As soon as I hit the send key I realized the error. But come to think of
it sham is appropriate for you too.

Dan/W4NTI

"Kim" wrote in message
. ..
"Dan/W4NTI" wrote in message
nk.net...
Hey Kim.....so what?.....At least I didn't pay (how many bux???) for a
callsign that brings sham on yourself.

How you like that?

Dan/W4NTI


"shame"

Kim W5TIT

Mike Coslo wrote:
wrote:
Mike Coslo wrote:
Dave Heil wrote:
LenAnderson@ieeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eeeeeeeeeeeeeeeeeeeeeeee.org 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.

Oooh, there could be a problem there! There are limits to the
compression, and we have exceeded them in some forms already.

Of course! But it all depends what you consider "acceptable quality"...

Check to
see how many vertical pans there are on video signals lately.
The
compression on the digital signals (note that even if you are
getting
your feed via analog cable, you are still almost certainly
looking at a
digital signal) already calls for some major aliasing.

OTOH, if all you want is B&W ~CGA video....

There are limits, and there are limits. How much more are we
going to throw away?

Always a tradeoff. Hams routinely use 1.8 kHz wide SSB filters for
"communications quality". Hardly hi-fi but it can make the difference
between QSO and QRJ.

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.

What're we going to do when the data rate that we need is darn
near(or above) frequency in use?

Use modes designed for the purpose. See below.

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.

Always?

No mode always gets through.

But if you have enough S/N, all sorts of things are possible.

Here's one way. I apologize if you are way beyond this simplified
example:

Consider how PSK31 works in BPSK mode. There are just two basic
modulation states - 0 degrees and 180 degrees. One bit per unit time.

But in QPSK mode, there are four basic modulation states - 0 degrees,
90 degrees, 180 degrees and 270 degrees. Two bits per unit time, but
the bandwidth is no greater than with BPSK. Only problem is that you
need a transmitter, receiver and transmission medium whose total
distortion is low enough that you can accurately tell the four states
apart.

Now consider a theoretical "256PSK" mode, in which there are 256
states: 0 degrees, 360/256 degree, 720/256 degrees, etc., all the way
to ~359 degrees. 8 bits in one unit time, in the same bandwidth! But
you need a transmitter, receiver and transmission medium whose total
distortion is low enough that you can accurately tell the 256 states
apart.

You can see that if we just keep increasing the number of states, the
number of bits per unit time in the same bandwidth keeps going up. But
you need more and more accurate modulator/medium/demodulator - IOW,
better and better signal-to-noise. Or to look at it another way, the
mode carries huge amounts of data in a tiny bandwidth but has very
little tolerance for noise that takes the form of phase distortion.

Now imagine multiple spaced carriers in the 2.5 kHz bandwidth all
carrying data - lotta bits, huh?

Of course you may find that in practice it's not that easy to get a
modulator/medium/demodulator setup that meets the requirements -
particularly if the medium is HF RF with relatively low power.

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

And software.

I really didn't think it was all that simple.

Nobody said it was simple!

Why don't we get together
and pop off a live video system for say the 160 meter band. The video
would be real time, 30 fps, and otherwise like broadcast video. Better
yet, Why don't we do it at computer resolution?

Ask the PROFESSIONALS, Mike. Remember, ham radio is a HOBBY, according
to them....

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.

I did hear that DRM was capable of doing imagery. I couldn't find any
examples tho'. And they were very vague about it.

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

The journey beats all.....

Exactly.

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.

Ain't that the truff?

I ask for enlightenment, I get invective.

Are you surprised?

Nope. It doesn't make for a very good discussion tho'.

Discussion is not what the invective-hurlers want, Mike.

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.

They might attract others of their ilk.

You see that happening right here.

I'll bet they like some of the "wonder antennas" that keep cropping up...

Exactly.

73 de Jim, N2EY

wrote:
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.

An important detail indeed if the image is going to be transmitted in
real time. Presumably some time might be alloted if the image were to be
delayed by a second or so.


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".

Forgetting signal to noise is what makes me believe that these claims
are more snake oil than substance.


