Author Topic: Hantek - Tekway - DSO hack - get 200MHz bw for free  (Read 1667586 times)

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Online tinhead

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #675 on: July 06, 2011, 11:59:50 pm »
I launch TTScope and it connects to the scope but it says: "No exsit [sic] configuration files to this machine!", whatever that means. The only thing that seems to work is the "Auto Set" function from the Setup list.

download the latest ttscope from Hantek website ... it is compatible with Tekway DSO.
http://www.hantek.com.cn/Product/DSO5000Series/DSO5000/TTScope.EXE

you can also use the latest drivers (there is for 32 and 64bit OSs)
http://www.hantek.com.cn/Product/64Driver/DSO5000.rar


PS: I rather shoot myself in the foot than trying to replace a PB-free BGA. Thanks for the warning.

hehe, easier as you think, in each every country there a mobile phone/xbox repair stores, they can do it for you.
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 JRoque

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #676 on: July 07, 2011, 12:20:54 am »
Ok, where do I send you a Paypal donation? That worked flawlessly. See if you can PM me your email address or if you have (you should!) a Paypal donation button somewhere that would work too.

Also, waiting a minute or two for the DSO to fully boot is also working.

Regards and, really, thank you!
JR
 

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #677 on: July 07, 2011, 01:18:44 am »
you welcome, and no, donation is not necessary, my support if free of charge!
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 colinbeeforth

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #678 on: July 07, 2011, 04:42:48 am »
Hi Tinhead,

Thanks very much for the improved English language file. I greatly appreciate your work on this!

I have been using my Hantek DSO5102B for much of my work lately, and comparing the results to my LeCroy 9310M.  In general, the Hantek is not as logical as the LeCroy, but I understand - it achieves a lot with cheaper hardware.  I am beginning to appreciate it's usefulness, the nice screen and the small bench size.  I wish it would not crash quite so often.  Like you advised me a while back, I've tried not to stress too much about exactly how it achieves what it does, and just use it.  Hantek sent me a list of timebase setting versus digitiser speed, and it's a bit strange, but obviously trying to get around some sort of hardware limitations.  In practical usage, the Hantek screen usually looks like the LeCroy screen, if you are not trying to do something tricky with the LeCroy's waveform processing maths.  I've often used waveform processing to extract information where any other digital scope would be useless, but I'm not doing so much of that research type work these days.  So, I took your advice, and stopped fussing so much, and I'm getting some work done with the scope.  Thanks again for the improved language file, that really does help to make using the machine nicer.  It's a shame that Hantek/Tekway couldn't do that in the first place...  It doesn't look like they will ever admit they need some help.  Cheers, Colin, Melbourne, Australia
 

Offline rf-loop

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #679 on: July 07, 2011, 08:43:45 am »

  Hantek sent me a list of timebase setting versus digitiser speed, and it's a bit strange, but obviously trying to get around some sort of hardware limitations. 

Is it possible get this information?
I like to see how they have explain it.

If practice and theory is not equal it tells that used application of theory is wrong or the theory itself is wrong.
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Harmony OS
 

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #680 on: July 07, 2011, 04:58:33 pm »
Thanks again for the improved language file, that really does help to make using the machine nicer.  It's a shame that Hantek/Tekway couldn't do that in the first place...  It doesn't look like they will ever admit they need some help.

I've send all modified files to Hantek, they promised to review it and implement evt. in later fw versions.

For sure we could blame Hantek, but actually we know that Tekway designed the multilanguage version in the first place,
so some things has been just overtaken. And you probably know how company merger works,
an CEO or even product manager will not look into such technical details (and you can be sure these ppl speak perfect english).
On the other side i know many talented engineers over the world not talking (or actually writing) perfect english.
So it is just something between company overtake/merger and QC. Sure, Hantek website does have
some typos too, but other and bigger companys are not that much better, so what.

For me is important that they reading this thread, in contact with me (and some other ppl here),
that they listening carefully and trying to improve their products. This is more than actually expected from
a non-global player (think just Fluke and their no-response to Dave's issues).

