Author Topic: Hantek 6022BE 20MHz USB DSO  (Read 406868 times)

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Offline Fraser

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Hantek 6022BE 20MHz USB DSO
« on: May 27, 2013, 08:12:32 PM »
To add to my growing stack of Hantek test gear, I have just ordered their budget DSO, the 6022BE.

I have already purchased the 1025G Function Generator and 4032L Logic Analyser so I thought adding a basic oscilloscope would complete the set  ;) It has two channels, FFT and 48Msps real sampling rate (single shot).

Make no mistake, this will be a very basic USB oscilloscope with only 48msps but it will have its uses none the less. Sadly no external trigger input is provided so one channel will provide the trigger. It does have the x-y mode that I need so that is a bonus. I see that there is an 'OpenHantek' project that may support this DSO in the future. An SDK is provided by Hantek.

Once the unit arrives I will provide internal pictures of it and a run down on the software performance. This DSO is not an alternative to 'real' DSO's with >1Gsps but at GBP49 ($75)delivered, its cheap enough to have in the test equipment inventory and competatively priced in the marketplace.

My unit is coming from 'Goodlucksell'

http://www.ebay.co.uk/itm/Hantek6022BE-PC-Based-2-CH-Oscilloscope-20MHz-48MSa-s-gl-/281110701285?pt=UK_ToysGames_RadioControlled_JN&hash=item417380e4e5


I expect this two channel unit to be 'cheap and cheerful' but the software quality, or lack there-of
will be the key to its usefulness. There has been a recent software update to fix some issues.
« Last Edit: May 27, 2013, 08:15:32 PM by Aurora »
 

Offline amyk

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #1 on: May 27, 2013, 09:01:06 PM »
That 48Msps suggests something very common inside...
 

Offline Fraser

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #2 on: May 28, 2013, 12:29:40 AM »
When you look at what you get for GBP49 it can't be a very expensive chipset inside the unit ?

I will let you know when I get it.
 

Offline Fraser

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #3 on: June 13, 2013, 10:23:20 PM »
The 6022BE arrived today.

I have quickly whipped its clothes off to see what lives inside.

For GBP49 delivered I did not expect a lot but see what you think.

The key components are as follows:

1. CY7C68013A-100AXC
2. 24LC02 EEPROM
3. Dual Channel ADC with glued on heat-sink. Likely to be a 40MHZ AD device.
4. 2 Analogue input channels. Each contain 74HC4051, 5 pin 'HRA' amplifier, Qty 2 in cascade and a 3 pin 'A7' device.
5. AMS1117 3v3 regulator


There are positions on the PCB for another CY7C68013A-100AXC, 24LC02 and a SMSC USB2512A USB Hub. These would provide a 16 Channel Logic Analayzer function to the unit.

There is also a position for a 5V supply. Interestingly, the only components needed are a socket and a diode. There is no polyfuse in the external supply rail unlike the USB feed.

Pictures to follow.
« Last Edit: June 13, 2013, 10:45:08 PM by Aurora »
 

Offline Fraser

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #4 on: June 13, 2013, 10:47:11 PM »
Ok here are the pictures.

Nice PCB. It is laid out in a logical manner.

The parts count is relatively low and a CY7C68013 development board costs around $10 from China. But I still don't think I would bother to build one of these using such a board as the additional parts, case, scope probes and my time would make it far more expensive than GBP49. In those terms it is very good value for money. Next test will be to see how the unit performs with the infamous Hantek software package !
« Last Edit: June 13, 2013, 10:51:37 PM by Aurora »
 

Offline tinhead

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #5 on: June 13, 2013, 11:00:59 PM »
from pinout i would say the ADC is AD9288.

Btw, do have have higher res pictures? PM
« Last Edit: June 13, 2013, 11:10:16 PM by tinhead »
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Offline Fraser

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #6 on: June 13, 2013, 11:08:24 PM »
Yes I have the 8mp pictures that my camera produces but I didn't want to eat Dave storage with them. I will upload a couple of higher resolution pictures of the PCB for you.

