Author Topic: EEVblog #487 - Tekway DST1102B Oscilloscope Review  (Read 32945 times)

0 Members and 1 Guest are viewing this topic.

Offline Mike Warren

  • Supporter
  • ****
  • Posts: 402
  • Country: au
    • Personal Website
EEVblog #487 - Tekway DST1102B Oscilloscope Review
« on: June 25, 2013, 01:08:40 PM »


With the latest firmware from Tekway I've had no more crashes, but as Dave says, you get what you pay for.

Hantek/Tekway thread:
http://www.eevblog.com/forum/testgear/hantek-tekway-dso-hack-get-200mhz-bw-for-free/
« Last Edit: June 25, 2013, 01:10:54 PM by Mike Warren »
 

Offline tinhead

  • Super Contributor
  • ***
  • Posts: 1798
  • Country: 00
    • If you like my hacks, send me a donation
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #1 on: June 25, 2013, 06:45:05 PM »
Ok, before i edit this response (and add a loooong list of things) let me tell you soemthing Dave, your model is a bit strange. The serial number on the enclosure didn't match the serial number of the mainboard, so someone have already played with that board/DSO.
Hard to say how deep playd and if/what changed (you can e.g. disable the bw filter), but that just a side note.


Let me answer few things here:

- Long memory (4k and 40k are working however fast and good, it make as well to enable "50" refresh rate in display menu to speedup a lot knobs response) is just crap slow. Sure, it can be used for one off things, but to work all the time enabled you would get crazy. The reason is actually simple, they reading the whole 1M from sample buffer (SRAM connected to FPGA and CPLD) into the ARM buffer and working with that data (measurments, what so ever) and displaying that whole waveform. Today this is very uncommon way, normally you would leave the whole data in buffer and read only what necessary to be displayed at once on screen (e.g. 800pts). Btw, the sample buffer is like on Rigol DS1000E in external SRAM, so they filling the stream from FPGA to SRAM already at slower speed (this is why all these DSOs can't do 1GS/s and 1M at time). When you enable the long memory on Rigol, the screen is much faster than on Tekway, already here the difference in data readback is visible (but it should not as both doing the same on hardware level, actually Rigol is even slower here due the non DPO-like buffer). I don't have access to fw sources, but to debug versions, and from what in the code i can see that they working like described, and well, reading the whole buffer only once per second (see init_store_depth functions). This can't be simply changed as the ARM SoC can't just read much more at once. When measuring/looking on the SRAM/CPLD on FPGA (the trigger registers) i can see the DSO running muuuch faster, sure, it is always 4k ring buffer running at full speed. They would have to change the firmware to read only that part what need to be displayed, not the whole buffer.


- Tekway confirmed that wfms/s is up to 2500, like mentioned on their website http://www.tekway.net/views2.asp?newsid=205&sess=2
Hantek told me 2000, but they haven't even edit properly the user manual so who knows :P Not that i really trust them both, but i trust my measurment and my eyes. From the code i can see that 40 captured frames will get read at once from sample buffer and that 50 times per second when the screen refresh is set to 50. So 2000 wfms/s max here. The firmware before "merger" with Hantek was much faster (responding), so i assume the 2500wfms/s was measured on that version. When i change the on current version the size of DPO-like buffer all i can get is ~2152 wfms/s is max. So that can be the limit, but of course it can be as well FPGA firmare limit. Anyway, due the fast that the "40 frames to one" buffer can be read back 50 times per second the wfms/s can't be constant, it will be more like burst mode. You can see it on that video i made some time ago (don't get confused, i'm stopping ACQ as soon captured and restarting, so count only the second from restart point to captured on screen^^)



and here compared to TDS700A (doing here 6k wfms/s)



Of course both didn't said anything to question "is the wfms/s conctant or burst mode?", not a real issue as persistency can help here out to let the glitch visible, but it would be better t have constant wfms/s rate.


- there are bugs, as mentioned below i'm helping them out with that. Lot of things fixed since Jan 2013, but not all. Let's hope the best^^. I will not give up that fast, i have a lot of time now.


