[TenTec] Enhanced SSB

[Carl Moreschi]

Simply because it sounds nice.

Carl Moreschi N4PY
Franklinton, NC
----- Original Message -----
From: "George, W5YR" <w5yr at att.net>
To: <tentec at contesting.com>
Sent: Saturday, April 19, 2003 5:12 PM
Subject: Re: [TenTec] Enhanced SSB


> What are the advantages of transmitting voice frequency components in the
> range of 50 to 300 Hz?
>
> 73/72, George
> 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!"
> <mailto:w5yr at att.net>
>
>
>
>
>
> ----- Original Message -----
> From: "Paul Christensen, Esq." <attorney at broadcast.net>
> To: <tentec at contesting.com>
> 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,
> increase
> > efficiency, and pass only the necessary voice bandwidth for
> communications.
> >
> > 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
> overall duty-cycle);
> > 4) A reduction in transmitted bandwidth without necessarily compromising
> transmitted fidelity;
> > 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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