Siglent SDS2000X Plus

[FiveFiveFive]

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.

[Martin72]

The second one without having the cal-sheet, makes me curious if I got one...
Open the package, I got one.
It was folded and stucked inbetween the quick start guide....

[steve1515]

Martin72, I was taking a look at your schematic for the deskew fixture and I think the current loops are in the wrong location. Shouldn't they be under the voltage probe nodes?

The more I look at this, I'm also wondering if we could just make a cheaper version with a terminal block where you could connect a wire and loop it as many times as you wanted. Seems simple enough. The only thing I'm not sure of is why the two loops have different voltages at their test points? The large loop has 2.5V and the small 3.5V at the voltage point. Is there a reason for this difference?

Also it looks like Siglent copied the Keysight fixture since the small loop is labeled 147mA, but I calculate it out to be 143mA. 

[Martin72]

Hi Steve,

Shouldn't they be under the voltage probe nodes?

For me they do ?

[steve1515]

I mean they should be under the voltage probe node and the R22/R23 and the same for the large loop. Currently they are on top of the voltage probe node in the schematic, so when the FET is conducting, current is still being sensed in the loop as drawn on the schematic, but the board doesn't look like it's that way. On the actual board, when the FET is conducting, you should get no current through the loop.

Hope that makes sense. If not, I can draw out what I mean.

[Martin72]

Hi Steve,

On the actual board, when the FET is conducting, you should get no current through the loop.

https://www.eevblog.com/forum/testgear/siglent-sds2000x-plus-coming/msg3137612/#msg3137612

Maybe I get you wrong as english was not my "mother language", but I will examine the board tomorrow again.

[steve1515]

In the picture here, I've modified your schematic to show what I mean. You can see on the PCB, the red line is where the current flows when the FET is conducting, and the blue line when the FET is not. I hope this helps. 

[2N3055]

Hi Steve,

On the actual board, when the FET is conducting, you should get no current through the loop.

https://www.eevblog.com/forum/testgear/siglent-sds2000x-plus-coming/msg3137612/#msg3137612

Maybe I get you wrong as english was not my "mother language", but I will examine the board tomorrow again.

Steve is partially right, mosfet should short top resistor to the ground. You take voltage out from bottom resistor. Current loop in the middle.

[Martin72]

Hi Steve,

Seems to make sense, check this finally "tomorrow", then correct it if it needs, will give feedback then.

Martin

[2N3055]

Lt spice of the mosfet /loop part

[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.

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 !

As resellers we might hold stock for some months before sale and particularly now as airfreight is cost prohibitive so it is not as straightforward as it once was to get fresh units from the factory however all this depends on your location as to whether you are served from the factory directly as I am or from one of Siglents branches where they have been supplied by seafreight and then units are further shipped on to authorized resellers and then to the buyer.

In the above scenario a buyers receipt of an instrument might have the 1yr Cal cert approaching expiry and some reason why resellers chose to omit Cal certs so to not disclose if it's old stock or not. 
From our POV it's now even harder to judge the marketplace on what and how much we might order and mainly due to 2 factors, the Covid impact on spending budgets and the recent difficulties of stock resupply.


However until recently (IDK when), Cal certs were single side printed on A4 paper but latest are double side printed to include a 180 day NO USE exception to the Cal cert expiry date which IMO is a very welcome addition specifying that time spent shipping or being held in stock won't affect Cal accuracy for 180 days since Calibration.

Attached is a pic of the rear side of the latest Cal cert where you can see how this exception is explained and now we have this there is no good reason why Cal certs are not shipped from resellers with new units.

[Elasia]

I've never had any siglent hardware not come with a cert paper 

[Martin72]

Me too.

[2N3055]

I only have sdg6000X from Siglent and that one came with cert.

[Sighound36]

I m sure Tautech should be able to advise if you can view these via a factory database possibly?

[tautech]

I m sure Tautech should be able to advise if you can view these via a factory database possibly?

View ? 

Working on getting copies of the originals ! 
GM in Germany notified and chasing this up.

[Martin72]

Hi Steve,

Seems to make sense, check this finally "tomorrow", then correct it if it needs, will give feedback then.

Martin

Thank you Steve, indeed I must correct it:



The full schematic see below (change txt to sch, eagle format)

Martin

[Martin72]

First job was very gently Dremel the edge of the 1 turn current loop to allow fitment of a Tek P6021 current probe as they have just a 3.6mm cable capacity whereas the DF2001A deskew PCB has ~4mm current loop and ~0.5mm of PCB wider again.
P6022 is smaller again, only allowing for 2.75mm cable diameter. 

Two possibilities imho:

You cut of a little piece of the layer and solder a flexible wire over it.
Or you cut a piece out and solder a massive wire of say 2mm diameter between the edges, see below.

[2N3055]

Yep, that looks allright...

[tautech]

First job was very gently Dremel the edge of the 1 turn current loop to allow fitment of a Tek P6021 current probe as they have just a 3.6mm cable capacity whereas the DF2001A deskew PCB has ~4mm current loop and ~0.5mm of PCB wider again.
P6022 is smaller again, only allowing for 2.75mm cable diameter. 

Two possibilities imho:

You cut of a little piece of the layer and solder a flexible wire over it.
Or you cut a piece out and solder a massive wire of say 2mm diameter between the edges, see below.

A third based on #2.


Drill holes through the PCB current loop trace either side of the cut then fit and solder wire for better strain relief. 

Fine idea Martin and briefly looked at the PCB again today while a buddy was here and looking at all the shiny new stuff that's arrived. He spent some time using a 2104X Plus and was pretty impressed so I just gotta get him to part with his DS4000 first.   

[steve1515]

Does anyone know why the voltages in the deskew fixture are set to 2.5V pk-pk for the large loop and 3.5V pk-pk for the small loop? I was thinking of making my own with only one loop (actually a coil of wire that you can change), but I'm not sure what to set the voltage to. Does it matter?

[tautech]

Does anyone know why the voltages in the deskew fixture are set to 2.5V pk-pk for the large loop and 3.5V pk-pk for the small loop? I was thinking of making my own with only one loop (actually a coil of wire that you can change), but I'm not sure what to set the voltage to. Does it matter?

The p-p doesn't matter much at all only the nice sharp rise times for accurate deskew.
In PA mode deskew is automated but you can do it manually easily enough by just increasing the timebase and adjusting channel skew so the rising edge of both current and voltage probes cross the trigger point as close as you can get them.
Not at all hard. 

[Martin72]

Just for fun I took my Ascel milliohm meter and measure the "loops".
As the values vary a little bit because of not ideal contact, the 1 loop vs 8 loops are vaild.
8 loops are appx 155 m , 1 loop appx 18...19m .
As I said, just for fun. 

[Elasia]

Just for fun I took my Ascel milliohm meter and measure the "loops".
As the values vary a little bit because of not ideal contact, the 1 loop vs 8 loops are vaild.
8 loops are appx 155 m , 1 loop appx 18...19m .
As I said, just for fun. 

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

I'd done it already if i wasnt buried under projects lol.. no time for fun time but at least i got a job in this economy... i should have moved to canada before the border was shut down

[2N3055]

Just for fun I took my Ascel milliohm meter and measure the "loops".
As the values vary a little bit because of not ideal contact, the 1 loop vs 8 loops are vaild.
8 loops are appx 155 m , 1 loop appx 18...19m .
As I said, just for fun. 

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

I'd done it already if i wasnt buried under projects lol.. no time for fun time but at least i got a job in this economy... i should have moved to canada before the border was shut down

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...