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

[Randy222]

I keep the 703S just to have around.
I did order a FNIRSI Dpox180h

[Randy222]

703S with the v127 FW

Anyone trying to Calibrate and it fails to calibrate?

[tonyalbus]

Yes mine failed to, but then i found out, i had switched off 1 of the channels,
So switch both channels back on, or set it first to Defaul.. and than do a calibrate, then it will work.
Silly yes.

[Randy222]

Thanks tonyalbus for that tip. You would think the meter would tell you "turn both channels on". If it's in the manual, well, I not read the manual fully.

[tonyalbus]

Yeah manuals who reads those
i agree, there should be some sort of message or they just need to switch the channels on.. its silly.
when i got the failed message, i was just thinking, what i did last and that was switching the channel off.
but in the back of my mind i was thinking, neah that can not be it, that would be stupid... but it was.

[Atlan]

Software error, either inform me about it or turn on the channels.
Fnirsi doesn't win.

[Randy222]

Software error, either inform me about it or turn on the channels.
Fnirsi doesn't win.

What does this mean?

[Randy222]

When in the low ohms range, is there a REL setting to zero out ends of the probes?

[Atlan]

That it can be easily fixed in the new firmware. 

Fnirsi will also have similar problems in the firmware.

[Randy222]

Was using the Zoyi to measure my 1833C LCR meter in measurements.

Oddly, the Zoyi is useless on scope side if it's not in Auto mode. As soon as you change the V or T scale, the scope prints wrong frequency number. It was reading 1833C 100Hz a-ok in Auto mode, I change the T scale to see more or less cycles on the screen and the freq counter goes goofy.
And yes, I even made sure trigger was good to get good stable waveform on the screen.

Maybe the fnirsi dpox180h will be better? Will test that when it arrives in a few days.

[tonyalbus]

Received my 'real' zt-703s sample from Zotek i had teh SNAKOL version before
What i see it that the BOOT version is newer from Zotek.
The firmware can be updated, but the BOOT i dont know. it is maybe a hardware version.
The serial number is way newer also and even the box it comes in has iproved
it looks very nice now istead of the 702s box with a sticker saying its a 703s.

[naiclub]

Received my 'real' zt-703s sample from Zotek i had teh SNAKOL version before
What i see it that the BOOT version is newer from Zotek.
The firmware can be updated, but the BOOT i dont know. it is maybe a hardware version.
The serial number is way newer also and even the box it comes in has iproved
it looks very nice now istead of the 702s box with a sticker saying its a 703s.

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I would like to ask, is the zt-703s still worth using or not?

[tonyalbus]

one page back you find my review, decide yourself.
i don't understand the question i think maybe
If you are still deciding 702s or 703s, than i would think go for 703s.

[Veteran68]

Received my 'real' zt-703s sample from Zotek i had teh SNAKOL version before
What i see it that the BOOT version is newer from Zotek.
The firmware can be updated, but the BOOT i dont know. it is maybe a hardware version.
The serial number is way newer also and even the box it comes in has iproved
it looks very nice now istead of the 702s box with a sticker saying its a 703s.

Interesting. I have the SNAKOL version too, with the same older 1.0.13 BOOT version as you. My serial starts with 003700 -- I'm not certain if that makes it older than your 003900 serial or not, but since the new one has a smaller number at 002F00 then either it's not meant to indicate sequence... or they're counting down. Mine is updated to the latest 1.2.7 firmware.

I definitely got the old style box, which was the same box for the 702S (and other Zoyi meters I have), not the more modern looking one you got this time.

So the question is, are there material differences in hardware and performance between the SNAKOL version and the newer one? Not that this is a serious instrument for me, it's more of a novelty to add to my growing collection, but I'm curious. And also annoyed if Zoyi released to market a grossly immature product instead of waiting just another month or two to release the final version. And is SNAKOL complicit in anything here? It did seem a bit shady that they were pre-selling for so long without calling it a pre-sale.

[tonyalbus]

when one buy before official release date from non official zoyi store one can expect an early model. thats the risk one takes.
but luckily the firmware updates work also on the early models.

but yes i want to open both to see if there is an real hardware difference.

[ahakman]

Being back home now (actually been back most of the week, but was busy with other stuff), I decided to check out some more things on the ZT-703S
I still have the original 1.0.9 firmware on mine.

When running in "High" mode, the frequencies output by the generator accessed from the menu (Menu -> left -> F4) are WRONG other than the 1khz probe compensation signal, which is actually correct. In any other output mode though, the frequencies are wrong.

