New 2ch pocket DSO+SG - Zeeweii DSO2512G

[lcp]

Hi, hope my reply will help you guys. The ADC of the DSO2512G is MXT2088, which has built-in dual ADCs, can run up to 125Mhz, and can reach a single channel of 250Mhz at 180° clock phase shift, so the physical sampling rate of DSO2512G is 250Mhz. But why declare 500Mhz? FPGAs can actually achieve "equivalent sample rates," and competitors claim their toys as 500M and 1Ghz sample rates, so you have to make a compromise between market survival and integrity. The 8091 chip can easily drive a 50R load, and the bandwidth exceeds 200Mhz at G=1, so the analog front end will not make any restrictions on the 120M frequency. No CMOS op amp has a high "slew rate," so measuring high-frequency signals requires an X10 probe to reduce the input voltage. All of Fnirsi's oscilloscopes over $50 use the MXT2088, and the actual vertical sensitivity = 100mV due to the lack of a 10x gain amplifier (claiming 50mV is because they use software to process waveform amplitude).
In my opinion, the DSO2512G is the best oscilloscope with the highest bandwidth/10mV sensitivity/performance for less than $90, if you find a better model than the DSO2512G at this price, please let me know.

[Aldo22]

Thanks for the expert explanation lcp! Great!

In my opinion, the DSO2512G is the best oscilloscope with the highest bandwidth/10mV sensitivity/performance for less than $90, if you find a better model than the DSO2512G at this price, please let me know.

That's what this device is all about.
There is simply nothing better in this price range imho.
Nobody claimed that it was perfect or that it was comparable to more expensive devices.
But for many hobbyists it is absolutely sufficient.

[smg]

@jebem: thank you very much!
Most likely an error with R25, R32?
Their value should bу = 20 kOm - not 30 kOm.
Look at my picture with the analysis of your circuit

update - see https://kiloohm.info/eia96-resistor/30C

[Asmartex]

Hi guys. Is it possible to find firmware for DSO2512G now? Or maybe someone can make a dump from p25q23?
My board revision is 9.1

[Aldo22]

Hi Asmartex

Hi guys. Is it possible to find firmware for DSO2512G now? Or maybe someone can make a dump from p25q23?
My board revision is 9.1

I don't think that is possible, because new firmware versions always seem to come with newer hardware versions.
It seems unlikely to me that there will be a backport of new features to older hardware.

I asked once and got the answer:

"Hi, we don't recommend you to upgrade it, we only have improved firmware for V1.2.9C version now. Unpredictable errors may occur after other version upgrades."

[tatel]

Hi, hope my reply will help you guys. The ADC of the DSO2512G is MXT2088, which has built-in dual ADCs, can run up to 125Mhz, and can reach a single channel of 250Mhz at 180° clock phase shift, so the physical sampling rate of DSO2512G is 250Mhz. But why declare 500Mhz? FPGAs can actually achieve "equivalent sample rates," and competitors claim their toys as 500M and 1Ghz sample rates, so you have to make a compromise between market survival and integrity. The 8091 chip can easily drive a 50R load, and the bandwidth exceeds 200Mhz at G=1, so the analog front end will not make any restrictions on the 120M frequency. No CMOS op amp has a high "slew rate," so measuring high-frequency signals requires an X10 probe to reduce the input voltage. All of Fnirsi's oscilloscopes over $50 use the MXT2088, and the actual vertical sensitivity = 100mV due to the lack of a 10x gain amplifier (claiming 50mV is because they use software to process waveform amplitude).
In my opinion, the DSO2512G is the best oscilloscope with the highest bandwidth/10mV sensitivity/performance for less than $90, if you find a better model than the DSO2512G at this price, please let me know.

Of course it helps. Thank you very much.

From your assertion "physical sampling rate of DSO2512G is 250Mhz" could we say it's a 50 MHz device, both channels activated? 100 Mhz with just one channel?

I have to say, fellow forum member gitm reported 36-40 MHz bandwidth IIRC, using good quality, 250 MHz probes.

