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Good question...
Several Answers..
1. The
rest of the world can already experiment on HF.. and will do so..whether we
change our regs or not...
2. HF has very
different propagation characteristics that necessitate different DV solutions
than those on VHF and UHF.
3. HF is much
more crowded and not channelized - which will necessitate different DV solutions
than those on VHF/UHF
4. HF DV has
to be able to work in QRM and very low S/N ratios... not usual conditions on
VHF/UHF.
5.
HF space is much smaller... necessitating DV solutions that fit the much smaller
bandwidths...
So while you might be able to design something at
VHF/UHF... you need to be able to test it on HF...and the best way to test it is
for many people to become Beta testers....hence the need to change the
rules....
__________________________________________________________ Howard S.
White Ph.D. P. Eng., VE3GFW/K6 ex-AE6SM KY6LA Website: www.ky6la.com "No Good Deed Goes
Unpunished" "Ham Antennas Save Lives - Katrina, 2003 San Diego Fires,
911"
----- Original Message -----
Sent: Friday, February 03, 2006 2:10
PM
Subject: Re: [digitalradio] Re: ARRL
proposal removes baud rate limitations on HF
Gentlemen,
Like many of the members of this forum, I've
been following this thread with a great deal of interest. Please allow me to
(perhaps playing devil's advocate) ask a simple question. I understand the
propagation and fading issues which are unique to HF, but from an experimental
point of view, why couldn't USA hams do their development of new digital modes
on say UHF? Once the technological hurdles have been cleared on UHF by the
masses of USA hams that apparently aren't even allowed to experiment because
of the repressive government regulations they are burdened with, couldn't the
then proven technology be ported to HF?
Our HF spectrum is extremely
limited, to put it bluntly, hams all over the world are happily using it all
now, that is to say, it's full up. Until we have a digital solution that will
help solve that issue, and allow for more qso's in our little playground, why
can't we experiment on UHF, and not bother displacing the existing HF
activities? Just because we can use more bandwidth on 70cm, doesn't imply that
we have to, just consider one of the design criteria to be a band width
restriction.
As they say, 'Inquiring minds want to
know?"
73,
Erik KI4HMS/7
PS. I'm a no-code tech who has
run Amtor, Pactor, rtty, and cw on both 2m and 440, just because I could run
9.6k packet instead, doesn't mean I have to. I for one would be happy to run
experimental digital modes with other local hams on UHF, I see it as an
underutilized resource, perhaps we can help justify keeping it, if we start
using it to 'contribute to the advancement of the radio art.'
On Feb
3, 2006, at 11:48 AM, Dr. Howard S. White wrote:
JIm:
You
have made a very good case as to why we need to experiment and come up with
new technologies...
Instead
of concentrating on all the potential and imaginary negatives... which very
much reflect the old anti SSB and anti FM arguments...you need to look at
the positives...
There
are a myriad of technologies for squeezing high baud rates into tiny
channels... there are a myriad of new and not so new technologes out there
... such as TDMA, CDMA and Spread
Spectrum...
It's
going to take some clever hams to develop these into a practical DV system
for HF on Ham Radio...
I
believe that the technology is there to allow multiple QRM free multiple
QSO's to share a standard HF voice bandwidth... some ham needs to put it
together... and some ham (likely not in the USA under current baud rate
limited rules) will likely do it..
Equipment..
Anything Hams develop will likely be computer based... maybe even sound card
based as that is the cheapest technology.... and it is likely that you will
still be able to use your HF
transceiver....
New
Modes: Stop being so negative.....Heck... new
modes is what this Reflector is all about... Olivia, Contestia...new
versions of DV...we welcome new modes as they improve things....
I
do not have all the answers.. I just know that there has to be a better
way.....
DV...
has lots of potential to give us more channel capacity with less QRM... we
just need to legal framework in place so that we can experiment with it to
dispell all those imaginary
negatives....
__________________________________________________________
Howard
S. White Ph.D. P. Eng., VE3GFW/K6 ex-AE6SM KY6LA
Website: www.ky6la.com
"No Good Deed Goes
Unpunished"
"Ham Antennas Save Lives - Katrina, 2003 San Diego Fires,
911"
Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org
Other areas of interest:
The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/
DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion)
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