5.0 kHz => is actually 7.0 kHz
2.0 kHz => is actually 2.8 kHz
1.0 kHz => is actually 1.4 kHz
etc etc (same scaling factor of 1.4 is present at all frequencies).

Oddly, using the "other apps -> Gen", the frequencies are correct
But in Sine output mode, it doesn't meet the 2.5Vpp claim at all (more like 2.0Vpp) and above 400kHz, the waveform is very triangular, not sinusoidal. Same can be said for any of the "partial sinusoidal" waveforms - they get very triangular and aren't very sinusoidal.

Going the other way and looking at a signal from an external generator, I see some peculiar aliasing too:

Feed in a 20Mhz sine wave, at 10, 25, and 50ns/div, things look pretty good and the frequency reads correctly. At 100ns/div, the frequency measurement is wrong (probably due to the overall bug at 100ns/div). From 250ns/div through 200us/div things look ok-ish - what you'd expect, the waveform getting more and more "solid" as the timebase is too slow to see any detail in the signal. At some timebases, there is some overall AM-ish distortion of the overall envelope though - definitely some kind of periodic noise, or some kind of aliasing showing up. Then suddenly at 500uS/div, it looks like a pure sinewave again, perfectly triggered and stable, at a much lower frequency, but the frequency measurement shows 0 as it can't measure anything. Definitely misleading if you're looking at an unknown signal and manually moving through timebases to have such an aliased signal appearing.

Comparing the same signal on the Owon HDS2202S, you get none of that at any timebase with the same 20MHz sine signal being fed in - there are some "sinusoidal-ish" aliased signals at very slow timebases on the Owon (5ms/div), but they're not triggered and stable, but rolling, giving a good indication that that's not the true signal, and just an aliasing / sampling artifact.

On an Agilent DSO-X 2024, there is no hint of aliasing or any waveform that resembles a "slower sine" at any timebase right up to and beyond 1S/div.
If you compare sampling rate at timebases, the Agilent scope is using a far higher sampling rate at every timebase compared to the Owon. The ZT-703S doesn't seem to indicate sampling rate vs timebase at all, so it's really hard to know what it's doing.

With the cheap price of the Zoyi, or even the Owon HDS series, and it being potentially many people's "first scopes", they definitely leave a lot of "traps for young players" as Dave would say...

I'm not sure if there's anything else anyone wants me to measure before I upgrade the firmware - turns out I don't currently have a working function generator above 20Mhz, except for potentially with an SDR, or with a VNA not sweeping, but set to a fixed frequency. The wavegen in the DSO-X 2024 only goes to 20Mhz, and my proper RF sig gen needs repairs.

[Randy222]

Received my 'real' zt-703s sample from Zotek i had teh SNAKOL version before
What i see it that the BOOT version is newer from Zotek.
The firmware can be updated, but the BOOT i dont know. it is maybe a hardware version.
The serial number is way newer also and even the box it comes in has iproved
it looks very nice now istead of the 702s box with a sticker saying its a 703s.

My 703 from snakol came in a box that shows and says "3-in-1 dual-channel" on face of box, and, the pic used appears to be the 703S ("25000 counts", etc) but the actual model on the pic is not there, but duly noted the side of the box has two models listed as check-boxes, 702 and 703, and the 703 is marked on my box. There's no "703S" sticker on a 702 box.

The 703 I got has boot v1.0.14, but I am not sure the boot version matters too much.

So it does appear the 703 I got from snakol was the latest from Zoyi when snakol shipped to me. Earlier 703's were likely just being rushed out using 1st rev firmware stuff and 702 boxing, but I don't suspect the actual 703 hardware is any different.

[Randy222]

Being back home now (actually been back most of the week, but was busy with other stuff), I decided to check out some more things on the ZT-703S
I still have the original 1.0.9 firmware on mine.

When running in "High" mode, the frequencies output by the generator accessed from the menu (Menu -> left -> F4) are WRONG other than the 1khz probe compensation signal, which is actually correct. In any other output mode though, the frequencies are wrong.

5.0 kHz => is actually 7.0 kHz
2.0 kHz => is actually 2.8 kHz
1.0 kHz => is actually 1.4 kHz
etc etc (same scaling factor of 1.4 is present at all frequencies).

Well, "1.4" sounds like a math mistake in the old code.
Testing on the old FW is good for reference only.
Upgrade to the v1.2.7 FW and see what changes.

[Randy222]

I did get fnirsi depox180h today.
Have to say, the 180h is like the light in light-&-day vs the scope of the Zoyi.

