up on this scope and bought a Zeeweii DSO2512G.

The DSO2512G is probably not better overall, but definitely cheaper.
Good luck!

[Aldo22]

Some people complain that you don't see vertical lines with square waves.
What do you think?
Bug or feature?

I consider it a bug implemented as a feature

On the other hand, with "Digital Phosphor" they seem to be trying to imitate a CRO and they apparently showed square waves like that.

[vk6zgo]

Some people complain that you don't see vertical lines with square waves.
What do you think?
Bug or feature?

& it becomes more visible.I consider it a bug implemented as a feature

On the other hand, with "Digital Phosphor" they seem to be trying to imitate a CRO and they apparently showed square waves like that.

Not really, analog 'scopes all displayed the rise & fall of square wave signals.
Because the beam was more briefly in any discrete point during such transitions, the display was less bright than the top & bottom "flat" bits of the waveform but wind up the intensity, & it becomes more visible.

[Aldo22]

Presenting evidence that this cannot be right (see images), the response was:

I'm not quite sure if I understand you.
I believe the DPOX180H simply displays the difference between the dashed lines in relation to the respective vertical sensitivity (V1 Ch#1, V2 Ch#2).
It doesn't show absolute levels afaics (Like Y1, Y2 with the Zeeweii).
This is strange, but not directly a bug imo.

The DSO2512G displays the two absolute values Y1, Y2 and the difference dY in relation to the vertical sensitivity setting of the selected channel.
If you want to see the values in relation to the vertical sensitivity setting of the second channel, you can switch the channel priority. The values are then displayed in green.

[RAPo]

The statement from Fnirsi was: V1 and V2 are the voltage cursors of channel 1 and channel 2, respectively to distinguish.

In the image below, both channels are turned on and have the same sensitivity.
Turning the cursor *measurement* on, you see two different green dashed lines.
Both V1 and V2 have the same value. Moving one of the green lines, both values V1 and V2 change. Why on earth would you need that?

[Aldo22]

The statement from Fnirsi was: V1 and V2 are the voltage cursors of channel 1 and channel 2, respectively to distinguish.

In the image below, both channels are turned on and have the same sensitivity.
Turning the cursor *measurement* on, you see two different green dashed lines.
Both V1 and V2 have the same value. Moving one of the green lines, both values V1 and V2 change. Why on earth would you need that?

Yes, it's the same 'Delta' as dY on the DSO2512G, but it is displayed for both channels at the same time.
If both channels have the same vertical sensitivity, the same value is displayed twice.
That's why you see 4.04V and 808mV on your other picture, because 1V is set on the 1st channel and 200mV on the 2nd channel.
I don't like that the absolute levels are missing, but it's not really a bug imho. It's a feature! 

[RAPo]

but why is moving one cursor line to show a difference in both V1 and V2?

[Aldo22]

but why is moving one cursor line to show a difference in both V1 and V2?

Because it shows basically the same thing twice. Once in the vertical sensitivity of Ch1 and once in the vertical sensitivity of Ch2.

You probably expect these values (V1 and V2) to say something about the position of the dotted lines, but they don't!
They only show the difference between the dotted lines in the respective unit of Ch1 and Ch2.

Compared to the ZEEWEII DSO2512G, they only show dY, not Y1/Y2

[RAPo]

and why would you need that?

[coromonadalix]

gonna laugh at all this

people ask thoses little thingys a lot, you want good scope performance at this size

i would say lots of falses claims / specs  etc ...  you have to get prices cuts somewhere ?

but if Fnirsi  respond  and they are taking comments  i'll say its good for them and users

[Aldo22]

and why would you need that?

I don't know exactly. I don't like it either, but I get what it does.
If this is a bug, it's at the user interface level ("bad decision"), not necessarily in the implementation.

[RAPo]

Yes, they do reply, are looking into the things and that is a good thing.

[RAPo]

I don't know exactly. I don't like it either, but I get what it does.
If this is a bug, it's at the user interface level ("bad decision"), not necessarily in the implementation.

Yes, it is in the UI and, therefore, straightforward to change.

[RAPo]

people ask thoses little thingys a lot, you want good scope performance at this size

I only ask what they advertise

[Aldo22]

people ask thoses little thingys a lot, you want good scope performance at this size
i would say lots of falses claims / specs  etc ...  you have to get prices cuts somewhere ?

It's clear that in this price range, cheap hardware is used wherever possible, but that doesn't necessarily mean that something unusable has to come out if you put it together intelligently.
And that's where the ZEEWEII guys have done something right with the DSO2512G, in my opinion.
Of course, it has its drawbacks,maybe even some serious ones, but it doesn't suck and makes the most of itself.
Simply as much as is possible for this price and that alone is an achievement.

[ycui7]

This is exactly what you will see with digital phosphor with any brand. Vertical line should NOT show up. That is what you would see in the good old analog days.

So they implemented their digital phosphor correctly.