Siglent SDS2000X Plus

[Elasia]

He's probably waiting on me... 
I have it reverse engineered for some time, but waiting to buy current probe myself..

But I'm equally busy as you are... And also grateful that there is work despite the plague...
I also wanted to do it in Kicad (to learn and make it more open) but that thing is not my friend either...

I tried Kicad once.. seemed alright but never really go into it.. im just another altium whore and already know its command set, i'd rather do an export lol

What probe do you got your eye on?

[steve1515]

My plan was to make a small board allowing for adjustable frequency and a 2-pin terminal block where you could connect a small wire and loop it as many times as you wanted. One loop would be 125mA. Would there be any issues with this approach?

[Martin72]

You know enough now to completely recreate it and just get pcbs correctly sized to align your smaller probes instead of chewing up the stock one

It was tautech who had problems with it. 
I already got a fixure and I´ve drwan the schematic for those, who want to build one instead of wasting so much money.

[Martin72]

My plan was to make a small board allowing for adjustable frequency and a 2-pin terminal block where you could connect a small wire and loop it as many times as you wanted. One loop would be 125mA. Would there be any issues with this approach?

I don´t think so, but keep in mind that loops are inductives, so you should take care of ringing (therefore, in my opinion, there are two different gate resistors in the schematic).
Adjustable frequency reminds me of my nice to have breadboard "de luxe:"



Also simple using a 555 circuit, but you have squarewaves up to 100khz on board.

[2N3055]

My plan was to make a small board allowing for adjustable frequency and a 2-pin terminal block where you could connect a small wire and loop it as many times as you wanted. One loop would be 125mA. Would there be any issues with this approach?

I don´t think so, but keep in mind that loops are inductives, so you should take care of ringing (therefore, in my opinion, there are two different gate resistors in the schematic).
Adjustable frequency reminds me of my nice to have breadboard "de luxe:"

(Attachment Link)

Also simple using a 555 circuit, but you have squarewaves up to 100khz on board.

Well said, and dip switches are nice touch. Deskew fixtures usually don't have variable frequency, like with scope cal signal it's not needed... But it can't hurt...

EDIT.. variable, not stable..

[steve1515]

I have some parts on order to try some things out, but I think it would be pretty simple and would provide a fixed range of about 355Hz - 24kHz. I'm not to sure on how to calculate or determine the gate resistor into the MOSFET though. Do you think I can just put in something like the 475R resistor and it would be ok in most cases?

[Elasia]

I have some parts on order to try some things out, but I think it would be pretty simple and would provide a fixed range of about 355Hz - 24kHz. I'm not to sure on how to calculate or determine the gate resistor into the MOSFET though. Do you think I can just put in something like the 475R resistor and it would be ok in most cases?

Depends on the fet, check it's datasheet, usually there is a calculation page for what to drive it with, its not so much the resistor as it is you want to control the current flow and voltage arriving at the gate.. that will then tell you what resistor to use

One other thing.. i usually like to have small trimmer pots for these that is around the value instead of a fixed resistor.. this gives you some tunability while you are exploring the circuit for what you want

[tautech]

I have some parts on order to try some things out, but I think it would be pretty simple and would provide a fixed range of about 355Hz - 24kHz. I'm not to sure on how to calculate or determine the gate resistor into the MOSFET though. Do you think I can just put in something like the 475R resistor and it would be ok in most cases?

I don't know if a range of current loop frequencies is really even necessary. 

If we think back decades to the old legacy Tek models they often used a current loop in their probe compensation output which doubled for setting up current probes and like voltage probes it was just 1 KHz.

These deskew fixtures like the old Tek loops primarily offer a rising edge and flat top which provide an edge for channel skew adjustment and a fixed amplitude for obtaining attenuation factors.

Sure things have moved on from those days in terms of frequencies we might encounter hence the 22 KHz of the Siglent deskew unit which today some might consider to be a bit low but really how might another frequency effect skew of channels resulting from different probes on the same signal source ?
Bugger all I would suggest unless you're approaching the frequency limits of some POS probe.

Risetime nulling between probes is our primary concern here plus a known current output so to set current probe attenuation correctly.
IMHO frequency is of a much lesser concern.

[2N3055]

Most important is clean monotonic edge (as linear as possible, or at least with identical current and voltage shape) and flat top....
Going too fast might be counterproductive.
It is not used to verify frequency response... For that you need different fixture..