Btw, i said there are new products on Hantek websote, BM and BMV models. I got an confirmation that
they will be not ready before Sep 2011.
« Last Edit: July 07, 2011, 08:04:58 pm 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 A Hellene

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #681 on: July 07, 2011, 09:57:11 pm »
I am trying to see what a modern DSO input stage looks like: the most modern schematic I have found so far is from the Tek 2232 (June 1992 !).
Well, I think that you can consider yourself lucky, since I have just posted(!) the Rigol DS1052E HW58 (2011 March PCB revision) Channel 1 analog front-end schematics, while trying to troubleshoot my device!



Tinhead,
If you examine the schematics mentioned above you will discover a few differences that exist between them and the DST1102B schematics you have posted earlier.
I hope that helps a little...


-George



[EDIT]: Schematics updated.
« Last Edit: July 09, 2011, 12:49:10 am by A Hellene »
Hi! This is George; and I am three and a half years old!
(This was one of my latest realisations, now in my early fifties!...)
 

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #682 on: July 07, 2011, 10:31:38 pm »
i remember i posted few times the input stage, it wasn't complette anyway (or actually some copy/paste errors in values)

Attached the latest version, and yes there are some small diffs in attenuator compensation especially, but nothing
really important at all.

As i said before i will post soon the complette schematics, i have to find some time to ping here and there once again
to ensure everything match.

Btw: all important caps has been unsoldered and measured, all others are estimated values in circuit (when possible),
not important decoupling caps/inductors/ferrite bead skipped - every good EE know they are there.
CH2 is a bit different around HC595 as because HC595 within trigger circuit and both input channels HC595
are in same chain (you will see it)

« Last Edit: July 10, 2011, 10:18:23 pm 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 A Hellene

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #683 on: July 07, 2011, 10:36:46 pm »
Thank you, tinhead!

I'll do the same with my DS1052E HW58 (2011.03 batch) schematics, when they become ready for publishing.


-George



[EDIT]: Sorry for the delayed response; I did not see in time the additional information you posted.

I have not removed the capacitors to read their values, so the values in my schematics are estimated (measured on board and calculated). When I will find the time needed to do that I will remove the critical ones (the timing/ filtering/ etc.) and will update the schematics.

Regarding the 'HC595, Rigol uses the faster AHC595 (marked HA595), even though I cannot see the reason why they do that because they are driven (by the BlackFin) with relatively slow signals (10.0MHz) and their fan-out is almost the same. The three AHC595 are also cascaded in the DS1000 and they are also driving the two VGAs. When the processor is addressing the VGAs it sends a 16-bit word and toggles their LATCH input; when the BlackFin is addressing the 595 shift registers it sends a 24-bit word and toggles their RCLK lines that are tied together. The first 595 that controls the Ch1 components takes the MSB, the second 595 that controls the Ch2 components takes the middle byte (the NSB), and the third 595 that drives the Video amplifier (LMH6574) address lines (A1:A0), the HC4053 control and the trigger signal blanking takes the LSB.

On the other hand, the two HC4051 demultiplexers and the DAC are driven by the Lattice LUT in the same manner: The HC4051 share the same address lines (S2:S0) and their /Enable lines are driven individually. The DAC has its own driving lines and produces 10 discrete voltage levels that are demultiplexed by the two HC4051 and buffered & amplified by four of the five TLC274 quad op-amps.

It seems that those two designs (the Rigol and the Tekway/Hantek) are not so different after all...
« Last Edit: July 08, 2011, 03:48:20 am by A Hellene »
Hi! This is George; and I am three and a half years old!
(This was one of my latest realisations, now in my early fifties!...)
 

Offline A Hellene

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #684 on: July 08, 2011, 09:04:08 am »
You are welcome!

But the credit goes to Tinhead, since his work has been an inspiration for many of us.