I note that another forum member has posted a review of this unit here:

http://www.eevblog.com/forum/testgear/hantek-6022be-will-it-work-for-me/msg232007/#msg232007

I note that the screening cans have not been fitted to the input amplifiers but the PCB has positions for such. This may explain some of the noise issues that are reported but it could be other factors as well.
« Last Edit: June 13, 2013, 11:12:32 PM by Aurora »
 

Offline Anks

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #7 on: June 13, 2013, 11:49:13 PM »
Im sure there is a open source project making  better software for the scopes. Ill look back in my history see if I can find it

http://www.openhantek.org/
« Last Edit: June 13, 2013, 11:50:48 PM by Anks »
 

Offline Fraser

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #8 on: June 14, 2013, 12:12:27 AM »
Yes I found the open source software but sadly it does not support the 6022 yet. I will keep an eye out for other software that may work as the 6022 is basically a common CY7C68013A based DSO.
 

Offline Fraser

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #9 on: June 14, 2013, 12:17:36 AM »
Two slightly higher quality images...... as requested by some members. full Res pictures are 4mb in size and I can email if required
 

Offline tinhead

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #10 on: June 14, 2013, 01:11:58 AM »
Yes I have the 8mp pictures

got them, thanks !

I note that the screening cans have not been fitted to the input amplifiers but the PCB has positions for such. This may explain some of the noise issues that are reported but it could be other factors as well.

Sscreening cans, yeah, maybe used in higher bw model only? Savings :P

the noise could come from the DC/DC converter which powers the input stage (not that bad, two J-FET opamps AD8065).
The DC/DC converter, is it, Mornsun A0505S-1W ?
I don't want to be human! I want to see gamma rays, I want to hear X-rays, and I want to smell dark matter ...
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Offline Fraser

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #11 on: June 14, 2013, 01:33:18 AM »
Mornsun A0505S-2W
 

Offline womai

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #12 on: July 08, 2013, 01:30:10 AM »
I recently did a teardown wanted to do a review of the Hantek 6022BE myself but saw that Aurora has already posted a lot of good pictures and description of the instrument's guts - better quality than the cell phone pictures I took. What I can add is a review about the unit's functionality and usability (or lack thereof, as you will see below).

Full disclosure: I designed and am selling my own USB/PC based entry-level oscilloscope (the DPScope, see http://www.dpscope.com if you are interested in the details), so clearly this unit is my competition and there is a possible conflict of interest. So if you want to take any criticism from my side with a grain of salt, be my guest. That said, I will only report my objective observations; if you spot a mistake in my review, or if things change (e.g. new software version that fixes some shortcomings) please contact me and I will update the review. 

I was intrigued by the 6022BE's ultra-low price point (you can get it for around US$70 including free shipping if you shop around a bit), combined with what seems to be quite useful performance specs. Granted, 48 MSa/sec won't give you resonable display for a 20 MHz signal without some excellent sin(x)/x interpolation algorithm - which I did not expect to find here - but it's still a pretty good number. So off I went and got myself such an instrument so I could have a closer look.

Construction quality is actually pretty solid - sturdy extruded aluminum enclosure (many much more expensive models use plastic), the PCB inside is well layed out and soldering is good quality. Springs make sure the enclosure is connected to electrical ground. BNC connectors are metal throughout. So overall the hardware makes a very good impression, especially given the low cost of the instrument. (you can find older reviews of other Hantek scopes that show very shoddy construction so they clearly made a lot of progress in this department over the past few years).

Unfortunately that's already the really good part. Let's go to the mediocre stuff - the software. Functionality here is very basic - at first the GUI looks ok but then you quickly find lots of basic stuff that is missing. Why is there no datalogger mode for slow speed signals? Would be trivial to implement. Why can't you set the horizontal position? As others noted, there is no way to zoom in or scroll through the (supposedly 1M long) waveform except with hundreds of mouse drags; in other words, useless. Also this is the first scope GUI where you have to scroll the controls panel to have access to all controls (horizontal, vertical, trigger) - just make the controls a bit close together. There is no averaging mode to get rid of noise on the waveform (again, would have been trivial to implement in the software, so I fail to see why they didn't bother).

Now to functionality. This is where it really gets bad, especially if you initially believe the banner specs. I tested on two different computers (a laptop and a desktop, both fairly recent models, and both running Windows 7 64-bit home edition) but the results were identical on both.