[Martin72]

Do you think I can just put in something like the 475R resistor and it would be ok in most cases?

There must be reasons why siglent use different gate resistors on one turn/ eight turn loop.
My guess is, using a higher resistor value in the 8 turns schematic makes the fet switching "slower" because of the greater inductance of the loop.
If I would have here finally a current probe ( hello batronix, where is my new micsig? ), I would change the 475R into 150R and see what happening to the signal.

[FiveFiveFive]

Just a quick Telonic cal certificate update (I don't like to interrupt the entirely more interesting deskew-fixture chat).

I received a reply from Telonic to my email of Friday enquiring about calibration certificates, or the lack thereof. Apparently they don't send them out as a rule but are happy to provide a pdf of them, so they have sent that through to me for both my new toys -  the SDS2000X+ and the SDG2042X. Whilst it is less than desirable to have to chase up that information, and if they are included as standard I am bewildered as to why you would bother to remove them, I'm happy to have an electronic copy. Many thanks for everyone's advice.

[Elasia]

That is utterly bizarre... part of the cost you are paying for is that cert proof....

---

There is one area in particular changing the switching frequency would be good for and that is if you are doing something say like a boost converter.. in general though likely to almost always be close enough less you are doing studies and need to actually calculate error to that degree but if that is the case good chance you are already using something else

[Johnny B Good]

FWIW, I also received an SDS2104X+ (and a SDG2042X) from Telonic on Monday, and, as with JBG, no cal certificates were included. I've emailed (today) to see if they can be supplied but I'm not holding my breath. So, are cal certificates included as the norm with Siglent equipment, or is this something distributers do (or don't do)? I can't believe they have been removed (too much effort!), so I tend to think they were never there in the first place.

 I received an email from Karen (I'd ccd her in a second email to Becky about the missing certificate) with a pdf of the certificate attached (a two page pdf showing the 180 day provision).

 This was what she told me, and I quote:-

"We don't send the calibration certificate as a rule as there are no results, but happy to send as and when customers request.

Please find yours attached."

 I duly thanked her and left the question, which her statement had begged over the actual source of the paper certificates most recipients have found packed with Siglent products, unasked. In short, who is actually packing these printed certificates in with boxed Siglent products? Is it done in the Siglent factory or by their regional agents? That cryptic statement seems to suggest the latter rather than the former.

JBG

[Elasia]

Factory.. i get sealed boxes and they are always in the packet... dunno.. i'd probly not use that vendor again

[Martin72]

I wonder why your calibration "protocol" wasn´t in your package included.
But...
Personally I don´t give a thing about this one piece of paper.
What does it "say" ?
Nothing.
The first thing we ( in the company I work for) do when we buy new equipment, we let them calibrate.
And then it returns with a proper calibration protocol and not only one piece of paper which says nothing.
I got the certificate in my package, but if not, I won´t worry about it.

[tautech]

FWIW, I also received an SDS2104X+ (and a SDG2042X) from Telonic on Monday, and, as with JBG, no cal certificates were included. I've emailed (today) to see if they can be supplied but I'm not holding my breath. So, are cal certificates included as the norm with Siglent equipment, or is this something distributers do (or don't do)? I can't believe they have been removed (too much effort!), so I tend to think they were never there in the first place.

 I received an email from Karen (I'd ccd her in a second email to Becky about the missing certificate) with a pdf of the certificate attached (a two page pdf showing the 180 day provision).

 This was what she told me, and I quote:-

"We don't send the calibration certificate as a rule as there are no results, but happy to send as and when customers request.

Please find yours attached."

 I duly thanked her and left the question, which her statement had begged over the actual source of the paper certificates most recipients have found packed with Siglent products, unasked. In short, who is actually packing these printed certificates in with boxed Siglent products? Is it done in the Siglent factory or by their regional agents? That cryptic statement seems to suggest the latter rather than the former.

JBG

JBG/all
Germany Siglent GM mailed me explaining Cal certs on a EU few units were omitted at the factory.
He was sorting it when we last mailed one another last week.

If required I can you connect those of you missing Cal certs to the German GM as offered previously.

[Johnny B Good]

FWIW, I also received an SDS2104X+ (and a SDG2042X) from Telonic on Monday, and, as with JBG, no cal certificates were included. I've emailed (today) to see if they can be supplied but I'm not holding my breath.

