Hi! In a previous video, we took a look at this Zoi or Zotech Instruments ZT 72s and it's a 10 mahz bandwidth single Channel combined multimeter and oscilloscope and while there were a few issues with it, quite a few actually it was. The video was extremely, in fact, hugely popular. So um, these sorts of things at this sort of uh, price point which was about $80 but this is now at a street price of about $60 Um, it seemed to get a lot of people very excited. A lot of people uh, went out and bought this thing so a lot of people thought that something with this uh, feature set and this sort of price point actually met their requirements really well.

so they actually got one and uh, they're reasonably happy with it now. Um, Zot thank you very much. Have sent in a new one which is not the 702 S. it's the 703s so let's take a look at it so it looks at exactly the same, but this one is 50 MHz bandwidth.

it's dual Channel and it's 25,000 count instead of uh, 10,000 count which was the 702 and it's a currently street price. It's not widely available, but I Found a street price of um, $80 for this thing, but that was at a steep discount I think like 40% off or something like that. so possibly like not a lot more expensive than the 72s and Zot Tech instruments. actually rep to my previous video on this and actually said that uh, I Got like an early unit and a lot some of the things were actually uh fixed in uh previous updates and you can firmware.

You can remote firmware update by via the USB although I haven't tried that on my original and here it is: firmware upgrades and it's intelligent anti- burning just like the other one cuz well, you don't want to burn your LCD display do you? So yeah, curiously, they don't have the model number on there. this is just the Dual channel 50 MHz version and the 702 um is the single Channel 10 MHz version. so let's see what you get in the Box get exactly the same pouch. Uh, you get one oscilloscope probe I thought this was Jewel Channel what's going on? uh buer buer yeah juel Channel um anyway what do you expect for the price point? I guess Anyway, um yeah, the standard pre we got with the other one and it's a P260 60 MHz probe.

It's the uh near or something like that. It's what you expect. um, built down to a price for this thing. So these are basically identical instruments except for the Dual Channel versus single channel.

It's got the same USB uh C interface where you can, uh, charge and you can also access the screen captures uh, remotely uh from the drive and it's got the same function generator internally, but I suspect. just like this one, the function generator is just a gimmick, so just pretend it doesn't have it I Be greatly surprised if they've uh, improved that at all. But anyway, we'll have a look stop testing voltage in current mode. don't do it.

tear off before use. They've had too many people blow the fuses in these things and try and return them. Yeah, as a multier seller I can tell you that happens. You can't tell which one is which.

can you? Um, once again, don't believe the Uh 600 volt cat 4,000 volt cat uh 3 RA in it's not independently certified and it doesn't have the internal uh protection really required to meet any of that. So yeah, but that's typical of these, uh, lowcost instruments. what do you expect for the film Fici Andad. So I'd be surprised if everything's not absolutely identical in except for May the internals which is going to have dual channel.

It's got the fast turn on here. We've got our dual channels there. no look at this. I'm surprised the interface is different and the screen the screen is physically bigger.

I I Stand corrected. but I'm telling you these are physically identical uh products. Otherwise, got the same hard polycarb uh protection on it. No worries.

It doesn't really have any uh protection for falling flat on its face or anything like that, but you know she'll be right. It's got exactly the same uh tiling Bale It'll have the same 18650 re replaceable rechargeable battery in it, but you have to, uh, open the case to get to the fusers. We'll have a look at that later. but I am surprised that that screen has changed.

It should be the same Uh 320x 240 resolution screen I think just physically bigger and they've changed the look and feel. Oops, did that just power off there? Oh that was a screen saber. I think we should be able to turn that off? Uh yeah. and the Uh Zoom window display up there is physically changed.

Um, they the time base now says Nan instead of like an M colon in front of it here. Yeah, they just changed the look and feel of it. They changed the battery indicator and stuff like that, but one menu option has here changed it. now was AC over here, but now it's got a cursor over here.