  • no AC coupling (but at least the user can add a capacitor himself to get this.
  • uses two USB ports (but at least on my machine it worked just as well with a standard single-port cable. I did not measure the instrument's current draw but I'd be surprised if it exceeds 500mA. Probably they just re-used the same cable as for the other Hantek models.
  • Self cal did not execute, no matter what I tried
  • I did not see any way of displaying pretrigger wafeforms. Did I miss anything? The specs claim it can do pretrigger acquisition.
  • Trigger seems very noisy, i.e. it's hard to get a truly stable waveform on the screen; it will often trigger on the wrong edge (e.g. falling edge when you selected rising).
  • Trigger instability seems to get worse when you scroll the waveform far to le left (takes many, many mouse moves as stated above).
  • At 10 us/div and faster the scope no longer acquires full 1M data sets, but rather short ones (maybe 1000 or 2000 points).
  • At 5 us/div the acquisition gets completely messed up. Actually that sometimes happened already at 10 us/div. The acquired waveform is completely unstable. Single shot aquisition shows many short sections seemingly randomly joined together. Result is different every time you re-acquire.
  • At 2us/div (sampling at 8 MHz) and faster the display shows random sections of the waveform, most of the time there is empty space on the left or right side. Single shot acquisition shows that the scope seems to acquire a short data record (one screen width worth of data, maybe 1000 points or so), without any triggering, and then randomly misaligns it on the screen, so only a portion of the screen is filled. I can scroll back or forth to display the full record, but again, it does not seem to trigger on anything constant... so these sample speeds are completely useless. It could be the instrument simply fills its FIFO (4K, so that would be 2000 8-bit samples per channel) and without bothering with triggering, and then dumps it onto the screen on a random start location). Hard to believe they wouldn't have found this even with the tiniest bit of product testing.
  • Vertical sensitivity (part 1): The unit's maximum range is only +/-5V. So in 2V/div you can only use +/-2.5 divisions around zero. And even with the probes in 1:10 mode you can't display anything larger than 50V. Maybe that's Hantek's way of making sure you stay away from any dangerous voltage :=)
  • Vertical sensitivity (part 2): 20mV/div and 50mV/div are fake: Thge waveform gets simply blown up (like digital zoom on a digital camera), so the actual vertical resolution is very coarse. Becomes very obvious when you switch to "display dots", you can clearly see the large quantization steps. So the true smallest resolution is a poor 100 mV/div.
  • Unit is not galvanically isolated from the PC, but I would say this is to be expected given the low price. Even the cheapest galvanic isolation (data & power) would add a couple $$ to the component cost. Given the 50V limit (see above) the lack of isolation seems the least of my worries with this instrument; it's clearly intended for low-voltage work anyway.
  • Analog bandwidth: At least here actual performance does not seem to be orders of magnitudes off from what the vendor claims. Of course it is not trivial to get a useful acquisition where you can measure signal rise time, given the problems at fast sample rates above. But it looks like the true bandwidth is somewhere around 17 MHz for large signals (5V pk-pk, acquired at 1V/div), dropping to a bit below 10 MHz for smaller (100 mV/div).
  • Noise: there are spikes on the acquired signal, around +/-20mV. I suspect the switching regulator that is used to supply the analog input section. Visible but less concerning than other shortcomings, especially given the limited actual vertica, resolution (see above). Averaging would be a good way to make these spikes disappear in the display, as they are not correlated to the input signal - but as said, the software does not offer averaging...

So what's my overall verdict? Promising hardware and good build quality, but the software that comes with it is disappointingly shoddy, but far surpassed in terms of disappointment by the unit's real-world performance. As it is (broken acquisition at 5 us/div and beyond) even basic use is only possible for signals of around 200 kHz or less. That's a full 1% of the advertized range!! Even where you CAN see the signal and trigger on it, triggering is unstable. Overall performance is downright horrible compared to what Hantek claims it can do. So I would strongly recommend to stay away from it and get yourself something else for a few bucks more.