Welcome to the forum.

That's inexcusable IMO but I cannot speak for other resellers on this matter as it maybe their policy decision. 

So, are cal certificates included as the norm with Siglent equipment, or is this something distributers do (or don't do)? I can't believe they have been removed (too much effort!), so I tend to think they were never there in the first place.

EVERY unit I import includes a Cal cert and they are dispatched with it and without exception !

====snipped====

 The certificate I received this Monday afternoon from Karen@telonic had a calibrated date of 2020-06-22 just a mere three weeks before I took delivery of the 'scope.

 From the wording of that email, it looks like they've taken advantage of the need to open the box to chuck in a UK plug ended C13 mains lead to remove the certificate since they're not receiving any extra revenue from their customers to re-calibrate these Siglent products after the initial calibration period has expired.

 If that's actually the case here (ICBW), I think it's just a touch disingenuous of them to be removing these certificates from the packaging. I rather doubt Siglent would be favourably impressed by this practice if they were to get wind of it. After all, the very inclusion of these calibration certificates acts as an additional selling point whenever a youtube reviewer unpacks a shiny new Siglent product and comments favourably about the fact one is supplied with every brand new Siglent product they've received thus far.

 The one year validity isn't explicitly stated but rather implied by the examples given to work out how to apply the up to 180 day grace period between the factory calibration date and the date of receipt and first use of the equipment concerned. In my case, that means the original certification is good until 2021-07-13.

 I suspect most, if not all, hobby users would be more concerned over getting their Siglent kit repaired rather than  have its calibration re-certified. 

JBG

P.S I've just taken a very close look at that pdf they sent. The 180 day grace period notice was on the first page with the actual certification details on the second page. I could see a faint suggestion of a crease line on the first page with the second page seemingly absent any such when viewing the document at the "Fit to Page" view setting.

 Zooming in confirms that it is a very carefully aligned high resolution photocopy of a paper document. It was only by zooming in that the suspicious marks became all too obvious as crease marks both front and back. It seems that Telonic are doing just what I was suspecting to be the case after all. What I can't figure out is what the benefit is to Telonic in pursuing such a practice as implied by that email response I received from Karen.

 I suppose it's always possible that the perfectly aligned high quality photocopy is all Siglent's work (print off a batch of calibration forms to match the serial numbers of the product being tested and then photocopy the completed forms for their own records). Telonic may have simply not checked that a certificate had actually been packed inside the box and merely requested a copy from siglent to satisfy my request for one. Even so, that was a rather lame excuse proffered to explain its absence.

 Never mind, if truth be known, it will simply remain filed somewhere safe, never to be viewed again, just like I did with the SDS1202X-E certificate, except in this case, it isn't cluttering up the original packaging. 

JBG

[noreply]

*** BEGIN RANT ***

It’s amazing how much value people put in a piece of paper.


Whereas often the paper is not worth anything itself contrary to popular belief.


It’s the spirit of the agreement or purpose of the document which holds all of the value of the ‘paper’ and not the paper itself.


For those of you who think the above sounds like a lot of ballocks, then let’s look as some examples to prove the above statement(s).


1.   The most important piece of paper we all come across is – money. Why is THIS piece of paper  ‘worth’ anything? It’s not the intrinsic piece of paper itself – but the people and spirit which lies behind the piece of paper – in this case ‘money’. It is BACKED by HMG and they promise to honour its value (whatever is printed on it) to the bearer of the piece of paper.


2.   Another piece of paper most important to us – a property title. Long time ago – this was a beautiful looking document – something of great value to the person holding it. But, in reality its once again worthless on its own – only paper – the real value lies in the ‘system’ which protects your rights of what is written on the paper – the spirit of the document – which is defended by HMG and the registration system which validates the paper’s value in definition and not sole existence. Today – the value of such a piece of paper is further diminished, because property titles exist as entries on a database (again honored by HMG) – the ‘paper’ is just a record that such an entry was made on your behalf.


