Author Topic: EEVblog #1260 - $70 100MHz Oscilloscope?  (Read 22844 times)

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Offline cliffyk

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #25 on: November 17, 2019, 08:01:16 pm »
No oscilloscope lacking variable holdoff can reliably trigger on aperiodic or burst signals.

I disagree, the JYETech DSO112A I referenced above does quite nicely on anything I've thrown at it--used it recently to monitor the "Echo" pulse from an ultrasonic sensor, quite nicely and reliably. It also passes the 10 cycles of 10 kHz burst test the 5012H chokes on...
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Offline CatalinaWOW

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #26 on: November 18, 2019, 12:47:48 am »
For what these scopes are costing you can get a high quality used scope.  The used scope will likely have high quality documentation (both use and repair) available and be repairable.  The only advantage for these scopes is their small size and the isolation from battery operation.  Newbies looking for a new scope who do not live in a closet will probably be better off going used.  But these things do have uses, just as the pocket size multi-meters can be very useful for some things.
 

Offline David Hess

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #27 on: November 18, 2019, 02:17:26 am »
No oscilloscope lacking variable holdoff can reliably trigger on aperiodic or burst signals.

Th issue with 5012H is that it never properly triggers on single time events. Not eve once. There is a firmware bug.

The triggering could still be broken by design and admittedly some "toy" DSOs I have checked out were awful.  I am just saying even a perfect trigger can fail on aperiodic or burst signals.

I disagree, the JYETech DSO112A I referenced above does quite nicely on anything I've thrown at it--used it recently to monitor the "Echo" pulse from an ultrasonic sensor, quite nicely and reliably. It also passes the 10 cycles of 10 kHz burst test the 5012H chokes on...

Could it have had just exactly the right combination of sample rate and record length to produce a trigger rearm time long enough to produce good results on those specific tests?  I wonder what kind of algorithm for a DSO would allow automatic triggering on burst signals without user adjustments.

Back when I used analog oscilloscopes which lacked a holdoff adjustment, one of the tricks to triggering on a difficult signal if I was desperate was to adjust the variable horizontal control to trim the time/div to a point where the trigger rearm time was just right.  This left the horizontal scale uncalibrated but provided a stable display.
 

Online Fungus

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #28 on: November 18, 2019, 04:50:14 am »
Does anyone have opinions about the 2-ch SainSmart Mini Digital Oscilloscope DS212 or 4-ch DSO213??

yeh, the DSO213  seem the most interesting of the cheapie portable ones, and also quite expensive for the specs,  so perhaps do work better.

Assuming it's the thing that used to be called "DSO Quad" then the DSO2103 is a great little device, mostly hampered by the user interface.

They're not cheap but if you need something tiny and battery powered then it's the one to go for. I'll definitely get another one if mine ever breaks.

Edit: There's various firmwares available for them, I'm not sure which firmware the eBay ones ship with but it makes a huge difference.
« Last Edit: November 18, 2019, 04:57:20 am by Fungus »
 

Offline x86guru

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #29 on: November 30, 2021, 06:28:51 pm »
Hi guys,

I know this is an old thread but I recently got an FNIRSI-5012H to add to my T&M collection. I bought a FNIRSI-5012H directly from FNIRSI's official store on AliExpress to evaluate it myself.

https://www.aliexpress.com/item/33021370646.html?spm=a2g0s.12269583.0.0.6f82788eTtfVSJ

Surprisingly, FNIRSI provides a URL to the EEVblog YouTube video within their FNIRSI-5012H item page on AliExpress.

Of course, after I measured the actual bandwidth of the 5012H myself, I was disappointed like everyone else here. With a 25MHz 5V p-p sine, the FNIRSI-5012H is measuring 3.32V p-p. I measured the bandwidth of my FNIRSI-5012H at around 23MHz as 23MHz yields a -3dB amplitude drop. 

I was not surprised; however, I contacted FNIRSI directly about the bandwidth issue and was shocked by their complete arrogance. FNIRSI tried to convince me that the amplitude drop from a 25MHz 5V p-p input measured by the 5012H as 25MHz 3.32V p-p is <quote> "normal and all oscilloscopes will measure the same" <quote>.

FNIRSI is claiming that the 5012H has 100MHz of bandwidth because the 5012H can measure frequency correctly, regardless if the amplitude is attenuated below -3dB.