So I'm wondering whether or not. uh, this change was reflected back in the 702 S model cuz uh zot did say that I did have an early unit. Um, so maybe they have changed it I don't know if you know, leave it in the comments down below. If I can pull up some photos of a newer one, a 702 running this same Uh interface and slightly larger screen I'll let you know, but the interface should work identically here.

We're in Volts time mode here, so that changes our time base like that and that should change our vertical. Oh, I must be in X 10 mode. Does that show up anywhere? I Don't know if I mentioned it on this one over here, but yeah, that's wrong. There should be a X 10 indicator.

Anyway, they've moved. uh, the channel the vertical display from up the top. here. they've moved it to down the bottom which I like better.

but yeah, so yeah, we need to see. It tells us time 10 probe over there. We definitely need time 1. So yeah, that indicator needs to be off that menu.

That's not good enough. needs to be on the screen so you know what's what. So it's 20 Ms per division. Minimum Exactly the same and the relay should switch from 200 to 500.

Clunk? Yep, physical relay switch over, but there is a glitch in The Matrix there as we range change. But for this class of scope, yeah, not going to bother about that. Anyway, let's press the Mo button and go in into the multimeter over here and it's exactly the same so they haven't fixed. What I complained about before was the absolute useless bar graph over here.

Now this one is physically different. so there could be a different multimeter chipset in here. Perhaps this one went to M Volts by default. This one you have to do a different Mill volt over here.

There you go, but that's nicer. Look at the resolution now. Oh, one microvolt resolution. whereas this one only had 100 microvolts resolution.

So that's that's really nice. That's got a 20. That must be a 25 molt full scale mode. and here it is.

It's building up. Yep, it went from 25 to 20 and it switched over to the 500. It's building up so that's now. That shows that it's got a high impedance higher than the regular 10 me ohm input.

and if I put my hands over that, we should be able to cause that to. come on. Oh, rub my feet, rub my feet on the carpet. No, it's not building up that quick.

But yeah. there you go. Um yeah. High impedance input.

but that's a really nice one. microl. Wow. Auto Range test.

There you go. That's pretty quick. Um, same 10 mohm resolution. You'll see the older one is basically the same there.

continuity test. Yep, really fast latches, Very nice. It's loud enough. One thing they haven't fixed is the useless bar graph up here.

It doesn't scale properly. like if you change ranges it just goes like 20 5. It's exactly the same. They had the same problem over here.

it just went to fixed to 100. It's useless. Just get rid of the bar graph entirely. It's not like it's faster updating or anything and give me bigger digits like I asked for that last time like leave it in the comments.

do you agree? What's the point of having a bar graph if it's not far a faster and B and like it's not scaled properly? I Don't get it. What a waste. This gigantic, gorgeous screen on it, which by the way has you know a pretty excellent viewing angle on it. Like just check out the uselessness of this bar graph, look like it's not updating any quicker and it's just no, no, it's Dting all around.

The place doesn't even have an option to like actually do like a bar. it's more like a DOT um version n it's like useless I Gimmick. Now another gripe was that it didn't remember the range or the mode that you were in when it turned it off. So let's actually try that.

Oh, here we go. It's shutting down, shutting down, starting up, and um, yeah n well it does. However, at the very least, uh, remember the mode that you're in in terms of oscilloscope multimeter. So if we turn that off, it shuts down and if we turn it and back on and it goes back into uh, the multimeter mode.

So that's okay and it actually remembers uh, your last oscilloscope settings uh, in this particular case, single Channel only which was the second Channel and 400 Ms per Division and the position as well. So and your time base it remembers all that so that's handy. And just like the other one, the hold here is just a manual hold like that. It doesn't have like any Peak hold capability or you know OneTouch type thing.