It may be possible that some of the problems can be fixed either in software or in firmware. Please let me know if anyone hears or sees something in this respect. Most importantly, the faster timebase settings, followed by trigger stability. After that, averaging, datalogger (roll) mode, cleaner GUI layout. Not sure I am getting my hopes up too high, given the lack of software progress of the Hantek software for other models - hardly any changes/improvements for years.
« Last Edit: January 15, 2014, 06:42:15 AM by womai »
 

Offline Fraser

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #13 on: July 08, 2013, 03:03:06 AM »
Womai,

Thank you for this excellent insight into the limitations of this cheap DSO.

Mine is currently sat, still boxed, in a pile with the other Hantek kit I bought, awaiting use.

I own several DSO's including the Rigol DS1052E and a Tektronix THS720A so I will not shed any tears over this unit if it is total rubbish. It is a great pity that what looked to be decent hardware performs so poorly in the real world. There is no excuse for the odd behaviour that you noted.

I purchased my 6022BE as an accessory to my Hantek Logic analyser and function as it completed my little 'set' of portable test tools for use on my laptop. It was a 'whim' purchase, but at least it was cheap  :)

I also have a neat little ELAN USBscope50 50MS/s DSO which is little bigger than a USB memory stick. That unit is an isolated USB DSO that actually works so I will use that in my laptop kit for checking power rails for noise etc.

http://www.saelig.com/product/PSPCEL004.htm

I will fire up my 6022BE and test its behaviour. Not that I doubt your review content, but potentially you could have a duff unit ?

A classic case of "you get what you pay for"  :-BROKE
« Last Edit: July 08, 2013, 04:31:18 AM by Aurora »
 

Offline womai

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #14 on: July 08, 2013, 03:47:02 AM »
You're welcome to double-check my results. As I mention, I find it hard to believe that such gross malfunction as I observe could be missed at even the most cursory quality checkout. So there are two possibilities:

- They could not get triggering etc. to work in time (or because of some hard limitation of the design) and decided to drop whatever they had onto the unsuspecting customer, hoping most beginners won't notice.

or

- Something in my setup does not work well with the scope. Something broken in my Windows installation, some hardware detail, etc. Although the fact that two quite different PCs show exactly the same makes me less hopeful in this respect.

I am very curious to see what you find on your side.

At least that applies to the behavior at faster sample rates. Misbehavior at 5 us/div, noisy trigger, short records at 2us/div and faster, noise spikes have been noted by others before so I guess they are there by design...
« Last Edit: July 08, 2013, 03:49:48 AM by womai »
 

Offline Fraser

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #15 on: July 08, 2013, 04:45:45 AM »
Ok after a quick and dirty test on my lounge floor I have feedback on my unit.

I am driving the 6022be with a Sony Netbook running Win7 Home. The signal source is a Digimess FG100 20MHz function generator with its output set to 1V. 50R through-termination and decent test lead used.

1. I set the FG to 100kHz Sine and pressed the 'Auto' button for the 6022BE. Sine wave displayed perfectly with some trigger jitter but nothing more than I have seen on other cheap DSO's.
2. Set FG to 1MHz Sine and again used 'Auto' feature on 6022BE. Display showed a perfect Sine wave with good triggering.
3. Set FG to 1MHz Square and used 'Auto'. Square wave was represented well with good square tops and a little ringing on the leading edge. Triggering jittered a little then settled down.
4. Set FG to 10MHz Sine. Auto produced a perfect sine wave with stable trigger.
5. Set FG to 20MHz Sine. Auto produced a very respectable sine wave with good triggering.
6. Noise level with no input checked. on 20mV div range only 5-10mV noise and impulses could be seen.
7.Tried the scrolling of the waveform......... it only appeared to work for lower frequencies (slower time-bases). At higher frequencies only one screen of captured signal data was available to see. This 'function' really isn't much use at all.
8. During the displaying of the waveforms on the screen I noted that even after an AUTO setting the last half of a sine wave at the right hand side was flickering and you could stop the capture and have part of the waveform missing ! Most odd and no idea why this happens.

My view.... my unit does produce accurate renditions of the test sine wave all the way to 20MHz so its maths is working pretty well. The trigger is definitely stable enough on my unit to capture and view a live signal at all frequencies up to 20MHz. Stopping the capture produces a clean waveform.
The capture does have an odd flickering end to it on the right of the screen. This did not present a problem as AUTO sets the TB to show several cycles of the waveform. It could be a pain though if the flickering section contained the glitch that was being hunted for ! The memory is a mystery to me. The scrolling through a waveform is severely limited and practically useless. The noise on my waveforms was not invasive and was less than 10mV on my tests.