I was expecting FNIRSI to claim it has 100MHz bandwidth under certain conditions, but they claim it fully meets their specifications which bothers me. I could care less about the money as it's nothing, but I absolutely do care about being grossly misled and that really annoys me. I requested to return the 5012H on AliExpress at the "official" FNIRSI store, but FNIRSI keeps refusing and saying that it does have 100MHz of bandwidth because it can measure frequency correctly regardless of a massive amplitude drop way below -3dB.

I would be very happy if it was advertised as having 20MHz of bandwidth and 250MS/s sampling rate, but then again, none of us would have bought it to see if it's really true or not.
 

Online ataradov

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #30 on: November 30, 2021, 07:28:50 pm »
none of us would have bought it to see if it's really true or not.
I'm not sure if this is the case. Simply looking at the board design was sufficient to tell that this device is not going to have 100 MHz bandwidth.

I bought them expecting about what they deliver.
Alex
 

Offline james_s

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #31 on: November 30, 2021, 07:33:06 pm »
I'm quite bothered by falsified specs. If they advertised it as a 20MHz scope I probably would buy one and be very happy with its performance, there are quite a few uses for a pocket sized 20MHz DSO and the price is very reasonable. They flat out lie about the specs though and I will not reward that with a purchase.
 

Offline cliffyk

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #32 on: November 30, 2021, 07:41:10 pm »
I bought one on 9/30/2019,  branded as a "Yeapook 5012H"--got a similar arrogance from FNIRSI when I questioned the claimed "100Mhz bandwidth".

The good news is I got it through Amazon Prime, making my response easy:



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Online Bud

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #33 on: November 30, 2021, 08:21:07 pm »
I'm quite bothered by falsified specs.

That is the nature of the Beast. I do not know what else should happen to make people realize not to buy any meaninful T&M  from China.
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Online ataradov

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #34 on: November 30, 2021, 09:07:06 pm »
That is the nature of the Beast. I do not know what else should happen to make people realize not to buy any meaninful T&M  from China.
Nothing needs to happen. I personally buy based on the actual performance (expected or based on reviews), and I'm rarely disappointed. Just de-rate or ignore specs. This scope is an okay-ish rough waveform display unit, not a piece of measurement equipment.

Same thinking applies to non-Chinese stuff. Everyone lies on the specs to the extent they can. China often lies outright, Western vendors often chose unrealistic and non-representative testing conditions. When was the last time you've got stated battery life on literally anything?

Also, 250 MHz sampling rate is also a lie. It does supply 250 MHz (125 MHz*2) clock to the ADC, but MCU's port and DMA are not capable of receiving those samples, so you just get double of the same sample on two clocks.
« Last Edit: November 30, 2021, 11:02:54 pm by ataradov »
Alex
 

Online Fungus

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #35 on: November 30, 2021, 10:38:53 pm »
They flat out lie about the specs though and I will not reward that with a purchase.

Sellers have exaggerated/oversold their products since before money was invented.

We have the expression "Caveat Emptor" specifically for that.
 

Offline cliffyk

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #36 on: December 01, 2021, 02:33:13 am »
They flat out lie about the specs though and I will not reward that with a purchase.

Sellers have exaggerated/oversold their products since before money was invented.

We have the expression "Caveat Emptor" specifically for that.

There is also:

"if something sounds too good to be true..."

and,

"If you buy the cheapest there is, you will likely get 'the cheapest there is'.
-me ca. 1975-

and; from the IBM sales team in the late 60s/early 70s:

"No one was ever sorry they bought the best there was!"

I did not expect an $80 Asian "toy" 'scope to actually be capable of 100 MHz bandwidth, and was not "disappointed" that it didn't--more just pissed off that I was so blatantly lied to--but other than that, lost no "skin in the game"...
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Offline all_repair

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #37 on: December 01, 2021, 03:20:54 am »
Proof is in the usage.  For such a scope, one does not buy it and use it because of the 100MHz.  There are better models came out, I am still holding to my wallet because this beast is good enough and there is always another better model down the corner.  The auto-triggering, the small size and the good enough battery-life has made this scope 2nd most used equipment after handlheld multimeters.  Investment has been recovered many time over.  Can't say about a lot of high specification white elephants I had bought.
 