Now I Was just upgrading the firmware on this was pretty easy Download it from the website and plug it into the USB drag and drop the file and now it's doing it and it's almost at the end here. so let's have a look. I was in version 30 upgrade failed. Why? I don't don't know I Just remembered uh, this might be due to mine being like an older version.

Um, and it's not the current version but I can't actually power this thing off Now it's I hope I haven't bricked it? Damn. Yep. I have bricked it. Other people have successfully updated their 72s I think yeah, they just sent me a very early unit and I'm did now.

Unfortunately, it's got exactly the same error that we saw on the 72s. This is ridiculous. We're feeding in one milliamp and we're putting it into the milliamp Jack here correctly. But we've got amps selected here and it's uh, telling us that it's 115 milliamps.

This is like unacceptable I Know the range is not correct, but this is an easy mistake to make. This is just ridiculous. It should not be possible. So feeding in 100 milliamps, it's like um I think that's a warning beeper for exceeding the 10 amp maximum even though it's in the milliamp.

Jack This is just oh no. But if we switch over to milliamps of course, um, that wasn't there before. Um, it gave us that graphic symbol telling us which Jack to uh, put it in. Of course we measure the correct thing.

now. it's got the same resolution here of one micro amp there and everything's huny. Dory But if you choose the wrong jack here, you're you're absolutely screwed. So once again, right? I Put in 10 amp Jack We're in Milliamp mode 100 milliamps.

It says that we're 86 milliamps like no, this should not be possible. Of course, we put it in the correct setting. Once again, it tells us which Jack to actually put it in. It's very brief there.

It doesn't give you time to actually, uh, read it. but I Guess that' be annoying every time if that. PO If you made it longer so that you could see that particular message actually pop up, then it's like it's not long enough to read it. But if it was too long, then it'd be too annoying.

and you need a software feature to turn that off. But I don't think there's an option to actually, uh, turn that warning off. It's got to have a fail as a Mly meter when it's capable of just giving you incorrect readings like that without you being aware of it. Spot Accuracy test on uh 10K is fine and 1K is fine as well.

Volts DC Good enough for Australia It's within spec, no worries. Oh, that's that's a little bit. Is that outski? It's not bang on, but you know you don't buy this meter for its accuracy. It is 05% though, plus three counts.

So it is actually technically within spec there. so you're not buying this 25,000 count meter here to like as an accurate, like a really super accurate lab meter or something like that. You're just buying it because it has more resolution than the 10,000 uh, count that you had before. And in that particular case, let's check it out.

Can we do it? Yeah, we can do it, no worries. And where does it flip over there you go? It can go up 2.53 thereabouts. And of course there'll be some hysteresis on that, so you probably have to go down quite significantly before it'll Yep, before it'll go back. There's nothing wrong with that.

All meters will have a range hysteresis like that, and that's a good thing so that you know when you get fluctuating signals on there, it's not constantly. uh, like range changing. There's my 10 narad reference cap that's doing all right. and we've got the same problem as last time of like getting in there and like getting finger grip on that.

you can just do it. but if you try and like put in a a te piece for example, Um, yeah, good luck trying to spin that around if I want to lock that off I've actually got to get a pair of pliers in there and actually move that. That's ah yeah n okay. let's have a play around with the built-in function gen which is pretty much useless So just like the previous time, so let's go over here and you might think it's this output setting.

Okay, so you go in here and it's got Square wave great and maybe we can go in there and sign wave I haven't uh done the auto thing yet? So let's go out like this and let's Auto Range like that I've only got uh no. I got both channels hooked up. see what happens? come on and hello. Oh there we go.

Finally got it. But jeez, it took a while and um, not the same. they're both on X one don't know what's doing there so you can even use this setting here here. Okay, so you go in there like that and you can then go in here and you can adjust the frequency Okay, but you can't go up very high for sign so it's pretty useless.