-George
« Last Edit: July 08, 2011, 09:14:57 am by A Hellene »
Hi! This is George; and I am three and a half years old!
(This was one of my latest realisations, now in my early fifties!...)
 

Offline saturation

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #685 on: July 08, 2011, 11:06:32 am »
As the forum doesn't have a thank you button, need to express my personal thanks for the decoding of the PCB,  tinhead and Hellene, most excellent work.  I continue to follow all your posts closely!


You are welcome!

But the credit goes to Tinhead, since his work has been an inspiration for many of us.


-George
Best Wishes,

 Saturation
 

Offline A Hellene

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #686 on: July 08, 2011, 11:53:50 am »
Thank you for your kind words, saturation!


-George
Hi! This is George; and I am three and a half years old!
(This was one of my latest realisations, now in my early fifties!...)
 

Offline saturation

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #687 on: July 08, 2011, 01:10:02 pm »
Alas, without volume pricing on parts, we'll very likely pay more if we assembled it ourselves, given a free, open hardware design.  That's not adding the time and labor.  Its probably far easier to extend or modify existing hardware to improve its performance, than build from scratch.

When I see so many talented people struggling to make such proprietary DSOs work as expected, despite language, culture and manufacturer's short term-only vision, and put so many efforts in it, I am now sure it is worth trying to develop a decent open source/hardware DSO!
Best Wishes,

 Saturation
 

Offline Igor

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #688 on: July 08, 2011, 05:19:25 pm »
Tinhead, if in the window “Display” press F4 (Format XY) oscilloscope hangs and stops responding to all buttons. You can only revive the Power button (re-enable).
Do You encountered this error?
 

Offline rf-loop

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #689 on: July 08, 2011, 05:59:30 pm »
Tinhead, if in the window “Display” press F4 (Format XY) oscilloscope hangs and stops responding to all buttons. You can only revive the Power button (re-enable).
Do You encountered this error?

Mmmmh - first bug found where the scope always crashes??
· Press button "Display"
· Choosing XY instead of YT immediately chrashes my scope.
Can somebody verify that this crash happens everywhere?

yes, i noticed it too. It does have something to do with an overflow during channel activation.
However it works perfect if you enable (just turn on, it does not matter if then on AC/DC/GND) both channels
or actually disable (turn off) both channels before you enable XY mode.

A small bug only, normally you will anyway enable both channels, setup coupling etc. before you go to XY.

If practice and theory is not equal it tells that used application of theory is wrong or the theory itself is wrong.
-
Harmony OS
 

Offline A Hellene

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #690 on: July 09, 2011, 12:00:18 am »
Squonk,

Thank you for pointing that out. This was yet another copy error in my schematics... I am sorry about that. I will correct the schematics and re-upload them soon.

Actually, tinhead's version is the right one: In the pictures of both the Rigol and the Tekway front-ends it is clear that the buffered JFET output is fed to the inverting input of the VGA (pin 16) via the 33R2 (marking: 51X) resistor. This is the TP2_1/TP2_2 in Rigol and TP103/TP203 in Hantek/Tekway, for the Ch1/Ch2 respectively. The non-inverting input of the VGA is the TP210/TP111 in Rigol and is driven by a complementary emitter-follower stage with some heavy output decoupling electrolytic capacitors.

Regarding the relays, though I have not looked into it I think that they have a polarized coil of 5V/20mA or so.
A brief search for the Rigol's relays (FT B3GA4.5) revealed this, which confirms the polarised coil of 4.5V/30mA.


-George



[EDIT]: Done!
« Last Edit: July 09, 2011, 12:47:15 am by A Hellene »
Hi! This is George; and I am three and a half years old!
(This was one of my latest realisations, now in my early fifties!...)
 

Offline rf-loop

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #691 on: July 09, 2011, 08:22:31 am »
Hantek relays:

NEC  UD2 - 4.5NU  datasheet

I can not see S in typecode between voltage 4.5 and option NU marking.

"Latch type
Nil: Nonlatch type
S: Single coil latch type"


Here you find picture about Hantek HW rev 7 (newest)  front end


And, also in Rigol

...GA....

