New Hantek DSO2X1X models?

[LZ4TU]

My reply was to BrutoDetestsSB, but I saw your problem and it can be bad soldering, bad PCB, or even defective IC, so it will be better to ask for return/repair, really sorry and I hope you will find a solution.

[DavidAlfa]

Just checked mine:

[bianchifan]

You can get this upk from the dso3kb_PT24C02_damp.zip which I have posted above https://www.eevblog.com/forum/testgear/new-hantek-dso2x1x-models/msg3860255/#msg3860255

I beg your pardon but I didn't noticed that post. I just downloaded the files.
I'll have a look the next days.
Did I understand you corrcetly that you want me to upgrade to 2D15 first?

[vistorik]

You can get this upk from the dso3kb_PT24C02_damp.zip which I have posted above https://www.eevblog.com/forum/testgear/new-hantek-dso2x1x-models/msg3860255/#msg3860255

I beg your pardon but I didn't noticed that post. I just downloaded the files.
I'll have a look the next days.
Did I understand you corrcetly that you want me to upgrade to 2D15 first?

Before doing anything read FAQ of DavidAlfa https://www.eevblog.com/forum/testgear/hantek-dso2x1x-firmware-updates-and-best-use-practices/msg3590160/#msg3590160. If you want to activate and use the signal generator of your device the only way to do it is to upgrade the device to 2DXX, does not matter when, you can make a rollback at any time. First run dso3kb_backup_builder.upk, dso3kb_Eeprom_backup.upk from DavidAlfa disk https://drive.google.com/drive/folders/1vYFqXzPl2nOZJnx58TLhZa37cmvpqkPY and dso3kb_system.inf_backup.upk to make a full backup of your system.

[LZ4TU]

New SW "dso3kb_20211221.upk" on Hantek's website, from what I saw they fixed FFT bug
From: Fernando Santos "CT1EFF / PY2ZFC / PX2Q3525"

Looks like perfect Christmas gift from Hantek  !

[masta_k74]

I am a little confused.
Since the new firmware update, the error with the interference signal occurs extremely rarely. When it does occur, it seems to disappear by itself if you adjust the time base briefly. (I have not yet been able to test whether it disappeared completely by itself or whether it was due to the adjustment of the time base, as it now occurs so rarely).
Has Hantek really managed to fix this within the software? According to the Official Store, their engineer wanted to take care of it.
That would be too good to be true.
I'll keep testing...

[LZ4TU]

HANTEK ROCKS 

[masta_k74]

I have noticed something new. (With the latest firmware from the Hantek website, 2021-12-28) The interference signal can be provoked when the unit is warm and the input is clearly overdriven, i.e. when the peaks clearly exceed the screen. Sometimes it disappears by overdriving again, sometimes only a restart helps.
I don't know yet whether this also happens when the unit is cold.
Overall, the oscilloscope is much more stable with the new firmware.

[.rpv]

I have noticed something new. (With the latest firmware from the Hantek website, 2021-12-28) The interference signal can be provoked when the unit is warm and the input is clearly overdriven, i.e. when the peaks clearly exceed the screen. Sometimes it disappears by overdriving again, sometimes only a restart helps.
I don't know yet whether this also happens when the unit is cold.
Overall, the oscilloscope is much more stable with the new firmware.

Hi.

I don't think that your scope problem it's software-related, either is picking the signal from some external appliance (yours or from your neighborhood) or some component in your scope isn't working properly. Can you second channel pick the signal too?, this happens with the probes dis/connected?.

Dave made a video about something similar here:



In Dave's case was that he forgot to install the shield can on one channel, but it was way less severe, your scope it's picking something like 400mv+ signal so it's very likely to be a hardware failure.

[masta_k74]

It only affects channel 1. It is most likely to be provoked by overdriving and frequent changing of the measuring range (time and voltage). It disappears partly by itself, but not always. After it disappears, it can be provoked again.
Vibrations (knocking on the housing) do not change anything.
In this picture, both channel using the same signal source. (calibration output for Probe)
When I switch to 40kpt memory depth, it disappears immediately.