But if we go for square, you go in here and you can't adjust any of those, it's absolutely useless. So what we can do right? we can exit that and we can go into more apps over here. Okay, and then it's got another Gen interface here. Which is this one? So why have two different interfaces things and operate in different ways so we can turn it off and on there.

it? It's just ridiculous. Go to 500 khz I believe? Yep. Max So 500 khz? let's Auto Range that and see what we get. Come on, you can do it.

There you go. Um, something wrong with the Um scales there? Trust me, both are times one and all the moving and other controls works exactly. uh, the same as it did last time. and once again, it's pretty noisy on there.

Just ignore the fact that this has a function generator. it's useless. Anyway, we'll go down in time base there and probably can't get that to Alias at this particular Sig Gen. Oh yeah, there we go.

Well, it doesn't. It doesn't like that at all and it's got more than enough memory I Kind like was a 50k or something. more than enough memory for uh, the purposes of such an instrument like this. and they seem to fix that uh, trigger level thing that we had in the 702 like trigger level offset seems okay.

now. Anyway, we can go into our measure menu here and we can go volts Peak to Peak so we can choose that and we can choose frequency down here. that's not too shabby. There you go, just overlays that nicely there.

1 mahz a spot on 1.9 volts. Well, it's actually 2 volts Peak to Peak But yeah, whatever. And somebody on the EV blog Forum mentioned a Time base setting problem on the Uh 702 at 500 nond per division. Well on this one, it's bang on 500 nond per Division and 1 mahz input frequency so it's working just fine here.

And good news is they have completely fixed that overrange uh thing that we had on the uh, previous 702 model. Um, there's no more 1.25 micros per division. It's only one or two now so your time base has changed up a bit. but check it out, we can go I've got 10 volts Peak to peak in there and we can go uh, right down to 20 Ms per Division and there's no clipping and that weird stuff that we saw before which you know was really not good.

but yeah, they fixed it nice. So that indicates like a different front end or different sampling system ADC whatever. But we'll find out inside. and as far as bandwidth goes, I Don't believe the 50 MHz and I don't even have to measure it to know that's not the case.

That's 10 mahz that's 20 MHz 30 MHz 40 MHz Oh we chucking the wobblies there H the wheels have falling off the Billy card and that's 50 MHz So yeah n maybe single Channel Okay, single channel on channel 2 10 MHz 20 MHz 30 mahz 40 MHz Not comes the Gser again. So yeah n but like I don't even know why they bother going for these. You know, higher bandwidth things. 10 MHz is plenty 10 20 MHz plenty for a little handheld scope like this.

No worries. But yeah, it certainly works as a scope if you, uh, want to, actually you know, view some waveforms out in the field or something like that at a in a pinch it's like doesn't replace a a better like a more featured you know, tablet oscilloscope or something like that from one of the bigger players these days. like your mix IGS Um, but for you know, something you take into the field and certainly for the price point, it works. So there's a 50 Mt Peak to Peak signal.

Nice and clean so you know it's doing a decent job at the low end and there's the same signal at 4. MHz Unfortunately, the frequency detection is a bit how you're doing there. Um, trust me. Yeah, yeah, there you go.

you have to just zoom out a bit. Otherwise, uh, that little bit of Jitter in there was, uh, causing a bit of problem, but you know it's It's got reasonable performance and the update rate is more than adequate for a portable scope like this. It's actually, really, uh, quite quick. There's 100% modulation.

uh, test there and we can zoom in on that bad boy. There you go, so you know it's it's quite decent. Um, like just as a port. Little portable scope just to get some uh signals up.

and it's got a cursor measurement as well. You can do that if you're uh, really? Keen But meah, All right. quick look inside here. We'll compare the 72 on the left here to the new Uh 703 on the right here.

um, multimeter front end same HRC fuses same Arrangement Uh, we've got exactly the same Reay here. same input MTH Uh High voltage resistors here. Um, single PTC is exactly the same. All the clamping is exactly the same here.