"A : Standard type
B : Latching type (1 coil)
"

Btw. I did not understand what is "polarized".

But this I know that there may be monostable, bistable with one or two coils, relays in electronics and even more complex... . As many time they are called "impulse" relays also.

Example HP old digiscopes use 2 coil bistable relays in front end. Power off... and nothing can ghange. Power on and nothing change.

But, what I do not like.... Manufacturer/designer have not read these relays specifications... or simple, he/she do not care.
And why this most bad model in this relay series..  is it price question or "so what" case in design.

I do not like what happends in Hantek input as you start oscilloscope (or off) (not maybe always)

To where and how input is connected after shut off...and in startup time.

This design bug is terrible. I name it bug, maybe some other can accept it but I dont.
What if you have allready high level (example maximum level) voltage connected to input... but of course, develop test lab with peoples who really have not enough experience  how good lab machines need work...  who can teach them? Customers?

Look these schematics, look these agen...and look agen and same time think. Always designer can think... no need care... or: so what.

Voltage and current what come out from CH1, CH2 sometimes in shut off time or startup time... what hell  they are thinking.
But what is source...  (yes this current is not high, voltage is not high but enough to affect sensitive things.

Ok, go to do some (imagined) industrial service work with this. So, that you example try find some problems in situation where all systems are running with full speed... then you keep your scope connected and watching... and there come lunch time... you shut off your scope... (or come back and shut on)  one PID loop swings from one end to one end... after ten seconds whole system is short time heavy disturbed, alarm rings and paper breaks... oh...thank you Hantek... it was only some tens of kilo euro. (imagined worst case scenario ;) )

(this is one reason why Agilent (oh maybe I'm wrong and need say, old Hewlett-Packard)  or Tektronix professional series instrumets (not hobby series) are very cheap in use.)

« Last Edit: July 09, 2011, 10:09:09 am by rf-loop »
If practice and theory is not equal it tells that used application of theory is wrong or the theory itself is wrong.
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Harmony OS
 

Offline rf-loop

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #692 on: July 09, 2011, 10:54:41 am »
If I design some day oscilloscope front end (I do not want - If need I copy Tek or old golden years HP) I do not recommend this kind of cheap toy relays at all. They belongs to cheap entertainment equipments. But not to serious _good_ oscilloscope.

Max. switching voltage 250 VAC / 220VDC ! But my scope front reads 300V CAT II  "so what"
Min. switching load * 0.01mA, 10mVDC !    who knows, who care ... and "so what" as long as boss pay my salary...

Of course with this price class oscilloscope it can live with these.

I mean if need something good. If need design _good_ oscilloscope front end put these Rigol-Hantek style front ends to garbage and never tough them. But agen...in this price class they are ok and "not so bad". It is totally different case if go to scopes where price are ten times.

Poor flatness and extremely poor filtering is also problem for these both, Rigol and Hantek, front ends.

Yes with sinewaves no big problem but if need really measure some pulses shape or other littlebit more difficult things... this can not use. Becouse  do not know if you measure your scope or DUT.
But agen, in this price class, with this can live.

This do not mean that I tell Hantek is bad scope. NO, it is very very nice scope in its price class.
But I mean, if want do better (example some open project development)... do not look these front ends at all, only for learning what all mistakes need avoid.

Simply nice test for this design bug...

Connect 2 Hantek scopes "parallel" looking same signal.. example 1MHz sinewave and example both 2mV/div DC. Konnect signal simply by 50 ohm cable with simple T to both scopes CH1
Adjust signal so that both scopes looks same and signal is vertically center.

Shut off a oscilloscope. Look b display. Then agen start this a scope.
Look still this b screen.  maybe it do not this all times but mostly. Why this b display signal swing vertically.

Write User manual agen.