In summary. This DSO  will meet my needs for checking computer power rails for noise but it is not useful in trying to find a glitch in a large capture of signals. Not junk though. I am pleasantly surprised.

Basic ? Very !
Good software ? NO ! The hardware quality far exceeds that of the software.
Accurate ? It appears to be accurate enough for most basic tasks.
Trigger ? Satisfactory.
Noise ? 5-10mV.
Memory ? Virtually unuseable
Value for money ? You decide. It can be purchased for around US$70.

What this thing needs is to be supported in the Open Source software that has been developed for Hantek's more expensive DSO's.

http://www.openhantek.org/

http://hantekdso.sourceforge.net/
« Last Edit: July 08, 2013, 05:27:08 AM by Aurora »
 

Offline Rick Law

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #16 on: July 08, 2013, 05:16:53 AM »
Yes I have the 8mp pictures that my camera produces but I didn't want to eat Dave storage with them. I will upload a couple of higher resolution pictures of the PCB for you.

I note that another forum member has posted a review of this unit here:

http://www.eevblog.com/forum/testgear/hantek-6022be-will-it-work-for-me/msg232007/#msg232007

I note that the screening cans have not been fitted to the input amplifiers but the PCB has positions for such. This may explain some of the noise issues that are reported but it could be other factors as well.

What I posted then was more personal experience with this scope than I formal review.  I so much wanted to see some review but this thread didn't exist then, so I shared some of my views and experience with others.

(Thanks, Womai pointed out this thread).  Now I can add my 2 cents in....


 

Offline womai

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #17 on: July 08, 2013, 05:52:34 AM »
Hmmmm, based on Auroras feedback I went back and gave it another try. Here's what I found:

It seems I have to use autoset at least once at some higher timebase. Then it will trigger even at faster timebase settings. (I work a lot with scopes and don't use autoset too often, that's why I didn't try autosetting after initially checking that it does work at some slow frequency). If I just start the software and try to set some fast timebase manually the triggering will not work, as noted in my initial post. After the autoset I can manually change the timebase and it still works. Bug in the software?

I also observe the flickering waveform. It seems the scope can't really start the capturing at a precise moment relative to the trigger so there is an uncertainty of ~1 signal period where the record really lies with respect to the trigger. The software seems to align the waveform correctly (at least after auto setup) but it means some variable portion of the waveform at the beginning and/or the end is missing - different at each capture. Basically only the center portion of the acquired record is consistently usable. You can see similar flickering at the record start when you scroll to the beginning of the waveform.

That said, 5 us/div still does not work at all. Even with autoset there is never a stable display. Aurora, maybe you could try that? (set frequency to around 30 kHz to make autoset go to 5 us/div).

Still have problems with somewhat unstable triggering at slower timebase settings. I use a Rigol DS1022A signal generator which from previous experience I know produces a very clean signal with very little noise. My other scopes have not problem whatsoever to cleanly trigger on its output signal.
« Last Edit: July 08, 2013, 05:54:55 AM by womai »
 

Offline Rick Law

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #18 on: July 08, 2013, 06:26:26 AM »
...Now to functionality. This is where it really gets bad, especially if you initially believe the banner specs. I tested on two different computers (a laptop and a desktop, both fairly recent models, and both running Windows 7 64-bit home edition) but the results were identical on both....

Actually, the software may be more XP friendly than Win7 then.  I use XP and the software ran well (no lags, smooth and snappy) on even a very slow but very small 1GHz laptop I often use for space reasons.

The software is portable (don't need to install - just copy the installed folder.  You do need to install the driver).  I just copy the folder over and without fuss the software is running.  (Without having to run install means I am having less junk clogging up the system and adding junk to the registry.  I like software that just copy-and-go.)

  • no AC coupling (but at least the user can add a capacitor himself to get this.

Yeah, I hate that too.  I have a couple of capacitors at hand just because of that.

  • uses two USB ports (but at least on my machine it worked just as well with a standard single-port cable. I did not measure the instrument's current draw but I'd be surprised if it exceeds 500mA. Probably they just re-used the same cable as for the other Hantek models.

