From: "Dee Flint" on Mon 4 Jul 2005 20:59

"K=D8HB" wrote in message
link.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 to=
ld
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

Frommy understanding of John's comments, he is saying it can be done now
with current technology.

I've seen live, streaming video on my computer years ago, all
working through ONLY the 3 KHz bandwidth of my single telephone
line. There ARE thousands of examples. Today.

He does not however tell us how.

This newsgroup does not support binaries with the attendant
schematics, simplified diagrams, equations, etc., etc., etc.
There are dozens of BOOKS available "in the engineering
profession" (as well as purchaseable from Amazon.com) on the
subject.

He just chatters
on about "compressing it enough" without stating the degree of compression,
etc.

"In the engineering profession" (where I've been for decades)
lots of Design Reviews had "chatting." They also had arguments,
sometimes heated, where one would adamantly REFUSE to believe
in an explanation...! Senior type, titled, etc., etc., etc.
[several anecdotes could be inserted here but I digress...]
Sound familiar? :-)

INFORMATION compression is going on all the time in nearly ALL
communications media. [I use "information" rather than "data"
to avoid the emotional baggage associated with "lesser" forms
of amateur communications, "lesser" relative to the epitome of
all amateur radio modes (morse code).

Most wired telephone calls are digitized, compressed, re-
expanded on circuits to distant central offices. Modems
operating on telco lines (limited bandwidth of about 3 KHz)
do it locally. Webcams - at the arbitrary Coslo standard
of 7 frames per second or faster or slower - do that over the
same telco bandwidth. Wired telemetry of many and varied
forms coupled through telco circuits do that. All of those
operate in bandwidths almost exactly that of an amateur SSB
voice circuit.

Hey I'm all for the "eureka" when it happens but the problem is that it is
unpredictable.

Do you wish for EXACT dates of miracles? Scheduled epiphanies?
:-)

Or aren't you just being snarly for the purposes of winning
message points for yourself in this newsgroup?

Not only is it unpredictable in time but in the nature of
the breakthrough.

How can you say that, given that you are "in the engineering
profession?" Have you given up reading of the breakthroughs in
recent history of the "engineering profession?" They are many.

A retrospective:

1. Ed Armstrong was told his FM system won't ever be as good
as good old, practical, used-every-day AM (then all of a bit over
a decade old) and that he should give up. FM broadcasting got
very practical...evolved not only to binaural ("stereo") sound
(compatible with monaural) but also to carry an isolated,
independent sound circuit (such as "storecast"). It works.

2. Mobile FM was described as impractical, wouldn't work as good
as AM, but Link and Motorola said phooey to that and proved it
was good, beginning with police department two-way radios prior
to WW2. The U.S. military saw that, said great, lets do that for
everything from backpack walkie-talkies to tank radios. It works.

3. Single Sideband Suppressed Carrier modulation is inefficient,
impractical, too costly, too complex for amateur radio use said
the olde-tyme hamme old-fahrts. "You can't get me to believe it
works!" said many in private. It's now standard voice on HF. It
works.

4. You can't make an active amplifying device without vacuum or
gas said the olde-tyme tube makers. Three guys at Bell Labs
showed them different back in 1948, eventually won a Nobel Prize.
A new hire at Texas Instruments, not allowed a company vacation,
made the first integrated circuit during the plant close-down.
[Jack Kilby, who recently passed away after many many honors]
Integrated circuits are now a mainstay in all electronics (which
includes "radio"). [I am looking at a virtual 17-inch integrated
circuit called an "TFT flat panel display" with at least one
transistor junction per pixel as I write this] Solid state
devices work well.

5. It is impossible to send data through a 3 KHz bandwidth at
faster than 300 bits per second (300 Baud) said the literalist
lookers-at-only-conventional-modulation-simplistic-explanations.
Impossible! they kept saying at each stage of rate increases
to 1200, then 2400, then 9600, and finally to 56,000 bits per
second. Those all work fine. [56K modems are near bumping the
upper limit of Shannon's Law]

6. Olde-tyme experts involved with analog image transmission
insisted one needs much bandwidth to transmit video, at least
4.5 MHz for NTSC, 5.0 MHz for PAL. IT MUST BE THAT WIDE! they
shouted. MPEG (Motion Picture Experts Group) said not quite
and proved it. The "Grand Alliance" (industry-broadcaster
association) evolved HDTV which carries 20 MHz analog bandwidth
video, quadraphonic sound, closed-captioning text with alternate
languages, and an optional isolated sound channel all in digital
WITHIN a 6 MHz bandwidth...the video having nearly double the
pixel resolution of old NTSC analog video. It works. Not only
that, it works with perfect clarity down to the minimum RF
signal level.

