Author Topic: FNIRSI-1013D "100MHz" tablet oscilloscope  (Read 33198 times)

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Online Martin72

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #350 on: July 21, 2020, 03:41:14 pm »
Bodnar-Pulse :

[attachimg=1]

Terminated with 50 \$\Omega\$ ,although it makes no difference... ;D

Offline cliffyk

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #351 on: July 21, 2020, 03:51:28 pm »
Playing around with the stb-3 board :

[attachimg=1]

The demo board provides a variety of testsignals, ideal for doing a quick "overall" test on new scopes.
Sinewaves, squarewaves, pwm, runt, glitch, modulation, eres and several serial bus signals.
And inbetween it´s limitations, the scope performed well.
PWM signals are no problem:

[attachimg=2]

Runt and glitch pulses....Well, no.  ;)
Also it couldn´t display the AM signal (25Mhz carrierfrequency) proper, but the rest is not too bad, single/normal trigger works fine.
Showstopper is the minimum resolution of 500mV/div. in 10x mode and the missing of other triggerfunctions.
Interesting:
Frequency will only be measured when the trigger is in "auto" mode, in normal mode it doesn´t work.
Also you can´t "zoom" in after stop.

Continue playing with the board and scope...

Mine does "zoom" (alter gain and timebase), "pan" (change trigger level and position), toggle FFT, and all that in Stop mode? 

Duty cycle +/- and time +/- are also blocked in Normal and Single trigger mode. As I have said before 10x mode is irrelevant for my needs, I do wish triggering worked at slower (<10 ms) time base settings.
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Offline cliffyk

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #352 on: July 21, 2020, 03:58:45 pm »
I quite understand and we needed to do maths on the fly with a CRO however most DSO's are able to display waveforms in the units of Amps.

But the amount of menu-diving required simply isn't worth it.

Another FAIL for FNIRSI.  ::)

Yeah, total fail. They totally should have added a whole extra menu just for that.  Not. :palm:
We need ask ourselves who might buy this $120 tablet instead of a proper DSO or for that matter a working CRO ?
At least an order of magnitude sensitivity better is available in all other scopes and totally without the apparent sensitivity to 10x probes.  :o
Yes older instruments do have their limitations too but not so for the most basic of measurements like these.

A buyers expectations of getting a somewhat capable instrument would not be met and for once on this forum I'd recommend the purchase of a CRO so not to be so disappointed. Yes I said that !  :palm:

Yet member bd139 picked up a mint condition TDS210 DSO yesterday for the same price as the topic of this thread of which I strongly suggest will be a much better investment.

I agree and stated earlier I suspect 99.44% of the buyers have no need for 100 MHz or < 50 mV/div performance--half of that number probably don't even know what those specs mean...
« Last Edit: July 21, 2020, 04:03:06 pm by cliffyk »
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Offline jemangedeslolos

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #353 on: July 21, 2020, 04:10:17 pm »
I don't understand why people are so shocked by the lies and the performance of this oscilloscope.
if you have 150$...
I'm not shocked!
Actual price is 100$ (on taobao.com in China, price is 699 RMB = ~100$), this is how much I paid...
Do you know any alternative for the same price?  :)

No, it is why I have one in front of me right now.
Perfect for me when I need to see something
 

Online Martin72

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #354 on: July 21, 2020, 04:15:51 pm »
Quote
I suspect 99.44% of the buyers have no need for 100 MHz or < 50 mV/div performance--half of that number probably don't even know what those specs mean...

As stated before, this thing is a nice little toy you could do rudimental measurings with.
But in my opinion, it´s not a scope for beginners, they should save their money to buy a little siglent or rigol - Or buying a used, well known scope.

Offline gf

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #355 on: July 21, 2020, 04:18:31 pm »
Yep. It's 200MS/s actually as both ADC's in the one chip are clocked out of phase, same signal goes into both ADC channels.

I'm wondering, are the two ADCs still clocked anti-phase in 2-channel mode?

