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

[Randy222]

Just got my 703S. It took me some time to realize that the function generator available via the 'More Apps' menu does not work together with the scope functionality at all. Either use the scope or the enhanced function generator! The low frequency generator accessible via the 'Output' option on the other hand is always available. However it seems that setting some of the other waveforms (triangle etc) then imposes a 100us minimal timebase setting.

fw is 1.29

Did it ever work the other way? All I saw was freq gen made signal a bnc and the signal being generated was in the display.

Does the manual say it works any other way?

[lchao]

Just got my 703S. It took me some time to realize that the function generator available via the 'More Apps' menu does not work together with the scope functionality at all. Either use the scope or the enhanced function generator! The low frequency generator accessible via the 'Output' option on the other hand is always available. However it seems that setting some of the other waveforms (triangle etc) then imposes a 100us minimal timebase setting.

fw is 1.29

This issue is present in v1.27 too. In the below video a workaround is described:
https://youtu.be/T7kXdiVXet4?t=55

You should turn on the signal generator through the More Apps menu, in this case you can go down to 10ns.

[Veteran68]

My ZT-703S arrived today, purchased from AliExpress. I was surprised it wouldn't turn on since the batteries are usually delivered with 50% charge. I opened it up and found that I have no battery inside!!!

I'm wondering if it's worth the effort of sending it back, or probably I'll just buy a battery and put it in myself. Does it matter if I install an ICR or IMR 18650? Are they interchangeable? Which should I be using in this?

Depending on seller, destination country, shipment method (passenger air vs cargo air vs sea), and probably some other variables, lithium chemistry batteries are considered hazardous and are banned from being shipped as regular cargo. I've had a number of items ship from China without their batteries, while others come with. Sometimes they tell you they're shipping sans batteries, and other times they do not. It's pretty much a lottery. Either some sellers are applying the regulations to everything they sell just to avoid hassling with who gets batteries and who doesn't, or they don't care about regulations and ship batteries regardless.

I'm not usually concerned about it, because typically if I'm ordering from AliExpress and the like it's because of a price advantage anyway, so the extra cost of a battery is a non-issue. Fortunately I maintain a supply of most common rechargeable formats including 18650's and a few different LiPo pouch types, so unless it's some exotic battery it's seldom much of an inconvenience for me. It would be courteous for the seller to clearly state in their listings that they ship without batteries, and what type is required, just so buyers can be prepared.

All that to say this is not unusual, and you're unlikely to get a battery from the seller, thought they might be generous enough to refund you a couple bucks to supply your own battery.

[Harrow]

I just wanted to post a PSA, most probably know this already but when buying anything of value from AliExpress please video record the opening of your package in one continuous shot all in frame.

I purchased the ZT-703 2x now from AliExpress the first one was returned to the seller because the package weight didnt match the discription during shipping and never made it out of china. The second one was flat out scammed and the seller sent me some gel pads that look like small shoe inserts or something. It came in a large order with several items. The recording i made was corrupt (not sure what happened) Luckily AliExpress refunded my purchase without it. Ended up buying a ADS1013D for 50$ off ebay for use in the mean time. Again just wanted to share my cautionary tale.

Interesting. I was about to spend almost $1000 on an oscilloscope on AliExpress. Now you've got me wondering if it's a bad idea.

[Harrow]

Depending on seller, destination country, shipment method (passenger air vs cargo air vs sea), and probably some other variables, lithium chemistry batteries are considered hazardous and are banned from being shipped as regular cargo. I've had a number of items ship from China without their batteries, while others come with. Sometimes they tell you they're shipping sans batteries, and other times they do not. It's pretty much a lottery. Either some sellers are applying the regulations to everything they sell just to avoid hassling with who gets batteries and who doesn't, or they don't care about regulations and ship batteries regardless.

I'm not usually concerned about it, because typically if I'm ordering from AliExpress and the like it's because of a price advantage anyway, so the extra cost of a battery is a non-issue. Fortunately I maintain a supply of most common rechargeable formats including 18650's and a few different LiPo pouch types, so unless it's some exotic battery it's seldom much of an inconvenience for me. It would be courteous for the seller to clearly state in their listings that they ship without batteries, and what type is required, just so buyers can be prepared.

