Hi !
i have a cheap scope that does not provide AC coupling.
And i would like to see noise in DC power supply (gross noise ... 50 mV up ... they are SMPS).
I am having a hard time to figure out the best way to get it
Why they do not put a such useful feature as default i really do not understand.
This is a toy ... i have bought a toy
I guess that the cleanest way could be an accessory with the cap inside to mount between probe and scope ?
Do you have any kind advice ?
Thanks a lot, gino
i have a cheap scope that does not provide AC coupling.
And i would like to see noise in DC power supply (gross noise ... 50 mV up ... they are SMPS).
I am having a hard time to figure out the best way to get it
Why they do not put a such useful feature as default i really do not understand.
This is a toy ... i have bought a toy
I guess that the cleanest way could be an accessory with the cap inside to mount between probe and scope ?
Do you have any kind advice ?
Thanks a lot, gino
Hi and thanks a lot for the very helpful advice. I am a beginner
0.1 uF/1kV on the probe tip ... good !
Just out of curiosity. I read that there are amps to amplify low level signals.
Are they expensive ?
However as a first i will try to "see" the noise in SMPS. i will start gross
Lately i have become obsessed by noise ... i think that noise impact on sound has been underestimated.
I put a very silent line preamp in my system and i was amazed by the difference in detail ... shocking.
Noise masks the low level detail, so important for instance for the rendering of a good 3D virtual soundstage.
Very impressive.
Thanks a lot again. gino
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switch to AC and you have AC coupling between the probe and the circuits inside the scope.
Switch to DC and the probe is directly coupled to the circuits inside the scope.
Download a help file for new users of scopes.
There might even be some help Threads on this Forum.
Hi and thanks a lot for the very valuable reply
Do you mean that i have to check better the commands ? let's hope for an oversight indeed
That would be much much better
As i said i am a little exhausted to check for noise by ear ... i would like to approach the issue in a more educated way
At least i have to try ...
Thanks a lot again, gino
Are you sure, I've never seen one without AC coupling. That would render the scope unusable in most circuits.
What scope do you have?
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Yes, I've also never seen a scope without AC coupling... Cheaps cheap, but to drop AC coupling REALLY?
Hi it is a Hantek 6022BE .... it seems obsolete
http://www.hantek.com/en/ProductDetail_2_153.html
i see no switch on the box or in the SW
I will get an Audio Precision next time that ... i win the lottery
Seriously ... i would like something like this but with all the very important function.
I wonder how much would a decent entry level usb scope cost
I like the idea of being able to use a wide pc display.
Thanks again, gino
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Hi and thanks for the valuable confirmation.
I understand that Rigol scopes have good quality/price ratio.
Digital Oscilloscopes | Rigol - Beyond Measure
something like this one here has the AC coupling ?
DS1052E 50 MHz Digital Oscilloscope | Rigol - Beyond Measure
Thanks again, gino
For low noise work you should really look at a FFT analyser - when you say switching PSU noise its noise within the Audio bandwidth is more important then the HF ripple you would see on the Scope.
Cheap digital scopes are not the place you should be look towards if you want low noise performance.
If you can find a Tektronix 7000 series mainframe with 7A22 amplifier plugin you would have one of the best low noise scopes systems ever made.
Tektronix 7A22 Differential Amplifier Plug-In | eBay
If you keep your eye on Ebay you will find decent 7K mainframes for sale in Europe - or Ship from the US
Cheap digital scopes are not the place you should be look towards if you want low noise performance.
If you can find a Tektronix 7000 series mainframe with 7A22 amplifier plugin you would have one of the best low noise scopes systems ever made.
Tektronix 7A22 Differential Amplifier Plug-In | eBay
If you keep your eye on Ebay you will find decent 7K mainframes for sale in Europe - or Ship from the US
I could be wrong here - but I understand that some of the cheaper Digital scopes (Rigol)? use "Digital" LPF for AC coupling so you loose the advantage of wide input volt range...
There is a new king in town, he came last week.
GW Instek GDS-1000B Oscilloscope blow out of the water RIGOL DS-1000Z
Man! It seems there's always a "gotcha" lurking somewhere these days. That would be a pretty big one right there...
-- Jim
There is a new king in town, he came last week.
GW Instek GDS-1000B Oscilloscope blow out of the water RIGOL DS-1000Z
That looks like a nice scope. Had I still been in the need for one, I would certainly have considered it.
But is it fair to compare these with the Rigol DS1000Z-series? I mean, will these be priced similarly? Right now, the best I can find is "by quote only".
Looks like the lower end brands are playing the same game as Keysight and Tektronix, constantly trying to outsmart eachother with a new feature or better performance...
For low noise work you should really look at a FFT analyser - when you say switching PSU noise its noise within the Audio bandwidth is more important then the HF ripple you would see on the Scope.
Cheap digital scopes are not the place you should be look towards if you want low noise performance.
If you can find a Tektronix 7000 series mainframe with 7A22 amplifier plugin you would have one of the best low noise scopes systems ever made.
Tektronix 7A22 Differential Amplifier Plug-In | eBay
If you keep your eye on Ebay you will find decent 7K mainframes for sale in Europe - or Ship from the US
For really low noise measurements, I agree that most scopes, even the more expensive ones, are not that useful. If they were, we wouldn't have AudioPrecisions and spectrum analyzers around.
Did you mean spectrum analyzer, btw? An oscilloscope with FFT and a "real" spectrum analyzer are two different things.
Lets just say that the FFT function on the Rigol DS1000Z-series is rather limited, not intended for serious use.
The Rigol DS1000Z series input range is specced at CATI 300 Vrms and CATII 100 Vrms.
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