I was thinking of something like:
http://www.w9gr.com/
"Anonymous" <someone@microsoft.com> wrote in message news:...
>
> "Mark" <makolber@yahoo.com> wrote in message
> news:1139417980.646987.93170@g44g2000cwa.googlegroups.com...
> > Clark,
> >
> > The AF (adaptive filter) you are describing automatically adapts the
> > overall bandwidth of the signal...OK...good... but does it actually
> > compensate for selective fading the way an adaptive equalizer does for
> > digtial modulation... i.e. if the selective fading causes a 5 dB tilt
> > across the channel, will your AF compensate for that tilt by creating
> > a reverse tilt or will it just reduce the bandwidth because the SNR is
> > poor....
> >
> > Mark
> >
>
> An AF needs some known component or statistic by which to generate an
error
> term from. With voice AM there really isn't any fixed parameter to lean
on.
> A loss of amplitude could be fading on the RF OR the person speaking could
> have just stopped talking. If it were FM you could probably uses the
> constant envelope of the signal, but I don't see any way to do it with AM.
>
> Maybe ALC on the audio will work for you I just know that an AF in the
> predictive mode worked well for us in the past to make HF audio much more
> tolerable to listen to.
>
> There used to be several companies selling little dsp boxes that you hung
> off your radio speaker to do this. I can recall a name right now.
>
> -Clark
>
>