7. AT&T brought out "PicturePhone" in the 1960s. Rather wide
bandwidth but with some compression by slowing frame rate, it
evolved to work over standard telco lines (and limited bandwidth).
It failed, not from anything technical, just from customers
turning the picture OFF for privacy. It was withdrawn for
reasons of not producing a profit. After divestiture a number of
entrepreneurs tried various schemes of their own, but with
marginal acceptance in the market. One-way broadcast-like
"webcams" are the only result...but do allow streaming video
over dial-up, limited bandwidth telco lines connecting to the
Internet. "Slow-scan" works well technically, just ins't
accepted.

8. Good old reliable manual telegraphy was 56 years old in 1900,
mature industry that had spread worldwide. Average throughput
was perhaps 20 words per minute. Then teleprinters got developed
and standardization had begun. Teleprinting TOOK OVER the wired
manual morse code telegraph business and "telegrams" began being
sent by teleprinter. Morsemen were being "downsized" (out of work,
replaced by 60 word per minute machinery operable by non-
specialists). Radio saved them from finding new work. Electro-
mechanical teleprinters eventually evolved to 100 words per
minute in commerce, industry, and government. Then the electro-
mechanical teleprinters were themselves "downsized" by electronic
data transmission means, much faster, and with on-line encryption
for security.

9. You can't possibly put a two-way radio in a telephone handset
(along with image and data transmission) that works at microwave
frequencies cried the olde-tyme telephone experts...they will all
interfere with one another they echoed. The U.S. Census Bureau
said that two years ago the number of cellular telephone in the
USA had reached 100 MILLION subscribers. Cell phones are now a
part of our lives. They fit easily into a shirt pocket or purse.
They work well in a cell area.

10. You can't possible send thousands of digitized voices over
a single optical fiber cried the communications experts decades
ago. It isn't as good or practical as copper wire lines they
sang in chorus. Fiber-optic carrier systems now operate at
4 GHz bits per second and are self-repeating (amplification) by
means of a second optical "pump" wavelength. The longest carrier
line in the world goes from the UK through the Med through the
Indian Ocean, around southeast Asia and on up to Japan. It works.

11. You can't possibly put a mainframe computer in every home
said the experts of 1960. One expert even said that no more
than a dozen mainframes would do the entire job of computing
for the USA then. Today's personal computers in laptop size
have 100 times the clock rate, 1000 times (or more) mass memory
storage than the largest mainframe computers of 1960...and cost
less than $2000 each (for laptops, half that for desktops).
Those work very well...except for some operators of same.

12. You can't possibly put an entire 3-hour motion picture on
a single CD said the movie experts of 1970, citing the equal
impossibility of putting 6 hours worth of music on the same size
disk! The MPEG showed them how. Today DVDs are fast replacing
the older bulkier VHS tape cartridges and music CDs have taken
over from vinyl disc "LPs." All the major auto makers make
options for having DVD players for back-seat passengers; my wife
and I declined that option on buying a new Malibu MAXX two weeks
ago...the standard MAXX rear sound console with wireless headsets
(stereo) was good enough for us. The DVD works very well.

13. Todays ready-built amateur transceivers are more digital than
analog, "bells and whistles" are an easy task to add with a good
programmer and interface designer...can include memories, a separate
"split" VFO, digital signal processing, even a spectral display to
see signals on either side of what you are tuned to...all for less
than $4K (list) or slightly more if the entire "radio" is to be
controlled entirely by a personal computer. Imagine what the size
of those would be if done entirely in analog circuitry...couldn't
possibly fit on a desktop. Want squeaky-narrow bandwidths for that
109 year old style radiotelegraph signal? Easy, just use DSP, all
digital using a microprocessor operating at high clock rates.

All of the above happened within my lifetime. I watched some of it
happen even before being IN the engineering profession. My father
and father-in-law were both born in the year 1900...a year before
Marconi got his S across the Atlantic, three years before the
Wrights finally succeeded in sustained HEAVIER-THAN-AIR flight at
Kitty Hawk. They both watched the first humans walking on the
moon over live television in their lifetimes.

"Breakthroughs" are always happening. If you really pay attention
to the engineering profession you are "in," you would see that.
Those happen because a few humans have the curiosity, the
willingness
to TRY to make something new work. They are seldom disauded by the
self-propelled "experts" who say "it can't possibly work!"

Or, you can sit back in the recreation of yesteryear, championing
a 161-year-old primitive manual communication mode, getting all
kinds of nice certificates (suitable for framing) for becoming
expert at carrier-banging and pronounce judgements upon the
"improper" attitudes of others...in a recreational radio HOBBY.

"CW gets through when anything else will" - B. Burke