Carl Moreschi N4PY
cjm@qvssoftware.com
----- Original Message -----
From: "Carl Moreschi" <cjm@qvssoftware.com>
To: "Beamer, Jay" <JBeamer@PanAmSat.com>
Sent: Thursday, March 23, 2000 3:56 PM
Subject: Re: [TenTec] CAUTION: SSB Comments Only (for N4PY)
> Jay,
>
> Your a genius. I just looked at the code to set up the center freq for
the
> tx
> filter and your comments seem to reflect what the code does. It looks
like
> once the TX bandwidth goes above 2600 hertz, the lower cutoff gets 200
> hertz added to it. I think all I have to do is remove the addition of the
> 200
> hertz from the formula.
>
> The formula in the code for the center bandwidth is as follows:
>
> If the bandwidth is less than 2600 hertz, use a fixed center of 1500
hertz.
> If the bandwidth is greater than or equal to 2600,
>
> center = bandwidth/2 + 200
>
> I use a bandwidth of 2550 hertz which is the factory default. This would
> cause
> a center freq of 1500 hertz which would yield a range of 225 to 2800
hertz.
> A 3000 hertz filter would yield a center of 1700 hertz and a range of 200
> to 3200 hertz.
> It may be if using USB that this gets inverted and that the 25 hertz loss
at
> the bottom
> in this example actually ends up at the top.
>
> Anyway, thanks for the info, and I'll play with it and see what I can
> determine.
> The code part looks extremely easy, its figuring out what you want thats
> hard!
>
> 73,
>
> Carl Moreschi N4PY
> cjm@qvssoftware.com
> ----- Original Message -----
> From: "Beamer, Jay" <JBeamer@PanAmSat.com>
> To: "'Carl Moreschi'" <CarlMoreschi@worldnet.att.net>
> Cc: <tentec@contesting.com>
> Sent: Thursday, March 23, 2000 12:50 PM
> Subject: [TenTec] CAUTION: SSB Comments Only (for N4PY)
>
>
> >
> > Carl,
> >
> > Had a thought on the Pegasus the last couple days that you might like to
> > look into in your spare time.
> >
> > As you may know, I've been playing around with enhanced audio for a
while
> > now on my omni V using 2.8K Inrads and the thoughts are related to
> improving
> > the Pegasus SSB audio.
> >
> > I have listened fairly closely to several Pegasus out here locally and
it
> > appears as though when a wider xmit bandwidth is selected, the low
> > frequencies seem to disappear.
> >
> > For example, at a xmit bandwidth of 2.4K the xmit freq response might
be,
> > let's say, 100Hz - 2500Hz. Then when 3k is selected for the xmit
> bandwidth,
> > the response might be 300Hz - 3300Hz. In other words the lowest freq
> > produced is shifted up. At least that's what it seems like. Now grant
it,
> I
> > only have a 2.8K rcv bandwidth with my Inrads, but even friends that are
> > listening to the Pegasus through 6k filters agree that the lowest freq
> > shifts up when going to a wider bandwidth.
> >
> > So, if the freq is being shifted up when changing bandwidth, I believe
it
> > can be shifted back down, at least I'm hoping so. Maybe it could even be
> > selectable, like the Kn 870. I didn't know the 870 had that capability
> till
> > last night.
> >
> > Anyway, what a tremendous tool this would be to tailor one's audio
> frequency
> > response.
> >
> > ciao for now,
> >
> > J/KM6VX
> >
> > --
> > FAQ on WWW: http://www.contesting.com/tentecfaq.htm
> > Submissions: tentec@contesting.com
> > Administrative requests: tentec-REQUEST@contesting.com
> > Problems: owner-tentec@contesting.com
> > Search: http://www.contesting.com/km9p/search.htm
>
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