All that to say this is not unusual, and you're unlikely to get a battery from the seller, thought they might be generous enough to refund you a couple bucks to supply your own battery.

There was no mention in the ad of it being 'sans battery', however, I just looked at the reviews and a lot of people have made the same comment. Anyway, no big deal. Online ordering is always a lottery and I'm pretty happy that the product arrived with two probes and that it works.

**UPDATE**  I just got a return message from the seller saying they can't ship with a battery. So, I can just order an 18650 from AliExpress and hope they don't send me an empty package and say the same thing, lol.

BTW, do I need to use a 'protected' cell?  I've never used an 18650 before and just saw a post about it.

[Atlan]

The battery takes a long time to arrive.  (more than 30 days) Because they probably go by train or ship.  He was born from other things that go by air.  The package with the battery is usually marked with a yellow sticker and a battery and fire pictogram.

[ksxx]

Just got my 703S. It took me some time to realize that the function generator available via the 'More Apps' menu does not work together with the scope functionality at all. Either use the scope or the enhanced function generator! The low frequency generator accessible via the 'Output' option on the other hand is always available. However it seems that setting some of the other waveforms (triangle etc) then imposes a 100us minimal timebase setting.

fw is 1.29

Did it ever work the other way? All I saw was freq gen made signal a bnc and the signal being generated was in the display.

Does the manual say it works any other way?

No, the manual does not say anything about that but it also does not state that it is NOT possible to see the waveforms on the scope. Maybe it is just me, but it feels like you buy a car with a radio and then find out that you can listen to the radio only when the motor is off. The reviews were at least unclear or the reviewers were confused themselves. Just to make the facts clear again to the followers of this thread, as of FW 1.29, the only generator signal that allows for the full capabilities of the scope (no 100us limit) is the 1kHz square wave calibrator signal. Other signals up to 2-5kHz can be used with together with the scope function (100us limit). The extended generator options (up to around 100kHz etc) can only be used stand-alone in the separate App. If you encounter the 100us time base limit in your scopemeter  and want to go back to normal, you need to go to the output menu (generator) and select the square wave option (the one were frequency and amplitude show no values ---)
Overall, the scopemeter works quite reliable with the 1.29 firmware. No crashes, little menu weirdness, triggering works fine and the operation in the single channel mode is fun. With two channels the operation is more cumbersome but also works ok.

[Mortymore]

I just wanted to post a PSA, most probably know this already but when buying anything of value from AliExpress please video record the opening of your package in one continuous shot all in frame.

I purchased the ZT-703 2x now from AliExpress the first one was returned to the seller because the package weight didnt match the discription during shipping and never made it out of china. The second one was flat out scammed and the seller sent me some gel pads that look like small shoe inserts or something. It came in a large order with several items. The recording i made was corrupt (not sure what happened) Luckily AliExpress refunded my purchase without it. Ended up buying a ADS1013D for 50$ off ebay for use in the mean time. Again just wanted to share my cautionary tale.

Interesting. I was about to spend almost $1000 on an oscilloscope on AliExpress. Now you've got me wondering if it's a bad idea.

A very bad idea in my opinion. One my find great and honest sellers in Aliexpress, but also many dishonest sellers, from those who sell garbage, item not as stated, cancel deals many days after purchase, and I even received an empty bag stating 10g of weight, hence, obviously empty, just for fun. Had to report that to authorities, as Pyapal requested, because Aliexpress didn't do anything for days, so I turned into Paypal, the only method I use to pay on Aliexpress.

Despite a deal can go smoothly, one has to think about support. I would never risk to spend $1000 in an item in Aliexpress and expect local support if needed.
Just my 2cents

[Aldo22]

Depending on seller, destination country, shipment method (passenger air vs cargo air vs sea), and probably some other variables, lithium chemistry batteries are considered hazardous and are banned from being shipped as regular cargo.

Most of the products I have ordered so far have come with a "built-in" rechargeable battery.
As far as I can see, the zt703s has an officially "replaceable" battery.
Maybe that's the difference?

Is there a difference in safety whether a battery is built-in (officially non-removable) or not?

P.S. I don't have a zt703s, I'm just guessing.

[MarkusWandel]

Cheap scope expectation management.