Didn't need instructions manual to learn the menu's, 10min of just pushing buttons, and now super ez to use it. Hidden menu's? Not sure yet.

Out of the box, no idea about FW versions, all the functions seems to work ok. BNC's twist on and lock, unlike Zoyi.

Signal gen a-ok up to 20MHz, and there's like ~8 or so signal profiles to choose from, and you can dial in the freq one digit at a time.

The one item of interest for me on the 180h, is the FFT. I need to test it some to see if it reads harmonics ok, but having FFT in a small handheld is something I have been looking for.

Now just need to Zo-tek folks to fix the bugs in the 702/703 FW.

[wedgehog]

Being back home now (actually been back most of the week, but was busy with other stuff), I decided to check out some more things on the ZT-703S
I still have the original 1.0.9 firmware on mine.

When running in "High" mode, the frequencies output by the generator accessed from the menu (Menu -> left -> F4) are WRONG other than the 1khz probe compensation signal, which is actually correct. In any other output mode though, the frequencies are wrong.

5.0 kHz => is actually 7.0 kHz
2.0 kHz => is actually 2.8 kHz
1.0 kHz => is actually 1.4 kHz
etc etc (same scaling factor of 1.4 is present at all frequencies).

Oddly, using the "other apps -> Gen", the frequencies are correct
But in Sine output mode, it doesn't meet the 2.5Vpp claim at all (more like 2.0Vpp) and above 400kHz, the waveform is very triangular, not sinusoidal. Same can be said for any of the "partial sinusoidal" waveforms - they get very triangular and aren't very sinusoidal.

Going the other way and looking at a signal from an external generator, I see some peculiar aliasing too:

Feed in a 20Mhz sine wave, at 10, 25, and 50ns/div, things look pretty good and the frequency reads correctly. At 100ns/div, the frequency measurement is wrong (probably due to the overall bug at 100ns/div). From 250ns/div through 200us/div things look ok-ish - what you'd expect, the waveform getting more and more "solid" as the timebase is too slow to see any detail in the signal. At some timebases, there is some overall AM-ish distortion of the overall envelope though - definitely some kind of periodic noise, or some kind of aliasing showing up. Then suddenly at 500uS/div, it looks like a pure sinewave again, perfectly triggered and stable, at a much lower frequency, but the frequency measurement shows 0 as it can't measure anything. Definitely misleading if you're looking at an unknown signal and manually moving through timebases to have such an aliased signal appearing.

Comparing the same signal on the Owon HDS2202S, you get none of that at any timebase with the same 20MHz sine signal being fed in - there are some "sinusoidal-ish" aliased signals at very slow timebases on the Owon (5ms/div), but they're not triggered and stable, but rolling, giving a good indication that that's not the true signal, and just an aliasing / sampling artifact.

On an Agilent DSO-X 2024, there is no hint of aliasing or any waveform that resembles a "slower sine" at any timebase right up to and beyond 1S/div.
If you compare sampling rate at timebases, the Agilent scope is using a far higher sampling rate at every timebase compared to the Owon. The ZT-703S doesn't seem to indicate sampling rate vs timebase at all, so it's really hard to know what it's doing.

With the cheap price of the Zoyi, or even the Owon HDS series, and it being potentially many people's "first scopes", they definitely leave a lot of "traps for young players" as Dave would say...

I'm not sure if there's anything else anyone wants me to measure before I upgrade the firmware - turns out I don't currently have a working function generator above 20Mhz, except for potentially with an SDR, or with a VNA not sweeping, but set to a fixed frequency. The wavegen in the DSO-X 2024 only goes to 20Mhz, and my proper RF sig gen needs repairs.

I think it did say in the manual not to use high mode below 30 MHZ or something?

[gtv]

customer review from Snakalstore:
....................
Additional feedback
28 Jan 2024
For information, Snakal Global Store and Snakal Instruments Store are the same seller with the same legal details.

[YurkshireLad]

Snakol == Snake Oil?   

[lchao]

Has anyone tried the newest v1.28 FW update available on Zotek's website? http://www.szzotek.com/h-col-159.html

[naiclub]

Has anyone tried the newest v1.28 FW update available on Zotek's website? http://www.szzotek.com/h-col-159.html

Has anyone tried it yet? And how does it compare to the previous version?

[Altair8800]

Has anyone tried the newest v1.28 FW update available on Zotek's website? http://www.szzotek.com/h-col-159.html

When I went to this site my antivirus program gave a virus warning.

So I'm not going to try it out...