LF: Re: + 7dB in 424uHz , convert to 2.5Khz ?

To:	<[email protected]>
Subject:	LF: Re: + 7dB in 424uHz , convert to 2.5Khz ?
From:	"James Moritz" <[email protected]>
Date:	Sun, 11 Mar 2012 13:17:17 -0000
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Dear Graham, LF Group,

How  do  you  scale  these  uHz  d/b levels  to   other   bandwidth's ?

If  the  b/w  is   848 uHz   is the   dB  level     + 3.5 dB  ?

+ 7dB  in  424uHz ,  convert to  2.5Khz   b/w?

The noise power is proportional to the bandwidth; the signal power stays thesame. So the SNR is inversely proportional to the bandwidth. It can becalculated like this:


2.5kHz / 424uHz = 5.9 x 10^6

10 log10 (5.9 x 10^6) = 67.7dB

SNR in 2.5kHz BW = (SNR in 424uHz BW) - 67.7dB

= 7dB - 67.7dB = -60.7dB

Cheers, Jim Moritz
73 de M0BMU

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