Not to confuse others, it adds two devices via one usb connection - one for each channel.  So, one single USB cable does it.

  • Self cal did not execute, no matter what I tried

This one confused me a bit at the start too.  Until I read the manual that both channel need to be grounded.  It does execute but no feedback.  My volt readout is still high (by about 2-5%) but not as much over as before I ran the self calibration (by about 5-7%).

  • I did not see any way of displaying pretrigger wafeforms. Did I miss anything? The specs claim it can do pretrigger acquisition.

After using it for a while, I got the trick worked out now:
- pause the display
- kill the cursor (otherwise, mouse click sets cursor)
- now point at wave form, press mouse button, and drag the wave from left to right
Then you can see the part of the wave before the trigger.  Problem is, the amount of info before the trigger is random.  What I guess is this: The software appear to treat the memory buffer as a ring.  The data just get written in and once it gets to the end, it returns to the start but clears the entire buffer.  So, when the trigger occurs when the WRITE pointer is near the end, you captured lots of pre-trigger but little post trigger wave form when the buffer is plotted start to finish linearly.  However, when the WRITE pointer is near the start of the buffer, you captured darn little pre-trigger info.

  • Trigger seems very noisy, i.e. it's hard to get a truly stable waveform on the screen; it will often trigger on the wrong edge (e.g. falling edge when you selected rising).
  • Trigger instability seems to get worse when you scroll the waveform far to le left (takes many, many mouse moves as stated above).

No kidding here.  The noise is awful and it does cause trigger to hit.  It is very annoying but at least is is still useable.  I was able to find the 50mV resonance wave to measure an inductor's inductance.  I do find a reboot sometimes helps.  So it could be picking up the noise from other connected devices.

  • At 10 us/div and faster the scope no longer acquires full 1M data sets, but rather short ones (maybe 1000 or 2000 points).
  • At 5 us/div the acquisition gets completely messed up. Actually that sometimes happened already at 10 us/div. The acquired waveform is completely unstable. Single shot aquisition shows many short sections seemingly randomly joined together. Result is different every time you re-acquire.
  • At 2us/div (sampling at 8 MHz) and faster the display shows random sections of the waveform, most of the time there is empty space on the left or right side. Single shot acquisition shows that the scope seems to acquire a short data record (one screen width worth of data, maybe 1000 points or so), without any triggering, and then randomly misaligns it on the screen, so only a portion of the screen is filled. I can scroll back or forth to display the full record, but again, it does not seem to trigger on anything constant... so these sample speeds are completely useless. It could be the instrument simply fills its FIFO (4K, so that would be 2000 8-bit samples per channel) and without bothering with triggering, and then dumps it onto the screen on a random start location). Hard to believe they wouldn't have found this even with the tiniest bit of product testing.
I think I was caught with this same confusion too, but here is what I found out:
At 2us or below is when it captures at 48msps and at merely 1060 datapoints.  At 5us or slower, it goes to over 100K datapoints at 16msps.  The slower the more datapoints.
BUT...
When you freeze
the display and zoom in/out (say capture at 5us and zoom to view at 100ns), the display does not show your capture frequency (5us=100,000+ samples) and instead it shows what it would be at 100ns (1060 samples at 100ns).  After I realized that, I can see that it works.  Of course, the noise still make that difficult.

  • Vertical sensitivity (part 1): The unit's maximum range is only +/-5V. So in 2V/div you can only use +/-2.5 divisions around zero. And even with the probes in 1:10 mode you can't display anything larger than 50V. Maybe that's Hantek's way of making sure you stay away from any dangerous voltage :=)
  • Vertical sensitivity (part 2): 20mV/div and 50mV/div are fake: Thge waveform gets simply blown up (like digital zoom on a digital camera), so the actual vertical resolution is very coarse. Becomes very obvious when you switch to "display dots", you can clearly see the large quantization steps. So the true smallest resolution is a poor 100 mV/div.
  • Unit is not galvanically isolated from the PC, but I would say this is to be expected given the low price. Even the cheapest galvanic isolation (data & power) would add a couple $$ to the component cost. Given the 50V limit (see above) the lack of isolation seems the least of my worries with this instrument; it's clearly intended for low-voltage work anyway.
  • Analog bandwidth: At least here actual performance does not seem to be orders of magnitudes off from what the vendor claims. Of course it is not trivial to get a useful acquisition where you can measure signal rise time, given the problems at fast sample rates above. But it looks like the true bandwidth is somewhere around 17 MHz for large signals (5V pk-pk, acquired at 1V/div), dropping to a bit below 10 MHz for smaller (100 mV/div).
  • Noise: there are spikes on the acquired signal, around +/-20mV. I suspect the switching regulator that is used to supply the analog input section. Visible but less concerning than other shortcomings, especially given the limited actual vertica, resolution (see above). Averaging would be a good way to make these spikes disappear in the display, as they are not correlated to the input signal - but as said, the software does not offer averaging...

