New Zoyi multimeter+oscilloscopes - ZT-70xS, up to 50MHz/250MSps (nov 2022)

[scroeffie]

is this one good enough for videogame consoles like snes and c64 etc

Zoyi ZT-703S

[lchao]

is this one good enough for videogame consoles like snes and c64 etc

Zoyi ZT-703S

Check out this: https://youtu.be/Po_2bXn6Ba8?t=976

[nikbry]

Trigger in version 1.4.2 does not work with time scale 250ns/div and less. So I can't observe 100-200-400ns pulses in good resolution.

I can't confirm your conclusions. On my device with version 1.4.2, the trigger works normally over the entire duration range.
Show your video of the malfunction?

Give one pulse 1-10 uS. And you won't see him. He will be behind the screen.

Would you mind sharing your exact experiment setup? I'm trying to reproduce the problem on FW 1.32 and can't. I must be missing something. Thanks

[LinuxHata]

I have 703s model, how to turn off built-in generator?
it limits use of scope - "time base limitation"
I go to apps/more, set all outputs to OFF, but when back into that menu, one is always on.
And 2nd one has no way to be turned off?

[nikbry]

I have 703s model, how to turn off built-in generator?
it limits use of scope - "time base limitation"
I go to apps/more, set all outputs to OFF, but when back into that menu, one is always on.
And 2nd one has no way to be turned off?

2nd one can't be switched off and must be in square wave mode to avoid the "time base limitation" on the scope.

[matefon]

The second generator is actually always on for a reason: reference signal. It is used to calibrate the scope probes.
Like nikbry mentioned, you should set it to square wave and you won't have troubles with it.

[csuhi17]

Trigger in version 1.4.2 does not work with time scale 250ns/div and less. So I can't observe 100-200-400ns pulses in good resolution.

I can't confirm your conclusions. On my device with version 1.4.2, the trigger works normally over the entire duration range.
Show your video of the malfunction?

Give one pulse 1-10 uS. And you won't see him. He will be behind the screen.

Would you mind sharing your exact experiment setup? I'm trying to reproduce the problem on FW 1.32 and can't. I must be missing something. Thanks

Setting up the signal generator:
1kHz pulse, 3Vpp, without offset, the width of the pulse is 991ns, my signal generator does not allow 1ms at a frequency of 1kHz.

Setting up the scope:
1V/Div, single trigger.
I will try it first in 500ns/div.
the second time in 250ns/div.
You can try the same with the normal trigger.
You start with 1us/div and switch to a faster time base.
500ns, 250ns, 100ns.
The pulse will disappear at 250ns/div and below.

single trigger will catch something, but you won't see the wave.

+ it seems that the waveform before the trigger is not saved.

I set the signal generator to 2Vpp pulse, 1MHz and 10% width.
I set the scope to 500ns/div and the trigger to approx. I set it to single trigger at 2V so that it does not trigger on the signal.
Then I set the voltage on the signal generator to 4Vpp.
And you can see that there is no 2Vpp before the trigger.
and at 250ns/div, that the trigger is delayed by 9 divisions compared to the signal.

[LinuxHata]

Thanks for the explanation!
I assume, there is no way to turn off beep when changing the modes?

[koks1960]

Trigger in version 1.4.2 does not work with time scale 250ns/div and less. So I can't observe 100-200-400ns pulses in good resolution.

I can't confirm your conclusions. On my device with version 1.4.2, the trigger works normally over the entire duration range.
Show your video of the malfunction?

Give one pulse 1-10 uS. And you won't see him. He will be behind the screen.

Would you mind sharing your exact experiment setup? I'm trying to reproduce the problem on FW 1.32 and can't. I must be missing something. Thanks

I tested firmware 1.38 and higher. The trigger works correctly only in 1.38. I have not tested it below this version.

[nikbry]

Setting up the signal generator:
1kHz pulse, 3Vpp, without offset, the width of the pulse is 991ns, my signal generator does not allow 1ms at a frequency of 1kHz.

Setting up the scope:
1V/Div, single trigger.
I will try it first in 500ns/div.
the second time in 250ns/div.
You can try the same with the normal trigger.
You start with 1us/div and switch to a faster time base.
500ns, 250ns, 100ns.
The pulse will disappear at 250ns/div and below.

single trigger will catch something, but you won't see the wave.

+ it seems that the waveform before the trigger is not saved.

I set the signal generator to 2Vpp pulse, 1MHz and 10% width.
I set the scope to 500ns/div and the trigger to approx. I set it to single trigger at 2V so that it does not trigger on the signal.
Then I set the voltage on the signal generator to 4Vpp.
And you can see that there is no 2Vpp before the trigger.
and at 250ns/div, that the trigger is delayed by 9 divisions compared to the signal.

First off, thank you for taking the time to post your setup with screenshots and a detailed explanation, it helped a lot.
I've run your experiment and tested it with FW1.32 on the ZT703 and also on the OWON VDS1022i and could NOT replicate any of the trigger problems you mentioned, the behavior is also identical to the Owon's.

Does anyone remember the bugs 1.32 has? I do remember :high frequency jitter, low frequency waveform artifacts,  cursor disappearance, CH2 activation after Auto Range. Anything else?

[Edmiri]

Why when i try to calibrate the probe nothing changes in the square wave form. I tried both probes.

[xKertx]

Why when i try to calibrate the probe nothing changes in the square wave form. I tried both probes.

Calibration is done without probes connected.
Or, did you mean the probe compensation adjustment? Switch the probe to 1x mode.
EDIT: 10x not 1x 

[xKertx]

I tried to use my UNI-T UTG932E to replicate the problem with the trigger, but i'm getting this weird looking mess.
It looks normal when the trigger is in auto mode. But if i put it single-capture mode and turn on the function generator channel, it looks like in the screenshot. 
Not sure which one of these cheap units is causing this. Is it the Uni-T or Zoyi 

[indman]

Why when i try to calibrate the probe nothing changes in the square wave form. I tried both probes.

