wrote in
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.

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.

I think that emergency comms might make use of large amounts ot data
transmission, but the average ham needs to use the modes in order to
have the modes available during those emergencies. IOW, it's a matter
not of what I get for emergencies, but what Joe Ham is going to get
along with me so we can use it when there isn't an emergency. Otherwise
it isn't of a whole lot of use.

And then there is that old bugaboo of bandwidth. HF really isn't
the place for wide bandwidth modes.

...

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.

Our "hamness" tend to make us gravitate towards those open source
modes. And it isn't just my ceap tendencies. I've tried most of the
digital modes at least once. That would not have happened if I had
to pay for every mode.



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.

Often people will wonder why Hams don't run to every new mode that
comes along. Some assume that we are not adaptable as a group. I
would say it has a lot more to do with simply having someone on the
other end to talk to. We need an early following to get the ball
rolling, then there needs to be a good reason to use the mode. The
difference between say Spread spectrum and say PSK31 is that PSK
apparently serves some purpose for a growing number of Hams, and SS
doesn't.

- 73 de Mike KB3EIA -

Mike Coslo wrote on Sat, 17 Mar 2007
18:32:21 CST

Often people will wonder why Hams don't run to every new mode that
comes along. Some assume that we are not adaptable as a group. I
would say it has a lot more to do with simply having someone on the
other end to talk to. We need an early following to get the ball
rolling, then there needs to be a good reason to use the mode.

Mike, you've seen enough other licensed radio amateurs by now to
understand that, technically, they are rather conservative in
adopting "new" things. My own opinion is 'uber-conservative' but
that is just personal. :-)

PUBLICITY on new things, new modes is the key to getting attention.

I'll recite that PSK31 was innovated in the UK and air-tested by
many amateurs in Europe for years before it got its first write-up
in QST for USA amateur radio consumption. Why? I don't know for
sure but I will start shining some light on editors and frequent
contributors to QST. I think that they were honestly unaware of
it. It isn't like they are unaware of the RSGB periodicals.

Another case is Mike Gingell's polyphase audio network. Mike, now
a resident and ham licensee in the USA, did his PhD dissertation
on that network. It enabled four quadrature-phased audio outputs
with excellent phasing accuracy using lower-tolerance parts. It
was publicized in Pat Hawker's column in Radio Communication
magazine in 1973, the experimenter trying it out was Peter Martinez,
G3PLX, the guy who would come up with PSK31 later. European hams
have been trying it out for SSB modulation and demodulation ever
since; makes for a smaller SSB sub-assembly. It got some attention
from 1974 onwards over here, but not a lot. It even got lots of
attention in the IEEE Communications magazine for frequency-
multiplexed telephony but that was displaced by up and coming
digital time-multiplexing right afterwards. Long-distance
wired telephony was the first user of SSB, BTW. :-)

Conservative USA amateurs tend to stay with what they know and
learned when young...except for the few who actually work with
higher-tech modes for a living...and some of those tend to
"relax" with tried-and-true modes off-work. That re-enforces
the conservative approach to "state of the Art" advancement.

Part of that conservatism may be the "made only in America"
thinking. Look at D-Star that's been getting publicity by
the Big3 amateur radio makers of Japan. D-Star has been
around for three years, innovated by the JARL. It seems to be
very good in providing flexibility to connect with the Internet
through VHF-UHF repeaters. [I got a demo of it just recently]
No, it's not a "practical" thing on "the bands" (what so many
amateurs call the HF bands) but it seems to work just dandy
on handling both voice and data together on VHF-UHF.

The
difference between say Spread spectrum and say PSK31 is that PSK
apparently serves some purpose for a growing number of Hams, and SS
doesn't.

Ummm...PSK31 was originally designed for HF ham bands and was
deliberately narrow-band. Spread-Spectrum modes are for wider
bandwidths available only on UHF and up in frequency. DSSS is
already a proven winner in multiple-user WLANs in other radio
services (no discernable interference or catastrophic BERs) but
is good only for LOS radio paths. As a result, it will see
application only in more densely populated urban areas in the
USA. Conservative radio amateurs here stay on HF and all its
narrowband limitations.

Now, it MIGHT be that FHSS could be adapted to HF, even if only
to 10m with that band's 1.7 MHz total bandwidth. That is uncertain
since it absolutely requires a higher-accuracy timebase than is
found in most upscale HF+ transceivers. [think timing update
and correction via GPS] It will NOT be "tunable" like the older
analog modes, at least that I can envision. Neither will it cause
much interference to those legacy-mode users already there.
However, it does have a potential of getting more users in the
same bandwidth for higher throughput than is possible with analog
modes.

Many, many things are possible, even the digital voice and music
on HF now being used for BC purposes. But, that's a niche thing
and only proves the mode is practical and viable. On the other
hand, there's some "comfort" in staying "establishment," of not
having to spend time finding out how those new-fangled things
work; i.e., survivalist conservatism. :-)

73, Len AF6AY

On Sun, 18 Mar 2007 18:02:45 CST, "
wrote:

Mike, you've seen enough other licensed radio amateurs by now to
understand that, technically, they are rather conservative in
adopting "new" things. My own opinion is 'uber-conservative' but
that is just personal. :-)

Some of it is just economic. I'll be damned if I'm going to buy an
$800 ICOM D-Star VHF/UHF digital radio that operationally doesn't give
me any more than my existing VHF and UHF ICOM "rice boxes".

Especially since I just invested $2K in an Elecraft K2/100 HF rig with
all the bells and whistles.
--

73 de K2ASP - Phil Kane

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

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