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.

You are correct, Jim. That RF bandwidth must be capable of carrying
whatever "audio bandwidth" there is. Listening to the audible portion of
a digital signal is an interesting metric though! ;^)

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

Very very important.


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.

Waaayy overly simplified. If it were just a matter of compressing the
signal until it fit into whatever bandwidth was desired/needed/mandated,
don't you think we would have gone that route, instead of inventing
faster modems, T-lines, Cable modems and DSL? There are limits which we
passed a long time ago, after which data MUST be thrown away. There are
finite limits that imagery or video cannot be compressed without
sacrifices in fidelity.

But that's not the only issue.

Hardly!

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.

Oh, yeah. A lot of people forget about that one. We need someone to
communicate with.

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.

But that can be fixed.

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.

Some things for people to think about:

There is nothing preventing the use of digital imagery or video at HF
frequencies. NO majik involved.

But!

The bandwidth needed for the data being sent may very well approach or
exceed the frequency being used for the transmission!

This means that the data needs compressed or the time needs expanded.

Compression has well defined limits. Beyond these limits, data must be
thrown away. This is why original images (or video) should be performed
in as high a resolution and as low a compression as possible. It is
always possible to throw away data, but not get back data that has been
discarded.

So beyond whatever minimal image quality is agreed upon, time must be
expanded. 300 baud is exceptionally slow by today's standards. I worked
up some times on transmission of a level 5 640 by 480 jpeg earlier in
this thread. I don't consider those times acceptable.

So here we are.


- Mike KB3EIA -

"Mike Coslo" wrote


So here we are.


Yup, and no one has persuaded me it can't be done. I've only been persuaded
that we haven't figured out how yet. (Sorta reminds you, doesn't it, of how
those old-tymey hams must have felt when they were told to take their party to
"200 meters and below".) You, Jim, and Dee bemoaning how hard it will be, and
John raising the tantalizing notion that we may only be a few "eureka!!!"s away
from something workable. Outside my area of competence, but I'll watch the
dialog with interest.

73, de Hans, K0HB

It was mostly, Dan, to highlight that mistakes--and ignorance--can and do
happen in any circumstance. That I do not understand the technicality of
most of amateur radio, is as much similar to the fact that you make common
grammatical and spelling errors in a language you fluently speak.

So, as abrasive as you are, surely you are human enough to recognize that
your criticism, chagrin, hateful conduct, and judgment of me is pretty
darned ridiculous. If you are not human enough, so be it. And, come to
think of it, your sentence structure, below, should have been: "But, come to
think of it, sham is appropriate for you, too."

You may as well define what sham I am undertaking. Are you implying that I
am not a licensed amateur radio operator? What "sham," Dan?

Kim W5TIT


"Dan/W4NTI" wrote in message
ink.net...
As soon as I hit the send key I realized the error. But come to think of
it sham is appropriate for you too.

Dan/W4NTI

"Kim" wrote in message
. ..
"Dan/W4NTI" wrote in message
nk.net...
Hey Kim.....so what?.....At least I didn't pay (how many bux???) for a
callsign that brings sham on yourself.

How you like that?

Dan/W4NTI


"shame"

Kim W5TIT

Mike:

300 baud is ridiculous, in Dee's first post mentioning 300 baud I
tossed it out the window--that was fine up to about 1985, then only
the mentally challenged continued to run 300 baud modems!

At the speeds needed, an arthritic old amateur with a brass key would
be more successful at sending binary data than a 300 baud modem!
tongue-in-cheek

More than 90% modulation on the carrier of a HS data transmission is
what to be wary of, begins to cause splatter like no ones business, a
heavy duty compressor on the audio might be a fix, I have thought
about it...

John

"Mike Coslo" wrote in message
...
wrote:
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.

An important detail indeed if the image is going to be transmitted
in real time. Presumably some time might be alloted if the image
were to be delayed by a second or so.


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".

Forgetting signal to noise is what makes me believe that these
claims are more snake oil than substance.


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.

