[TenTec] Pegasus enhanced audio

[George, W5YR]

"Thomas C. Jednacz" wrote:
> 
> > Just a comment re those "broadcast-sounding" stations on 75 and 20:
> >
> > Almost to a man they are running Kenwood rigs that have been
> > substantially modified with wide 6 KHz transmit and receive filters,
> > low-frequency transmit and received audio response extended down to 40
> > to 60 Hz, etc.
> 
> If they push the filter rigs down to 40 or 60 Hz they run the risk of not
> suppressing the other sideband because of the slope of the filters. That is
> why all filter rigs set the lower frequency at about 200 Hz.

Some of these stations have a curious sound unless they are tuned
*exactly* on frequency - I suspect a lot of that is due to opposite
sideband not being properly suppressed as yuou suggest.

I heard a couple of the faithful this morning adjusting the response of
a station - they were really sweating 1 db changes at 40 Hz!
> 
>  Also, don't overlook the fact that they run high power with large, high
> beams to
> > deliver an S9+++ signal.

> And some of them do not know how to handle such power. I hear their splatter
> 10 KHz away from the operating frequency.

You are absolutely correct. 
> 
> Only the "digital SSB generation" type transceiver can achieve true low
> frequency response. The other sideband is cancelled mathematically for
> perfect opposite sideband suppression. We had great sounding SSB way back in
> the '50s and '60s because we used "phasing SSB generation". This is not as
> good as today's digital because it is impossible to get a phasing network of
> physical components to be flat in phase angle across the entire audio
> spectrum.

Yes, that is why I get such "excellent audio" reports from my Kachina
and IC-756PRO - both use DSP "phasing" for SSB generation. The Kachina
transmit audio response is from 100 Hz to over 4000 Hz.

72/73, George   W5YR - the Yellow Rose of Texas      NETXQRP 6	       
Fairview, TX   30 mi NE Dallas in Collin county	     QRP-L 1373
Amateur Radio W5YR, in the 55th year and it just keeps getting better!
Icom IC-756 PRO #02121 (9/00) Kachina #91900556 (12/99) IC-765 (6/90)

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