Some resistors have changed here for the M for the Uh chipset here. because the multimeter chipset has changed. we'll try and get the number in a sec. Uh, but it is 25,000 Count versus 10,000 count.

so it's different. but um, basically, um, exactly the same Arrangement input protection apart from the count uh, value and the accuracy in it. same. So it's a DM 1109 for the 7, the older 702 and there's the reference LCL 869 DC ZR and the new one same voltage reference.

Um, but of course the accuracy comes from uh, the resistors and the calibration. but what? what? what? They've laser trimmed that off so they don't want us to know what the that chipset is. Why? not? As far as the oscilloscope go, as you can see, of course, dual channel 50 MHz versus single Channel 10 MHz are significantly larger. can actually cover in both.

There, we've got three once again, looks like they've laser etched whatever that is off. Um, and the isolation looks exactly the same. So they got the same isolated ground uh path, but they've got a greater copper fill on this Uh layer here compared to over here cuz there's just more stuff. Check it out.

Check out all the stuff over here. there's just more I won't go through that looks like it. You know that's like Sig gen type stuff. So anyway, I won't go into details, but you know.

um, you do get significantly more there and it looks like this header sdg v um, that's moved to over here. Yeah. I'm going to have to get the can off to. uh, go any further I'll get back to you.

Okay, so there's the board out. There's the LCD connector that's the bottom of the board there. and and yeah, they've completely laser eted the part number off. We saw it in the previous one.

so um, yeah. I'll leave it watch the previous, uh, tear down. It's probably just another variation of the same part. I Don't know why they're lasering it off though.

that's just that's just ridiculous. It's probably the same one. Probably had more than enough grunt for the Dual channel 50. Well, maybe no, no, Well, maybe it's a different uh processor solution.

but yeah. anyway, why I hide it? So let's get that can off Pop Pop Goes the Weasel nice and will this side just pop off? it does. Oh look at that, we're in like Flyn Let's get that bottom can off way. there we go.

Aha, there's the other solder point there I Was wondering where it was. Pop go the weasel on that one and our can is off and Tada and looks like more laser trimmed uh part numbers. Unbelievable. Anyway, um yeah it is.

Um I think that's significantly different to the other front end As you'd expect, dual channel 50 MHz versus single channel uh 10 MHz And like, why would you laser these off? These are clearly 4051 Seos um switches here. This is just this is just ridiculous H Why? why? why? why? why? why it's it's clear what they are and so yeah. I don't know if that I assume that the processor has, uh, changed somewhat. Oh, Wiggle Wiggle Wiggle year There bit of Trace length matching going on there with the pair next to it.

Um, so we had a separate ADC before and likewise, we now have another separate ADC It's different to the one we had before, but lays it off so yeah. leave it in the comments down below. Once again, uh, they've got uh, length matching there for all the uh data outputs. Looks like it's um, 8bit uh data and so 8bit parallel output.

that would be a dual Channel um ADC I don't know some TI jobby or something like that. Once again, we're going to have prob these are probably 405 ones, right? There's just like there's no reason to do this. None whatsoever. Anyway, you're not going to write home to your mom about this.

uh, front end. but hey, here's our input here. Here's our Um AC coupling. Here's our solid state relay there just to bypass.

uh, the coupling. We've got an attenuator section here which has its own uh, bypass capsule should be using my yellow pointer there. Everyone Likes the yellow pointer. If you want to know, this is a spudger, it's got this.

It's designed for like, you know, open in phones or whatever. Just so look for yellow spudger if you want one of these pointers. Anyway, so there's significantly more stuff. Um, yeah, but it's just like a different ADC and a different process.

ear a little bit more uh to get the uh bandwidth. But yeah, Bob's your uncle? Um, just don't expect uh, you know, fancy panty? um I Like how they've got a poly switch over here for the USB there. That's nice. Um, it's amazing that they can sell these for the price, right? We're talking like street price of like $80 although, but that is like an on sale price.

but still it's It's amazing what you can buy for the price here. and yeah, it's It's not a spectacular mold met. It's not a spectacular oscilloscope. it's a jack of all trades masters of none.