Do not keep any signal connected to scope when you on or off oscilloscope power.
If practice and theory is not equal it tells that used application of theory is wrong or the theory itself is wrong.
-
Harmony OS
 

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #693 on: July 09, 2011, 11:20:50 am »
I noticed in this picture these 3 strange new unpopulated footprints between the AD8370/LMH6552 and the AD8510... Really looks like a crystal with foot capacitors layout, but I am sure this can't be the case.
hehe, no not for cristal, probably temp sensor, however we should track back these pins.

Still, I don't understand the lack of current limiting resistor for the OptoMos: this device is a Cosmo KAQY214S solid-state relay with MOSFet output, with a max forward voltage of 1.5 V, and max forward current of 5 mA.
oh there is one, such things are like decoupling caps and just skipped in my schematics now

Also, although I may understand the reason why the input capacitor before the JFET and the dual BAV99 diodes is angled at 45 degrees to shorten the trace in this particularly sensitive area, however I don't understand why Tekway also angled all the AD8370/LMH6552 stuff this way? Is this to stress their pick-and-place machine? ;D

no, that's basics of HF design in combination of limited space for input circuit.

Do not keep any signal connected to scope when you on or off oscilloscope power.

right, the input is never ever really off.
« Last Edit: July 09, 2011, 11:37:23 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 rf-loop

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #694 on: July 09, 2011, 11:25:43 am »
...
Ok, go to do some (imagined) industrial service work with this. So, that you example try find some problems in situation where all systems are running with full speed... then you keep your scope connected and watching... and there come lunch time... you shut off your scope... (or come back and shut on)  one PID loop swings from one end to one end... after ten seconds whole system is short time heavy disturbed, alarm rings and paper breaks... oh...thank you Hantek... it was only some tens of kilo euro. (imagined worst case scenario ;) )

(this is one reason why Agilent (oh maybe I'm wrong and need say, old Hewlett-Packard)  or Tektronix professional series instrumets (not hobby series) are very cheap in use.)[/size]
In a good design, I would recommend:
  • to put a 2kV spark gap at the input, with very good path to ground for ESD protection, see Dave's videos if you are not sure what I am talking about :o
  • to provide a normally-open GND coupling relay at the input, which would physically disconnect the device under test when the scope is turned off and during start-up transients, to avoid any harm to it, or don't go out for lunch during tests ;D

1. Scope input capacitance and inductances need keep low. Every extra millimeter trace make it more bad.
2. This is not "start up transient" what I'm talking.  Also cutting signal with some relays in input stage... and specially if you want cut both... GND and signal... maybe this can collect more problems than goods.

2kV sparc gap in scope input. What it protects? Maybe something but I do not want any pF more to input. I'm happy about any pF what can take off. I think it is more clever to make small add to input BNC so that peoples who do not know what they are doing can also safely use scopes. (safety plug in... for low freq signal looking) It needs small box and M and F BNC and then these protection components. ;)
If practice and theory is not equal it tells that used application of theory is wrong or the theory itself is wrong.
-
Harmony OS
 

Offline rf-loop

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #695 on: July 09, 2011, 11:35:39 am »

right, the input is never ever really off.

But, where it is sometimes connected in (only) boot up time and sometimes (power drop) off time shortly?
(I have not yet inspect what there happend exactly...  next time I have time and front end open, I want look carefully what is going on with there relays in boot time and specially if there is any posibilty that CAL realay do something... if CAL relay do connect... momentarily,...  then it is good to install switch  to front panel... (Cal/no cal ... haha)

(this all start as I test parallel lot of these scopes...  and also one other test procedure... there was one component damage and I'm still not sure if it was natural die or... outside from scope in start up situation come signal.... if this signal what I use was going to wrong road... (to calibration circuits). But this time it is onlu speculation.