I agree with you 100% here...  Only 8 bit resolution to +- 5Volts, so it is about 40mV per ADC bits.  I am not sure if they have a way (such as lowering their reference voltage) to get the lower readings.

At best sampling rate (48msps), it is about 21ns between samples.  With a 10mhz wave, you have 100ns per period, 50ns high and 50ns low.  Best case is 2 samples during wave-high, and 2 samples during wave-low with PERHAPS another sample somewhere in the middle.  Can't measure rise time with that.


Overall though, I am please with the scope.  For merely $70, it does more than I expect.
 

Offline Fraser

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #19 on: July 08, 2013, 06:30:05 AM »
I should have mentioned that I also experienced the failure to trigger unless Auto was used initially. Thanks for pointing that out. It is strange that the trigger appears totally non functional until Auto is initiated. Software bug likely. I have put the unit back in the lab. I will try the 5uS range and let you know the result.

I only went down to 100kHz so will repeat the test at lower frequencies to see how the trigger behaves.

Thank you for reviewing this unit, it gives me the incentive to test my unit  :)

I think we are seeing that US$70 buys a DSO with flaws, hence why I purchased the DS1052E after seeing Dave's review...its a real DSO that does not leave you fed up because of 'niggles' in firmware/software.
 

Offline Rick Law

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #20 on: July 08, 2013, 07:08:39 AM »
Hmmmm, based on Auroras feedback I went back and gave it another try. Here's what I found:

It seems I have to use autoset at least once at some higher timebase. Then it will trigger even at faster timebase settings. (I work a lot with scopes and don't use autoset too often, that's why I didn't try autosetting after initially checking that it does work at some slow frequency). If I just start the software and try to set some fast timebase manually the triggering will not work, as noted in my initial post. After the autoset I can manually change the timebase and it still works. Bug in the software?

I also observe the flickering waveform. It seems the scope can't really start the capturing at a precise moment relative to the trigger so there is an uncertainty of ~1 signal period where the record really lies with respect to the trigger. The software seems to align the waveform correctly (at least after auto setup) but it means some variable portion of the waveform at the beginning and/or the end is missing - different at each capture. Basically only the center portion of the acquired record is consistently usable. You can see similar flickering at the record start when you scroll to the beginning of the waveform.

That said, 5 us/div still does not work at all. Even with autoset there is never a stable display. Aurora, maybe you could try that? (set frequency to around 30 kHz to make autoset go to 5 us/div).

Still have problems with somewhat unstable triggering at slower timebase settings. I use a Rigol DS1022A signal generator which from previous experience I know produces a very clean signal with very little noise. My other scopes have not problem whatsoever to cleanly trigger on its output signal.

Womai ,

Do you mean 5ns or 5us?

I have encounter no problem triggering at 5us at all.  It gets crazier as it gets lower.  At 2ns and 5ns it gets really crazy.

It captures only about 1 screen wide worth (10 division) of data for display - at 5ns, that would be merely 50ns worth of display or 2 samples at 48mhz (20.8ns/sample).    So I can see any slight shift in trigger causing the display major jitter.

Attach a screen capture of triggering at 100ns to capture a 2mhz square wave - 100ns is 50 times faster than 5us.  Works just fine with very slight jitter.

