New toy(?) scope, DSO154pro, 1ch, claimed 40MS/s

[tatel]

Textbook stuff. 

Yeah, I obviously have much to read, and even more to play

[tautech]

PS: It can also stop and then zoom out. Take that, Siglent!

Oh so you have 500uV sensitivity, 14Mpts memory and a Zoom mode that provides for zoom out, do you?

You may not know yet but processing all memory available impacts on WFPS rates allowing scopes to miss events.

[Fungus]

You may not know yet but processing all memory available impacts on WFPS rates allowing scopes to miss events.

Um, it only has to zoom out in STOP mode, not when it's processing events.

[Matamipru]

My scope is 34.1mhz in square wave . One bug detected?

[Matamipru]

Unfortunate my probe came faulty. I can't reset my oscilloscope

[ataradov]

Even real scopes have trouble measuring the frequency if there is not a full period or a few periods  are displayed.

What is wrong with the probes and what that has to do with the scope reset?

[Matamipru]

It's a long story, it's a lot of emails with the factory. The tip screw does not work.

https://youtu.be/eEznWkH_MVg

My scope is 34mhz ? Thanks

[Matamipru]

I'm sorry, I sent the wrong video

https://youtu.be/D-gZIZkC1Fs

[Matamipru]

I want to reset because over time the memory accumulates unnecessary data. The manual reset method does not work, nor the method that the factory indicated in the email

[ataradov]

I don't understand what the issue is. As they replied, probe compensation is only implemented in 10X mode. So, the adjustment capacitor will not do anything. This is not a defect, this is how probes work.

Just use 10X mode and forget that 1X exists, it is not useful in most day to day tasks.

No, it is not 34 MHz, it is an error in measurement based on the incomplete data. You need to adjust the time scale so that a few periods are visible. There is no way to measure a "frequency" of a simple edge transition.

[Fungus]

Unfortunate my probe came faulty.

That's not faulty, that's normal.



1x probes never have full bandwidth, you should use 10x for normal use.

[Fungus]

My scope is 34mhz ? Thanks

No.
a) A 40Mhz sampler can never show a 34MHz signal correctly.
b) It can only measure frequency correctly when there's several pulses on screen.

I'm sorry, I sent the wrong video

https://youtu.be/D-gZIZkC1Fs

It all looks correct to me. Now you need to find out why... 

[__Jack__]

Hello.
I got my device yesterday but it seems I have strange situation. Theoretically I bought "full" version ( 18MHz, 1x10 probe, internal battery ). Unfortunatelly, it seems to have no more than about... 2.5MHz of 3dB bandwith. I tested it via sine wave from external signal generator using crocodiles cable. I know that this cable  is worse than regular probe but it is only few MHz. When I looped internal generator ( 1Mhz squere wave ) via this cable, signal looked very limited and distorted. Absolutely it was not similar to what other colegues inserted in their pictures.
Is it possible I got 1MHz version or something is damaged?

Regards
Jack

[Fungus]

I tested it via sine wave from external signal generator using crocodiles cable. I know that this cable  is worse than regular probe but it is only few MHz.

Is it possible I got 1MHz version or something is damaged?

It's the cable. You'll see the same with the probe in 1x mode.

The only time you get full bandwidth is with the probe in 10x mode.

[Matamipru]

The alligator show square wave better than probe x1 and x10. I want to reset my dso154pro. Can you reset yours? Greetings

[Fungus]

The alligator show square wave better than probe x1 and x10.

It should be about the same as 1x.

Here's mine with the probe on 1x:


And here with the probe on 10x:


There's quite a difference in bandwidth.

(voltage is low because I'm testing battery life and there's only one pixel of battery left...)

[Fungus]

(voltage is low because I'm testing battery life and there's only one pixel of battery left...)

Update: Battery indicator turned red and some strange glitches started to appear on the signal:

[Fungus]

Update2: Battery indicator is flashing and the glitches are getting much worse:

[__Jack__]

Thanks colleagues. You were right. In my measurements I have  both crocodiles and probe x1 connected together.
Yesterday I made comparisons with my Rigol osciloscope and it turned out that x1 probe has some kind of lowpass filter.
Even Zeeweii manufacturer told me about it when I described them my problems.
I do not know why they attache such probe,  but any other probes I have , do not cut bandwith by lowpass filter on x1 position.

Regards
Jack

[Fungus]

I do not know why they attache such probe,  but any other probes I have , do not cut bandwith by lowpass filter on x1 position.

Try your Rigol probe on this 'scope... 

[__Jack__]

My Rigol has two probes. I tried one of them yesterday.
I had no bandwith limitations neither on x1 nor on x10 positions.
I wiil try to do some tests again on everything I find at home

Regards
Jack

[tatel]

[tatel]

Got this from the vendor:

Hi, dso154pro there was an update, it mainly added zeeweii icons, there is not much difference in function. Due to hardware limitations, it does not support firmware updates.

[Matamipru]

14mhz SINE wave at -3db , stable square wave at 500khz

Please someone tell me which oscilloscope can show lossless 3mhz square wave?  thanks

[ataradov]

Ideal square wave has infinite spectrum, so no scope can show that. But generally bandwidth 10x the frequency of the square wave shows acceptable results, something that can be called square.

For square waves it is generally better to talk about rise time rather than bandwidth. Those parameters are directly related, but the rise time is easier to visualize and reason about.

Rise time = 0.35 / F_3db. So pick a rise time that you think still looks like a square to you, and you will know the minimum necessary bandwidth  to get that.

And your generator would also have some limited rise time, and you will not be able to observe it better than that. So another way to know what is the best scope for the task is to understand your source.