On Feb 26, 2010, at 1:33 PM, Nick Arnett wrote:
And the possibilities only multiply when you feed that audio from
the radio into, say, the sound card of a computer, and vice versa.
DigiPan is only one of a nearly infinite number of possible examples
of that. All the DSP capability of your computer interfaced quite
elegantly with that old Hallicrafters tube rig from the attic and
maybe an audio interface with an audio-triggered transmit relay. I
don't know about you, but I find that thought rather exciting. :D
Wowza... just read a little about DigiPan. Amazing. Personal
computers sure have transformed amateur radio from when I first got
interested.
They've totally transformed it, in many ways. And with DSP only
improving with time, we've probably only scratched the surface of what
can be done along those lines. http://gnuradio.org/redmine/wiki/gnuradio
might give you some ideas.
I think the first time I ever encountered it at all was in 1968,
when my older sister was an exchange student in Columbia and we
talked to her via HF at the University of Pittsburgh's radio club.
I remember it sort of freaking out my younger sister, the one who
died last month. She was only six or seven years old and found the
whole thing scary. They patched the audio into a telephone handset
and that helped her deal with it.
And yes, there are still places cellphones won't work and phone
patches still play a role. Not as big a role now as they used to
(especially on VHF/UHF repeaters) but there are places they're still
hard to replace. Especially in disaster recovery.
(And an interesting experiment: Feed the I and Q outputs of a
quadrature detector to a pair of stereo headphones. Apparently the
brain's auditory cortex is wired in a way that takes unique
advantage of that format. And you're literally *listening to
signals on the complex plane*. What's not cool about that?
It must be very cool, since don't quite understand what you're
saying. ;-)
I'm trying to remember which issue of QST I saw it in. The effect is
basically "stereo single sideband", and signals appear to come from
various points around your auditory horizon, making them much easier
to isolate than they are if you're listening to a straight detector
output in both ears. Haven't heard much about it since then, but it
was quite fascinating when I saw it. The term they used was
"panoramic reception", I think.
"Listen, when you get home tonight, you're gonna be confronted by the
instinct to drink a lot. Trust that instinct. Manage the pain. Don't
try to be a hero." -- Toby Ziegler
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