-
Interesting that I couldn't replicate the noise test the same way you did it, can't see any noise on both scopes. Only if I set vertical to 1mV/div on the scope with the probe I'm able to see the "noise" at 1.5mV level
Then i decided to try a different approach instead of a shorted loop, i used a ferrite inductance as an antenna to "amplify" the noises and I'm able to detect more information from the lower middle to the left, on the back you can get a stronger noise detection.
With the little trick of using a "ferrite inductance" you can even "see" smps control chip working signals without having to touch the chip
My probe is just a 100MHz oscilloscope probe set on X1 and shorted by the ground cable to form a small loop, and the oscilloscope was set to X1 as well, with 10mV/div.
Try moving the probe *slowly* around the border of the left lower corner of the DUT as seen in my pictures, where the antenna is the ground cable.
A little deviation and the signal indeed reduces dramatically and fade away on a 10mV/div scope.
My DUT unit is generating in excess of 20mVpp on a single point that I guess is closer to the Touch Screen IC from the front side. This TS chip is installed on the flat cable. This noise amplitude and frequency readings changes with the selected time base on the probing oscilloscope.
If you can't detect it, probably you have a different version of DS4T252 hardware assembly.
My DS4T252 unit measures in excess of 700uVpp of internal noise on 1mV/div, while yours shows quite lower levels of noise.
I wonder if the manufacturer didn't install the shield covers at the front side of the PCB assembly facing the display on some production batches from where my unit came from.
That would partially explain why your units are quieter than mine.
Anyway, I am not planing to open my unit at this time to check the shielding.
I just redid the probe loop test the same way has you did, this time I used 200MHz probes and there's no noise on both scopes, can't find a single spot were noise come out like yours.
Are you sure that noise doesn't come from any other device you have connected? like a led bulb?
On the photo I post now, the above scope was set to 1mV/div notice the small spikes it captures from the DUT yellow line one, up to 200uV amplitude
-
when did you bought your scope? I bought both directly from the manufacturer, the first one 15 days ago, and the second 7 days ago. Overall I'm satisfied with them, the 2M memory are really handy. My understanding is that they are still working on them, improving the firmware and correcting bugs.
My unit was ordered around two weeks ago from DreamSourcelab Store on AliExpress.
I am quite happy with this DSTouch DS4T252 model, it is a great oscilloscope that features touch screen controls (very handy), and with two features that I was looking for on a low cost device:- Trigger holdoff and
- 1mV/div sensitivity;
- While the "deep" sample storage is not so important to me, it is good to have it, and apparently is not impacting the performance of the device (more stored data may take more time processing it leading to missing events - I guess the FPGA/MCU are doing a fine job here).
The shipped firmware was v1.00 (the same one available for download at their website).
While I acknowledge that it may have some bugs like the ones you mentioned, it seems very stable in operation and I am happy with it as it is.
In general, I don't expect low cost devices to have much attention from the manufacturers, but some of these Chinese makers cares about the customers enough to try to fix the bugs.
I find this 500 - 700uVpp noise a little intriguing, because it is a large value when compared to the 1mV/div sensitivity they specified.
While I still find it useful, I can't stop thinking on how did they missed this.
I understand that they had to design a amplifier stage with a minimum gain at least 10 times higher than what is seen on oscilloscopes with just 10mV/div (like the other more expensive DSTouch DS4T1012 is using).
Hence the increased noise, but I still think it comes from internal EMF sources, like the TS Display and Power Supply that for some reason were not properly shielded, and not from the OpAmps themselves.
If the case could be opened in a regular way, I would check it. Obvious causes would be insufficient (1) shielding and (2) power supply decoupling at the vertical gain stages.
-
Are you sure that noise doesn't come from any other device you have connected? like a led bulb?
That is not possible in the test I did because, as seen in the posted pictures, I have no noise picked up until the DS4T252 is powered up.
And the noise is clearly coming from that lower left corner at a very specific place were the probe GND cable was placed.
Clearly your oscilloscopes were built differently from my unit. I find no other explanation.
-
Are you sure that noise doesn't come from any other device you have connected? like a led bulb?
That is not possible in the test I did because, as seen in the posted pictures, I have no noise picked up until the DS4T252 is powered up.
And the noise is clearly coming from that lower left corner at a very specific place were the probe GND cable was placed.
Clearly your oscilloscopes were built differently from my unit. I find no other explanation.
