"Frank Gilliland" wrote in message
...
On Fri, 25 Mar 2005 00:05:20 -0500, "Leland C. Scott" wrote:
"Frank Gilliland" wrote in message
.. .
If the FCC only permits voice communication on CB, doesn't that
prevent deaf people from using the band?
Yup.
I think TTY, as well as CW,
should be permitted for that reason alone.
Interesting but I doubt it's all that practical for hearing impaired
users.
For TTY you need a clear channel, i.e. one transmitter at a time.
Good point. There are quite a few clear channels in my area at any one
time, and while I know that's not the case everywhere, I'm sure it's
true in a lot of places. There is also the squelch knob, and not every
CBer is out to DX. Maybe a channel could be unofficially designated
for use by hearing impaired CBers? Or authorization for the use of
between-channel spaces? Maybe CW would be permitted if sub-audible
and/or below 300 Hz like those old tone-loc systems?
So how
often do you think that's going to happen and are CBer's displined enough
not to try and jam the TTY station?
Another good point. I'm not sure how easy it is to jam TTY, but I do
know that those tone-decoder devices are pretty noise-resistant. That
sounds like it would make a good experiment.
For CW the same thing however you would need some expensive filters to
get
more use out of a 10 KHz wide channel using a mode that needs anywhere
from
300 to 500 Hz at most. The transmitting station needs a way to move it's
signal around on the channel etc. so more that one can use the extra
bandwidth. Using different tones for each station would work, but then
you
still need the narrowband filters at each end to selectively filter the
tone
for the one station you want to hear.
I was thinking about that, which is what prompted this idea. All it
would take to transmit is to attach an audio oscillator in SSB.
Receiving might be a bit more difficult, but using a fixed-frequency
audio filter and the clarifier knob you can pick up just about any CW
signal in the channel bandwidth.
That was an idea I didn't consider, but sounds like it would work.
For a filter, you can run both sides
of a stereo equalizer in series, and it can even tune different audio
freqs.
The stereo equalizer idea wouldn't work, bandwidth isn't narrow enough.
However a cheap DSP based single frequency audio band filter would do the
job. As cheap as these things, DSP chips, have become it shouldn't be a big
deal.
After that, all you would need is a tone detector with a light
bulb. So the most expensive piece of equipment is already made and is
pretty common, while the other two pieces could be built from a kit by
just about anyone with a soldering iron.
The detector, indicator, device could be incorporated in to the DSP filter
assembly.
I'm sure there are other ways it could be done. But I think the
hardest part is hooking everything together.
If it became a petition,
would it pass?
I don't think so from an operational stand point. Too many problems and
besides they would likely use "texting" on their new cell phone anyway.
It
does what you proposed already.
Well, voice cell phones haven't eliminated CB yet. And maybe the
problems could be addressed before the fact.....
There is another benefit I see from this: it might encourage some of
the more enthusiastic CBers to get a license instead of freebanding or
operating illegally. It may also encourage more QRM on the channels,
but I'd like to think positive.
It is something to think about anyway.
--
Leland C. Scott
KC8LDO
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