I have an old 15MHz analog scope.  It is honestly 15MHz.  If you put in a higher-bandwidth signal, you see a 15MHz low-pass filtered version of it.  For example, a 6MHz square wave will look pretty rounded, but rock steady with no strange artifacts.

This thing claims to be 50MHz bandwidth, which may well be true, but I don't think there's anything even resembling a 50MHz "brick wall" low-pass filter.  So if you sample a higher-bandwidth signal you can get some gruesome artifacts.   I don't have access to high-quality lab equiment, specifically no function generator and no better quality scope to compare to.  What I do have is a 3.6864MHz clock oscillator module which, based on lab experience in a past life, puts out a clean signal - it had better, being a clock source.  Let's put it on (first pic).

Whoa!  I could handle "ringing" on the edge, but every edge looks different!  10s persistence shows the variation.

Well, that's overmagnification.  In high speed mode, this thing does something like 250Ms/s but at 50ns/div that's only about one sample every other pixel.  So zoom out to 100ns/div (second picture).  This shows several different "versions" of the rising and falling edges, now at roughly 1:1 ratio between horizontal pixels and samples.

Right, get a hold of yourself.  This is not a $20K lab scope.  This is a scopemeter.  What do people use them for?  Debug power supply issues, audio issues, and, in the old days, standard definition TV issues (that's the world my 15MHz analog scope was born into).  I do still have a single SD video source in this house - an old video camera.

Third picture:  Pretty!  That's the 3.58MHz colour burst on the "front porch" of a scan line.  Zoomed in (4th pic) it still looks pretty good, though not particularly sinusoidal.  So back to reality.  This thing totally does what hobbyist scopes need to do.  You could debug a switching power supply with it, for example.

Just for laughs, back to the square wave at the same horizontal resolution (250ns/div) as the last capture.  You can see the artifacts, but all in all it looks square wave-ish.  Note the probe was compensation adjusted at 1KHz so it may not be perfect at this zoom level.

It's not the probes by the way.  I tried a high quality, Tektronix 250MHz scope probe that I happened to have, and the waveforms look essentially the same.

[RAPo]

Well, the version mystery is solved.

Zoyi states:

Just to let you know, the factory's latest version right now is 1.2.7. If someone says they got 1.3.0, that's actually an internal naming method by the engineering department.
In reality, both versions are the same. Whenever there's a new update, I'll let you all know here first.

See this video:

[wasedadoc]

Whoa!  I could handle "ringing" on the edge, but every edge looks different!  10s persistence shows the variation.

Totally to be expected. The sampling rate would need to be an exact integer multiple of the signal fundamental frequency to make every cycle display the same.

[Altair8800]

Anyone else getting BLOCKED from going to thedmm.com website?

It might just be my particular AntiVirus (AVG)...  AVG is stating:

"We've safely aborted connection on thedmm.com because it was infected with URL:Blacklist"

[Atlan]

That sounds like a bad joke It's great to release new firmware versions that don't change anything But it looks like product support exists.

[Razvan_N]

It's funny that all three downloadable versions have different sizes, although Tim claims they are all the same!

[Fimek]

Hello, what I have noticed is the occasional appearance of artifacts around the triggering edge. Besides, there are extra artifacts when persistence is turned on (as far as I remember - they have been mentioned within this thread). Also - there are problems with trigger level. To provide stable signal it must be set close to a signal base line. If it it set closer to the upper level but still below the signal amplitude then the oscilloscope looses synchronization. In fact the occasional artifacts around the triggering edge and problems with triggering are the most annoying. And the buzzer - is generates sound in multimeter mode while it remains silent in oscilloscope mode. There should be an option of controlling the sound in both modes at once. This is why I'm very much interested in release of an updated firmware

[Altair8800]

My hunch is that some of these versions might be beta version that their engineers are working on and they have not yet a stable (for release) version yet.   

I think Tim (Zoyi/Zotek) might not have said it the best way...

[Dave_g8]

Cheap scope expectation management.

I have an old 15MHz analog scope.  It is honestly 15MHz.  If you put in a higher-bandwidth signal, you see a 15MHz low-pass filtered version of it.  For example, a 6MHz square wave will look pretty rounded, but rock steady with no strange artifacts.

I agree with the comment of managing the expectations of these devices.