- there is no intensity grading as know from other DSOs, Tekway/Hantek is using DPO-like grading, 4 steps (each in 4 intensity steps, so 16 steps total in intensity but still only 4 depth, anyway^^). In run mode, with persistency on auto which is the "off" position, the waveform looks like attached picture - same sine waveform captured twice as screen snapshoot (and zoomed on PC to show details). The DPO-like grading is clearly visible (no, this is not a TFT display persistency error, that are captures from memory), however, i would prefer to have here higher depth. Probably FPGA is too small for more. Easier could be to implement only the intensity grading, like Riolg did it on DS1000Z/DS2000, instead of trying to simulate Tektronix. Not that i don't like that idea, as TEK fan i do for sure, but it is not easy to achieve good results at no price. Even TEK didn't managed it in their low-end models.




- the frontend story :P For a long time i was fighting with ppl in German forum, i was wondering why they getting crap waveforms on their scopes where my was looking much better. Long story short said - for (unknown to me) reason Tekway/Hantek changed some resistors in their frontend. Btw, this is the same frontend what Rigol is using in DS1000E (that affected part exists even on DS2000). Of course Siglent/ATTEN are using exact the same frontend, hehe. Anyway, i and some other ppl made lot of measurments and simulations, finally we have working combination, it is even better that original DS1000E and even better than my old Tekway. There is no need to change anything on org. DSOs, but on hacked (or all what need to work over 100MHz, this is why this never was an issue on DS1000E). All the necessary information about is in the Tekway hack thread: http://www.eevblog.com/forum/testgear/hantek-tekway-dso-hack-get-200mhz-bw-for-free/msg212054/#msg212054


- jitter, yeah. I actually made measurments (with proper equeipment) and reported the skew between clocks, Tekway almost fixed it (not perfectly but definitely acceptable). Since Nov 2012 they have again new FPGA design (83EB) which seems to be worse than the working one (83E9). The DSO you tested have the 83EB. It seems that very few (i know only 2 by now) current models can't use 83E9, reason seems to be on power rail (smaller caps than before, heh). Some have different DAC installed (on botton side of PCB, so visible from outside), with that DAC 83EB need to be used. For all others is a good idea is to use FPGA design 83E9. Before someone ask "why is 83E9 not perfectly fixed?" Well, don't be naive, Siglent/ATTEN/Rigol C/D/E are clocked by FPGA, and if that not enought with not dedicated clock out pins, this is a worst case 300ns jitter. What all these manufacturer doing is to calculate avg values to middle the results. So far everything ok. However Tekway is having different architecture (DPO-like), so the resulting waveform jumps bit more (as it can be avg and DPO-like together). I worked here with external jitter cleaning chips (thanks again to Silabs for providing me dev boards, lot of samples and lot of help), that solution was working perfectly, but it was too expensive for undr 1k DSO. Honestly i wish Rigol will make lot of presure on other DSO manufactuers with their DS1000Z (they doing it already with DS2000). That will help a lot, the only way to fix such jitter/interleave distortion issues is to use less ADCs and proper clocking, and nobody will spend money without a need. For existing users, well, a very good clock source for FPGA (like CCHD-575) is reducing the jitter as well. More information in the Tekway hack thread.


- i have no idea who is that "smart person", but someone is always trying to cut some parts and save money. I told them this multiple times, it seems they ignoring it and trying it each every few months again. Your review would probably help to fix that. Examples are the forntend (as said above), or some caps near FPGA (they released different FPGA design to fix potential issues, lol), JFET in frontend was changed to crap solution for 3 months or so (they fixed it, but fuck why they did it in first place?), voltage ref is different (still acceptable but it was better one), XO is ±50ppm (but it was for some time ±25ppm, ok datashee talk about 50ppm for timebase so still within specs somehow). I know that the engineer behind the hardware/software is a smart person, all the hidden things in firmware and all the potential extension in hardware are really great, i doubt he is the person reducing costs. Sure, as entrepreneur i know how important is cost reduction, as EE i know there is invisible line which should be not crossed over. Some ppl in china seems to not know that to cut by 1% (with "component savings") works only once and that every month "only 1%" means 12.68% after a year, and thats crap and not quality.

##################################################


So let's summarize - as you said Dave, they almost there, but here and there small and less small things that need to be fixed. Firmware is the "easy" part (if i and they didn't give up), hardware can be only fixed with newer hw revisions (but as said above, others with similar hardware are not better here, that means all Siglent/ATTEN (except the 4channel models), Rigol DS1000E, most UNI-T models), and new models are on the way. No idea how many hw things has been fixed in these Hantek "P" models (with 24k memory only!) and how many will be in new "B" models, but we will soon see it.

