Rigol DS2000 Hardware version 2.0

[PA0PBZ]

 

[Carrington]

I see, but where is the trick? I mean, what did you do?

[PA0PBZ]

I see, but where is the trick? I mean, what did you do?

SCPI command: CHAN1:IMP FIFTY for 50 Ohm and CHAN1:IMP OMEG for 1 Meg.
Or if you prefer the other channel: CHAN2: ...

Now to enable it on the front panel, that is another story of course.

[Carrington]

With future versions of firmware, I guess you could do it from the front panel as well. 


I think that here is stored the serial number:
  † A3P015 and A3P030 devices do not support this feature.
http://www.microsemi.com/products/fpga-soc/fpga/proasic3-e#design-resources
http://www.actel.com/documents/PA3_DS.pdf


I need a JTAG, but I have no desire to go crazy looking for the best value for money for a JTAG.
Any recommendation, please send me a PM, thanks.

[Mr Simpleton]

Paul, where did you get your scope from??
When I asked my supplier why I got a rev 1, he said Rigol.eu did not have any v2 in stock and did not know when it would ship!

Seems do-able to stuff a relay and resistor at the input, but what circuit do the switching??
Not having 50 ohm on my new scope is like have a pebble in my shoe 

But honestly could just do as good with a 50 ohm feed thru load.

[JimmyMz]

I need a JTAG, but I have no desire to go crazy looking for the best value for money for a JTAG.
Any recommendations.

http://www.amontec.com/jtagkey-tiny.shtml

[Carrington]

JimmyMz: Thanks for the recommendation. 

[Gallymimus]

Paul, where did you get your scope from??
When I asked my supplier why I got a rev 1, he said Rigol.eu did not have any v2 in stock and did not know when it would ship!

Seems do-able to stuff a relay and resistor at the input, but what circuit do the switching??
Not having 50 ohm on my new scope is like have a pebble in my shoe 

But honestly could just do as good with a 50 ohm feed thru load.

Seriously just buy 50 ohm terminators.  Sure it sucks but it's hardly a problem.

[PA0PBZ]

Paul, where did you get your scope from??
When I asked my supplier why I got a rev 1, he said Rigol.eu did not have any v2 in stock and did not know when it would ship!

I bought it locally on July 30, when I called them they said they just had a new shipment in. The sticker on the box says it was shipped from Rigol EU in Germany on the 25th.

[ElectroIrradiator]

PA0PBZ,

Are you able to measure the actual input impedance of the V2.0 hardware in 50 ohm mode, using a VNA or some other suitable tool, please?

The original input is 1M || 16pF, and if they just slapped the 50 ohm across the input, then the 16 pF may still be there. That would create a rather wonky impedance mismatch above 50 MHz or so, not good in many situations.

[PA0PBZ]

Unfortunately I don't have a VNA, only a scalar one. But I can do a return loss on my SA, see the attachment.

[tom66]

Ugh. Do I spot CapXon on that power supply?
I have pulled and replaced hundreds of those absolutely abysmal capacitors.

EPCOS = So-so
CapXon = Terrible

Why Rigol, why? Clearly no care to keep instruments functioning long past the warranty period.

[Carrington]

tom66: What brand do you recommend for replace them? 

[ElectroIrradiator]

Unfortunately I don't have a VNA, only a scalar one. But I can do a return loss on my SA, see the attachment.

Thanks, that should do nicely.

However, if my algebra isn't completely off, then it very much looks like Rigol simply connects a 50 ohm resistor across the input, as you would expect. If we assume the real parts of the load and source impedances are both 50 ohm, and with no reactances in the source impedance, then I get an input impedance of about 50 -j29 ohm at 300MHz. That is equivalent to 50 ohm || 18 pF.

That would make it a bit of a challenge to make a 'flat' active probe design, good to 200 MHz. Hmm, maybe I should buy a DS2072 DS2202 and try to make one...

[tom66]

tom66: What brand do you recommend for replace them? 

Any of Panasonic (FR, FM, FC), Rubycon (YXF, ZLH, ZLJ, ZLK), Nichicon (PW, PM), United Chemicon (KY).
From best to very good.

[PA0PBZ]

Yeah, from what I see on the frontend pcb it's just a relay switching the 50 ohm resistor across the input, so your math is probably ok. But please keep in mind that it is not possible to switch the input to 50 ohm using the channel menu on the scope, it is not functional yet so who knows what they are up to.
And any excuse to buy one of these will do 

[Wim13]

Well on hardware version 1.01, i can switch it on, 50 ohm, BUT is not there,
input measure still 1 Mohm....

[Carrington]

Any of Panasonic (FR, FM, FC), Rubycon (YXF, ZLH, ZLJ, ZLK), Nichicon (PW, PM), United Chemicon (KY).
From best to very good.

Thanks, I take note.

[staze]

Anyone happen to know if HW 2 is out in the US yet, or is that what they're referring to as the 2000A series?

[Carrington]

Anyone happen to know if HW 2 is out in the US yet or is that what they're referring to as the 2000A series?

Yes, I think. And far as I know DS2000A=DS2000

[staze]

Anyone happen to know if HW 2 is out in the US yet or is that what they're referring to as the 2000A series?

Yes, I think. And far as I know DS2000A=DS2000

Okay. At least as far as tequipment.net is concerned, they're not available in the states yet (late October). =/ Boo!

[tom66]

Is the only major feature the 50 ohm terminator? Any improvements to things like noise floor?

[PA0PBZ]

Is the only major feature the 50 ohm terminator? Any improvements to things like noise floor?

Noise floor measurements did not reveal any difference, and even the 50 ohm terminator is not accessible in the normal (menu) way, so I'd say there is no difference at all between the hardware versions for the user. Inside it is a different story, apart from the terminator there is room for the LA and FG on the pcb, so there will probably be S and D models sometime in the future.

[Carrington]

Yes, but if you can choose Which you want? 1.0 or 2.0? 
Now, I do not know, but who knows in the future. 

[tom66]

But from what I've seen, the LA is a large FPGA+buffers, not easily modded in later, and the FG probably won't be a user-accessible add on. So I can't see any difference myself?