You are correct, Jim. That RF bandwidth must be capable of carrying
whatever "audio bandwidth" there is. Listening to the audible
portion of a digital signal is an interesting metric though! ;^)

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

Very very important.


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.

Waaayy overly simplified. If it were just a matter of compressing
the signal until it fit into whatever bandwidth was
desired/needed/mandated, don't you think we would have gone that
route, instead of inventing faster modems, T-lines, Cable modems and
DSL? There are limits which we passed a long time ago, after which
data MUST be thrown away. There are finite limits that imagery or
video cannot be compressed without sacrifices in fidelity.

But that's not the only issue.

Hardly!

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.

Oh, yeah. A lot of people forget about that one. We need someone to
communicate with.

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.

But that can be fixed.

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.

Some things for people to think about:

There is nothing preventing the use of digital imagery or video at
HF frequencies. NO majik involved.

But!

The bandwidth needed for the data being sent may very well approach
or exceed the frequency being used for the transmission!

This means that the data needs compressed or the time needs
expanded.

Compression has well defined limits. Beyond these limits, data must
be thrown away. This is why original images (or video) should be
performed in as high a resolution and as low a compression as
possible. It is always possible to throw away data, but not get back
data that has been discarded.

So beyond whatever minimal image quality is agreed upon, time must
be expanded. 300 baud is exceptionally slow by today's standards. I
worked up some times on transmission of a level 5 640 by 480 jpeg
earlier in this thread. I don't consider those times acceptable.

So here we are.


- Mike KB3EIA -

binary data is two state data from its very state of being, on or off

normalize your noise level (to a value which will always be subtracted
from the "on markers") then there is only two states in question, an
on and an off

next, you are NOT actually transmitting ones and zeros (on's and
off's), but are transmitting "markers", the length (time)between the
"markers" is what determines if it a one or a zero (or a sting of two
or more ones or zeros, under proper compression techniques.)

If those markers are above the noise level--you have uncorrupted
data--if not, you do have corrupted data, since data is transmitted in
"packets", and since each and every (say in this case) 1024 bit packet
is checked against a CRC (Cyclic Redundancy Check "value"), corrupted
packets are tossed away and a request to resend is initiated. Packets
are sequentially numbered so as to keep their display sequence in
proper sync.

My experience is that most digital transmissions can take place with
acceptable success if cw can... and I expect that statement to fall to
heavy challenge! smirk

John

wrote in message
oups.com...
Mike Coslo wrote:
wrote:
Mike Coslo wrote:
Dave Heil wrote:
LenAnderson@ieeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eeeeeeeeeeeeeeeeeeeeeeeee.org
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.

Oooh, there could be a problem there! There are limits to the
compression, and we have exceeded them in some forms already.

Of course! But it all depends what you consider "acceptable
quality"...

Check to
see how many vertical pans there are on video signals lately.
The
compression on the digital signals (note that even if you are
getting
your feed via analog cable, you are still almost certainly
looking at a
digital signal) already calls for some major aliasing.

OTOH, if all you want is B&W ~CGA video....

There are limits, and there are limits. How much more are we
going to throw away?

Always a tradeoff. Hams routinely use 1.8 kHz wide SSB filters for
"communications quality". Hardly hi-fi but it can make the
difference
between QSO and QRJ.

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.

What're we going to do when the data rate that we need is darn
near(or above) frequency in use?

Use modes designed for the purpose. See below.

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.

Always?

No mode always gets through.

But if you have enough S/N, all sorts of things are possible.

Here's one way. I apologize if you are way beyond this simplified
example:

Consider how PSK31 works in BPSK mode. There are just two basic
modulation states - 0 degrees and 180 degrees. One bit per unit
time.

But in QPSK mode, there are four basic modulation states - 0
degrees,
90 degrees, 180 degrees and 270 degrees. Two bits per unit time, but
the bandwidth is no greater than with BPSK. Only problem is that you
need a transmitter, receiver and transmission medium whose total
distortion is low enough that you can accurately tell the four
states
apart.