I bet all chinese manufacturers (except Rigol, they seems to have good contract with RuiFeng? or AD?) will switch to ADC08D500 as soon they recognize how Instek overclocked these ADCs ^^. That will change the game again.

I'm sure Tekway will learn as well how to achieve higher wfms/s, not that they are bad with 2000 (2500) wfms/s, but Rigol DS1000Z with 30000 and UNI-T with 150000 is complettly different story. Sure, Tekway decided to do it DPO-like, but that was in 2009 and today they can give that up and simply do the "Rigol" (i would say Agilent way here, but i know that Rigol was using that way already in CA models, so before E models has been designed. They simply frozen that idea due costs, E models are working and cheaper).

Anyway, thanks for the review (yes, i know it was not a real review).
« Last Edit: June 26, 2013, 07:43:09 AM by tinhead »
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 ...
I want to reach out with something other than these prehensile paws and feel the solar wind of a supernova flowing over me.
 

Offline fenclu

  • Regular Contributor
  • *
  • Posts: 112
  • Country: pl
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #2 on: June 25, 2013, 06:55:08 PM »
Ehh, too bad. Looks like every DSO under ~$400  is a piece of shit (except for the Rigol of course). Isn't there really anything useful on the market in that price range except for a 5 year old Rigol with a small screen (both size and resolution)?
If anything can go wrong, it will.
 

Offline kaushleshchandel

  • Contributor
  • Posts: 8
  • Country: in
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #3 on: June 25, 2013, 07:10:12 PM »
I bought a Rigol two years back only after seeing Dave's video. I am pretty happy with it.

This one seems nice for the price band.
 

Oracle

  • Guest
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #4 on: June 25, 2013, 08:43:24 PM »
Ehh, too bad. Looks like every DSO under ~$400  is a piece of shit (except for the Rigol of course). Isn't there really anything useful on the market in that price range except for a 5 year old Rigol with a small screen (both size and resolution)?
A pc oscilloscope maybe. I tried it. I's pretty annoying compared to a bench oscilloscope.... Anyway, if you want something good at least $500 you have to spend... If you are lucky you may found something refurbished and calibrated for interesting price.....
 

Offline amyk

  • Super Contributor
  • ***
  • Posts: 5044
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #5 on: June 25, 2013, 09:11:19 PM »
Am I the only one who thought "why did they call the menu on/off F0", and the one at the very bottom F6, and then have the lone F7 up near the V0"? I also looked around for a V1 or V2... ??? somewhat weird UI there.
 

Offline valentinc

  • Regular Contributor
  • *
  • Posts: 116
  • Country: ro
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #6 on: June 25, 2013, 09:29:35 PM »
Quote
Ehh, too bad. Looks like every DSO under ~$400  is a piece of shit (except for the Rigol of course). Isn't there really anything useful on the market in that price range except for a 5 year old Rigol with a small screen (both size and resolution)?


     There is, the Siglent SDS1xxxCML, for example, the differences between that and the Rigol DS1052E were discussed in another thread...

And I totally agree with Dave, this scope is damn slow in my opinion, why do they put 2 Mpts of memory if you can't use it because of the slow update rate ?  It's just useless... And even considering it's hackable, I much prefer a Tektronix 2235 analog scope than this one, any time... Or the Rigol DS1052, if the space on my bench is a problem... Or the Siglent... But this is a waste of money in my opinion...
Valentin
 

Offline JackOfVA

  • Supporter
  • ****
  • Posts: 350
  • Country: us
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #7 on: June 25, 2013, 09:45:13 PM »
As a guess with respect to the pulse fidelity ... since the Tekway is hackable for 200 MHz, this suggests a switchable input filter under firmware control. If the filter is not a Gaussian type, it can introduce pulse ringing when enabled.

One way to determine the input filter characteristics in the frequency domain would be to plot the frequency response and look for dips or peaks and also look at the roll off rate. Gaussian should not have peaks and dips and should give a smooth roll off.

Also with respect to the periodic small peaks in the pulse response seen on all the 200 MHz and above scopes at around 15 ns intervals, that looks a lot like cable reflection from mismatches - even though a 50 ohm through is used.
 

Offline iloveelectronics

  • Frequent Contributor
  • **
  • Posts: 915
  • Country: hk
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #8 on: June 25, 2013, 10:38:23 PM »
For what it's worth, the Uni-T UTD1102CM I spent a couple of hours with was MUCH MUCH more responsive!

