wrote in message
oups.com...
On Mar 15, 11:38�pm, John Smith I wrote:
wrote:


[snip]

PSK is too slow for
data transmission of LARGE and multi-megabyte amounts of data, end of
story.

Not the end of the story at all.

Yes, PSK31 is too slow for large amounts of data - because
it wasn't designed for that. PSK31 was designed to be a
keyboard-to-keyboard mode that uses very little bandwidth and has
excellent performance with low S/N ratios. It was
meant as an improvement to FSK RTTY for such QSOs.


My question on this is why would we be sending large amounts of data on
amateur radio? The need for it doesn't exist in general. If it did,
someone would have developed the appropriate digital mode by now.

Dee, N8UZE

On Mar 17, 2:19�am, "Dee Flint" wrote:

My question on this is why would we be sending large amounts of data on
amateur radio? *

I can think of a couple uses for it, Dee.

First there's emergency/public service comms. The served agencies
are used to being able to send emails with sizable attachments through
the usual networks. A mode that would let them do that via amateur
radio
when the usual networks are not available would be a really good tool
in the emcomm toolbox. IMHO it's the thinking pushing WinLink.

Second, there are plenty of times in an ordinary QSO when it
would be good to be able to send a picture, station description,
article, a sound clip, etc. directly by radio, and have it in digital
format at the other end. In the past, such modes as SSTV have
gained limited acceptance because they required lots of extra
apparatus, but with the widespread acceptance of PCs today
the big limitation is software, not hardware.

The need for it doesn't exist in general.

In some cases, if something is presented to people, they
will find a use for it. Look back on predictions about
computers - in the early '50s it was predicted that a half-
dozen or so general-purpose computers would serve all
the needs of the USA, and in the '70s it was said that no
ordinary person would ever need a computer in their home.
Both pronouncements were made by knowledgeable
professionals, and at the time seemed quite reasonable.

Of course "if you build it, they will come" doesn't always
work out.

*If it did,
someone would have developed the appropriate digital mode by now.

I disagree. One of the big problems is that such development
tends to be protected by the developers, and *not* made
open-source. PSK-31 and Linux are exceptions, not the rule.

In the bad old days, the focus was on hardware, and the
idea of controlling a mode-concept wasn't taken too
seriously. SSB, FM, SSTV, RTTY, AX.25 packet,
etc., all came to amateur radio essentially as freebies.
The standard was widely and publicly
available, just meet it and go on the air.

But you can't homebrew
a Pactor 2/3 modem today the way you could homebrew
an SSB rig 50 years ago.

The "bell-the-cat" question is still *who* is going to develop
such new modes and then just give them away for free.
Groups that have tried (TAPR and the spread-spectrum idea)
have taken years without much to show.

All IMHO

73 de Jim, N2EY

wrote:
On Mar 17, 2:19�am, "Dee Flint" wrote:

My question on this is why would we be sending large amounts of data on
amateur radio?

I can think of a couple uses for it, Dee.

First there's emergency/public service comms. The served agencies
are used to being able to send emails with sizable attachments through
the usual networks. A mode that would let them do that via amateur
radio
when the usual networks are not available would be a really good tool
in the emcomm toolbox. IMHO it's the thinking pushing WinLink.

Yes, I agree that this is exactly what's pushing WinLink.

This is one of those areas in which I have very strong opinions both pro
and con. It's almost like the devil on one shoulder and an angel on the
other, each speaking into one ear.

On the pro side, it really makes a lot of sense in theory. If we hams
could offer this kind of capability to emergency agencies, it would
provide a much-needed communications capability in times of disaster.
But it would need to be stand-alone and not depend upon repeaters that
might be out of service, which to me implies HF.

On the con side, a real disaster is the worst possible scenario for
trying to get this technology to work reliably. You're potentially in a
high-noise low-signal poor-antenna situation. The equipment required is
fairly complex, and you need a fair amount of technical knowledge to set
it up. When I build a mental image of someone at a shelter trying to
set up this gear, it's hard for me to see success. Finally there's the
issue of what data gets sent; some of it probably is not appropriate for
transmission using amateur radio.

