EEVblog 1540 - The $80 Zotek ZT-702S Osciloscope Multimeter REVIEW - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: April 27, 2023, 12:28:24 pm
content: Is an $80 combo oscilloscope/multimeter any good? A look at the Zotech ZT-702S, with street price around US$60https://s.click.aliexpress.com/e/_DFsZNAV

author: Per Hansson
author_rank: Unknown
timestamp: April 27, 2023, 04:40:43 pm
content: It's really odd how the suppliers on Aliexpress etc does not have the name of the thing in the title of the page!Like, how do they even come up with this title: "Digital Storage Oscilloscpe Multimeter Auto True RMS Tranistor Probe Multimetro 48M/S 10Mhz PC Waveform Digital Oscilloscope"I guess writing "Zotech ZT-702S" would be too complicated

author: thm_w
author_rank: Super Contributor
timestamp: April 27, 2023, 10:04:08 pm
content: The point of the titles is to hit on as many key words as possible. But yeah leaving the name out is stupid, if I search google for it I can't find it at all.. maybe they'll fix it after its "released". As some kind of preventative measure in case they get a ton of bad reviews.Zotech has responded in the youtube comments saying they'll fix some of the bugs. But no mention of the useless bargraph.

author: abeyer
author_rank: Frequent Contributor
timestamp: April 27, 2023, 10:58:08 pm
content: QuoteSounds like the most glowing review Dave's ever given a Chinese handheld scope.

author: wilfred
author_rank: Super Contributor
timestamp: April 28, 2023, 11:23:12 am
content: Quote from: abeyer on April 27, 2023, 10:58:08 pmI thought so too. Makes me want to buy one. I got burned by Aliexpress on some cheap piece of test equipment a few years ago that Dave reviewed. Never did receive it and couldn't for the life of me work out how to get a refund. I haven't use Aliexpress since.I do realise it isn't impossible to get refunds but I didn't manage it then.

author: tunk
author_rank: Super Contributor
timestamp: April 28, 2023, 04:55:36 pm
content: Also sold as Richmeters 702S, so I guess it soon will show up as Anengs etc.:https://www.aliexpress.com/item/1005005505224392.htmlAnd wonder what the ZT-703S (2ch/250MSps/50MHz) will cost?

author: RAPo
author_rank: Super Contributor
timestamp: April 28, 2023, 05:55:39 pm
content: QuoteI'm looking for it, but can't find it.

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 28, 2023, 07:43:15 pm
content: Ahah, it's pretty meh.Still, we would have killed to get something like that at this price, 25 years ago.

author: Fungus
author_rank: Super Contributor
timestamp: May 01, 2023, 10:40:59 am
content: Quote from: SiliconWizard on April 28, 2023, 07:43:15 pmCompared to what at this price range?

author: Kleinstein
author_rank: Super Contributor
timestamp: May 01, 2023, 04:34:29 pm
content: The DMM part is not that great, though still not as bad as the Habor freight ones. At least it looks like one has the USB interface available and a low voltage range is also not that bad - at least if it actially works and is not cheating on zero noise with a dead band. I would consider the DMM part more like an add on extra. The main point is the scope function. So don't compare to a $80 DMM - more like a $10 meter and $70 scope.It is obvious that the CAT rating is not to be trusted - no real surprise on this. No idea why they add this obvious wrong rating, that could hurt exports to the EU.From the video the scope part looks pretty decent for a portable one, though with a small screen. Not sure if I would prefer a Fluke 123, which in a way higher price range.

author: CChin254
author_rank: Regular Contributor
timestamp: May 02, 2023, 02:46:46 am
content: Could you please post high resolution photos of the PCB of this device?

author: EEVblog
author_rank: Unknown
timestamp: May 12, 2023, 10:04:02 am
content: It was very nice of Mr Li Hong himself to say thanks and invite me to visit if I'm over there

author: EEVblog
author_rank: Unknown
timestamp: May 12, 2023, 10:04:50 am
content: Quote from: CChin254 on May 02, 2023, 02:46:46 amhttps://www.flickr.com/photos/eevblog/albums/72177720307943576

author: bobale
author_rank: Contributor
timestamp: May 13, 2023, 04:45:49 am
content: Can somebody please clarify something about this scope. In the specs it states it has 150V maximum input voltage. Does that mean it's 150V if the probe is in x1 mode? Does that mean it can be much higher if you switch it to x10? I need a scope to probe around switchmode PSUs, so 150V is not enough for that purpose.