Did you see the Kerry review on YT?
Please see at 9:22 where he checks the 1mV/div sensitivity.
He got basically the same noise I have on my unit.
Here:
-
Are you sure that noise doesn't come from any other device you have connected? like a led bulb?
That is not possible in the test I did because, as seen in the posted pictures, I have no noise picked up until the DS4T252 is powered up.
And the noise is clearly coming from that lower left corner at a very specific place were the probe GND cable was placed.
Clearly your oscilloscopes were built differently from my unit. I find no other explanation.
Did you see the Kerry review on YT?
Please see at 9:22 where he checks the 1mV/div sensitivity.
He got basically the same noise I have on my unit.
Here:
Probably you got one of the first batches, the same as he did, because the new box is smaller, that's my guess. And as I told you I bought directly from Dreamsourcelab.
-
Probably you got one of the first batches, the same as he did, because the new box is smaller, that's my guess. And as I told you I bought directly from Dreamsourcelab.
Yes, most probably there are at least two different hardware builds of this DS4T252 model.
And that is a good thing, it means they are addressing the issues.
Meanwhile I found some YT videos advertising the DreamSourceLab DSTouch DS4T252, and in one of them someone claims 90uVrms of noise at 1mV/div.
The small letters clearly state that "The noise level data is based on empirical measurements and may vary slightly due to environment factors".
Also they omit in what conditions they got that reading.
Now, those 90uVrms would translate to 90*1.414*2 = 254uVpp. on pure sinusoidal waveforms only. Here we have a complex waveform.
Checking Google AI and it enthusiastically assures me that for noise signals (assuming Gaussian noise distribution) we may multiply the RMS value by 6.6 to get Pk-Pk.
If we try that, we get 90 * 6.6 = 594uVpp, and this is close enough to my readings on the oscilloscope.
OK, to check that, I went to my balcony where there are no external EMF sources close by, switched the DS4T252 on and set it 1mV/div.
Only this time I have chose RMS in addition to Freq and Pk-Pk measurements.
As I was guessing by now, the above claim from someone seems to be valid: My unit never went above 90uVrms in any time base.
And the FPGA/MCU must be doing a good work estimating the RMS value from the Pk-Pk readings (or vice-versa).
For my testing, please see the attached pictures.- DS4T252_noise_floor_1mVdiv_10mS: Time base at 10mS/div, reading 1.551 MHz, 800.000 uVpp, and 88.549 Vrms.
- DS4T252_noise_floor_1mVdiv_10nS: Time base at 10nS/div, reading 18.578 MHz, 366.667 uVpp, and 77.544 Vrms.
See the advert here at 0:30 playtime:
-
Probably you got one of the first batches, the same as he did, because the new box is smaller, that's my guess. And as I told you I bought directly from Dreamsourcelab.
Yes, most probably there are at least two different hardware builds of this DS4T252 model.
And that is a good thing, it means they are addressing the issues.
Meanwhile I found some YT videos advertising the DreamSourceLab DSTouch DS4T252, and in one of them someone claims 90uVrms of noise at 1mV/div.
The small letters clearly state that "The noise level data is based on empirical measurements and may vary slightly due to environment factors".
Also they omit in what conditions they got that reading.
Now, those 90uVrms would translate to 90*1.414*2 = 254uVpp. on pure sinusoidal waveforms only. Here we have a complex waveform.
Checking Google AI and it enthusiastically assures me that for noise signals (assuming Gaussian noise distribution) we may multiply the RMS value by 6.6 to get Pk-Pk.
If we try that, we get 90 * 6.6 = 594uVpp, and this is close enough to my readings on the oscilloscope.
OK, to check that, I went to my balcony where there are no external EMF sources close by, switched the DS4T252 on and set it 1mV/div.
Only this time I have chose RMS in addition to Freq and Pk-Pk measurements.
As I was guessing by now, the above claim from someone seems to be valid: My unit never went above 90uVrms in any time base.
And the FPGA/MCU must be doing a good work estimating the RMS value from the Pk-Pk readings (or vice-versa).
For my testing, please see the attached pictures.- DS4T252_noise_floor_1mVdiv_10mS: Time base at 10mS/div, reading 1.551 MHz, 800.000 uVpp, and 88.549 Vrms.