Second, there are plenty of times in an ordinary QSO when it
would be good to be able to send a picture, station description,
article, a sound clip, etc. directly by radio, and have it in digital
format at the other end. In the past, such modes as SSTV have
gained limited acceptance because they required lots of extra
apparatus, but with the widespread acceptance of PCs today
the big limitation is software, not hardware.

This one I find intriguing. I do think that if the capability existed,
and did not require purchase of hardware in addition to a PC, that it
would be interesting to enough hams to create a critical mass. It
provides an alternative playground for hams who prefer to experiment
using the keyboard of their PC rather than their soldering iron.

73, Steve KB9X

"Steve Bonine" wrote in message
...
wrote:
On Mar 17, 2:19�am, "Dee Flint" wrote:


[snip]

On the pro side, it really makes a lot of sense in theory. If we hams
could offer this kind of capability to emergency agencies, it would
provide a much-needed communications capability in times of disaster. But
it would need to be stand-alone and not depend upon repeaters that might
be out of service, which to me implies HF.

On the con side, a real disaster is the worst possible scenario for trying
to get this technology to work reliably. You're potentially in a
high-noise low-signal poor-antenna situation. The equipment required is
fairly complex, and you need a fair amount of technical knowledge to set
it up. When I build a mental image of someone at a shelter trying to set
up this gear, it's hard for me to see success. Finally there's the issue
of what data gets sent; some of it probably is not appropriate for
transmission using amateur radio.

Another thing to keep in mind that as our infrastructure becomes stronger,
hams will only really be needed in the absolutely worst disasters. Not only
do you have the bad signal to noise ratio and poor antennas, you may be
power limited. People remark on the low power capabilities of PSK31 for
example but they are only looking at transmit power. You really need to
look at power consumption. That means adding in the computer/monitor combo.
One might actually be better off with voice.



Second, there are plenty of times in an ordinary QSO when it
would be good to be able to send a picture, station description,
article, a sound clip, etc. directly by radio, and have it in digital
format at the other end. In the past, such modes as SSTV have
gained limited acceptance because they required lots of extra
apparatus, but with the widespread acceptance of PCs today
the big limitation is software, not hardware.

This one I find intriguing. I do think that if the capability existed,
and did not require purchase of hardware in addition to a PC, that it
would be interesting to enough hams to create a critical mass. It
provides an alternative playground for hams who prefer to experiment using
the keyboard of their PC rather than their soldering iron.

73, Steve KB9X


I agree that the fun of it is the most probable driver. Yet SSTV has not
grown as rapidly as one might expect when it became possible to do it all
with one's computer.

Dee, N8UZE

On Sat, 17 Mar 2007 14:37:57 CST, "Dee Flint"
wrote:

Another thing to keep in mind that as our infrastructure becomes stronger,
hams will only really be needed in the absolutely worst disasters.

There will always be a need because no matter how strong the
infrastructure is, situations will arise that exceed that capability.
Design of public safety communication systems is the specialty of my
engineering firm and I'm all too painfully aware of the real-world
limitations

Example: One of our med center nets is an inter-hospital net that
carries traffic on bed availability, staff availability, and medical
supply status and need to and from the Metro Regional Hospital
dispatch, the "czar" of inter-hospital operation, which directs
ambulances and supply resources to the available facilities. It is
currently staffed by personnel located in another neighboring med
center. The VHF simplex and repeater ham portion (ham stations
located in the Emergency Departments of all the local hospitals) backs
up a system which is a user group on the City of Portland's 800 MHz
trunked system. When things get tight, the trunked system will be
overloaded with police and fire operations, assuming that the system
survives at all. That's where the hams come in.
--

73 de K2ASP - Phil Kane

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon

e-mail: k2asp [at] arrl [dot] net

Phil Kane wrote in
:

On Sat, 17 Mar 2007 14:37:57 CST, "Dee Flint"
wrote:

Another thing to keep in mind that as our infrastructure becomes
stronger, hams will only really be needed in the absolutely worst
disasters.