[ I'm asking because on my Hantek 2000 this is unfortunately the case, leading to 1/2 ADC clock cycle delay between the displayed CH1 and CH2 signals :( Usually hardly visible w/o zoom-in, nevertheless significant in cases where it matters. ]
 

Online tv84

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #356 on: July 21, 2020, 04:19:26 pm »
tv84 is in the place so he will soon be able to unlock the serial bus decoding, the eye diagram and the zone triggering :-/O

Yep, eye diagram: almost there. Just waiting for Sighound's MXR to do some comparison tests.  ^-^

This thing is so streamlined that it doesn't have much code for options! Even for bugs!!  :-DD
 

Offline hughtmccullough

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #357 on: July 21, 2020, 04:55:25 pm »


Look: https://mysku.ru/blog/aliexpress/80036.html#comment3580231

Quote
If R12 is reduced to 10-22 Ohm, the frequency response at the HF will become flat to 100 MHz.
If you increase C2, it will level out at the low frequency response.


Maybe the Chinese are more clever than the Russians.  A simulation only gives the answer to the question you ask it.  If the combined capacitance of the switch contacts, op. amp and any other stray capacitance is about 10pF then the frequency response will be flat without the bump at 10kHz.  It looks as if the simulation only includes the capacitance of the op. amp and it is safe to assume that the design doesn't use relatively expensive low capacitance relays and that there will be other stray capacitance of the same order of magnitude.

If this is the case then the switching (using the values in the circuit) will follow fairly closely the sequence 5V/div, 2.5V/div, 1V/div, 500mV/div, 200mV/div and 100mV/div.  This leaves the 50mV/div scale and it is quite possible that it is done in software, reducing the resolution to 7 bits, unless there is another gain stage after the OPA356.

The specification claims both AC and DC coupling but the simulated circuit clearly has AC coupling only.  Does the real circuit have another switch that bypasses the input capacitor?

 

Offline rhb

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #358 on: July 21, 2020, 06:30:04 pm »
Bodnar-Pulse :

[attachimg=1]

Terminated with 50 \$\Omega\$ ,although it makes no difference... ;D

That's quite respectable.  Makes me think that if the critical caps were variable you could trim it up and do better.

Have Fun!
Reg
 

Offline boggis the cat

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #359 on: July 22, 2020, 02:41:11 am »
Has anybody measured the bandwidth in 1x mode?

What specifically did you want verified?

The measurements I took – with the instrument set to 1x mode, Active Heads set to 1 MOhm impedance – suggested a BW close to 50 MHz... however, the amplitude seems to bounce around above 30 MHz-ish, so it depends on what you're assessing.

It's pretty solid through to 20 MHz.  Beyond that it starts getting hinky.

I would call this a 20 MHz 'scope with the 3 dB around 30 to 40 MHz.  (The hinkyness factor that this instrument has going on isn't something you get with most 'scopes, even the most el cheapo varieties.)
 
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Online Fungus

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #360 on: July 22, 2020, 05:37:23 am »
Has anybody measured the bandwidth in 1x mode?

What specifically did you want verified?

I was wondering what the bandwidth was with the supplied probes in 1x mode. What would a 10Mhz square wave look like with probes in 1x mode?
 

Offline snoopy

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #361 on: July 22, 2020, 05:44:53 am »
I quite understand and we needed to do maths on the fly with a CRO however most DSO's are able to display waveforms in the units of Amps.

But the amount of menu-diving required simply isn't worth it.

Another FAIL for FNIRSI.  ::)

Yeah, total fail. They totally should have added a whole extra menu just for that.  Not. :palm:
We need ask ourselves who might buy this $120 tablet instead of a proper DSO or for that matter a working CRO ?
At least an order of magnitude sensitivity better is available in all other scopes and totally without the apparent sensitivity to 10x probes.  :o
Yes older instruments do have their limitations too but not so for the most basic of measurements like these.

A buyers expectations of getting a somewhat capable instrument would not be met and for once on this forum I'd recommend the purchase of a CRO so not to be so disappointed. Yes I said that !  :palm:

Yet member bd139 picked up a mint condition TDS210 DSO yesterday for the same price as the topic of this thread of which I strongly suggest will be a much better investment.

