I think it would be even more feasible to implement something like that in
PC / soundcard software. Once the mode has proven itself, we might get TT
interested in incorporating it in their radios, but don't hold your breath.
Look at the popularity of PSK31 and I still don't see any transceivers that
have that mode built in.
----- Original Message -----
From: "Duane Grotophorst" <firstname.lastname@example.org>
Sent: Tuesday, April 22, 2003 21:38 PM
Subject: Re: [TenTec] Slightly OT: SSB vs AM
> Yes I do remember the NBVM (ACSSB) units being
> advertised back in the late 70's early 80's. Sure
> didn't catch on then I suspect because it was
> relatively complicated and expensive.
> But you now have to wonder if that particular
> modulation scheme can be implemented in the new DSP-IF
> radio with just a firmware upgrade?? Wouldn't that be
> a neat gimmick feature of the Orion? It could be a
> bunch of fun right along with an "inside the radio"
> implementation of the Thales digital voice system.
> Its a shame to see all this DSP IF technology in
> radios like the Orion to be only used for the same old
> SSB/CW/AM/FM modes that the less sophisticated
> competitive radios already do quite well.
> --- email@example.com wrote:
> > At 11:38 AM 04/22/2003 -0500, Jerry wrote:
> > >The voice spectrum has two major groups, one at a
> > few hundred Hz and
> > >another out maybe three times that frequency with a
> > gap in between.
> > >There was a proposed scheme in the ARRL handbook a
> > few years back to
> > >separate those with separate bandpass filters, then
> > heterodyne the upper
> > >one into the gap at the transmitter, then shift it
> > back to its normal
> > >range in the receiver. Saved at least a third of
> > the spectrum, maybe
> > >more, but it went over like a lead balloon.
> > There was a commercial unit made, think it was
> > called
> > NBVM (narrow band voice modulation) or something
> > similar.
> > It comes to me that Henry radio produced it, or sold
> > it..... (?)
> > ......and Jerry was right. It was a bust! Probably
> > because it
> > sounded bad when listening on standard receivers....
> > w8au
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