I was actually surprised Dave sounded rather happy and diplomatic at the beginning of this video and and it took him almost 20 minutes to really started entering his usual ranting mode  :-DD
My email address: franky @ 99centHobbies . com
My eBay store: http://stores.ebay.com/99centhobbies
 

Offline dr.diesel

  • Super Contributor
  • ***
  • Posts: 1913
  • Country: us
  • Cramming the magic smoke back in...
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #9 on: June 25, 2013, 10:41:44 PM »
For what it's worth, the Uni-T UTD1102CM I spent a couple of hours with was MUCH MUCH more responsive!

I was actually surprised Dave sounded rather happy and diplomatic at the beginning of this video and and it took him almost 20 minutes to really started entering his usual ranting mode  :-DD

Yeah, assuming the front-end problem not a botched hardware design, both serious issues could be fixed via firmware, might change his rating.

Offline tinhead

  • Super Contributor
  • ***
  • Posts: 1798
  • Country: 00
    • If you like my hacks, send me a donation
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #10 on: June 25, 2013, 10:44:59 PM »
Ehh, too bad. Looks like every DSO under ~$400  is a piece of shit

a ty co qwra? co ci w moim arcydziele przeszkadza?  :box:

Ehh, too bad. Looks like every DSO under ~$400  is a piece of shit (except for the Rigol of course). Isn't there really anything useful on the market in that price range except for a 5 year old Rigol with a small screen (both size and resolution)?

as i compared directly Tekway vs Rigol, i decided to take Tekway. That was 2009. Today i would still do the same, but probably i would be bit more pissed off about thing which has been not yet fixed or has been disabled (sure, on my request, but better without them than with bad implementation which might cause misinterpretation of results). Honestly today the firmware is "almost there", like a dejavu as in 2009 it was same situation, but then instead of fixing few things they started to add more and more things (and there are a LOT of things not finished in the firmware, hidden from enduser) which increased amount of (potential) bugs, and they they lost the track complettly (hw1005 disaster).

On the other side, a 400$ street price means something like 200$ at 1k pcs manufacturer price, when you count BOM there is not much left, hard (actually i have no idea how they can pay anthing) to pay development, support, what so ever. This is one the biggest issues today, in 2009 it was easier for all manufacturers.

For Rigol it was bit easier anyway, their firmware is in principle taken from their former models, and they already 10 yrs old today. In the golden time period Rigol made lot of money, the DS1000E has been paid out by far before they started with the production (as lot of things in E models are coming directly from other models, so only bit of modifications they made). Today with all the good contracts they managed to earned lot of money, and a lot of knwledge from e.g. Agilent. This is a complettly different player today.

For Siglent/ATTEN almost same situation, they didn't spend lot of money on hw dev, they copied simply. Sure, they wrote won firmware for that, no doubt, that costs time/money as well. Today they have contract with LeCroy, not sure how this really works and who is the winner, but for sure this helpd them a bit as well.

Tekway started their dev and production in 2008, so really new company. Yes, sponsored by Synway (www.synway.net), but their budget was by far not that high. The first models was actually ok, i do have it here as well, the current (and second) model was ok as well in 2009, sure few things open but as i said "nothing what can't be fixed". The disaster started as Hantek started the production.

That was costs consolidation as the Hantek and Tekway shareholders are the same people. And that the problem, already in 2011 Hantek screwed up the whole hw1005, 90% of boards not working. They lost half a year to design new working boards, a realy crap situation.
Tekway told me once "when you would pay for x or y we would implement it". That was for me, together with the Hantek hw1005 disaster, the idiction that i have to spend more time on these DSO to help them fix issues, and of course for free. I proposed some help, unfortunately they recognized that the bad ass hacker is the same person who wish to help, so it tooks some time (for them) to recognize that free of charge help from a hacker is better than no help. Since Jan 2013 many things has ben fixed, few still open.
I had to made some break due my company bankruptcy, but i got now another test hardware (yeah, the court took everything) so i will continue my work. And no, i don't have (for reason) access to any code, i do only debug and testing, which is actually lot of work.

