John Smith wrote:
N2EY:

Most of that is incorrect.

Most of what?

First you use "on the fly" encryption/decryption/"data
compaction" and
have it occurring in "real time." This has the effect of being
"transparent" and the user is not even aware that it is going
on.

That's what

"Convert the pictures and video into highly-compressed digital
formats for transmission." means, John. Whether it's done in "real
time" is just a detail.

Next, forget the sn/noise ratio other than it has to acceptable for
transmission of understandable communication (however, this is
required no matter what the form of data--i.e., voice, ssb, cw, etc)

Signal-to-noise is an integral part of Shannon's thereom. It cannot
simply be "forgotten".

Next, listen to digital signal occupying audio bandwidth (it is audio
bandwidth that is of concern here, NOT rf bandwidth,

No, that's not correct.

The discussion is about transmitting pictures and video on the amateur
HF/MF bands. RF bandwidth is a very important thing there.

except
with the
possibility of fm and how you implement the data compression
and
transmission, i.e., just make it fit the existing rf bandwidth and NO
changes are needed--however, larger rf bandwidth will ALWAYS
result in
a drastic increase in transmission speed and wideband fm can
easily
offer itself to 1MBS and faster) a digital signal can be
treated just
like a analog signal if desired, the use of CRC checksums and
error
checking of the data is just more intense under these
circumstances
and there is NO standard established for this--so you MUST be
able to
make and use your own custom hardware and software. To avoid
this, just grab off the shelf digital hardware/software.

And the simplest way for hams to do that at HF/MF is to use an SSB
transceiver and a computer with a sound card.

But that's not the only issue.

Next, for every patented form of audio video protocols there
are FREE
forms, usually the free ones are more acceptable, efficient and
suitable to ones needs, an example:
Use ogg vobis compression of audio as opposed to mp3
--in video--
Use xvid as opposed to divx 4-5

And make sure the folks at the other end are similarly equipped.

However, any of this requires a sound and current education and
knowledge of the state of technology--and something which is
obviously lacking here.

Yes, John, your lack of a sound and current education about amateur
HF/MF communications is quite evident. Good to see
you admitting it.

There's also the issue of FCC regulations. Of course those regulations
can be changed, and there are several proposals in development or
before the FCC to change them. But until they are changed, amateurs
will be constrained by the current rules, such as the 300 baud
limitation on HF. The vast majority of hams are not going to break
those rules, regardless of the available technology or their education.


The question raised by KB3EIA and N8UZE remains: How can video
be sent in a 2.5 kHz RF bandwidth on the amateur HF bands? I've
answered that question in a theoretical way. I don't think you
even understand the question and all its implications, John.


wrote in message
oups.com...
Mike Coslo wrote:
Dave Heil wrote:
wrote:

How we be gonna scale those pictures and live video to fit into 2.5
KHz?

Two steps:

1) Convert the pictures and video into highly-compressed digital
formats for transmission.

2) Use different modes/modulations/protocols

Shannon's Theorem tells us that we can get very high data rates
through
very narrow bandwidths *if* we have adequate signal-to-noise ratio.
Note that "noise" takes many forms, not just the thermal noise we're
used to.

For example, PSK has an advantage over OOK when dealing with thermal
noise. But when dealing with other types of noise, OOK can have an
advantage. It all depends on the transmission medium. What works on
a
telephone line may not work on an HF path of the same apparent
bandwidth.


I thought that we were going to be able to send live video
and digital images on HF?

You can do that now - just need enough S/N.

Simply by hooking our computers to our rigs via the
proper interfaces.

And software.

Now it seems that the *idea* is that we are going to use
DRM, and we're
going to need to get more spectrum in which to use.

There are all sorts of solutions. But there's a world of
difference between people talking theory and actual
application.

Most of all, some folks confuse the journey and the destination.

Does complex and newer equal better?

Sometimes. Not always.

Is analog simpler than digital?

Sometimes!

Does having a computer that attaches to the Internet
make a person a digital expert?

Some folks think so! I don't. And besides - "digital expert" doesn't
mean someone knows much about radio.

I ask for enlightenment, I get invective.

Are you surprised?

Appears to be what there is to offer.

Now consider how effective such a person would
be trying to sell amateur radio - with or
without a code test.

73 de Jim, N2EY