What are the advantages of transmitting voice frequency components in the
range of 50 to 300 Hz?
Amateur Radio W5YR - the Yellow Rose of Texas
Fairview, TX 30 mi NE of Dallas in Collin county EM13QE
"In the 57th year and it just keeps getting better!"
----- Original Message -----
From: "Paul Christensen, Esq." <firstname.lastname@example.org>
Sent: Friday, April 18, 2003 10:42 AM
Subject: Re: [TenTec] Enhanced SSB
> > I understand that the purpose of SSB was to minimize the bandwidth,
> efficiency, and pass only the necessary voice bandwidth for
> After researching the subject matter from QST issues during the '40s and
'50s, I have concluded that SSB was developed as a mode
> which would offer greater articulation of communications through:
> 1) A reduction in transmitted power for a commensurate level of
intelligibility compared with that of AM;
> 2) A reduction in equipment weight;
> 3) A reduction in power supply capacity and loading (owing to a lower
> 4) A reduction in transmitted bandwidth without necessarily compromising
> 5) The elimination of an unnecessary redundant sideband; and
> 6) The elimination of an unnecessary "power hungry" carrier.
> A note concerning point #4 above: The fact that SSB transmitted audio
bandwidth has been relatively restricted during the past forty
> years without an emphasis on low-frequency energy, is due to limitations
in crystal filter technology: in order to achieve
> reasonable alternate sideband rejection, the carrier set point must
necessarily be placed in a region which compromises low
> frequency energy.
> While the "phasing" method of eliminating the opposite sideband first
appeared as a solution, maintaining good carrier suppression
> and alternate sideband rejection became a problem with temperature and
mechanical changes and deterioration. It wasn't until the
> advent of DSP technology that better fidelity could be reasonably
transmitted. If DSP techniques were available in the '40s and
> '50s, the overall audio quality and bandwidth we hear on the bands today
would be much different.
> -Paul, W9AC
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