[TenTec] Weak Sig/Filter BW [was:Ten-tec noise and RX questions}

JimN0OCT@aol.com JimN0OCT@aol.com
Wed, 27 Oct 1999 14:01:56 EDT


Mmm, lunch!

My opinion on the narrow bandwidth/noise/weak signal phenomenon is that when 
trying to copy a weak sig out of the noise, narrower is worse(er).  The 
reason being, the noise is limited to a frequency bandwidth that is *really* 
close to the frequency [say, 600 Hz] that you are trying to copy.  It's 
harder for your brain to distinguish that.  Broaden the filter, and the weak 
signal is easier to copy because the adaptive filtering in your head can pick 
out as 'noise' all the garbage that is occuring in a wider [say 2,4 kHz BW] 
filter, even the stuff close to that 600Hz tone you are trying to copy.

I have probably been clear as mud.  Turn your filters off/on as necessary to 
get useful information from the above paragraph.

73, Jim     
NĜOCT

In a message dated 27-Oct-99 12:51:29 Central Daylight Time, 
dacalvin@us.ibm.com writes:

> Sometimes, the narrower the bandwidth, the more difficult to hear.
>  I think there is something going on in the ear/brain connection that allows
>  us to integrate out the noise better when it is broadband, but when the
>  noise bandwidth is narrower, it's harder for us to distinguish the signal
>  in the noise against it.
>  

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