People who want a compact battery operated portable scope they can take with them anytime and can also do floating measurements etc ;) If you have something better to offer let us know. So far I haven't seen any offers of something better for the price. I've seen a lot worse for the price for a portable scope with tiny iddy biddy screens or limited bandwidth etc :( If I want to make my TDS3012 portable I would have to pay $500 US just for a battery and extra for a charger etc !! Yes it's a lot better scope than this one but for on the job in-situ measurements this would be adequate in most cases and compact as well.

cheers
 

Online tautech

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #362 on: July 22, 2020, 07:33:48 am »
People who want a compact battery operated portable scope they can take with them anytime and can also do floating measurements etc ;) If you have something better to offer let us know. So far I haven't seen any offers of something better for the price. I've seen a lot worse for the price for a portable scope with tiny iddy biddy screens or limited bandwidth etc :( If I want to make my TDS3012 portable I would have to pay $500 US just for a battery and extra for a charger etc !! Yes it's a lot better scope than this one but for on the job in-situ measurements this would be adequate in most cases and compact as well.

cheers
I get that and for those that understand the limitations of these tablets the price is good however I would never recommend them as a beginners scope which due to their price is tempting to those with a limited budget.

This is a prime case to use a recent Keysight slogan: Get a real scope !
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Offline boggis the cat

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #363 on: July 24, 2020, 08:30:43 am »
What specifically did you want verified?

I was wondering what the bandwidth was with the supplied probes in 1x mode. What would a 10Mhz square wave look like with probes in 1x mode?

This is all using the timing signals from the calibrator.  1 Vpp at 10 MHz, nominally squarewave.

The supplied probes were used first, both set to 1X.

FNIRSI Channel 1 / probe A @ 1X:
[attach=7]

Shifted supplied probe A @ 1X to Siglent Channel 1:
[attach=11]

FNIRSI Channel 2 / probe B @ 1X:
[attach=1]
(Note: the signal on this probe seemed markedly more unstable.)

Shifted supplied probe B @ 1X to Siglent Channel 1:
[attach=8]


Setup used:

[attach=4] [attach=5] [attach=6]


Tested the same signal to Channel 1, but using a Siglent probe set to 1X.

FNIRSI Channel 1 / Siglent probe @ 1X:
[attach=2]

Shifted Siglent probe @ 1X to Siglent Channel 1:
[attach=9]

Tested the same signal to Channel 1, but using a Siglent probe set to 10X.

FNIRSI Channel 1 / Siglent probe @ 10X:
[attach=3]

Shifted Siglent probe @ 10X to Siglent Channel 1:

[attach=10]
« Last Edit: July 24, 2020, 08:52:27 am by boggis the cat »
 
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Offline boggis the cat

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #364 on: July 24, 2020, 08:57:45 am »
I get that and for those that understand the limitations of these tablets the price is good however I would never recommend them as a beginners scope which due to their price is tempting to those with a limited budget.

This is a prime case to use a recent Keysight slogan: Get a real scope !

If you can get a decent second-hand one for the same money, sure.

However, you may want a battery-powered device for cheap.  So that means something similar to this.


As an aside, I have ordered one of these: Hantek 2D42.



Once I have it I'll give it a look over.  My expectations are low, but we'll see.
 

Online Fungus

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #365 on: July 24, 2020, 09:08:58 am »
I was wondering what the bandwidth was with the supplied probes in 1x mode. What would a 10Mhz square wave look like with probes in 1x mode?

This is all using the timing signals from the calibrator.  1 Vpp at 10 MHz, nominally squarewave.

The supplied probes were used first, both set to 1X.

 :-+

Food for thought. I'm surprised at how much difference the probes made at this frequency. There's other threads here that show even the cheapest eBay probes working fine at frequencies an order of magnitude higher.

eg. https://www.eevblog.com/forum/reviews/cheapest-100mhz-oscilloscope-probes-hands-on-review/

Edit: Did you compensate the probes on each device before the screenshots? Images like this say "uncompensated probe" to me:


« Last Edit: July 24, 2020, 09:17:23 am by Fungus »
 

Online Fungus

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #366 on: July 24, 2020, 09:10:50 am »
Once I have it I'll give it a look over.  My expectations are low, but we'll see.