(EDIT - typo -- it was 1us, not 100ns, replaced paragraph above)
Attach a screen capture of triggering at 1us to capture a 2mhz square wave - 1us is 5 times faster than 5us.  Works just fine with very slight jitter.
« Last Edit: July 08, 2013, 08:08:22 AM by Rick Law »
 

Offline Rick Law

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #21 on: July 08, 2013, 08:03:21 AM »
It captures only about 1 screen wide worth (10 division) of data for display - at 5ns, that would be merely 50ns worth of display or 2 samples at 48mhz (20.8ns/sample).    So I can see any slight shift in trigger causing the display major jitter.

By the way, having used it for a couple of months...  I learn to deal with it: If I am looking at fast things, I have to use capture and view.

I capture at 2us/div however fast the signal.  At 2us/div, it captures at the max speed of 48msps and a screenful of data is 10 division = 20us worth.  I have 20us of data to zoom in on - that is 1000 points.   Probably it is a bit more than a screenful since saving the data would save 1060 points.

Anything faster just reduces my data points.  Capturing too much faster doesn't work mathematically - For example, at the timebase of 5ns to capture, I have only 1 screenful which is 50ns worth of data.  50ns is 2 data points of data since 48msps=21ns/sample.   Everything is a straight line with only 2 real data points captured in the duration.
« Last Edit: July 08, 2013, 08:13:05 AM by Rick Law »
 

Offline womai

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #22 on: July 08, 2013, 08:14:15 AM »
I really mean 5 us (microseconds), not ns (nanoseconds). Slower than that and it works pretty well except for the glitchy trigger. Faster than that (2 us and up) we have the issue of the truncated waveform but at least triggering is stable after autoset. (I guess you are right that the small record size at that speed just makes the trigger-to-data alignment issue more visible, it's probably just the same for slower timebase settings but there the buffer is large and the flaky area at the beginning and the end is far outside the default display area).

I would say from the hardware side the unit has potential. But firmware/software would need a through scrub for it to show. Fix the trigger instability either by adding hysteresis (assuming trigger is done in hardware) or by simply discarding "wrong" captures in the software. (although one would need to know more about the actual design internals to be able to tell if a good, solid fix is possible at all). Add averaging. Definitely add a slider and a numerical display for the horizontal position. Add indication of the trigger position on the time axis.

Right now I must say I'm glad this is just a toy to play around for me and I am not dependent on it to do real work...
 

Offline womai

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #23 on: July 08, 2013, 08:19:00 AM »
>Attach a screen capture of triggering at 1us to capture a 2mhz square wave -
> 1us is 5 times faster than 5us.  Works just fine with very slight jitter.

1us/div works fine or me as well (after doing at least one autoset, that is), as does anything slower or faster than 5us/div. 5us/div is the only timebase setting that just won't trigger and produces garbage data (lots of partial waveforms stitched together).
 

Offline Rick Law

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Re: Hantek 6022BE 20MHz USB DSO
« Reply #24 on: July 08, 2013, 09:13:14 AM »
>Attach a screen capture of triggering at 1us to capture a 2mhz square wave -
> 1us is 5 times faster than 5us.  Works just fine with very slight jitter.

1us/div works fine or me as well (after doing at least one autoset, that is), as does anything slower or faster than 5us/div. 5us/div is the only timebase setting that just won't trigger and produces garbage data (lots of partial waveforms stitched together).

Interesting...  I had the program still running so I switched to a 1Mhz wave at 5us and after about a minute, I switch to 10us trigger with the same 1Mhz square wave oscillator.  It showed for 20 seconds and the program did an abnormal termination.  Whether it is program bug with Hantek or with other programs, I am not sure. 

I rebooted it again, ran it for 5 minutes so far... 5us trigger with a 1mhz square wave.  No problem aside from small noise jitter.  I placed the cursor at the rise and fall point and for 5 minutes the wave stay within the cursor except for once.  The frequency measurement window shows 1mhz on the dot.

After 5-7 minutes, I switch to 10us trigger with the same 1 mhz square wave.  It is jittering a bit more since they are now narrower.  But it triggers just fine.  The measurement shows 1mhz on the dot.

The 1mhz oscillator I have is too fast for 10us trigger.  The wave is too narrow to see details.  Too bad I do not have a good stable signal source below 1mhz.  I guess I will wait and see with you to see what Aurora comes up with.
 


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