author: Kleinstein
author_rank: Super Contributor
timestamp: May 13, 2023, 08:24:32 am
content: The voltage limit is a bit tricky. The actual amplifier input only sees the voltage after the probe division. Howeven when in AC coupled mode things depend on how the AC coupling is done. At least the switch has a good chance to also see the full voltage even with a x 10 probe. It is also likely that the coupling capacitor gets a higher (maybe all) voltage. Both the switch and the capacitor and maybe creep distances may not be made for a higher voltage. A nasty surprise can also come from the charge stored in the coupling capacitor when switching to another voltage later - I once damages a scope input this way, going from some +150 V to some -150 V (or the other way around) with a scope that is good for some 200 or 250 V max.There is another problem with using a not grounded scope with high voltage. Most of te normal probes are designed to work with a grounded scope and thus have no (good) isolation on the ground side. So one should at least check the probes manual, if they are OK to be used with a floating scope / ground. It anyway needs extra care.

author: LektroiD
author_rank: Frequent Contributor
timestamp: May 14, 2023, 01:48:06 pm
content: Does anyone know where the firmware update page is hosted?Despite a couple of pitfalls (expected at this price range), it's a great little portable scope, very useful for my line of work. Thanks for the review, Dave!

author: evlo
author_rank: Contributor
timestamp: May 18, 2023, 08:50:44 am
content: This or Owon HDS242?Does this have any advantage other than being 50usd cheaper? 10MHz/40MHz stands out.

author: tunk
author_rank: Super Contributor
timestamp: May 18, 2023, 11:04:10 am
content: The Owon has two channels, a bigger screen and it comes from a more reputable manufacturer.Edit: A better comparison would be the not yet released 50MHz two channel ZT-703S.

author: WI_Hedgehog
author_rank: Newbie
timestamp: May 19, 2023, 06:21:37 pm
content: Quote from: Per Hansson on April 27, 2023, 04:40:43 pmThe title has a limited number of available space, and/or the scope might be a clone/knockoff of the Zotech. It's common in that market to push the capabilities when the brand is perceived as not well known.That Artery processor is a beast for such an affordable meter!$60-$80 is a screamin' deal. No last-mode memory, but it is affordable! Love it for what it is!"Doesn't this look smick?"--awesome line."Stop testing voltage in current mode."--awesome sticker! I want one!!!

author: maelli
author_rank: Contributor
timestamp: May 20, 2023, 09:12:37 am
content: Another small issue: Probe calibration depends on the attenuation.Different for 2V or lower range to the 5V or higher range. (when the relay clicks)How did I find out?I happen to have a Tek 310A scope. This tube scope has a 100V 1kHz calibrator.It is possible to calibrate the probe to be o.k. ish for both ranges, seepic1.png 2volt range, undercompensatedpiic2.png 5volt range, overcompensatedGood enough for a 80$ scope.

author: Uniityy
author_rank: Newbie
timestamp: May 22, 2023, 02:27:48 pm
content: For those wanting to swap out the included 18650 cell for one of your own, it doesn't work with flat top 18650s by default.I've modified mine by adding a little shim on the top connector so it makes good contact with my LG HG2 flat top. 2000mAh to 3000mAh in a little over a minute of work.Pics here:https://imgur.com/a/WdQWFBR

author: maelli
author_rank: Contributor
timestamp: May 23, 2023, 10:21:58 am
content: quick follow up on the input capacitance.Measured it with my LCR meter. 1kHz.In the low voltage settings <=200mV/div @1:1, input capacitance of the scope is 9.2pF higher than in the high voltage ones >=500mV/div

author: Shonky
author_rank: Frequent Contributor
timestamp: May 30, 2023, 12:16:59 am
content: Has anyone seen any sign of the firmware update or binary image for these?I have some ideas for essentially using the hardware but would like to see the firmware first.

author: Sonny_Jim
author_rank: Unknown
timestamp: June 03, 2023, 08:15:03 am
content: I bought one of these based on Daves review and for what I use it for (pinball machines), it's fine. The one thing that sold me on it (and this will seem faintly ridiculous) was the fast continuity response which is great. The screen is big and bright enough for it to sit in the corner of a pinball machine cabinet and still be easily read, although I haven't really used the scope functionality on it other than using it to check the output of some PIAs. The only gripes I have are mostly the same as everybody else, the useless bar graph and it not remembering what mode you were in.Pretty sure that comment about the 'we will supply updated firmware' was either a straight out lie or overly enthusiastic staff member as it should have surfaced by now.

author: maelli
author_rank: Contributor
timestamp: June 05, 2023, 11:22:22 am
content: another BUG: 500ns/div range is wrong. It is actually a 625ns/div range!See picture showing a 1Mhz signal.This one really needs a firmware bugfix.

author: Zebble
author_rank: Newbie
timestamp: June 29, 2023, 01:29:30 am
content: There's a firmware update available. Not sure what it fixes. I've installed it succesfully, just haven't done any extensive testing.https://zotektools.com/firmware-update/

author: Shonky
author_rank: Frequent Contributor
timestamp: June 29, 2023, 02:24:09 am
content: Looks semi encrypted. Well obfuscated at least as there are some repeating patterns that look like blank space. Not very well encrypted if so.

