### Author Topic: FFT Function on oscilloscope -> basic spectrum analysis?  (Read 1914 times)

#### chromesphere

##### FFT Function on oscilloscope -> basic spectrum analysis?
« on: March 05, 2013, 07:26:08 PM »
Once i get onto something, i wont let go

So i'm researching oscilloscopes and i saw on afrotechmods youtube video of an oscillocope it showed his oscilloscope could do a basic frequency analysis (is that what FFT means?).

Do you have this function on your oscilloscope / do you use it?  I know its not going to be a replacement for a spectrum analyser, but i thought it might be ok for audio / guitar pedal stuff?  Also i know there are other options out there, pc software, pc oscilloscopes with built in spectrum analysers etc but im specifically interested in the frequency analysis feature of an oscilloscope.

EDIT: Just to clarify, the question is 'is FFT a basic sort of spectrum analyser?' and if so 'is it useful / do you use it?'.  Sorry my question wasnt clear.

Thanks for any help as always,
Paul
« Last Edit: March 05, 2013, 07:30:59 PM by chromesphere »
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#### amptramp

##### Re: FFT Function on oscilloscope -> basic spectrum analysis?
« Reply #1 on: March 05, 2013, 09:49:16 PM »
Yes, it is a form of frequency analysis.  FFT stands for Fast Fourier Transform which is a mathematical means of deriving frequencies from time-based waveforms.  The Fourier Transform has some symmetries that can be exploited to speed up processing and that is why it is called FAST Fourier Transform.

#### chromesphere

##### Re: FFT Function on oscilloscope -> basic spectrum analysis?
« Reply #2 on: March 06, 2013, 03:10:08 AM »
It will be interesting to see how useful it is when analysing a signal through a circuit.  Hopefully you can see the bandwidth in some detail.
Paul
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#### Seljer

##### Re: FFT Function on oscilloscope -> basic spectrum analysis?
« Reply #3 on: March 06, 2013, 04:18:37 AM »
Its also useful for spotting noise, particulary power supply noise where its at a constant frequency.

Another fun thing to do is to put white noise through a phaser and watch the notches move around.

#### Paul Marossy

##### Re: FFT Function on oscilloscope -> basic spectrum analysis?
« Reply #4 on: March 06, 2013, 03:09:38 PM »
I need to get a modern scope that will do these sorts of things. My o'scope is ancient.

#### pickdropper

##### Re: FFT Function on oscilloscope -> basic spectrum analysis?
« Reply #5 on: March 06, 2013, 04:31:16 PM »