User interface looks awful.
 

Online Martin72

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #367 on: July 24, 2020, 02:23:46 pm »
Hi,

Got enough time to play with the siglent demoboard and made some captures of it, see below - Not too bad for this cheap thing, especially see the runt pulses/glitches.

Only the 50mV/div. thing is bad :
Take screenshots from my deskew fixture, one is with "large loop" ( 125mA*8 turns = 1A), the second is "small loop", which means 1 turn and 147mA.
And you see...nothing.
It couldn´t display the 15mV ( 100mV/A).

« Last Edit: July 24, 2020, 02:27:10 pm by Martin72 »
 

Offline cliffyk

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #368 on: July 24, 2020, 06:20:06 pm »
In a not at all bandwidth related exercise I tested the 1013D's battery life.

It ran continuously for 6 h 45 m while monitoring two phases of a 4-phase stepper motor being accelerated and cycled clockwise/anticlockwise over a 270° sweep, pulse frequencies 7 to 44 Hz...

Pretty damned good, first thing I've tested that bettered the claimed spec. It took a 3½ hours to recharge at 1.8 A tapering to 0.3 A over the last ½ hour...
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Offline GeorgeOfTheJungle

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #369 on: July 24, 2020, 09:24:17 pm »
That's very good, but the MicSigs last as long too.  :-+
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Offline CDaniel

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #370 on: July 24, 2020, 09:51:25 pm »
25MHz sinus looks pretty distorted , no wonder why the 10MHz square wave is odd .
 

Offline cliffyk

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #371 on: July 24, 2020, 10:02:02 pm »
25MHz sinus looks pretty distorted , no wonder why the 10MHz square wave is odd .

I believe it is an AM signal, unless I missed it the modulating frequency does not seem to be stated....
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Offline cliffyk

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #372 on: July 24, 2020, 10:05:32 pm »
That's very good, but the MicSigs last as long too.  :-+

They cost 3.5 to 4 x more as well...

My Infiniti M37 is much better than many other cars, in fact the best car I have ever owned, at $52k it damned well should be. I suspect Rolls-Royce's are even nicer...
« Last Edit: July 24, 2020, 10:11:40 pm by cliffyk »
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Online Martin72

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #373 on: July 24, 2020, 10:15:02 pm »
25MHz sinus looks pretty distorted , no wonder why the 10MHz square wave is odd .

Hm, could test the FFT too.

Quote
I believe it is an AM signal, unless I missed it the modulating frequency does not seem to be stated....

One is the "pure" sinewave, the pic beside is the AM Signal with 25Mhz carrier and 2.5Mhz modulation signal.

Offline Kosmic

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Re: FNIRSI-1013D "100MHz" tablet oscilloscope
« Reply #374 on: July 25, 2020, 02:06:46 pm »
I was wondering what the bandwidth was with the supplied probes in 1x mode. What would a 10Mhz square wave look like with probes in 1x mode?

This is all using the timing signals from the calibrator.  1 Vpp at 10 MHz, nominally squarewave.

The supplied probes were used first, both set to 1X.

 :-+

Food for thought. I'm surprised at how much difference the probes made at this frequency. There's other threads here that show even the cheapest eBay probes working fine at frequencies an order of magnitude higher.

eg. https://www.eevblog.com/forum/reviews/cheapest-100mhz-oscilloscope-probes-hands-on-review/

Edit: Did you compensate the probes on each device before the screenshots? Images like this say "uncompensated probe" to me:



I got similar results testing the probe that came with my FNIRSI 5012H. Probe was compensated and then I used a 1V square wave at 2Mhz with 1ns Rise time.

Fnirsi probe:


Generic P6100:


Lecroy AP020:
« Last Edit: July 25, 2020, 02:16:02 pm by Kosmic »
 
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