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Online Fungus

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #38 on: December 01, 2021, 08:09:25 am »
Proof is in the usage. The auto-triggering, the small size and the good enough battery-life has made this scope 2nd most used equipment after handlheld multimeters.  Investment has been recovered many time over.

Yep. If you're working in the kHz range, or even up to single digit MHz (eg. Arduino) then this thing is a bargain. The difference between being able to see a signal or not is like night vs. day.
 

Offline x86guru

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #39 on: December 02, 2021, 04:09:23 am »
I opened a dispute on AliExpress with FNIRSI's Official store who sold me the FNIRSI-5012H.

Here is the FNIRSI's Official store on AliExpress claiming their FNIRSI-5012H meets their advertised specifications.

This shows you how blatantly dishonest FNIRSI is.



They also posted these pictures as evidence that it has 100MHz of bandwidth. The first picture is the picture I showed them of a 5V p-p signal and the 5012H only measuring 3.32V p-p. They marked it up to show that it can read 25MHz correctly, completely ignoring the 3.32V p-p measurement which shows how completely incompetent FNIRSI is:





I posted this back, I assume everyone here does agree?



 
« Last Edit: December 02, 2021, 05:00:08 am by x86guru »
 

Offline cliffyk

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #40 on: December 02, 2021, 05:57:10 am »
I have in the past bought from AliExpress, however adter a similar row with their customer "support" over something i bought but never received (a Wen portable band saw) I swore I'd never deal with them again. The vendor claimed it had been shipped, but could provide no proof of delivery; nonetheless AliExpress stood 100% behind the vendor, essentially telling me to screw off.

Pay a bit extra and get it from Amazon--"Prime" is my preference; free 2-day (1-day on some stuff) shipping and NO hassle returns--worth every penny...
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Offline cliffyk

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #41 on: December 02, 2021, 06:12:39 am »
Proof is in the usage.  For such a scope, one does not buy it and use it because of the 100MHz.  There are better models came out, I am still holding to my wallet because this beast is good enough and there is always another better model down the corner.  The auto-triggering, the small size and the good enough battery-life has made this scope 2nd most used equipment after handlheld multimeters.  Investment has been recovered many time over.  Can't say about a lot of high specification white elephants I had bought.

Agreed, I have the Yeapook branded 1013D dual trace 'scope, also claimed to be 100 Mhz, but really just 34 Mhz. It also has a maximum vertical sensitivity of just 50 mV. Nonetheless I used it quite often troubleshooting automotive and bike ignition and other engine control systems.

At 7000 rpm even a 10 cylinder 4-stroke/cycle engine is only firing at 585 Hz. It is only within the various controllers that Mhz frequencies can be found, and signal levels are all well above 50 mV.
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Online Fungus

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #42 on: December 02, 2021, 06:52:29 am »
I opened a dispute on AliExpress with FNIRSI's Official store who sold me the FNIRSI-5012H.

Here is the FNIRSI's Official store on AliExpress claiming their FNIRSI-5012H meets their advertised specifications.

This shows you how blatantly dishonest FNIRSI is.

Meh. All this was known a year ago, there's multiple threads on here. Nobody was even surprised by the measurements, it simply isn't possible to make a device with those specs at that price. All we wanted was to see how bad it actually was.

FNIRSI aren't being dishonest (in their eyes), it's simply the way business is done in this world, eg. when did you last see a car that meets its official fuel consumption figures in the USA? Would you expect to get a refund for a car by making a fuss over it?

Open your eyes and you might see you now own a useful, cute, portable oscilloscope that didn't cost you much money.
« Last Edit: December 02, 2021, 06:55:19 am by Fungus »
 

Offline cliffyk

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #43 on: December 02, 2021, 07:27:53 am »

Meh. All this was known a year ago, there's multiple threads on here. Nobody was even surprised by the measurements, it simply isn't possible to make a device with those specs at that price. All we wanted was to see how bad it actually was.

That's the "If it sounds too good to be true..." part.

Quote

FNIRSI aren't being dishonest (in their eyes), it's simply the way business is done in this world, eg. when did you last see a car that meets its official fuel consumption figures in the USA? Would you expect to get a refund for a car by making a fuss over it?