But DC swing out from CH input is not very nice... tens of millivolts sometimes (and changing) over boot up time. After boot is just stop. This is not wise.,
If practice and theory is not equal it tells that used application of theory is wrong or the theory itself is wrong.
-
Harmony OS
 

Online tinhead

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #696 on: July 09, 2011, 11:59:30 am »
replace all these cheap relays/optoMOS by more adequate models

well, don't care that much about CAT II specs, 10x probe is standard for me.

replace BAV99 diodes

why? They good enough.

replace the 2 BC846 transistor for current mirror by at least a matched pair (BC846B)
that's already matched pair of BC846B (actually you don't have to much them today anymore)

replace the AD8310/LMH6552/VariCap by the LMH6518 above
for what? Actually you mean AD8370 and not 8310 (or you mean the AD8510 in LF path?)
Anyway, there is no reason to replace them. I can tell you something, Rigol did it in 300MHz CA models
and switched back to AD8370/LMH6552 because this combination works better.
Varicap is actually only part of the story, it 20MHz bw limiter, yes, but it does have only
mariginal influence on HF bw (just calculate back the filter corner freq. given by varicap+caps, out/in imp. and the
resistor networks and you will see it is much higher than necessary. The bw filter is within firmware)

straighten the signal trace as much as possible
hmm, it is stight, then 45° to first opamp then again stright ... the only think i don't like
it are the replays switching ADCs together, but the influence is as far as possible reduced
by self-calibration

keep the signal trace as short as possible and away from other traces
that would be complettly new PCB, much bigger anyway. Hantek/Tekway did it anyway better
(they have at least better shielding) than Rigol/ATTEN where the PSU is so close to ADCs/Trigger
stage/1MSs-500MSs relays that you have already influence.
« Last Edit: July 09, 2011, 06:30:34 pm 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.
 

alm

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #697 on: July 09, 2011, 01:43:28 pm »
I am trying to see what a modern DSO input stage looks like: the most modern schematic I have found so far is from the Tek 2232 (June 1992 !).
There's a more modern service manual for the Tek TDS520 available, I think on tek.com. Not exactly modern, but fairly detailed.
 

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #698 on: July 09, 2011, 02:02:24 pm »
Really? Do you have more details on this? Maybe pictures, schematic of it? I am really interested!
well both, but i can't publish as they has been created by someone else who don't wish to publish them,
which i will of course respect. But actually there is not that much difference
(except 50Ohm input switch and resulting gain switch)

This can't be, you have to do anti-aliasing filtering before sampling, not after. Maybe you mean that filtering is controlled by firmware?
no you don't, or not in form of what you interpreted from the schematics. It is hard to say what exactly Rigol/Atten/Instek/UNI-T/Tonghui are doing within the firmware because nobody (yet) reversed it. However it is simple to reverse Hantek/Tekway
as the firmware is on Linux based system, therefore we know some details how this works.
Sure, FPGA/CPLD design are not known, so we can only guess, but already from the application itself we know that
a sharp digital filter is implemented to replcae a typical analog bw filter. As all these DSOs are  (more or less) identical (like Rigol/ATTEN/HanTeway) or the concept identical (UNI-T/Tonghui/Instek vs Rigol/HanTekway) we can assume that
all these non linux based DSOs are doing it exact the same way HanTekway is doing.

For Rigol it has ben already tested before i started to play with it, if you even remove all caps/varicap and even
replace resistors to what HanTekway is having the circuit will not maigally allow 200MHz -3db bw,
even if you solder exact same components are 300MHz CA series is doing it will not works.
So the logical answer was for me "it must be firmware", and after i looked for it i found how at least HanTekway is doing this.

The details are here:
https://www.eevblog.com/forum/index.php?topic=1571.msg45275#msg45275
https://www.eevblog.com/forum/index.php?topic=1571.msg45649#msg45649
« Last Edit: July 09, 2011, 02:11:31 pm 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.
 

alm

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Re: Hantek - Tekway - DSO hack - get 200MHz bw for free
« Reply #699 on: July 09, 2011, 02:16:34 pm »
Unfortunately, Tek schematics are only block level after the Tek 2232, so is the TDS520 :-\
Really? Have you checked? The document is called 'TDS 520B Mod CM Digitizing Oscilloscope Component Service Manual', and those schematics don't look like block level to me.
 


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