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- เผยแพร่เมื่อ 20 ก.ย. 2024
- Is a modern digital oscilloscope noisier than an old analog CRT oscilloscope?
Are analog scopes better at displaying signals?
You might be surprised.when Dave demonstrates the display of some common mode noise on both types of oscilloscope.
An aside video from the common mode noise video:
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Hi Dave, Very interesting point regarding mains born noise. I am into HAM radio and mains born switching noise is a real problem these days when using sensitive receivers especially on the low frequency bands 1 - 20MHz. I have somewhat improved the problem by using an isolating transformer to supply the workshop combined with an earthing spike array to create a clean earth. I have connected the clean earth to one side of the of the secondary winding of the Iso TX creating a neutral. It works!!
My bench is comming back to life thanks to you.
The other end is connected to the output of/ a linear power supply thru a banana-to-BNC adapter. He was tracking down the source of common mode noise seen as apparently coming from the linear supply.
It's just like being on Wikipedia. You start with a power supply review and wiki all through different subjects and end up comparing analog and digital scopes.
I still like the DS1102 you convinced me I needed to buy last year.
I like to take the scope probe, connect the shield to the tip like you do, and then touch that combination to the circuit ground and watch the difference. If CM noise, then it will pick up just touching the grounded probe tip which you wouldn't think should show up anything but of course you are completing the noise current path through the capacitance or whatever is coupling the noise.
Also, try running the scope probe wire through a ferrite toroid. The more wraps or turns the better, typically. If the right material is chosen, it will usually help reduce the noise due to the toroid acting as a common mode filter.
boB
Thanks Dave, a nice simple demonstration there.
I liked my Tek 2232. It had both analog and digital modes, so you could use whichever suited the task. I used digital mode most of the time, but if I wanted to see a weak signal amidst noise the analog mode was better. The Tek 492B spectrum analyzer had analog and digital display modes as well.
This video is very required ! Thanks sir !
Love the asides. Perfect for my shorter span of attention.
best electronics channel ever thank you
Whoa... This video has proper (professional?) captioning? How did that happen?
Hi. I know this was a long time ago, but still.. You do not tell what are you connecting to the input of the scope? And what are the BW settings of both scopes? To examine the scope input maybe you should connect only a 50 Ohm to the input and express the noise floor in Vrms/Hz or similar?
Don't miss the refresh rate of the CRT monitors vs the digital... the low intensity of the noise on the analog Oscilloscope can be caused by the slow refresh rate of the pixel of the CRT monitor vs the digital where the pixel has no pixel intensity related to his signal, a pixel #FFFFFF will be white. Simple as that.
The same annoying argument is had by people claiming analogue is better than digital for audio. Based on a pre-notion without any real true understanding of why.
Great video thanks.
look at that big parcel in the background, tasty mailbox monday!!!
And how is that a bad thing?
I tend to go off on tangents...
The speaker never explained what is on the other end of that coax cable that he plugs into each scope. Is it connected to another piece of equipment, or is it just a probe dangling off the edge of his bench?
wow... I always thought the analog scopes are better because of the continuous sampling, but it turns out they arn't... Now I start thinking about some new much faster method od displaying for analog scopes... :) Anyway I don't have to worri about this since I don't have any kind of scopes yet... XD
Great video thanks! :) Thumbs up!
Analog vs digital wars are a bit silly IMHO. Scopes, and all devices -have characteristics. Understanding those characteristics, using them to your advantage and knowing when and why they may mislead is the secret to happiness. That said, "new players" can easily get sent on wild goose chases by equipment that is more powerful than their experience and knowledge prepares them to effectively utilize or interpret. I own and use analog and digital scopes, both have a place -think complementary.
Fantastic video.. Thanks for making it and sharing it :)
Yeah, after seeing how much noise cheap coax picks up near a digital scope I wanted to see him hold the coax near the CRO and see what the digital scope shows.
I was wondering exactly the same :)
Is the Nintendo Gameboy/Colour/Advance due a teardown soon? I enjoy playing them greatly but have no idea what makes them go!
Thanks You :)
Have you compared XY mode on analog versus digital?
And tangents to those tangents.
I think you have a chance to see something (e.g. a type of scope or logic analyzer) you might not see between your theory, practical, and colloquial (invited lectures at the department, etc.) studies, so you should; it'll save you time long term. Meanwhile, perhaps a 24kt. gold plated test accessory (your current avatar pic.) is not the most open and global conversation starter that it is in undergrad dorms, and you should freely cite the author and edition of your integration text. Variances…
Why would you even do something without knowing if it is useful or not?
It's good!
This video is an aside to an aside
Please DO go off on tangents...Nothing more boring in life than staying on the beaten path! Bob's our uncle!
A tangent off a tangent? Hm, interesting concept xD
He's going off on a bitangent.
Eevblog-ception!!!
that crt is screaming at you to stop
My tek 475a can easily pick the noise of my laptop power supply
Can you do something about common noise, except don't buy cheap China stuff :p
Your tangents are more often inherently more relevant than most people's main ideas...
It seems well attended? Well, everyone has their Passover rituals.
There isn't much exciting in one, not much different from those PDAs he has torn down.
Digital better than analog :)
so what. LOL