[.rpv]

It only affects channel 1. It is most likely to be provoked by overdriving and frequent changing of the measuring range (time and voltage). It disappears partly by itself, but not always. After it disappears, it can be provoked again.
Vibrations (knocking on the housing) do not change anything.
In this picture, both channel using the same signal source. (calibration output for Probe)
When I switch to 40kpt memory depth, it disappears immediately.

You channel 1 it's completely unreliable, this makes your channel 1 unusable, it makes sense that the signal it's present only at higher memory depths, more memory it's essentially more data/resolution.

Try to see the signal with no probes connected, just to discard a defective probe, but if is still there then you should use your guarantee and return it 

But if you got it from China too, I'll probably try to fix it my self...

So you can check:

1. if the BNC it's properly soldered to the PCB.
2. if the shield can it's properly installed.

if the previous seems fine I'll try next:

1. Remove the shield can on your channel 1 and look for bad solder joins.
2. look for components with physical damage, ceramic capacitors with cracks or something that didn't seem right, you can compare it with your channel 2, it's all symmetrical and should be all the same.
3. look at the components around one of the big ICs with scratched top, marked as u38 (maybe u36).

[masta_k74]

I have carried out further, extensive tests. The problem also occurs on channel 2, but less often.

It occurs when the memory depth is 400kpt, 4mpt, 8mpt and the unit is running for more than about 5 minutes.

The easiest way to provoke it is by clearly overdriving the channel with V/DIV knob.

If I do not adjust anything during the measurement (time base, V/DIV) it does not occur.

It disappears immediately when the memory depth is set below 400kpt.

Since the update of 2021-12-30 (latest on official Website) it takes longer to occur / happens less often.

It appears with disconnected probes too.

Still waiting for answer from Hantek...

Yes it's from China (Hantek Official Store on Aliexpress)

[Tomi_sl]

Again - new software ( I fink with new bug) - but I can be wrong.

[michal_nt1]

Hi Everyone,
it's for those who have precise calibrated multimeters ... and factory calibrated internal  AWG's

Could you please measure DC voltage generated with the AWG(high impedance mode) and post your results for:
-10 mV
0 V
100 uV
1    mV
10   mV
100 mV
1 V
3,5 V 

? 

[Algoma]

Could you please measure DC voltage generated with the AWG(high impedance mode) and post your results

I will take a set of measurements with my SDM3055 (5.5digit, still within Factory Cal) and post my results for you tomorrow.

[michal_nt1]

Thanks Algoma,

 after I see the results I will probobably post how to calibrate the AWG if someone needs it,

ps. before measurments warm up the scope, it roughly takes 30 min, it's drift is really temp related. 

[Algoma]

ps. before measurments warm up the scope, it roughly takes 30 min, it's drift is really temp related.

Yes, Definitely warming up the scope.

Here's a 1 Hour warmup to a 1V target.

[DavidAlfa]

The awg is more like a toy, it's useful for a lot of stuff, but by no way expect such accuracy from it.

[Algoma]

Results for Hantek DSO2D15:  (Using SDM3055 calculated average over 2 minutes (600+ Samples)

Required 4 hours warmup to achieve full stability. (And "helpful" Toddler)

​*Curiously the SDM3055 will reveal the hidden resolution of it's 24bit ADC on the Trend Chart and statistics, beyond what the Numeric 5.5digits will display when the reading is close to 0V.


-10 mV   -0.009949           (-09.949mv DC)
0 V       0.000277934   (00.277mv DC) 
100 uV    0.000269175   (00.269mv DC)
1 mV    0.002067           (02.067mv DC)
10 mV    0.010011           (10.011mv DC)
100 mV    0.099501           (99.501mv DC)

1 V      1.00155         (Measured with 2V Range)

3.5 V      3.4954          (Measured with 20V Range)

100uV didn't really output a valid value.. Anything below 10mV was generally questionable output.