Calibration is done without probes connected.
Or, did you mean the probe compensation adjustment? Switch the probe to 1x mode.

It's the other way around, he needs to switch the probe to the 10x position 

I tried to use my UNI-T UTG932E to replicate the problem with the trigger, but i'm getting this weird looking mess.

You need to increase the pulse amplitude to 3Vpp

[csuhi17]

xKertx
The disturbance before the trigger in the wave is 99% the fault of your signal generator.
I copied your settings and with DG912Pro.
It triggered 12 periods later after the very first wave.
In other words, the tigger was delayed by almost 250 us.
The time base you use is not the same as what is wrong with us.
We notice the strange behavior with the trigger at 250nanosec and the faster one at 100ns, 50ns, 25ns, 10ns.

I did a few quick tests, the delay is not the same every time.

If you use your setting in normal trigger mode and start reducing the time base, that is, you speed it up.
 From 25microsec to 100nanosec, you will find that at 250 nanosec and faster timebases the triggering is unstable. This is in 250MSa/s mode.

If you turn on the 280Msa/s mode, the trigger becomes unstable at 500nanosec, even if the peakdetect switch is on.

[csuhi17]

In the picture in which the wave in front of the trigger is not visible, I think it is lost, not because of the Zoyi.

When I change the amplitude of the signal, the Rigol DS912Pro turns off the output for 14ms.
Even when adjusting from 200mV to 210mV.

[Obi-Wan]

Hi, do you guys managed to calibrate the multimeter mode in ZT-703S? Mine is showing 928mA when putting 1A through it. Any thoughts?

[m72]

Hi, do you guys managed to calibrate the multimeter mode in ZT-703S? Mine is showing 928mA when putting 1A through it. Any thoughts?

The multimeter chip resembles the well-studied DTM0660. That's why I simply saved the contents of the soldered-in I2C EEPROM. The address 0x2A contains the calibration coefficient for current with a limit of 2.5A. By changing it I adjusted the readings.

[Obi-Wan]

The multimeter chip resembles the well-studied DTM0660. That's why I simply saved the contents of the soldered-in I2C EEPROM. The address 0x2A contains the calibration coefficient for current with a limit of 2.5A. By changing it I adjusted the readings.

Ow, you are a lifesaver... Waiting for my eeprom reader/writer to arrive and I will try to change the coefficient.

[Spirex]

Did you manage to find out which SPI microcircuit is in the 703 model? I calculated the dump.
The data seems adequate, but it is definitely not the 25 series, it looks like AT45XXXX

[nikbry]

I wanted to use the Rigol PVP3150 150MHz probe with this scope because it has 20MHz bandwidth in 1X mode and i thought it would be good for low voltages.
And while it seems to have much less noise, for some reason in 10X mode it shows annoying overshoot at the edges and the compensation adjustment wont help much.
The compensation kind of works, but the spike at the beginning remains no matter whitch position i turn the compensation screw.
Any ideas what could cause this?
I would have thought that a probe, that costs almost as much as this oscilloscope, would perform flawlessly. But atleast in this case the cheap probe that came with the scope works better.
Or, does it have something to do with the fact that the more expensive Rigol probe probably has lower capacitance and the cheap probe is somehow matched with the scopes input capacitance?
On the screenshot the CH1 is the probe that came with the ZT-703s and CH2 is the Rigol PVP3150.

I went back to this post regarding the probe issue, because I'm seeing strange things myself. I'm feeding a 5V sine wave into the 10x probe, and am observing a significant voltage attenuation when going beyond 300kHz. I need to retest tomorrow more thoroughly, but when reaching the low MHz range I'm down to 4.6-4.7V. The 1X setting shows more accurate values - 4.8-5V
I connected my OWON probes and the attenuation is even worse, i.e., 4.3V
Given my ignorance I'm suspecting a problem with the scope's gain or maybe the probe itself!?

Can anyone shine some light on this? Thanks.

[r6mf49t2]

Can anyone shine some light on this? Thanks.

The included probes are extremely bad. Buy at least the P6100.

[xKertx]

The included probes are extremely bad. Buy at least the P6100.

But problem is that other brand probes can't be compensated properly with this scope.
At least the Rigol PVP3150 150MHz probes didn't work properly.

[r6mf49t2]

But problem is that other brand probes can't be compensated properly with this scope.
At least the Rigol PVP3150 150MHz probes didn't work properly.

I'll try to check in the next few days with all the probes I have. What frequencies are you interested in?

[csuhi17]

Can anyone shine some light on this? Thanks.

In which time base did you measure the signal?
I measured 100kHz in 10microSec/div.(us)
It was 5.2Vpp and at 10x.
I increased the frequency to 400kHz, I did not change the time base.
And the automatic measurement says 4.2Vpp.
The wave on the display did not change significantly, it shrunk a little, but not to 4.2Vpp, measured with the cursor it was 5.1Vpp.
It behaves the same on both channels.

If I change the time base, the automatic measurement writes 5.2Vpp again.
In my case, the attenuation was a maximum of 0.3V. I looked up to 20MHz.

Measured with the Owon HDS120 in oscilloscope mode, 5.2Vpp.

I played with it a little more, I used the same 6100 100MHz measuring probe. I can't find the one I got for the Zoyi.

I simply connected the BNC to another scope, Owon HDS2202, Rigol DHO924S, Micsig to1104. All measured 5.9Vpp. Bad probe.

Measured with the device's own measuring probe, the signal is around 5.1V. Good probe.

It is possible that you only have the time base set incorrectly, try measuring it with the cursor.