- DS4T252_noise_floor_1mVdiv_10nS: Time base at 10nS/div, reading 18.578 MHz, 366.667 uVpp, and 77.544 Vrms.
See the advert here at 0:30 playtime:
I just finish two more tests, my idea is to see how the scope is capable of catching and displaying bellow 2mVpp sine and square wave signals.
Since my UTG932+ only drop to 2mVpp I inserted a 52ohm termination so that the signal that goes to the scope be reduced to approx half of the original amplitude.
Frequency used: 1MHz
Let me add this, this generator is outputing 2.667mVpp, i haven't figured out how can I calibrate the UTG932. If anyone know the "secret" kindly share it. Thanks
-
I'll repeat the test again tonight and see if I can catch anything like you did.
when did you bought your scope? I bought both directly from the manufacturer, the first one 15 days ago, and the second 7 days ago. Overall I'm satisfied with them, the 2M memory are really handy. My understanding is that they are still working on them, improving the firmware and correcting bugs.
[/quote]
How do you know they are still working on the software? Do you think we can expect an update soon? -
I'll repeat the test again tonight and see if I can catch anything like you did.
when did you bought your scope? I bought both directly from the manufacturer, the first one 15 days ago, and the second 7 days ago. Overall I'm satisfied with them, the 2M memory are really handy. My understanding is that they are still working on them, improving the firmware and correcting bugs.
How do you know they are still working on the software? Do you think we can expect an update soon?
[/quote]
Because they told me to report back bugs, improvements, etc so I'm assuming that they're working on it. can't tell you 100% that a new firmware is going to be released. We just have to wait and see. -
Because they told me to report back bugs, improvements, etc so I'm assuming that they're working on it. can't tell you 100% that a new firmware is going to be released. We just have to wait and see.
[/quote]
I wrote to them asking about new models, and they replied that there are no portable oscilloscope models scheduled for release in the near future. So let's hope they'll continue working on these. -
Because they told me to report back bugs, improvements, etc so I'm assuming that they're working on it. can't tell you 100% that a new firmware is going to be released. We just have to wait and see.
I wrote to them asking about new models, and they replied that there are no portable oscilloscope models scheduled for release in the near future. So let's hope they'll continue working on these.
[/quote]
Yesterday I sent an email with my feedback with photos, videos, etc. we'll see if they reply. I have my expectations but with a pinch of salt because we know how these Chinese companies work and that is: WYSIWYG
Anyway for me the scope is good enough to have in my pocket for quick checks, the 1 sec boot is really nice to have, it's the most accurate I tried in this form factor, even the FFT won't let down. The one finger touch concept is almost perfect except minor situations. I can easily check PS ripple, turn on/off overshoot detection, signal glitches, signal instability, CAN detection although can't decode, UART decode fine, SPI and I2C haven't tried yet because I don't have my test board with me.
I've been comparing displayed signals with my siglent and there's not much of a difference, of course if I need a more accurate analysis I use the bench scope. But don't expect this little device to be a bench scope replacement because it won't.
I see this portable scope as my swiss pocket knife and being battery operated is really good to avoid those annoying signal interferences that come through the AC line.
It's an addictive portable little thing (but I'm suspect because I'm a fan of portable stuff) and for 100 bucks!
That's my personal opinion, everyone else has their own according to their needs and expectations
-
I’m about to buy a DS4T252 (for hobby use: audio, car diagnostics, power supply testing), but I’m still torn between it, Owon HDS2102S and Hantek TO1112D.
DS4T252 – nquite big screen, touchscreen, nice GUI, good battery life, high vertical sensitivity, FFT, RMS support, but only 50 MHz bandwidth.
HDS2102S – higher bandwidth and built-in multimeter, I know more rugged for field work, though I’d mostly use it at home.
TO1112D – looks most feature-complete with a 7″ screen, but I’ve seen mixed reviews (bugs, freezes, slow performance).
Has anyone here tried all three and can share some advice?
Currently I’m using this old DSO Quad, but the menu makes it pretty frustrating:
https://www.seeedstudio.com/DSO-Quad-4-Channel-Digital-Storage-Oscilloscope-p-736.html -
FYI, DS Scopes cannot save and transfer captured data (only screen shots).
-
FYI, DS Scopes cannot save and transfer captured data (only screen shots).
And what exactly do you miss? can you clarify? -
How do you know they are still working on the software? Do you think we can expect an update soon?