author: Harvey17
author_rank: Contributor
timestamp: July 01, 2023, 03:29:33 pm
content: Quote from: Zebble on June 29, 2023, 01:29:30 amWhat version is this? Mine came with v1.03.48

author: RAPo
author_rank: Super Contributor
timestamp: July 01, 2023, 03:35:28 pm
content: v1.03.51Quote from: Harvey17 on July 01, 2023, 03:29:33 pm

author: Lango1818
author_rank: Contributor
timestamp: July 10, 2023, 06:47:09 pm
content: I have just upgraded the firmware, not sure what it fixes either but will go and have a play. There is a short video on upgrading, and it was simple enough. After the upgrade it went from V1.03.48 to V1.03.51. Considering I paid $1500 for an analog basic scope in the late 80’s and $800 for my Siglent SDS1104X-E scope this $100 dollar AU thing is far better than the 80’s scope and of course not a patch on the Siglent. I think it is great for a portable cheap scope or a beginners scope.

author: rernexy
author_rank: Contributor
timestamp: September 25, 2023, 03:37:42 pm
content: Received mine today, bought from a guy named Ali of the Express shop. It has firmware version v1.03.55.But the website (https://zotektools.com/firmware-update/) still seems to offer v1.03.51 based on the name of the file "ZOYI-702S-FW-V51(3).ZTK".

author: kwass
author_rank: Frequent Contributor
timestamp: September 29, 2023, 11:12:58 pm
content: Quote from: Sonny_Jim on June 03, 2023, 08:15:03 amThe one just bought came with firmware 1.03.55. It remembers the mode (o'scope vs multimeter) and all the settings within the o'scope mode between power cycles. Multimeter mode always starts in DC volts after a power cycle but remembers all the settings (except min/max/avg) when switching to o'scope mode and back. That it forgets the min/max/avg values when doing this is a plus, as it provides a way to resent those values (I don't think there is any other way to do that).The multimeter functions are quite good. It's got a low burden voltage on A [less than 0.1 Ohms sense resistor] and mA [about 2.4 Ohms] and although it's resolution is only down to 1uA; excellent 1uV and 10mOhm resolution too. For $50 (what I paid on Aliexpress) is not that bad if it were just a multimeter. My only grip is that for some reason you can't rel-out the value resistance measurements, but you can on everything else, this must be a bug.

author: siealex
author_rank: Regular Contributor
timestamp: October 13, 2023, 04:23:41 pm
content: QuoteManually select the lowest range (or short the probes in auto mode), then short-press the power button. REL for resistance works only on the lowest range.

author: kwass
author_rank: Frequent Contributor
timestamp: October 14, 2023, 01:14:10 pm
content: Quote from: siealex on October 13, 2023, 04:23:41 pmOf course, you are correct, I don't why it wasn't working for me earlier. Thank you!

author: tonyalbus
author_rank: Super Contributor
timestamp: October 17, 2023, 08:12:20 am
content: 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 1.03.55After my review i told my Zotek contact and they just updated to the latest on the website today1.03.58 is ready for download.The reviewHave fun

author: Razvan_N
author_rank: Contributor
timestamp: October 17, 2023, 08:19:31 am
content: Are there some release notes? I could not find any on Zotek's website. What's new in this version of the firmware?

author: tonyalbus
author_rank: Super Contributor
timestamp: October 17, 2023, 08:28:20 am
content: Yes good one, i have asked, let see... if they profide it i will share it.What improved in 1.03.55 was the it boots in the last mode DMM or Scope.And the issue Dave had with the trigger bar not lining up was fixed in mine too... but i still have to try 1.03.58

author: Razvan_N
author_rank: Contributor
timestamp: October 17, 2023, 09:27:33 pm
content: I really like this meter. Here are my favorite accessories so far: a BNC adapter and two neodymium magnets that keep the meter safely on a cabinet wall, car body or another magnetic surface.The magnets are scavenged from 2.5" HDDs, are enclosed in heat shrinking tube and glued to the meter's tilt stand with Bison automotive double sided adhesive tape.Very solid and also non-permanent in case I change my mind

author: tonyalbus
author_rank: Super Contributor
timestamp: October 19, 2023, 12:00:50 pm
content: They have no release nots availble..

author: kwass
author_rank: Frequent Contributor
timestamp: October 19, 2023, 02:21:38 pm
content: I upgraded from 1.03.55 to 1.03.58 and can't find any differences at all. Also, after calibration I still find that the trigger level is slightly off.

