Mustool MT8205 - Useless

[LogicalDave]

I'm always looking for bargain test equipment, and sometimes I get burnt; hopefully this review saves you from wasting some time and money.

I bought the Mustool MT8205 from Banggood who advertise it as a "2 in 1 Digital Intelligent Handheld Storage Oscilloscope Multimeter AC/DC Current Voltage Resistance Frequency Diode Tester"; it sells for just under $50 shipped.  I love Banggood and have had lots of good experiences with them, but buyer beware: this product is a waste of money at any price.

While it looks good, feels solid, and comes with nice probes and case, it simply isn't useful for making measurements.

Let's start with how it works as an oscilloscope since that's the interesting feature of this device.  When I ordered it, the ad said 200ksps which would suggest it is useful to look at signals up to at least 20kHz...not great, but at good enough for looking at audio and PWM waveforms.  However, as the ad now says, the analog bandwidth is limited to 10kHz.  A 15kHz signal is severely distorted and it won't even try 20kHz.  A 10kHz ramp looks just like a 10kHz sinewave. 

You can see pictures on my blog post here: http://www.dalbert.net/?p=613 where I feed it a 15kHz sinewave and a 20kHz sinewave from a Rigol signal generator showing that the bandwidth is indeed limited to 10kHz (i.e. useless).  There are other issues too: there is no trigger control, the signal is always AC-coupled (so you can't measure anything DC), there are none of the controls you'd expect to find on an oscilloscope and it's too slow for virtually anything these days.  The scope feature is a complete bust.

To add insult to injury, the multimeter functionality is useless too!  The readout is only 3 digits and even those aren't accurate!  I hooked the meter up to a lab voltage standard and checked the output with a calibrated 7-digit HP bench meter.  The 10.0000V standard was dead on with the HP meter, but read 9.95v on the Mustool.  What's worse, when I used it to measure 2.5v and then used it to measure 10v again, it took several (I'm talking 4-5) seconds for the readout to gradually climb to 9.95.  Useless.

Summary:

    Large/heavy/manual-ranging multimeter
    Only 3 digits, only 2nd of which are accurate (see 10vdc lab standard)
    Incredibly slow: takes several seconds for voltage to read properly
    Limited to 10kHz analog bandwidth
    AC coupled only
    Oscilloscope has no controls so not even useful as a teaching tool

[sdouble]

what did you expect for 50 bucks shipped ?

[retiredcaps]

The readout is only 3 digits and even those aren't accurate!  I hooked the meter up to a lab voltage standard and checked the output with a calibrated 7-digit HP bench meter.  The 10.0000V standard was dead on with the HP meter, but read 9.95v on the Mustool.

According to banggood website, DCV accuracy is

DC voltage: 200.0mV ~ 1000V ± (0.75% rdg + 10dgt)

10 * 0.0075 = .075

10 - .075 = 9.925.

So the Mustool is within its stated specs.

And I would never buy a product like this.  If I got it for free, that's a different story.

[retiredcaps]

    Only 3 digits, only 2nd of which are accurate (see 10vdc lab standard)

3 digits is correct for a meter that looks to be 2000 count.  In the 20V range, you only get x.yz (3 digits).  If your measurement was 1V, it would be a.bcd (4 digits).

Again, while it doesn't read 10 exactly, it is within spec.

[DaJMasta]

They lost me at "2 in 1 Digital Intelligent Handheld Storage Oscilloscope Multimeter AC/DC Current Voltage Resistance Frequency Diode Tester".


I think it's a reasonable expectation to get something decent for $50 shipped, you can certainly get a reasonably well built brand name meter for that, though probably not a top brand or featureset.... I'm not sure going with something that claims to be an oscilloscope and a multimeter, especially if it's also manual ranging, will ever be your top value for money.

[001]

Hi!
It`s a very well known piece of shit 
See russian shopogolics sites like this https://mysku.ru/blog/aliexpress/53146.html

[LogicalDave]

Dear fellow eevbloggers (and moderators): I urge you to reconsider before posting comments like "what did you expect for $50".  Obviously the answer is: not to have thrown away $50 on a useless device.  My post was intended to help save others from wasting their time and money and (moderators please note) that sort of trolling discourages people from posting. 

There are plenty of high quality, very affordable pieces of test equipment that can be had in the $15-$80 range.  Uni-T, Aneng, and several other innovative Chinese manufacturers make excellent, accurate multimeters; Owon makes some very handy USB oscilloscopes that can be had for under $80 and work extremely well.   Unfortunately, Mustool doesn't appear to be such a company.

RetiredCaps, thank you for pointing out that the meter was in spec; please note that I didn't suggest that it was out of spec, just that it was useless: a $50 multimeter with only 2-3 useful digits is ridiculous these days and the 10kHz bandwidth and other limitations of the "oscilloscope" make it similarly useless.

[fluff]

Hello @LogicalDave, I just register to thank you for your post you saved me a few bucks 

[wraper]

The readout is only 3 digits and even those aren't accurate!  I hooked the meter up to a lab voltage standard and checked the output with a calibrated 7-digit HP bench meter.  The 10.0000V standard was dead on with the HP meter, but read 9.95v on the Mustool.

According to banggood website, DCV accuracy is

DC voltage: 200.0mV ~ 1000V ± (0.75% rdg + 10dgt)

10 * 0.0075 = .075

10 - .075 = 9.925.

So the Mustool is within its stated specs.

And I would never buy a product like this.  If I got it for free, that's a different story.

The problem is that $3 multimeters like 830 type usually are more accurate than that in practice.

[Wrenches of Death]

They lost me at "2 in 1 Digital Intelligent Handheld Storage Oscilloscope Multimeter AC/DC Current Voltage Resistance Frequency Diode Tester".

It looks like they hit all of the bases except for gluten free!   

WoD

[DaneLaw]

it was sold at 11.11 USD at  Banggood's 11-birthday 3 or 4 years back to BG's VIP5 with incl. 25% danish VAT & shipping..
I have no problems with it, but also judging it from a lower price point - but it goes without saying, it ain't a scope, but a crude waveform display.

https://imgur.com/a/3ca3Sq0
though never recall what that sketchy toggle-switch on the PCB is for..??      https://tinyurl.com/mtrvrcm7

I remember it had some stacked data-logging features on the screen with 99 entries for the DMM and a lower number for the waveform.
- and some auto-hold feature, where it would beep when it got a steady reading and save it, so you could see it stacked on top of each other but the interface was quite cumbersome and extremely limited and a product that more or less-  lands in between two chairs..

it exists in other brand names, not least EONE ET201 (EEV blog user HKJ [Lygte-Info] and Marco Reps [YT] also took a look).
https://lygte-info.dk/review/DMMEone%20ET201%20UK.html