Input signals with fast transitions can show ringing on the reconstructed displayed waveform due to sampling and interpolation. The sin(x)/x only works accurately for band limited signals presented to the ADC input.

In the Excel examples below, the blue dots show the sampled values and the red line the sin(x)/x interpolation.

The first case is with fast transitions and the second case is with slower (band limited) transitions presented to the sampling device.




The example below shows reconstructing a 7.1 MHz sine wave with a sampling rate of 40MSa/s.

[swampy]

Hi. I have been a member for a long time, but I just rejoined because my membership seems to have lapsed; possibly for lack of posting, lol. Anyway, I thought you might like to know that the latest firmware for the ZOYI ZT-703S, version ZOYI-703S-FW-V132.ZTK is now available on the official website here: https://zotektools.com/firmware-update-703/ I have installed the firmware without any issues. I have not yet had time to see what has been updated, except that I notice I now also have a X100 probe option. 

[ksxx]

Official update to 1.32 worked for me as well. Beside the 100x option, there seem to be no visible news in the menu. Not 100% sure, but the AUTO function seems to make better choices with offsets and sensitivity when using 1 channel vs 2 channel. The vpp,min,max measurements  give readings that do not depend on the vertical offset anymore. RMS though does change with the vertical offset. Still, the measurements are off by a lot for spiky signals like pulses with a low rep rate. It looks as only a fraction of the displayed data is used for the measurements and thus the peaks while visible might get thrown out of the analysis.

[ksxx]

a quick tip for the problem of the BNC connectors being too tight/short: Get a BNC T or 90deg adapter and file down the end of it by a few 100 microns. Probably leave it on the meter. 

[MarkusWandel]

If I update to the new 1.32 (the thing now has "1.30" on it) and something stops working that previously worked
- will it accept a firmware downgrade?
- where can I get the older 1.27 release, just in case?
Goes without saying I'll keep the 1.32 upgrade file around for potential future use.

[lchao]

If I update to the new 1.32 (the thing now has "1.30" on it) and something stops working that previously worked
- will it accept a firmware downgrade?
- where can I get the older 1.27 release, just in case?
Goes without saying I'll keep the 1.32 upgrade file around for potential future use.

On the thedmm.com the link still points to v1.27 (at least yesterday it was, right now I cannot check it):
1. go to the website: https://thedmm.com/shop/zt-703s/
2. Scroll down to the "Download File" button
3. Click on the button -> https://drive.google.com/file/d/1j5GLloua8nbk5bFO4p7Zw5z5m3VUuqUF/view?usp=drive_link

[Luvticus]

Downgrading from 1.3.2 to 1.2.7 works without problems as long as the USB-Mode works. I just had temporary problems with the scope getting recognized in USB-Mode with FW Version 1.3.2. The USB-letter appeared and disappeared on my Windows 11 Desktop after a
split of a second! I reverted my last change in the setup options and the scope was recognized again. The change was switching off the 4th parameter in the measure-Menue (VMAX also seen in the following attachments) on Channel 2, don`t know if this caused the problem. I could not reproduce it. Probably a reset to default would have solved the USB-Problem also.
Anyhow, the FW 1.3.2 like the versions before still has the problem of sporadically showing distortions in the waveform like in this examples:





Has anyone made similar experience?

Short update:
I got the USB-recognition-problem also with FW 1.2.7 and independent of the number of parameters shown in the measure box. Maybe I have a faulty unit...

[ksxx]

Anyhow, the FW 1.3.2 like the versions before still has the problem of sporadically showing distortions in the waveform like in this examples:

(Attachment Link)

(Attachment Link)

Has anyone made similar experience?

I was curious about this behaviour and did some experimenting. Used the built in generator with triangle and 100Hz to be in the same range as your signals. I can reproduce such signal shifts only if I set the the trigger horiz offset OUTSIDE the current time window. The 703 shows a small horizontal green arrow in this situation. Normally if the trigger is within the time window, there is also the trigger 'T' visible in this range pictogram at the top. Your last screenshots however show that the trigger is in the current time window and in this case I did not observe the  effect. It is a bit of a problem that potential large horizontal offsets after zooming into a waveform in STOP/HOLD mode are not reset when you go back to RUN mode. I have to click quite a bit to get it back into range. Maybe a long-press on TRIG should better not only reset the trigger level but also the trigger offset.