Author Topic: MSO5000 FFT question  (Read 1379 times)

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Offline SharpTopic starter

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MSO5000 FFT question
« on: December 11, 2021, 07:47:56 pm »
Hi guys

I have a MSO5000 and are now looking into the FFT functionality and have a question for your guys.

If you take a look at the attached MSO5000 screen dumps, I use a 10kHz sine wave 1 volt PP on the FFT 1 screen dump and a 10kHz triangular wave 1 volt PP on the FFT 2.
The FFT setup is dBV and the waveform generator and the MSO is 50 ohm terminated.

My question is on the FFT 1 screen dump – the 1 volt sine wave – The FFT analysis shows the first fundamental to -9.5 dBV – If I want to find the voltage from the FFT analysis I get:  Voltage = 10^(-9.5/20)  = 335mV  - why is it not 1 Volt – what is wrong here ???
     
 

Offline mawyatt

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Re: MSO5000 FFT question
« Reply #1 on: December 11, 2021, 08:20:54 pm »
Likely because 1Vpp is 0.3536Vrms for a sine wave.

Best
Curiosity killed the cat, also depleted my wallet!
~Wyatt Labs by Mike~
 
The following users thanked this post: Sharp, Wallace Gasiewicz

Offline SharpTopic starter

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Re: MSO5000 FFT question
« Reply #2 on: December 11, 2021, 09:13:11 pm »
 |O Of cause I’m stupid

@mawyatt  Thank you  ^-^
 
 

Offline Wallace Gasiewicz

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Re: MSO5000 FFT question
« Reply #3 on: December 12, 2021, 12:43:46 am »
Me Too!
 


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