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[TenTec] FCC Letters for "Enhanced SSB"

To: <tentec@contesting.com>
Subject: [TenTec] FCC Letters for "Enhanced SSB"
From: tjednacz@ieee.org (Thomas Jednacz)
Date: Thu May 29 14:56:59 2003

3 1:22 AM
To: tentec@contesting.com
Subject: RE: [TenTec] FCC Letters for "Enhanced SSB"


I think that getting better sound out of 2.8 kHz or less is an admirable
goal, and I understand that some hams have taken the time and effort to
determine not only what frequency response will provide that, but what
frequency response their equipment is providing.

** I agree! Anyone can get more fidelity simply by expanding the bandwidth
but it takes real skill and good amateur imagination and skill to stay
within the band width of 3Khz and have improved, more readable audio.

I have the Orion and when I set the BW to 6 KHz and look at the audio
spectrum analyzer, I see that the audio is going out to 6 Khz on some of the
fellows. Well - let me tell you that when you listen to the supposed high
quality signal with a 6 Khz bandwidth it is JUNK. Very harsh and tinny. Not
comfortable to listen to at all. If you narrow the bandwidth it sounds
better but why transmit 6 Khz when most receivers cannot hear it and when
they do it sounds terrible. No one needs to transmit 6Khz audio to have a
good sounding signal.

Most of these fellows do not know how amplifier circuits cause distortion.
They so overdrive the audio input stage that they generate all kinds of
audio 3rd IMD. Some drive directly into an A/D in the transmitter and think
that they are clean. They never read the specifications on the A/D and are
overdriving it so badly that the carrier is shifting and there is no
sideband suppression.

I guess the wide guys listen with a 2.8 Khz filter which is ridiculous when
you think about it.

My two cents worth.

Tom, W7QF

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