If we take oscilloscope bandwidth is 50 MHz (both channels active) a rapid calculation 1/sqrt((1/50²)+(1/250²)) gives me a little bit more than 49 MHz total system bandwidth. What would add up with that report is an oscilloscope bandwidth about 40 MHz instead. Could we explain this 20% difference?

To me 20 MHz would be good enough for the price. Of course if it doubles that, no problem at all.

However, even if I can agree it's the best device under €100,  I think we should be able to determine what the characteristics of DSO2512 really are, without any marketing hype. So newbies could knowlingly choose what they want to buy

We are not salesmen.

[Asmartex]

I don't think that is possible, because new firmware versions always seem to come with newer hardware versions.
It seems unlikely to me that there will be a backport of new features to older hardware.

Hi Aldo22
My problem is that my oscilloscope froze one day and then stopped turning on. After  teardown , I found 1.3 ohms between VCC 3vdc and GND.  With the help of a thermal imager, I found out that the problem is in F1C100s. I unsoldered it and the resistance returned to normal. Now I ordered F1C100s on aliexpress. But I don't know if just replacing it will help? Therefore, I would like to have a firmware or a flash memory dump just in case.

[Aldo22]

Hi Asmartex

Too bad your device isn't working anymore.

I would try to contact ZEEWEII Official Store via Aliexpress first.
https://de.aliexpress.com/store/911290279

I once got a reply within 1 or 2 days.
I don't know if they can or want to help you, but it's worth a try.

[tunk]

They also have a home page with contact info (but sadly, no firmware):
http://www.sigpeak.com/contact.html

[jebem]

@jebem: thank you very much!
Most likely an error with R25, R32?
Their value should bу = 20 kOm - not 30 kOm.
Look at my picture with the analysis of your circuit

update - see https://kiloohm.info/eia96-resistor/30C

Hi,

Thanks for your input.

Those schemas are drafts that I did not validate in full.
I used a multimeter to check the resistors whenever possible and these 30K values must have be taken that way.

Unfortunately I already closed my unit , maybe other member here can check the input resistors and report here.

Cheers.

[smg]

@jebem
see fragment of your photo with resistor marking 30C = 20kOm 1%
easy to check - turn on the power DSO, input mode in1=DC,
multimeter measure the R input - it will show 1000 kOm (470+510+20).

[jebem]

@jebem
see fragment of your photo with resistor marking 30C = 20kOm 1%
easy to check - turn on the power DSO, input mode in1=DC,
multimeter measure the R input - it will show 1000 kOm (470+510+20).

And that makes much more sense. Now the total sum of the series resistors gives a round number of 1000KR as it should be.

[jebem]

And our beloved oscilloscope is now added to the hall of fame in the virtual Radio Museum hosted in Switzerland to be remembered in 50 years time as one of the great achievements in specifications and miniaturization of the early 20's.

Here:
https://www.radiomuseum.org/r/zeeweii_handheld_oscilloscope_dso2512g.html

I really like this cheap scope, it is small, handy, triggers very well, acquires small signals in the few mili-Volt range at several dozen of MHz showing the correct frequency reading while I am checking my technologically old receivers.

I will not comment anymore on its shortcomings, as they are extensively covered here as well as on YouTube posts by different people, many of them using calibrated equipment that have consistently found out the same issues.

 

[Aldo22]

And our beloved oscilloscope is now added to the hall of fame in the virtual Radio Museum hosted in Switzerland to be remembered in 50 years time as one of the great achievements in specifications and miniaturization of the early 20's.

Haha! Great jebem! 
I didn't even know the "Radio Museum" was in Switzerland. More precisely, the address in the imprint is 4km away from where I live. 

[RAPo]

Good action jebem.

[NoMoreMagicSmoke]

Hi jebem!

I suspect it is currently set to the default "00" value.
I would try to test it with a value of "11".

Thank you! I will test this later, probably not tonight.

And answering my own question (half way).

