[Elecraft] Narrow bandwidth ESSB?

[Ron D'Eau Claire]

That's an excellent suggestion, Keith. 

My K2 has a bandwidth of about 2.8 kHz. When I tune in an AM station here in
the USA (with the 160 meter option it tunes down to about 1500 KHz), the
sound in my external loudspeaker is every bit as good as most AM radios. 

A little research indicates that the effective audio bandwidth of many AM
receivers is less than 3 kHz and some might be less that 2 kHz!* And that's
a media that broadcasts music to the satisfaction of a great many listeners.


It suggests that raw bandwidth isn't the main issue facing better voice
quality on the Ham bands. Indeed we might do very well with not much more
than what we're already using. 

Looking to what the "commercial" operators do as the answer isn't such a
good idea. If Marconi had done what the experts knew for a fact would not
work,  he'd never have made wireless a practical reality. Of course the
experts of the day didn't realize the effect of frequency on propagation.
Hertz' experiments that proved electromagnetic waves wouldn't bend over the
horizon or around many structures were done at what today we call VHF.
Marconi worked at much lower frequencies which we now know is a much
different world. 

That's the point. Highly-paid experts know just what's so, until someone
shows them differently.  

Finding a way to improve the sound of voice on the Ham bands without
drastically increasing bandwidth is just the sort of thing that has
attracted Hams over the years! The fact that commercial interests haven't
done it only means that it hasn't been done - yet. Often it's up to Hams to
prove it can be.

After all, it was Ham experimenters who proved that SSB was practical. In
the early 50's many expert engineers said the SSB was totally impractical
and would never be useful in normal operations. The frequency tolerances and
tuning were simply too critical for it ever to be practical. 

Hams showed them differently. 

Ron AC7AC

*  http://www.rwonline.com/pages/s.0044/t.4031.html

-----Original Message-----
I've wondered for a while how to achieve this.  By "this" I mean top-notch
SSB audio without resorting to wide bandwidth.
 
Say we limit the bandwidth to 2.8 KHz.  What sorts of things should be done
to make the audio as good as possible? I'm thinking a signal chain like
this:
 
 - Good condensor mic (probably not a communications mic)
 - Parametric EQ.
 - Compresser running 6:1 or so (RNC?)
 - Maybe a bit of overdrive (tube distortion, just a touch?)
 - BBE Sonic Maximizer to put some sparkle into things.
 
Any other ideas?  I think a lot can be done without resorting to wide
bandwidth.  I'm interested in clear audio that cuts through without sounding
"like a contester".
 
- Keith N1AS -
- K2 5411.ssb.100 -