author: 6gv5
author_rank: Newbie
timestamp: October 20, 2023, 08:24:28 am
content: Quote from: Per Hansson on April 27, 2023, 04:40:43 pmThis might be because over there brands come and go very quickly because they are nothing more than names. With some cheaper products the brand isn't even printed on the product itself, just on the box.My idea - corrections welcome - is that the brand is perceived as more important in the western capitalistic world, so that they stick different ones to various products built in the same factories then see the ones becoming more successful and keep using them for other products too.

author: Razvan_N
author_rank: Contributor
timestamp: October 20, 2023, 09:39:01 am
content: I'm not sure if Zoyi techs read this forum, but I'd like to see two changes in future firmwareversions.1. An option to disable key beeps. I like my meters quiet unless I'm doing continuity tests.2. Displaying the real open leads voltage in diode mode (approx. 3 V), instead of ".OL V".Showing "Overload" with the analog pointer at 100 looks a bit scary and it's not accurate,as a 0.2 V Schottky moves the pointer to line 2 on the dial, as if the full scale would mean10 V instead of 3 in reality.

author: MLXXXp
author_rank: Frequent Contributor
timestamp: October 22, 2023, 06:37:18 pm
content: Quote from: kwass on October 19, 2023, 02:21:38 pmFor one thing, waveform period (Prd) has been replaced with duty cycle (duty) in the"more measurements"display.

author: rsjsouza
author_rank: Super Contributor
timestamp: November 30, 2023, 11:59:07 am
content: Quote from: Sonny_Jim on June 03, 2023, 08:15:03 amI didn't see this video at all until today, but coincidentally I got the ZT-702S model back in July and find it to be quite useful due to the same qualities you pointed out (with the same gripes as well). Also, the form factor, size and above average mechanical robustness are aspects that help me take it to the field more often.When I got it, I put it in my toolbox for a roadtrip just for fun but not really considering it would be put to much use. We ended up having to make some things work on an el-cheapo car inverter and it proved quite useful to see if the 120VAC"modified sinewave" was still good enough to power some of the more sensitive things tied to its output. Back from the trip I saw myself taking this unit to the field more often than my regular DMMs simply due to the practicality of having a "waveform observator" feature that gives extra insights to see noisy or failing DC power rails and follow audio paths.Overall, a great surprise

author: sparrow321
author_rank: Newbie
timestamp: January 28, 2024, 10:06:29 am
content: just putting this here if anyone else was missing a updates version history:fromhttps://archive.is/3Kobdversion 1.03.51download linkis still liveversion 1.03.58(current)download linkam still looking for a v55 download which seems from this forum and someto be the most stablefrom what i gather v51 is the most stable functionaly.on v58 a power on mode memory and duty-cycle meas was added but serious bugs with autorange and other bugs(look in YT video comments) were introduced

author: 5free
author_rank: Newbie
timestamp: January 30, 2024, 12:55:47 pm
content: @sparrow321here it came from the official support .CRC32: 41DF6B6A

author: EEVblog
author_rank: Unknown
timestamp: February 03, 2024, 04:51:08 am
content: Quote from: Zebble on June 29, 2023, 01:29:30 amOops, I just bricked my 702S doing this update. I don't think my early unit was designed to be upgraded

author: Sonny_Jim
author_rank: Unknown
timestamp: February 06, 2024, 05:35:46 am
content: It does say in the video that you can't update v1.03.30, which I guess was what you had. For reference mine was v1.03.43 (ish, should have written it down)Just commenting to say I'm quite happy they eventually released the firmware and if anyone needs to switch it back into English after an upgrade:1. Switch to multimeter mode2. Press menu3. Press F1EDIT: Filename was "ZOYI-702S-FW-V58(1).ZTK" so I guess we are up to version 58 now.

author: marlar
author_rank: Newbie
timestamp: October 11, 2025, 09:14:21 pm
content: I have been looking for a handheld scope like this for a while. I know the limitations, but my needs are very limited and only once or twice a year do I need a scope for simple tasks. So I don't want to spend too much on it, and at the same time I really don't have space for a desktop oscilloscope. Given the quite positive, reviews I am considering ZT-702S.But I also looked at ET828Pro which gets pretty good reviews:However, it is not reviewed nearly as many times as ZT-702S.Does any of you know how ET828Pro compares with ZT-702S?

author: PlainName
author_rank: Super Contributor
timestamp: October 11, 2025, 09:33:24 pm
content: What I like about the ET828Pro, and which I miss from my old Fluke Scopemeter, is the oscilloscope part uses the same inputs as the multimeter. No need to have a pair of leadsanda bulky scope probe just to be able to see the input as V,R,C or a waveform. Less to carry around and get tangled up.In fact, I am seriously tempted to get this just on that basis. Often, when out in the field fault finding, I really want a multimeter but nevertheless want to see the shape of whatever it is, but really hate being overladen with cables as well as a decent selection of tools.