In principle, due all the unfortunately things and delays which happened, i could say the Tekway/Hantek firmware is today 2yrs old.
As Rigol started with E series, their firmare was already 4 yeras old, even ATTEN/Siglent had at that time 2yrs old firmware (and search inet, you will find how many ppl was pissed off about the bugs at that time). I'm sure, if we give them some time, they will manage to fix all issues. Or maybe not, f* who knows, maybe their management will screw it again up, with "savings" (see my first reply to Daves video to see what i mean).
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 ...
I want to reach out with something other than these prehensile paws and feel the solar wind of a supernova flowing over me.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 24005
  • Country: au
    • EEVblog
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #11 on: June 25, 2013, 10:48:31 PM »
I was actually surprised Dave sounded rather happy and diplomatic at the beginning of this video and and it took him almost 20 minutes to really started entering his usual ranting mode  :-DD

Well I got a good vibe when I first looked at it and turned it on, I was quite hopeful...
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 24005
  • Country: au
    • EEVblog
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #12 on: June 25, 2013, 10:50:11 PM »
Yeah, assuming the front-end problem not a botched hardware design, both serious issues could be fixed via firmware, might change his rating.

Of course. My ratings are always subject to change. Fix the firmware issues and it's probably not a bad scope aside from the pulse response. That needs to be investigated more, and IMO is a killer if it's confirmed as being poor on all units.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 24005
  • Country: au
    • EEVblog
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #13 on: June 25, 2013, 10:53:58 PM »
For Rigol it was bit easier anyway, their firmware is in principle taken from their former models, and they already 10 yrs old today. In the golden time period Rigol made lot of money, the DS1000E has been paid out by far before they started with the production (as lot of things in E models are coming directly from other models, so only bit of modifications they made). Today with all the good contracts they managed to earned lot of money, and a lot of knwledge from e.g. Agilent. This is a complettly different player today.

Yes, and that is not to be underestimated. The Rigol was an $800 scope 5 years ago. And it took advantage of few generations of previous model development.
New scopes coming in at the new Rigol price point have to cut corners. It's no surprise many just don't cut it.

 

Offline dr.diesel

  • Super Contributor
  • ***
  • Posts: 1913
  • Country: us
  • Cramming the magic smoke back in...
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #14 on: June 25, 2013, 10:56:14 PM »
You hit the nail on the head when you said these cheap Chinese scope almost got it.

I know their resources are limited but I'd assume a few of the manufactures watch these videos, with minimal effort they could make a ~$500 scope with reasonable performance that didn't suck.

I bet they are soon coming.


Offline EEVblog

  • Administrator
  • *****
  • Posts: 24005
  • Country: au
    • EEVblog
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #15 on: June 25, 2013, 11:54:40 PM »
I know their resources are limited but I'd assume a few of the manufactures watch these videos

They often can't. The Chinese government block Youtube.
One of the agents for a company had to physically burn a DVD with my video and hand it to them at a meeting when he went.

 

Telequipment

  • Guest
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #16 on: June 26, 2013, 01:07:36 AM »
Hmmmmm, been looking at the cheap scopes, I have made my decision , despite the Rigol  DS1052E may be old , that is the one I'm going for, I think as a hobbyist, who does a few repairs, I think will be a really good Oscilloscope, and I would say it will  really useful in my Amateur radio station too.
Paul M0BSW
 

Offline dr.diesel

  • Super Contributor
  • ***
  • Posts: 1913
  • Country: us
  • Cramming the magic smoke back in...
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #17 on: June 26, 2013, 01:18:14 AM »
Hmmmmm, been looking at the cheap scopes, I have made my decision , despite the Rigol  DS1052E may be old , that is the one I'm going for, I think as a hobbyist, who does a few repairs, I think will be a really good Oscilloscope, and I would say it will  really useful in my Amateur radio station too.
Paul M0BSW

You've read about the new models just about to hit right?

http://www.eevblog.com/forum/testgear/new-rigol-ds1000z-and-mso4000/

Citizen

  • Guest
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #18 on: June 26, 2013, 05:24:20 AM »

So, lets summ it up:

First Issue :"Alternate trigger mode not available"=> not actually an issue if you read the Dsiplay/Manual

Second Issue: "XY Mode doesn't work? with normal mode at the same time"=>Dave only connected one Channel, thats why it seems that XY Mode isnt working O RLY? (just tested my DSO-1062D, everything works fine, not very smooth, but works).

Third Issue: "Overshoot":Tested my DSO-1062D with HP 33120A @1MHZ Square wave. Any overshoot/undeshoot.



