=  NOW 20 WPM  =  TEXT IS FROM APRIL 2023  QST  PAGE 50 =

FILTER IN THE IF STAGE THAT I USE TO LISTEN TO SSB SIGNALS.  EVEN WITH IT
SET TO THE MAXIMUM, I STILL GET NOISE AND IT RUNS AT THESE LEVELS
CONSTANTLY.  A THE SHORT ANSWER IS NO.  WITHOUT GOING INTO A DEEP
EXPLANATION, NOISE IS AN UNCORRELATED, RANDOM SIGNAL.  HUMAN SPEECH, ON THE
OTHER HAND, IS HIGHLY CORRELATED, MEANING THERE IS SOME ABILITY TO PREDICT
UPCOMING SIGNALS BASED ON PREVIOUS SIGNALS.  THE DSP FILTER IN YOUR RADIO
ELIMINATES THE UNCORRELATED NOISE.  THE DEGREE TO WHICH IT DOES THIS
DEPENDS ON HOW YOU SET YOUR NOISE FILTER.  SOME NOISE HAS CORRELATION JUST
BY CHANCE, SO IT WILL GO THROUGH THE FILTER.  SIMILARLY, SOME HUMAN SPEECH
IS UNCORRELATED BECAUSE IT IS NOT PERFECTLY PREDICTABLE, SO IT WILL BE CUT
OUT BY THE NOISE FILTER.  IF YOU RUN THE OUTPUT THROUGH AN ADDITIONAL DSP
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