I did a slow output Sweep at 10mV 20mV and 30mV.. the sinewave isn't really a stable full scale output until about 50mV (See Attached)

Another Item of note.. Upon Hardware initialization at Powerup of the DSO2D15, the Wavegen outputs 3.2V for a few seconds while the relays are clicking. (Beware! if you have something sensitive attached at startup)

[naelolaiz]

I´m in contact with Hantek Official Store. They wanted a video of the problem. I am waiting for an answer. Someone here might also be interested, so I'm inserting the link here:
https://1drv.ms/v/s!AiPaG0Dlc3q2gZZ0pJNZPpmzM4aY8g?e=anox9T
After this Video, i´ve switched off and on again and the issue don´t happen again... Only after a full cooldown it comes back after some minutes.

I received mine a few days ago, and it has exactly the same problem. As it's my first oscilloscope and it is cheap, I thought that maybe it was like that, but I am glad to find that this is not expected.
I am warming it up to record my own video and contact the vendor.

[update] here it is with no probes: (at 4-40K it works well)

[masta_k74]

I am in contact with Hantek by e-mail. They have assured me that they are working on the problem. Let's see what happens next.

[michal_nt1]

Calibration of internal AWG DSO2X1X   ( DAC902E )

    If you lost  your orginal calibration of the AWG or want to recalibrate
here's what you can do.
    It's been noticed  that some DSO2X1X versions dont have the dds calibration data saved
in PTC  EEPROM thus platform tools in such case is not able to restore DDS calibration data to /DSO/cache. It results in an empty dds_calbration.dat.
    In such case we will have to create our own dds_calbration.dat and upload it to /DSO/cache folder.
To do it we need  a valid dds_calbration .dat that we can edit to our needs. For demonstration I will use dds_calbration.dat that can be foundfrom DavidAlfa's google drive\writable\file comparison... (sinceI  have it on hand now).
    Normally we would extract this file from dso3kb_fix_generator.upk using extract.sh from dso builder
tools. All we need is available in DavidsAlfa google drive.
 
  I've noticed that DAC curve is adjusted with simple function f(x)=ax+b   
where  a is the gain and b is the offset.
 
The attached screenshot  is a dds_calbration.dat viewed in HEX mode. The first yellow marked sequence is the gain and the second yellow highlighted is the offset. To use the hex values in equation
we need to make conversion from HEX to FLOAT number for mathematical operations. In presented screenshot we can calculate the adjusting curve as follows.


GAIN      3FEAF9D909F1F14A   to float  = 0.842999
OFFSET  401EB6B228DC981C  to float  = 7.678414       probably milivolts         
 
thus the curve would look like  0.842999 + 7.678414

Important to notice that the offset value should be measured when in SINE mode , this
mode gives us 100uV step resolution for most accurate measurment for offset calculation. DC steps are like ~1,3 mV...

 Of course after we edit hex file dds_calbrate.dat file we need to upload it to /DSO/cache folder
by making modified dso3kb_fix_generator.upk with build.sh script.

    When I have more time I'll try find  out how to create a quick method for creating  a,b values
after taking  measurments.  I think like , we measure some points, make a regression .  Calculate needed slope and intercept. And remember to warm up before measuring offsets...














Many Thanks to DavidAlfa , Vistorik, Algoma.

[DavidAlfa]

Great finding michal! 

[vistorik]

I've noticed that DAC curve is adjusted with simple function f(x)=ax+b   
where  a is the gain and b is the offset.

For my device (see the picture):
GAIN  (a)     3FEAE4BEC679CC75   to float  = 0.840423
OFFSET (b)  401F4BFD71B04684    to float  = 7.824209   
So a + b (0.8404237.824209) form a string in PT24C02. So if in PT24C02 there is the string with a and b it's very simple to create a calibration file dds_calbration.dat.

[Algoma]

 /DSO/cache/dds_calbration.dat

Offset(h)    00 01 02 03 04 05 06 07

00000000  10 00 10 00 00 00 00 00
00000008  63 EC 84 97 E0 54 EA 3F    (Gain(a)=0.822861)
00000010  00 00 00 00 00 00 00 00
00000018  00 00 00 00 00 00 00 00
00000020  8E 3E E6 03 02 5D 23 40   (Offset(b)=9.681656)