Mike:

Isn't it quite obvious the best method would be the pci shortwave card
to receive and feed the signal to a software decoder based in the same
computer as the card and feeding the decoded video signal to the video
card of the computer for viewing on the monitor? (I have the sw card
and am toying with it in my spare time but have a lot on the plate
right now, and I am addicted to news groups, instant messaging, irc
and webcams grin)

And, a transmitter feeding from an digital output from a software
modem running on the computer via the sound card to transmit the
digitized video?

And, the second best method would be to kludge together an external
modem to feed the mic input on a transmitter from a software encoder
running on the computer, to broadcast digitized video.

And, on the receiving end, the same or a similar modem being feed from
a digital output from the transceiver (dac/adc converter installed
between transceiver and computer--or implemented as software using the
sound card) to a software decoder running on the computer and feeding
the computers video card.

I mean there are several roads which all lead to the same end here.
Plus, a person in the industry with access to the parts and facilities
should be able to put together a dedicated device...

The one I see in practical use, uses the "kludged modem" dac/adc
conversion, it functions well, in well I mean is much superior to
SSTV--indeed, it is still in use to this day 15 frames per second of
BW video is normal with good signal strength...

I am not a "real hardware person" (my degree in that field is from
1972 and makes me a bit of a "hardware dinosaur" frown), I am a
hacker (but am able to fool my boss well enough to call me a Sr.
Software Engineer in assembly/C++ grin) all I did was write the code
to interface the modems/sound cards with the kludged hardware, I can
tell you about the data compaction and rs-232 communications between
the serial port-computer-modem and the decoding of the digital signal
from the sound card back to a video signal to feed to the computers
video card/monitor...

To put it simply, the way the kludge works is that the "phone line"
between the two modems (one on a receiver to grab the "digital video
signal" from an output on that receiver, and one on the transmitter to
feed the video signal) is just like they work on a phone line, only
you have replaced the phone line with a digital modulated audio signal
modulating the rf signal...

The guy who built the adc (analog to digital converter) and dac
(digital to analog converter) says there is a better way to do this
via the sound card its digital in/out ports and the transceivers--and
ditch the hardware modems all together--we worked on this and have it
at "proof of concept" stage, however we never get the time to get back
together and realize it as fully functional...

To be honest with you, during my whole lifetime I have built a few
basic receivers/transmitters and many, many linears and antennas--that
is about the extent of my hardware experience. I have been gifted to
have family members and friends who have a much greater interest in
hardware.

Let me be frank on this one point. I would be slow to put you in
contact with any of the young men here running this equip.--they are
trusting and would be easy to take advantage of and get into trouble.
These amateur news groups have demonstrated the true petty nature of
hams and how turning a person in for minor infractions of rules and
regulations really gets the old women fired up here and calling for
blood! I have been burned by petty hams in the past!

Certainly here there are hardware gurus who can explain all this much
better than my capabilities... where are the hams who are using this
technology in the "real world?"

I can't believe a "hardware type" hasn't already chimed in here and is
already offering block diagrams and schematics on how to build one!
Have you insulted all those away?

Surely after this post of mine they will chime in...

Even if you are not a programmer, I think there is probably a way to
make windows media player decode/encode the video to a protocol like
..asf (broadcast media which is already broadcast over the internet via
dialup modems at low fps) or such which would be acceptable to
broadcast video over the bandwidths in question at acceptable fps
(frames per second)... surely there are enough skilled people here to
put together a workable project, aren't there?

Don't be afraid to speak up hardware techies!!! Or, is Len right, you
have slaughtered all the "digital youngsters" with your large dinosaur
egos?

John

"Mike Coslo" wrote in message
...
John Smith wrote:
Len:

The words and wit which flow from your rather quick mind are
enlightening, entertaining and enjoyable, if not for you, this
thread is rather drab and boring...

John, do you have a technical dissertation on digital transmission
of imagery on HF? Not how it can be done, of course. That is a
given. But how it can be done practically, as in a reasonable amount
of time.

I agree that Len is quick witted. It keeps me reading his posts.

- Ciao - Mike KB3EIA -