There will always be a need because no matter how strong the
infrastructure is, situations will arise that exceed that capability.
Design of public safety communication systems is the specialty of my
engineering firm and I'm all too painfully aware of the real-world
limitations

Infrastructure by it's very nature becomes more fragile the more
there is of it. disasters by their nature tend to occur when multiple
problems happen. Seems like a "duh" statement, but we see it all the
time. We going to put satellites up to do emergency Operations? Right
away I see some issues. Those birds aren't cheap, so we'll probably put a
lot of stuff on them. We'll probably have a lot if interacency
"patching" available, trunking of course. It will probably be an awesome
piece of technology. Maybe it will work. Fortunately no satellite has
ever failed.... ;^)

- 73 de Mike KB3EIA -

On Mar 18, 8:18�pm, Mike Coslo wrote:
Phil Kane wrote :

On Sat, 17 Mar 2007 14:37:57 CST, "Dee Flint"
wrote:

Another thing to keep in mind that as our infrastructure becomes
stronger, hams will only really be needed in the absolutely worst
disasters.

There will always be a need because no matter how strong the
infrastructure is, situations will arise that exceed that capability.
Design of public safety communication systems is the specialty of my
engineering firm and I'm all too painfully aware of the real-world
limitations

* * * * Infrastructure by it's very nature becomes more fragile the more
there is of it. disasters by their nature tend to occur when multiple
problems happen. Seems like a "duh" statement, but we see it all the
time. We going to put satellites up to do emergency Operations? Right
away I see some issues. Those birds aren't cheap, so we'll probably put a
lot of stuff on them. We'll probably have a lot if interacency
"patching" available, trunking of course. It will probably be an awesome
piece of technology. Maybe it will work. Fortunately no satellite has
ever failed.... ;^)

Mike, PART of the "infrastructure" includes radio amateurs.

Back after the 17 Jan 94 Northridge earthquake here, the
existing infrastructure was behaving just fine and FEMA
brought in a bunch more communications equipment, some
of it used to show continuous video of family/friend messages.
For all of FEMA's highlighted "faults," they were equipped to
handle comms as needed. By now the Los Angeles
Communications Auxiliary (run more or less by the LAFD)
is equipped and able to roll with comm-center bus/RV
modifications. I took my exam at one such Aux station
now still called "Old Fire House 77" despite it being
re-assigned from fire fighting to communications. Some
members of that Aux group are also licensed radio
amateurs and can operate from fixed as well as mobile
station locations.

Things really aren't so scarce/rare insofar as comms
are concerned in this big city complex of 8 million plus.
It may be that much smaller areas have scarce
facilities but that is up to those locations. I'm proud
that this area I live in has beefed up its communications
in the 13 years since the Northridge quake hit. What it
has done can be a model of integration for other areas.

Just a view a bit different than most others in here.

73, Len AF6AY

"Mike Coslo" wrote in message
36...
Phil Kane wrote in
:

On Sat, 17 Mar 2007 14:37:57 CST, "Dee Flint"
wrote:

I didn't explain myself very well on my comments on infrastructure and hams
in emergencies. What I was trying to say was that the smaller disasters
will need hams less and less as the normal infrastructure becomes more
robust despite its complexity. Therefore when the big disasters hit that do
compromise the infrastructure, there will be a lower percentage of people
with training and experience available.

Dee, N8UZE

"Steve Bonine" wrote in message
...
wrote:
On the con side, a real disaster is the worst possible scenario for trying
to get this technology to work reliably. You're potentially in a
high-noise low-signal poor-antenna situation. The equipment required is
fairly complex, and you need a fair amount of technical knowledge to set
it up. When I build a mental image of someone at a shelter trying to set
up this gear, it's hard for me to see success. Finally there's the issue
of what data gets sent; some of it probably is not appropriate for
transmission using amateur radio.

