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The Rigol DS1052E

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rf-loop:
Mark_O

some comments.

HP pulse generator output is 1,3ns risetime or less. (in output connector)
(after this I have 2m Suhner RG223/U and some cheap quality T where is HP 50ohm terminator (medium quality, not high-end calibrator quality).
I do not know risetime in the oscilloscope input connector! (also Rigol input capasitance is quite high, around 15pF)

We can not calculate this 1,8ns risetime becouse bandwith curve is what it is. Rise is not line, it is curve and curve shape depends many things. I think real comparable risetime in Rigol is around 2,5 - 2,9ns but of course there are also more fast components. It is measured at  around 10 and 90% points as Rigol seems to do. In this point we need remember BW shape.  (and it also depends what is mV/div setting, I use now 50mV/div). Also I have not seen exactly specifications about Rigol "risetime" measurements.

Yes also of course I swap HP outputs. Not big differencies! (this difference in pulse level is not from scope. It is from HP littlebit uncalibrated levels in HP outputs, there are some small difference between channels. (but this we can forget becouse overall accuracy in these test is not so high)

I also look both scopes with Marconi (Aeroflex) 2041.



First I adjust 10kHz level so that 1102 show 300mVp-p (variations becouse noise etc 298-300)
Next I check 1052 with exactly same adjustments. It show 300mVp-p but variable between 300-302)

now... 200MHz (same level as qood as this signal source give, and now I use exactly same cable and same terminator and T for avoid any variations in terminator, T and cable so I use just same and NOT drive scopes parallel with 2 cable... never do this without high-end (and very expensive) splitter. Also good measurement need still do different way... it need calibrated precision terminator, calibrated precision power meter and high end splitter in the scope end of cable.)
But for hobby use accuracy this my measurement is enough accurate for this purpose now. It simpy  show that with these unique scopes modify works extremely well.

Both Equ time mode and average 8, dspl points,  and only one channel use (CH1) and 50mV/div

1052Emod
10kHz ~301mVp-p  ;  200MHz ~190mVp-p


1102E
10kHz ~299mVp-p  ;  200MHz ~174mVp-p

With these unique scopes it looks like BW is littlebit better in 1152Emod
(but remember I have not test frequency response curve shape. Only with these point frequencies. (yes I have fast look with hand sweep and I can not see any big differencies over band. )

note: I use p-p measurement but more important is that both scope get same signalsource with same adjustments. Values are not absolute but comparable between each others.

Later I look risetime also with Tektronix 284 70ps risetime pulser.


rf-loop:
One warning...

If some day modified scope fails... (I do not mean modify itself is reason for fail)

and if you can not restore original type and serial. (example scope do not start at all)

Then you send it to repair becouse it have 3 year warranty.

You can quess what happend IF they find wrong serial and type...

jone:
Hmm, I think I'm close - but it's not quite working for me yet..

Changing the serial number from DS1EDxx to DS1EBxx seems to have worked fine, and persists across restarts.

But the model always reverts to DS1052E on restart, any clues what I might be doing wrong?

Thanks in advance!

JimBeam:

--- Quote from: jone on March 16, 2010, 09:21:25 am ---Hmm, I think I'm close - but it's not quite working for me yet..

Changing the serial number from DS1EDxx to DS1EBxx seems to have worked fine, and persists across restarts.

But the model always reverts to DS1052E on restart, any clues what I might be doing wrong?

Thanks in advance!

--- End quote ---
Yupp, that's because I cursed any other scope on earth to be immune to the change  8) !

No, seriously - no idea, maybe there's more to it than changing the "first name" of the serial number. I was astonished from the beginning, that nobody had ever tried to change modelnumber and serialnumber before - since the docs about the "secret commands" are already dangling around a while. Perhaps all the fuzz about RIGOL losing money is obsolete, if this "patch" only works by chance...

Mark_O:
rf-loop,

thanks for all the additional information, and all the testing you've been doing.  Those 200 MHz results are quite impressive.


--- Quote from: rf-loop on March 16, 2010, 09:04:40 am ---Also I have not seen exactly specifications about Rigol "risetime" measurements.

--- End quote ---

The specs in the back of their models indicate 7 nS risetimes for their 50 MHz units, and 3.5 nS for their 100 MHz models.  These are standard industry values.


--- Quote ---(but remember I have not test frequency response curve shape. Only with these point frequencies. (yes I have fast look with hand sweep and I can not see any big differencies over band. )
--- End quote ---

Yes, I understand that, and it's a point worth remembering.  Unless you have a sweep generator, it's hard to examine the entire bandwidth.

- Mark

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