But you know it, it's going to suit some people's uh purposes. Um, for the price point. Uh, what happened to my BNC that one's straight up and down the pins. Um, this one is not so I can't even get it out.

Oh, did I do that with my pliers when I was trying to twist the things in before? Okay, standby current consumption: 1 yeah, 1.5 microamps. Okay, let's power it on and 350 milliamps in oscilloscope mode. Exactly the same as the 702 in multimeter mode though it's much less so. There you go.

Um, whereas the 702 in multimeter mode, that was still 350 so they've significantly dropped that so you will get more battery life out of this thing in for the 702 so that's handy. and that was with 80% backlight. So let's try and change the backlight. Here There You Go 100% And that's at 20% and then 40 and 80.

There you go. So yeah, improved battery life. so that's handy and the battery in this one is 3,400 Milah hours. So they claim uh, which I do believe is much bigger than what came in the 702.

but uh, that might depend on your supplier. so yeah, don't bet on that. But yeah, we're still only talking like less than 20 hours battery life in multimeter mode. less than half that, like sub 10 hours in oscilloscope mode.

so it's not terrific. That's why I Recommend. Always have like an everyday use multimeter that's not going to fail on you when you need it because of the battery and the horrible battery life. but that's the penalty you pay when you've got the uh back lit um color LCD Like that.

Oh well. so what's the verdict on this? Z ZT 703s Well, same as the previous one. Like it's still got issues like you don't buy this as your main multimeter I Would not go out in the field as this being my only multimeter. I Would you know have a proper secondary multimeter just from a convenience factor and from a safety and also battery life point of view because this thing, um, while it does have that 18650 uh battery in there, it's nice that you can actually change it so you could technically uh, carry spares and everything.

It's just not that convenient. It's nice that you get now get the 25,000 count instead of the 10,000 count. That's worth it. and they have fixed uh that overrange issue on the oscilloscope which is a big deal because the reason you're buying this is you're buying it for a because you want a portable scope and if it's giving you 4y readings in overrange then you can't trust it.

Of course this will still give you the faulty readings if you use the wrong amps Jack over here and that's inexcusable. but uh, apart from that, like having dual channel uh capability on here and the oscilloscopes more than add Ade quate it kind of like does the job if you just want to view some waveforms out in the field. So and it's like 20 bucks more for the Dual Channel forget about like yeah it is higher bandwidth but like forget about like 50 MHz Up Performance or anything like that that they claim, but it it is really quite remarkable what you can get uh, for the money and the capabilities of it. But as always with these sort of things, it comes down to price point.

and for like what 80 bucks street price, it seems to be only $20 more than the single Channel version I think that adds great Extra Value So unless you're counting every penny, then um, yeah I'd Um, if you're after something like this, I would go for the uh, dual Channel version. It's nothing to write home about, but could be useful for some people. So I can't give it a like a complete thumbs up just because like you can get incorrect readings in the multimeter range and stuff like that. but the oscilloscope seems to work.

reason me well, the function generator is absolutely useless. don't even bother. But I know some people are going to find this useful and it's reasonably capable. um, and quite capable actually for the price.

So yeah, it's a price point thing. So even though I don't give it a complete thumbs up, I will, actually, um, add this to the Eev blog. store Um, which is that's the web address Eev Blog. do store where you'll be able to buy this um through AliExpress and let me know if you want me to add other stuff um to the Eev blog.

Uh, store and I will do so cuz now I think I have the ability to do that. What beauty! Anyway, it's better in some important uh respects than the 702 so it's quite reasonable. I'll link it in down below. thank you very much Zoe for send or zot um for sending this in anyway.

if you like the video, please give it a big thumbs up. and as always, discuss down below catch you next time.