3.   A contract between two parties can be considered as an important business document one would think. If I lose this piece of ‘paper’, then the relationship between the two parties could be severed or jeopardized in some ghastly way? Again, totally misguided assumption – the paper is worthless. Any business contract is only worth as much as the spirit of the agreement between the two parties. If either party does not want to honor its commitment to the contract – the contract will fail – without exception. Oh, but I have a contract and can take legal action against you, if you do not honor our agreement. Sure you can do this – but you don’t change the fact – that the paper- yes PAPER – has no value. What has value is the implied agreement as seen in the eyes of the law or whoever the underwriters of the agreement were – it is they who make the paper worth something.
More and more examples can be given – but I hope the above three examples are sufficient to demonstrate the point I try to make in my opening statement – that the paper is often not worth anything – it’s ALWAYS the spirit of what the paper conveys and more importantly the people behind what is written on the paper itself.


Given the above, what is the intrinsic value of a CALIBRATION CERTIFICATE from Siglent?


1.   You want this piece of paper – because you want to ‘trust’ your test equipment to perform within the specifications claims of the manufacturer right? So you receive a nicely printed document, which clearly identifies the test equipment you have purchased and has a unique serial number – further confirming that the ‘paper’ relates to the physical device in your possession. Now you look at the paper where it states that an Agilent or Keysight or R&S instrument with its own unique identifier serial number, also shown on this piece of paper, was used to make a measurement on YOUR PURCHASED test equipment, which in turn confirms that your purchased equipment is indeed within the ‘specifications’ issued by the manufacturer – Siglent in this case. Of cause the equipment which was used to calibrate YOUR equipment was itself calibrated and on your piece of paper – it stated the ‘calibration’ dates of the 3rd party equipment used to calibrate YOUR equipment – all this is checked and signed by Mr WANG (made up name by me for the sake of this discussion), the senior test engineer in charge of Siglent ‘calibration certificates’ issuing department, sealed with Siglent company stamp and date of issue. WOW, that’s really impressive – you say to yourself. I now know that my new test equipment is fully calibrated and tested. I can rest in peace – knowing it’s all good! BUT do you REALLY know it’s all good?


2.   How do you know that the 3rd party equipment – used to calibrate YOUR equipment was calibrated in the first place? – just because Mr WANG told you? – did Mr. WANG include the 3rd party equipment’s calibration certificate with YOUR calibration certificate? Do you trust Mr. WANG?


3.   I hope you can see where I am going with this – the whole calibration certification process – is in essence a deep rabbit hole. Again demonstrating that the ‘paper’ whatever it’s called – in this case ‘calibration certificate’  is worthless without the trust and support of the people behind it!



After all of the above preamble, I can finally get to the main point I wish to make.



Siglent made the ‘test equipment’ you bought – and I presume they stand behind their product.



You bought your ‘test equipment’ from Telonic – and I know (not presume because I have prior experience to allow me to say this) that they will stand behind the product they sold you.



In both of the above ‘your guarantee’ are the PEOPLE and companies behind the people and not the paper issued by them. (Telonic AND Siglent)



If you did not receive a calibration certificate or the certificate you received looks ‘dodgy’ – it’s irrelevant – if the people behind the product you purchase confirm that the device was calibrated – then that’s good – it’s worth more than the ‘paper’ – because paper is paper and not the spirit of the certification and people behind it.



Like I said the calibration process is a rabbit hole – even if you got all the certificates you wanted – all signed and not ‘dodgy looking’ – how do you REALLY know the device was calibrated?



Well, if you are fortunate to have some ‘better’ equipment that you trust, you can check yourself.



After your ‘own testing’ you find its calibrated – as specified – you are now ‘happy’ we all move on!


OR


After your ‘own testing’ you find its NOT calibrated to specifications – you are NOT happy – despite what the ‘calibration certificate’ states – you believe – via your testing, that the equipment is NOT calibrated!


So what do you do?


Shout at the piece of paper which Mr. WANG issued – yelling all sorts of dislikes and comments?


Probably not – because it’s a piece of paper only.



You will most likely call Telonic and explain that you did some tests and found that your newly purchased Siglent equipment is not performing to specifications and might not be calibrated correctly – asking them – Karen in your case – to help you resolve this.



Guess what Telonic (or any other Siglent distributor) will do?



They will take note of all your comments and concerns about the equipment and ensure it is rectified to ‘specifications’ – because BOTH the distributor and the Manufacturer has given this implicit commitment – all despite the ‘piece of paper’ called the calibration certificate.



I hope that my little rant does not create offence – it certainly is not intended to do this.


