[AMRadio] Speech Processing

[W2xj]

Hey Jim

Interesting design. For the next go round may I suggest:

A 2 or 3 band design. Not the typical broadcast style intended for music but one based on speech formants. A two band would have a crossover at 1500 hertz and a three band would have bands 1000 hertz and below, 100 to 2000 hertz and 2000 to 4000 hertz. Each band would have it’s own clipper before re-combination. 

A final clipper more suitable for AM or SSB would be a Hilbert transform clipper. It will not overshoot on SSB rigs and is less susceptible to the overshoots caused by filters in AM rigs. Rockwell Collins used that design for military rigs going back to the 80s.  

Sent from my iPad

> On Sep 25, 2018, at 3:06 PM, Jim Tonne <Tonne at Comcast.net> wrote:
> 
> OK guys, things do indeed seem to have been slow
> but I am offering a topic to get stuff moving.  A favorite
> topic of mine is speech processing.  By that I mean
> contraptions that "ride gain" on your microphone signal
> to maximize modulation, or at least even it out.  Are any
> of you out there interested in discussing that subject?
> I am not interested in and don't want to get involved with
> existing commercial units.  Rather let's focus on new
> stuff.  I have been working on new designs and would
> like to get them out in the field for testing.  Having recently
> moved (seriously downsized) I no longer have lab or
> shop facilities and now have to rely on feedback from
> the field to confirm design validity.  The results are to be
> released to the public so we'll all benefit.  Open source,
> as it were.  Design using LTspice and hand off to others
> for proofing.
> 
> The Sep/Oct issue of QEX has my latest writing on this
> subject.
> 
> Or you can go to
> http://tonnesoftware.com/miscellany.html
> 
> and scroll down to
> "Speech Processor Article As Published"
> 
> or scroll down to
> "Speech Processor Talk"
> 
> If you are technically-inclined here is your opportunity to
> jump on the bandwagon and contribute to the state of the
> art !!
> 
> There - that ought to make this group stir to life  :-)
> 
> - Jim Tonne W4ENE
> 
> 
> 
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