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

[tunk]

If someone in the UK needs a ZT-702s, this is for sale at £34 (plus £5.15 shipping):
https://www.ebay.com/itm/166254908126

[siealex]

Will the firmware updates from the ZOYI site fit a device branded ANENG AOS02?

[sparrow321]

in their youtube guide someone commented that it is supported(aos02 in specifically mentioned).
But it seems the update adds more bugs than solves them so I wouldn't update myself.

[siealex]

But it seems the update adds more bugs than solves them so I wouldn't update myself.

The latest update (v. 51) added a visual description of lead placement in A/mA modes at EVERY switch to those modes (also between them).

[MLXXXp]

I've found that my ZT-702S with firmware version 1.03.51 sometimes does not give the correct value for Vmin and Vmax, which then also affects the VPP value. This happens in oscilloscope mode with DC coupling and seems to be when the displayed waveform swings over a large vertical portion of the screen.

The problem is that the Vmin value shows far more negative than it actually is. Vmax can change to a strange value as well and can vary from reading to reading. I haven't seen the problem occur with AC coupling.

Here are some examples, (with the probe in 10X mode):

This is the scope's calibration output at 1.0V/div. Displayed values appear to be correct.


This is the same calibration output at 500mV/div (and the 0V baseline moved down). Vmin has changed to -2.17V and Vmax to 0.99V.


This is the calibration output at 500mV/div with AC coupling. Displayed values appear to be correct.


This is a 5V 25.1kHz square wave at 2.0V/div. Displayed values appear to be correct.


This is the same 5V 25.1kHz square wave at 1.0V/div. Vmin has changed to -4.87V, with the corresponding wrong VPP.


Can anyone confirm this problem? Is it fixed in firmare version 1.03.55 (installed on recent units but not yet available for download)?

[indman]

MLXXXp, please show one beam on the display without a signal if you set it to the center of the screen at the 500mV/siv DC limit. And then check the position of the beam at the limits of 1.0V/div and 2.0V/div. Will it change its position when switching ranges?

[MLXXXp]

And then check the position of the beam at the limits of 1.0V/div and 2.0V/div. Will it change its position when switching ranges?

@indman,
No, there isn't a significant change in beam position when switching voltage ranges. The attached screen captures are with the probe shorted to its ground lead and the beam position and trigger set to the centre of the screen.

[kwass]

In multimeter mode, is there a way to reset the Min, Max and AVG values (displayed at the bottom, above the function key soft labels), so that they all start at the next reading and then change from there (without changing ranges or to a different function)?

Switch to scope mode then back.  This works on Version 1.03.55 at least.

[geb]

This works on Version 1.03.55 at least.

Is 1.03.55 available as a firmware update? The classic link https://zotektools.com/firmware-update/ seems to still have v51. At least, the downloaded filename ends in "51(3)" and it's showing as 1.03.51 on my unit.

[rsjsouza]

Can anyone confirm this problem? Is it fixed in firmare version 1.03.55 (installed on recent units but not yet available for download)?

Yes, I can confirm this issue on my unit with the same firmware as yours.

I can't upload images at this time, but if you raise the GND level of your waveform to 0V (center line), the problem goes away. As soon as you lower the GND level to something slightly below that, the Vpp wraps to -4.x V.

Later today I can upload some images that illustrate this, but give it a try.

[MLXXXp]

but if you raise the GND level of your waveform to 0V (center line), the problem goes away.

The problem with this is, for a vertical range where the problem occurs, raising the GND level to where Vmin reads correctly causes the high part of the waveform to be off the top of the screen. This causes Vmax to become incorrect (and thus VPP to still be incorrect).

[rsjsouza]

but if you raise the GND level of your waveform to 0V (center line), the problem goes away.

The problem with this is, for a vertical range where the problem occurs, raising the GND level to where Vmin reads correctly causes the high part of the waveform to be off the top of the screen. This causes Vmax to become incorrect (and thus VPP to still be incorrect).

Yes, of course this will happen. I just reported the boundary conditions that triggered this bug.

[tonyalbus]

New Firmware available 1.03.58 !!
https://zotektools.com/firmware-update/

Had the pleasure to play with the ZT-702S from Zotek directly,
As most noteced the firmware on the website was old 1.03.51 and newer devices came with 1.03.55
After my review i told my Zotek contact and they just updated to the latest on the website today
1.03.58 is ready for download.

The review


Have fun

[MLXXXp]

1.03.58 is ready for download.

The 1.03.58 firmware still has the "Vmin/Vmax/VPP values with DC coupling" problem I reported recenty.