The whole purpose of this ‘rant’ was to demonstrate that we ALL should not be bothered with too many ‘paper’ guarantees – the paper is worthless in every case – it’s the people / companies and spirit behind the paper that really makes the difference.


Buying something  from china direct – with a guarantee certificate in the box – the piece of paper included with your product - is not as good as buying something from a UK Siglent distributor without a guarantee certificate included the box.


Why?


Because you can trust a Siglent distributor better than an unheard and unknown entity who sold you a product from a distant land.



I hope this point is understood in our quest for ‘calibration certificates’ and the potential rabbit holes (yes multiple holes) they create.


Finally, for anyone who likes to keep paper rather than have the support of the  people behind the paper – then you should ask Siglent to ‘reprint’ the calibration document files on their database when they calibrated your test equipment and send this to you.


After you receive this ‘reprinted’ certificate from Siglent – will you be happy – case closed?


Not really, because after all you still hope that they did indeed calibrated your equipment and not just issued ‘blanket’ certificates for every device sold!


So – here we go again (we need to trust someone in the loop) – yet another rabbit hole – it’s never ending.


We must trust more people!

*** END RANT ***


Take care everyone


AND


Be SAFE!

[tautech]

3.   I hope you can see where I am going with this – the whole calibration certification process – is in essence a deep rabbit hole. Again demonstrating that the ‘paper’ whatever it’s called – in this case ‘calibration certificate’  is worthless without the trust and support of the people behind it!

Garbage ^^^ and you should/need know why.

The formal calibration process is inherently traceable completely to the international standards of all measurements. Every instrument in the chain from the calibrators that calibrate calibrators that calibrate all manner of calibration instruments can be have their accuracy aligned back to an international standard whatever one that might be.

An instrument calibrated by a traceable instrument proves an instruments accuracy meets datasheet spec.
To achieve such traceable accuracy test/measurement standards also must be met and these are also referenced on the SDS2kX Plus Cal sheet.

To make the statement that the average user can check accuracy of their instrument without also requiring the use of a calibrated instrument is also garbage as is often seen in this forum with widely varying -3dB BW points of the same instrument when tested by numerous owners.
How might we know the flatness of a signal source over the frequencies that we might use to check the -3dB point when we don't other than that instruments datasheet amplitude flatness spec when to do better requires a leveling head, itself requiring calibration.

Yes it is a rabbit hole and we must not only trust certified traceable calibration but accept it as gospel.

Some study for ya'll:
https://www.nist.gov/history

[tv84]

An instrument calibrated by a traceable instrument proves an instruments accuracy meets datasheet spec.

Accepted.

Additionally, distributing calibration certificates via .PDF should be done with digital signatures by the manufacturer who did the calib.

That prevents any intermediate vendor to issue their own "certificates"...

[Elasia]

Further to add to this... a major reason why the calibration industry exists in the first place...

QUALITY standards.  ISO being one of the biggest and if you are using any of this for manufacturing you better believe it you get that thing calibrated with in its expiry or face getting written up.  That quality standard certificate further then buys a lot of customer value in that they know you produce quality products.

Would you buy your sensors for 10 dollars off the back of some truck for your critical application or pay 15 to KNOW they will work?

[maginnovision]

Would you buy your sensors for 10 dollars off the back of some truck for your critical application or pay 15 to KNOW they will work?

Many many hobbyists seem to go for the $10. Same as many companies, cost first.

[2N3055]

Would you buy your sensors for 10 dollars off the back of some truck for your critical application or pay 15 to KNOW they will work?

Depends, if the system together with the sensor has to be calibrated and/or characterised anyways, than it might not make sense to go for fully qualified sensor...

But yeah, you are right most of the time it is cheapest to simply buy known good components than having to verify them all..
I, for instance, never buy any components of Ebay or Ali or something like that. Many times there is not even cheaper, and you never know what are you getting.

[2N3055]

What probe do you got your eye on?

Sorry I didn't see this..
I'm looking into Micsig CP2100B  2.5 MHz version.
I would like something like Tek, but new ones are too expensive, and I don't have courage to splurge 500 600-700 USD for a 30 year old used probe that won't work if it was dropped to the floor just once...

[Martin72]

I'm looking into Micsig CP2100B  2.5 MHz version.

Good choice..