Now consider a theoretical "256PSK" mode, in which there are 256
states: 0 degrees, 360/256 degree, 720/256 degrees, etc., all the
way
to ~359 degrees. 8 bits in one unit time, in the same bandwidth! But
you need a transmitter, receiver and transmission medium whose total
distortion is low enough that you can accurately tell the 256 states
apart.

You can see that if we just keep increasing the number of states,
the
number of bits per unit time in the same bandwidth keeps going up.
But
you need more and more accurate modulator/medium/demodulator - IOW,
better and better signal-to-noise. Or to look at it another way, the
mode carries huge amounts of data in a tiny bandwidth but has very
little tolerance for noise that takes the form of phase distortion.

Now imagine multiple spaced carriers in the 2.5 kHz bandwidth all
carrying data - lotta bits, huh?

Of course you may find that in practice it's not that easy to get a
modulator/medium/demodulator setup that meets the requirements -
particularly if the medium is HF RF with relatively low power.

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

And software.

I really didn't think it was all that simple.

Nobody said it was simple!

Why don't we get together
and pop off a live video system for say the 160 meter band. The
video
would be real time, 30 fps, and otherwise like broadcast video.
Better
yet, Why don't we do it at computer resolution?

Ask the PROFESSIONALS, Mike. Remember, ham radio is a HOBBY,
according
to them....

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.

I did hear that DRM was capable of doing imagery. I couldn't find
any
examples tho'. And they were very vague about it.

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

The journey beats all.....

Exactly.

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.

Ain't that the truff?

I ask for enlightenment, I get invective.

Are you surprised?

Nope. It doesn't make for a very good discussion tho'.

Discussion is not what the invective-hurlers want, Mike.

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.

They might attract others of their ilk.

You see that happening right here.

I'll bet they like some of the "wonder antennas" that keep cropping
up...

Exactly.

73 de Jim, N2EY

From: John Smith on Jul 4, 4:31 pm


Len:

That "vampire/sunshine" thing, that is good, can we use that in that
others guy movie with John Wayne? grin

You do and a computer-age Bela Lugosi II shows up, smiles, and
says "I vant to byte you in da NAK!" *


I picture a bunch of amateurs in coffins with transceivers, and
suddenly a young man shows up ripping coffins wide open, at high noon,
by the OK Corral!!!

John, careful with that toke inhaling when CBS shows
"Shanghai Noon" next...

I think your fast forward skipped right off the DVD track.


bit bit





* those who don't know the modem signal names had best ignore
lest ye be pun-ished.

From: John Smith on Jul 4, 6:56 pm

Len:

Keep a stiff upper lip man, only poor breeding reduces one to name
calling and personal attacks--they seek to include you among their
ill-bred lot.

Er, I think they're excluding rather than including.

Something about "showing dedication and committment to the
amateur community" an' stuff like thet there... :-)


A little "blood letting" is good for the spirit, just don't take 'em
seriously.

I gave at the orifice.

Most of these zombies got no blood...like cast members of a
bad remake of "Night of the Living (radio) Dead."


It is a gorilla war here, I will grant you that, some just wear
gorilla suits, others really are.

Gorilla fighting? Si! I was at Isla Flaca with Rene Santoni.

Goodall on you! :-)

OOK! OOK!

"KØHB" wrote in message
ink.net...

"Mike Coslo" wrote


So here we are.


Yup, and no one has persuaded me it can't be done. I've only been
persuaded that we haven't figured out how yet. (Sorta reminds you,
doesn't it, of how those old-tymey hams must have felt when they were told
to take their party to "200 meters and below".) You, Jim, and Dee
bemoaning how hard it will be, and John raising the tantalizing notion
that we may only be a few "eureka!!!"s away from something workable.
Outside my area of competence, but I'll watch the dialog with interest.

73, de Hans, K0HB

From my understanding of John's comments, he is saying it can be done now
with current technology. He does not however tell us how. He just chatters
on about "compressing it enough" without stating the degree of compression,
etc.

Hey I'm all for the "eureka" when it happens but the problem is that it is
unpredictable. Not only is it unpredictable in time but in the nature of
the breakthrough.

Dee D. Flint, N8UZE