This firmware has replaced waveform period (Prd) with duty cycle (duty) in the more measurements (MoreMeas) display. Similar to the above problem, incorrect duty cycle values are given in DC coupling mode.

@tonyalbus Perhaps you could inform your Zotek contact about these problems?

This is the probe calibration output with a 10X probe

[geb]

My experience with 1.03.58 firmware so far:

It reset my unit to Chinese language and lost other remembered things like the last scope voltage scale and cursor position, backlight brightness, etc. DMM calibration was *not* lost.

It now remembers when I shut it down in DMM mode, and upon restart it returns to that mode.  I think it messed up one time and booted into scope mode, but that could have been my quick fingers on the MODE button. I'll keep an eye out for any recurrences.

[npoc]

I just purchased a "ZT-703S" https://www.aliexpress.us/item/3256806076552722.html?spm=a2g0o.order_list.order_list_main.30.15d918026EtgUJ&gatewayAdapt=glo2usa

What are the chances that this device is legitimate?  Has anyone purchased this as well?  It bothers me that the name of the store sounds like "snake oil".

[Veteran68]

I just purchased a "ZT-703S" https://www.aliexpress.us/item/3256806076552722.html?spm=a2g0o.order_list.order_list_main.30.15d918026EtgUJ&gatewayAdapt=glo2usa

What are the chances that this device is legitimate?  Has anyone purchased this as well?  It bothers me that the name of the store sounds like "snake oil".

The ZT-703S with those specs (dual channel, 50Mhz) has been announced for some time, since the ZT-702S became known and popular, but it's not yet even showing on Zoyi's website.

https://zotektools.com/oscilloscope-multimeter/

Let us know if you get it. I have a ZT-702S and would probably upgrade it. Even though I have the far more serious and expensive HDS2202S, I really liked the little Zoyi for what it is.

[RAPo]

I've got my 702s from the snakol store. Delivery went smooth an the product arrived in good order.

[tunk]

There's a reference to the ZT-703S at the top of Zoyi's News page
(images dated 1 December 2023):
https://zotektools.com/news-with-zoyi/
https://cloud-fc.mmldigital.com/631/01172128/33b330ef6505142dd16851a0023aa5d-1024x1024.jpg

[ahakman]

I just purchased a "ZT-703S" https://www.aliexpress.us/item/3256806076552722.html?spm=a2g0o.order_list.order_list_main.30.15d918026EtgUJ&gatewayAdapt=glo2usa

What are the chances that this device is legitimate?  Has anyone purchased this as well?  It bothers me that the name of the store sounds like "snake oil".

I'm curious, did your ZT-703S ship? I bought one over the weekend from the same link and it hasn't shipped yet. I'm hoping they just batch their shipments, but I'm also hoping that it actually gets here before the 22nd when I'm leaving for a few weeks - I'd really like to throw it in my bag and take it with me!

[npoc]

They just canceled my order.

[JeremyC]

They just canceled my order.

I ordered the ZT703S from the “SNAKOL” store on 11/29/2023. As of today it hasn’t been shipped, so I canceled this order. I received information that the money will be credit back to my CC in 6 - 20 business days, however when I check “Refund and return” I see “Refund_returns_list_not_order”, when I try to message this vendor I’m getting stupid robo response. It’s not possible to get a human response.

It was my 1st in my life order from a chine site, and obvious it was a mistake. Who’s the “Alieexpress”, I’m assuming it’s another chines snake oil…

BTW, did you receive you money back?

[Veteran68]

AliExpress themselves are a reputable vendor. I've cancelled several orders with them over the years and always got my refund. They are like Amazon, they handle the payments and refunds, not the seller, so it's unlikely you'll be scammed if it's never been shipped.

For years I've ordered constantly from the big three Chinese marketplaces, AliExpress, Banggood, and Temu. Thousands of dollars over dozens if not hundreds of orders.

[Aldo22]

It was my 1st in my life order from a chine site, and obvious it was a mistake. Who’s the “Alieexpress”, I’m assuming it’s another chines snake oil…

You're really unlucky. I'm sorry for you.

I've placed 40 orders on Aliexpress this year and haven't had a single problem.
Not a single delivery was late, not a single piece was defective, not a single wire was even a millimeter too short and not a single piece was missing from the bag.
I really can't say anything bad at all about Aliexpress or Banggood.

[JeremyC]

@Veteran68, @Aldo22
Thanks for your response. I hope the company will credit me back.
I ordered the ZT703S just for fun, to play with it, new gadget for ~$87 its not a fortune. But I don’t like when somebody is trying to make fool of another people.

About Amazon, when I order from Amazon and I don’t like it they will notify me in ~10 minutes after disputed transaction. If I need to speak with human they will call me.