Can you show a picture of the HDS272 with a 30 or 40MHz square wave? I would be interested in that.

The more expensive Owon does not show a nicer square wave, rather the opposite, see the example for 10MHz in attachment.
For comparison: https://www.eevblog.com/forum/testgear/new-2ch-pocket-dsosg-sigpeak-dso2512g/msg4857962/#msg4857962

https://you tu.be/6v2UhBz3xZU?t=645
Btw. Does anyone know how to reference a youtube video in this forum without embedding the video?

That trace looked surprisingly terrible to me, so I had to see what my Owon looked like. Here is a 10Mhz and 20MHz square waves from my Owon.

[Aldo22]

Hi NoMoreMagicSmoke

That trace looked surprisingly terrible to me, so I had to see what my Owon looked like. Here is a 10Mhz and 20MHz square waves from my Owon.

Yes fine, but you used "STOP" here. If I do that on the Zeeweii, I also get a single trace.
And then that's the HDS2102S and costs around $220 vs. $80 for the DSO2512G.
You can't compare that.
The main issue here is the price.

[NoMoreMagicSmoke]

Hi NoMoreMagicSmoke

That trace looked surprisingly terrible to me, so I had to see what my Owon looked like. Here is a 10Mhz and 20MHz square waves from my Owon.

Yes fine, but you used "STOP" here. If I do that on the Zeeweii, I also get a single trace.
And then that's the HDS2102S and costs around $220 vs. $80 for the DSO2512G.
You can't compare that.
The main issue here is the price.

Agreed there is a significant price difference. I wasn't trying to argue that. Simply pointing out that there seemed to be something off in that reviews test setup. Here is a plot of the Owon in auto triggering.

[Aldo22]

Simply pointing out that there seemed to be something off in that reviews test setup. Here is a plot of the Owon in auto triggering.

The one in the video is a different model. There is no such thing as "the Owon". 
It is an HDS272S with half the sample rate of your HDS2102S and a bandwidth of 70MHz (specs).
It's available for around $170.
So the test setup is probably right.

[RAPo]

Mine came in today. What a delight with respect to the Fnirsi DPOX.

[Aldo22]

Hi RAPo!

Mine came in today. What a delight with respect to the Fnirsi DPOX.

I'm glad you like the DSO2512G, but I'm still a little amazed. I would have expected the DPOX180H to have more to offer than the cheaper DSO2512G.
I only have the DSO2512G and really have no comparison, all I can say is that it works fine for me.
It does at least what you can expect for this price and, in my opinion, has well thought-out and intuitively understandable functions.
I've never seen a crash or anything like that.

Where do you see the differences?

[RAPo]

Hi RAPo!

I'm glad you like the DSO2512G, but I'm still a little amazed. I would have expected the DPOX180H to have more to offer than the cheaper DSO2512G.
I only have the DSO2512G and really have no comparison, all I can say is that it works fine for me.
It does at least what you can expect for this price and, in my opinion, has well thought-out and intuitively understandable functions.
I've never seen a crash or anything like that.

Where do you see the differences?

Cursors, quick switching of channel settings, FFT. Signal generator output with dedicated easily accessible terminals (in the DXOH they are located between BNC connectors and USB charging port, which are very fiddly, in fact, I've modded my DXOH to have signal generator output like the DSO2512G. Probe connection is easier on the DSO2512G (unfortunately not shielded) than on the DPOXH (there they are shielded, but very hard to lock if you have fat fingers like me )

[markich]

Hello. I purchased a 9.15 revision osclograph. I wanted to post six photos of a printed circuit board weighing 36.9 MB, the site writes that the photos are too large. And I'm interested to know your opinion, especially jebem

[markich]

I'm new here, I don't know much. Who can, please arrange a photo on the site. And I read the comments with interest   https://disk.yandex.ru/d/chO3XrsQTHvisw             

[tatel]

There is a 5 MB upload limit I think. If the site says they are too large, probably they are. Try to rescale them to lower size. Then send them as attachments. At that size probably you'll need to send each picture in its own post