W4ZV> When using extremely narrow BW's on
SSB, you really need to fix PBT to +150 to 160 for maximum intelligibility.
What you are doing is shifting a very narrow passband to a better area
of the voice spectrum. Instead of your 1700 Hz filter spanning 0-1700
Hz, you shift it so it spans 150-1850 Hz, which is much more intelligible.
Speech energy is stored at low frequencies, intelligibility is carried at
high freqs and middle range around 1200 Hz can be notched.
Filter setting of 300-2000 Hz should be much better than 150-1850 Hz.
Collins engineers book on HF SSB is a strongly recommended reading.
73 de Mario, S56A, N1YU
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