A way this works with WinLink (and what we are implementing in MA) is that
you put full-up WinLink stations, with both HF and VHF capability, in a few
hardened (state-owned) EOCs. Local EOCs and shelters use AirMail (the
WinLink client) with VHF TNCs to communicate with the state EOCs, with
forwarding over the Internet if it's still up, or HF otherwise. A VHF-only
WinLink client station can be quickly set up in a temporary EOC or shelter,
and can even be used mobile.

- Dennis Brothers, N1DB

wrote in message
ups.com...
On Mar 17, 2:19�am, "Dee Flint" wrote:

My question on this is why would we be sending large amounts of data on
amateur radio?

I can think of a couple uses for it, Dee.

First there's emergency/public service comms. The served agencies
are used to being able to send emails with sizable attachments through
the usual networks. A mode that would let them do that via amateur
radio
when the usual networks are not available would be a really good tool
in the emcomm toolbox. IMHO it's the thinking pushing WinLink.


Perhaps they would like to have such but IMHO, when the catastrophe is
serious enough and wide spread enough that hams are truly needed, that is
apt to be coupled with power source limitations that would make it unwise to
send such length attachments in many cases. Plain ascii text would be the
most useful and results in low file size. There are several modes that can
handle that. In addition, the power source limitations might make running
computers as well as radios an unwise choice in some situations.

Second, there are plenty of times in an ordinary QSO when it
would be good to be able to send a picture, station description,
article, a sound clip, etc. directly by radio, and have it in digital
format at the other end. In the past, such modes as SSTV have
gained limited acceptance because they required lots of extra
apparatus, but with the widespread acceptance of PCs today
the big limitation is software, not hardware.


Yes the PC capabilities have done a lot for digital modes of all types.

The need for it doesn't exist in general.

In some cases, if something is presented to people, they
will find a use for it. Look back on predictions about
computers - in the early '50s it was predicted that a half-
dozen or so general-purpose computers would serve all
the needs of the USA, and in the '70s it was said that no
ordinary person would ever need a computer in their home.
Both pronouncements were made by knowledgeable
professionals, and at the time seemed quite reasonable.


Well the science fiction authors were envisioning small personal size
computers almost from the day computers were invented. I must have read a
lot of it as I've always believed that computers would become an everyday
tool for everyone.


Of course "if you build it, they will come" doesn't always
work out.

If it did,
someone would have developed the appropriate digital mode by now.

I disagree. One of the big problems is that such development
tends to be protected by the developers, and *not* made
open-source. PSK-31 and Linux are exceptions, not the rule.


Well I disagree with your disagreement. To me it seems that there are
enough hams that somewhere in that group are several people capable of doing
this it they deemed it worth doing. Then we would have modes and software
developed by hams for hams. Then there would be more likelihood that it
would be shared in the same manner as PSK-31. There is nothing stopping
anyone from doing that development other than lack of interest.


etc., all came to amateur radio essentially as freebies.
The standard was widely and publicly
available, just meet it and go on the air.

But you can't homebrew
a Pactor 2/3 modem today the way you could homebrew
an SSB rig 50 years ago.


Well the today's computer capabilities, the hardware aspect simply goes
away. It becomes a software issue.

The "bell-the-cat" question is still *who* is going to develop
such new modes and then just give them away for free.
Groups that have tried (TAPR and the spread-spectrum idea)
have taken years without much to show.


I think the problem with the spread-spectrum is that for ham radio
operators, the usefulness simply doesn't justify setting up to use it.
People want to get out there and find stations rather than having to have
pre-arranged schedules for everything.

If it doesn't seem useful to them, people will pass on it.

This occurs in all fields of endeavor. A person has a bright idea, packages
it, markets it, and it doesn't sell simply because the market doesn't
perceive any significant need for or pleasure derived from the product.

Dee, N8UZE