Sorry, but it looks like Rigol paid you to give negative feedback to their compatitors on low end market, like :"all those new scopes sucks, keep buying our outdated Rigol 1052e or pay more for our newer models...;)"
« Last Edit: June 26, 2013, 05:43:49 AM by Citizen »
 

Offline staze

  • Frequent Contributor
  • **
  • Posts: 787
  • Country: us
  • I _might_ have a problem...
    • Everybody Staze...
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #19 on: June 26, 2013, 05:38:53 AM »
ugh... it's ugly. jebus. I mean, the DS1000 series aren't the most attractive things in the world, but damn... the fonts just look terrible and nobs, etc. ugh.

Maybe I'm just not old-school enough to appreciate the looks. =P
« Last Edit: June 26, 2013, 05:42:32 AM by staze »
“Give a man an answer, he’ll keep his job for a day. Teach a man to Google, and he’ll be employed for a lifetime”
 

Offline tinhead

  • Super Contributor
  • ***
  • Posts: 1798
  • Country: 00
    • If you like my hacks, send me a donation
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #20 on: June 26, 2013, 06:18:57 AM »
Third Issue: "Overshoot":Tested my DSO-1062D with HP 33120A @1MHZ Square wave. Any overshoot/undeshoot.

Sorry, but it looks like Rigol paid you to give negative feedback

nah .. don't say that. Show me pictures of your frontend, maybe Voltcraft/Hantek finally decided to implement my changes to make the response better, here is what i mean :

http://www.eevblog.com/forum/testgear/hantek-tekway-dso-hack-get-200mhz-bw-for-free/msg212054/#msg212054

As a guess with respect to the pulse fidelity ... since the Tekway is hackable for 200 MHz, this suggests a switchable input filter under firmware control. If the filter is not a Gaussian type, it can introduce pulse ringing when enabled.

One way to determine the input filter characteristics in the frequency domain would be to plot the frequency response and look for dips or peaks and also look at the roll off rate. Gaussian should not have peaks and dips and should give a smooth roll off.

right, this is the case here, these DSOs have definitely flat and not gaussian response, so some ringing have to be there.

http://www.eevblog.com/forum/testgear/frequency-response-of-your-dso/new/?topicseen#new
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 ...
I want to reach out with something other than these prehensile paws and feel the solar wind of a supernova flowing over me.
 

Citizen

  • Guest
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #21 on: June 26, 2013, 06:42:55 AM »
nah, i dont want to take my  Voltcraft apart, it still has warranty i think.
 

Offline bilko

  • Frequent Contributor
  • **
  • Posts: 405
  • Country: 00
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #22 on: June 26, 2013, 07:09:20 AM »
Sorry, but it looks like Rigol paid you to give negative feedback to their compatitors on low end market, like :"all those new scopes sucks, keep buying our outdated Rigol 1052e or pay more for our newer models...;)"
I thought Dave's review was excellent. An unbiased independent review from somebody well qualified and respected for his opinion.

Just for the record I own both Rigol 1052 and Tekway 1102. Both have pro's and con's, although I must say that the Tekway/Hantek is far more quirky than the Rigol. I have much less confidence in the Tekway and usually have to double check my measurements. When you add up all the extra time involved, maybe the Tekway is not so cheap in the end.  I don't get paid by Rigol either.
 

Offline tinhead

  • Super Contributor
  • ***
  • Posts: 1798
  • Country: 00
    • If you like my hacks, send me a donation
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #23 on: June 26, 2013, 07:15:11 AM »
here we go, i edited my first post in this thread, and i hope answered all the questions/findings.
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 ...
I want to reach out with something other than these prehensile paws and feel the solar wind of a supernova flowing over me.
 

Offline LoyalServant

  • Regular Contributor
  • *
  • Posts: 65
  • Country: us
Re: EEVblog #487 - Tekway DST1102B Oscilloscope Review
« Reply #24 on: June 26, 2013, 08:27:53 AM »
I have a rigol and I have been very happy with it.
Of all the Chinese scopes IMHO they have come the farthest in actually making some decent test gear.

I was with Dave in the beginning... it really was looking good but the slow display and then the lockups were a major, major putoff.

Why is it that they can't seem to get the UI and the functionality all the way at times?
They get like 90% of the way there then fall on their face.

 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf

 

http://opalkelly.com/