They may not believe they are being dishonest--but they are, blatantly dishonest. That "...it's simply the way business is done in this world..." does not make it right; it's just yet another example of the devolved cesspool our society has become.

Automobile manufacturers use the EPA test schedules (I.e. laboratory tests) to come up with published fuel economy numbers--this is akin to using the -3 dB point to determine a 'scope's bandwidth. Using different test parameters; be it a different lost amplitude specification, or such as driving on real roads vs. on a dynamometer in a laboratory--will produce different numbers.

Quote

Open your eyes and you might see you now own a useful, cute, portable oscilloscope that didn't cost you much money.
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Online Fungus

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #44 on: December 02, 2021, 10:47:37 am »
They may not believe they are being dishonest--but they are, blatantly dishonest. That "...it's simply the way business is done in this world..." does not make it right;

We also know that the CAT ratings on cheap multimeters are a lie and don't take them into industrial power location expecting them to behave like Flukes.

On the bench when we're messing around with 5V DC? They're great little meters!

The truth about the FNIRSI is all over the Internet. There's no point in acting all indignant about it if you've just bought one.
 

Online tunk

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #45 on: December 02, 2021, 11:16:59 am »
It is not specified how those 100MHz is "measured", so instead of -3dB,
I guess it's something like this: The max frequency where you can still
see (if you squint) it's a sine curve.
 

Offline x86guru

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #46 on: December 02, 2021, 01:40:55 pm »
The truth about the FNIRSI is all over the Internet. There's no point in acting all indignant about it if you've just bought one.

Let's load up the hair trigger double barrel shit machine gun and take them out! :)

 

Offline cliffyk

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #47 on: December 02, 2021, 04:51:37 pm »
It is not specified how those 100MHz is "measured", so instead of -3dB,
I guess it's something like this: The max frequency where you can still
see (if you squint) it's a sine curve.

Yes, their not specifying the test parameters, thus leaving the customer to assume it is specified at the conventional -3 cB point IS the big lie. However there is no such "fudge" in their false claim of a 500 Mhz sample rate.

The fact is FNIRSI are a bunch of lying dog-faced pony soldiers, as are the various resellers that rebrand the device and make the same claims. The retailers offering it to the consumer are very near equally to blame despite their often well hidden allusions to "manufacturer's specifications" disclaimers.

That they all having been telling/selling the big lie for nearly two years does not absolve them of any wrongdoing anymore than calling a cow's  tail a leg means a cow has five legs--calling it a leg does not make it one. The bottom line is the makers and resellers are liars, and the retailers are their enablers.

I agree that this most recently deceived/aggrieved buyer apparently did not exercise due diligence prior to purchase. The overall failure complicated by not exercising same re: buying from AliExpress.

The best lessons in life often require making mistakes and learning the "hard way". That's how we all learned to walk and talk.
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Online ataradov

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #48 on: December 02, 2021, 05:42:17 pm »
Let's load up the hair trigger double barrel shit machine gun and take them out! :)
Why would I take out manufacturer of a product I enjoy and that fits the need? So my only option is to buy $2000 Keysight?

I would rather everyone was honest with advertising, but even in that case Chinese vendors would not be first on my list.

It is like complaining about 1500W speakers. Just be real, and if you are clueless enough to buy those products on the provided specs, then does it really matter to you?
Alex
 

Online fourfathom

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Re: EEVblog #1260 - $70 100MHz Oscilloscope?
« Reply #49 on: December 02, 2021, 06:28:12 pm »
Let's load up the hair trigger double barrel shit machine gun and take them out! :)
Why would I take out manufacturer of a product I enjoy and that fits the need? So my only option is to buy $2000 Keysight?

I would rather everyone was honest with advertising, but even in that case Chinese vendors would not be first on my list.

It is like complaining about 1500W speakers. Just be real, and if you are clueless enough to buy those products on the provided specs, then does it really matter to you?

Maybe it's "Peak Music Power" 100 MHz bandwidth? 

Anyway, I have one, it's a cute scope and often useful to me. I bought it knowing the issues, and would buy it again.  I have better scopes when needed.  It does suck that the specs are blatantly misrepresented, but this seems to be the world we live in.
We'll search out every place a sick, twisted, solitary misfit might run to! -- I'll start with Radio Shack.
 
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