The following is a reply I received today from DreamSourcelab about one of my reports:
"Regarding the issue mentioned at the start of the email about the “Amplitude tuning” feature not responding, this feature is not implemented in the current DS4T252 firmware. We will add this function in a future firmware update."
So, my understating is that they're working on a new firmware update.
-
So there is a pretty high probability that I will update, so today I ordered my DS4T252 through their website
The following is a reply I received today from DreamSourcelab about one of my reports:
"Regarding the issue mentioned at the start of the email about the “Amplitude tuning” feature not responding, this feature is not implemented in the current DS4T252 firmware. We will add this function in a future firmware update."
So, my understating is that they're working on a new firmware update.
-
So there is a pretty high probability that I will update, so today I ordered my DS4T252 through their website
The following is a reply I received today from DreamSourcelab about one of my reports:
"Regarding the issue mentioned at the start of the email about the “Amplitude tuning” feature not responding, this feature is not implemented in the current DS4T252 firmware. We will add this function in a future firmware update."
So, my understating is that they're working on a new firmware update.
You won't regret, if you are like me that love portable devices you will like it. The more I play with it the more I like it, and this scope is a real time sample rate, really good for non continuous signals.
If you have any wishes of functions you would like to see added to the scope please let me know. Maybe they add some to the next firmware, we can dream right?
-
Hello,
I think also to order one DS4T252, seem very valuable device for in the field measurements.
Anyway I don't know if I must order it directly from Dreamsourcelab web site, or via Aliexpress store.
I'm located to France and I don't know what would be the amount of duty if ordered to them directly.
Any feedback of buyers ?
Regards.
FRex -
Hello,
I think also to order one DS4T252, seem very valuable device for in the field measurements.
Anyway I don't know if I must order it directly from Dreamsourcelab web site, or via Aliexpress store.
I'm located to France and I don't know what would be the amount of duty if ordered to them directly.
Any feedback of buyers ?
Regards.
FRex
Yesterday I ordered the DS4T252 directly from https://www.dreamsourcelab.com/shop/oscilloscope/dstouch-ds4t252/
For Poland it’s 0% customs duty + 23% VAT (so around $122 instead of $99). There’s only a small handling fee on delivery because of the customs declaration. Today I got a PayPal notification that it has been shipped
On AliExpress it’s more expensive and there’s a risk of fakes – one seller even said it’s “original but without the original box.” That’s why I prefer buying directly from the manufacturer to be sure it’s genuine and under warranty. -
Thanks for your feedback dcm.
I did as like you, I ordered it from their web site.
Now, time to wait..
Frex -
Thanks for your feedback dcm.
I did as like you, I ordered it from their web site.
Now, time to wait..
Frex
It was supposed to take 3 weeks and I expected to pay additional VAT. I ordered DS4T252 from DreamSourceLab on 04.09, and by 11.09 the package was already in Poland – only 7 days, with no extra fees or VAT. In the end, I paid just $99.
So far, just unboxing and learning how to use it. I really like the interface – great UI, and the price-to-performance ratio is truly impressive. The company replies quickly and thoroughly to emails – excellent support. Now it’s time for some testing… -
My arrived today.
It's a great tool!
1mV maximum sensitivity!!! It's unique!
FFT and protocol decoding are very usefull!
Trigger is reliable, 2MB memory.
I'm very happy with it!
It would be very interesting to compare DS4T252 with the Zeeway DSO3D12. -
With 50 Ohm termination BW is 55MHz.
But, when connected to generator to 50 Ohm output through the supplied P6060 probes bandwidth rizes to 75MHz.
Not bad.
-
My arrived today.
It's a great tool!
1mV maximum sensitivity!!! It's unique!
FFT and protocol decoding are very usefull!
Trigger is reliable, 2MB memory.
I'm very happy with it!
It would be very interesting to compare DS4T252 with the Zeeway DSO3D12.
I'm glad that you like it, it's an addictive little device isn't it? If you have any suggestions to improve, like new functions, Ui, bugs, etc post here. -
Again, it's a bit sad that they didn't invest a bit more thought/effort into the trigger system. E.g. a protocol trigger or at least something like triggering on the start/or stop bit of an UART communication would have been helpful.
Also, I understand that it's not possible to store the currently measured waveform and transfer it to the PC (offline). Obviously only screenshots and "session files" (settings) can be transferred to the PC. That's also a major letdown.