| |
VE2HAR > MT63 10.03.05 07:35l 267 Lines 7859 Bytes #-7497 (0) @ WW
BID : 23394SENTTO
Read: GUEST
Subj: [MT63] Re: 20 kHz wide Digital Proposal
Path: DB0FHN<DB0THA<DB0ERF<DB0FBB<DB0IUZ<DB0PRA<DB0LJ<DB0RES<DK0WUE<7M3TJZ<
IW8PGT<TU5EX<F6GGY<VE2HAR<VA2HAR<VE2HAR
Sent: 050310/0522z @:VE2HAR.#MTL.QC.CAN.NOAM Laval #:40956 $:23394sentto
Brian:
As you are cross posting my non-yahoo group messages here (I
am "blathering Jeff" I'll address some of your specific questions. My
response to that message, which didn't make it to this list, you do
with it as you will.
--- In MT63@yahoogroups.com, "Brian Carling" <bcarling@c...> wrote:
> OK fascinating Walt, but do explain to me WHY it is that we need
> to send so much high speed data on HF?
Just like your income, more is better, which is not to say, you
shouldn't economize. Are you still happy with your 2400 bps phone
modem? Believe it or not (and I am dating myself here) my amateur
radio connection to the internet, was faster then my phone dialup at
one point. Amateur radio CAN be that shining star on that hill, if we
just let it. Yes, it is a quaint old hobby for old men, it always
will be, but it can push the limits. We just have to let it. We can
have our cake and eat it too.
> Wouldn't VHF and satellites do a lot better without ruining things
for
> the regular CW and phone operators who need their space?
Or we could all get on the internet, and that way the SWL's would
have a nice quiet band. The point is to utilize the bands, to gain
experince with them, to advance the state of the art, and ultimately
to have a useful service in times of need.
> By the way the MT63 signals are 1 kHz wide.
Last time I looked, they also had a 500hz and 2khz mode.
> We don't need to keep making wider and wider digital signals
> and if the digital audio needs to be 20 kHz wide, what is the point?
Mostly for coding gain. That is why when the Pactor PBBS fires up on
14.109.5, I often could continue to copy MT63 signals even though the
pactor 3 station was much stronger. Also, as you earlier alluded to,
it is not a all or nothing arrangement. With TDMA, multiple stations
can share the same channel, and with different chip codes (wider
modes begin to look like spread spectrum) users can actually
simulatanously share the channel (CDMA overlay).
> Why do hams need to transmit multiple channels of audio all at
> once? For an English and Spanish simulcast? :- )
And what good is a baby? Point being, we are in a world that is in a
digital convergence, and amateur radio should follow suite. I can't
say there wouldn't be conflict (there sure is now with the P3
stations) but the proper means to address it is not to throw the baby
out, but teach the baby how to properly co-exist. We will all be
better off for it.
I don't see the problem with the proposal, and am really suprised it
is getting the negative play on the MT63 reflector.
73
Jeff wb8wka
>
> You wrote:
>
> > Brian,
> >
> > Well yes and no. What the HSMM is suggesting is that you allow
up to
> > 20 KHz signals. But we're taking about 56KBPs throughput that
would
> > allow one or more voice channels actually multi-mode all on one
> > signal.
> >
> > You might see 56KBPs data but it would only be on-the-air for a
short
> > time. The "channel" would be shared.
> >
> > Right now we have MT63 at 200 WPM thoughput on a 2 KHz wide
bandpass
> > at a -5 dB SNR on a poor CCIR channel. But we really need to push
> > 800-1200 WPM at the same signal level. I don't see doing that
with
> > less than a 6 KHz channel even exploiting some of the new OFDM
type
> > modulation protocols being developed.
> >
> > How many CW QSOs running at 20 WPM will it take to produce 1200
WPM
> > error free copy at a signal level that MT63 can copy? These are
> > signal levels that even the best CW operator can't copy a signal
at.
> > So the answer is that NO number of CW QSOs can produce the
throughput
> > of 1200 BPS, near error free, at a -5 dB SNR on a poor CCIR
channel.
> >
> > All this IS possible if we are willing to step out of the box.
> >
> > AND the new modes that will develop will be FAR SUPERIOR to
Pactor III
> > or anything being done today on HF.
> >
> > We're also looking at doing much of this work using a computer
sound
> > card so separate controller hardware is not needed.
> >
> > 73,
> >
> > Walt DuBose/K5YFW
> > Asst Chairman
> > ARRL HSMM WG
> >
> >
> > Quoting Brian Carling <bcarling@c...>:
> > >
> > > On 8 Mar 2005 at 19:11, David J. Ring, Jr. wrote:
> > >
> > > > I don't think the digital signals they want are 20 kHz wide!
> > >
> > > Want to bet on that?
> > >
> > > There IS in fact a proposal out now for a digiotal mode that IS
20
> > > kHz wide for high speed data transefer on HF ham bands. (as if
> > > Cra... er, I mean Pactor is not jamming the HF bands enough
> > > already!)
> > >
> > > Here it is:
> > >
> > > On Janauary 19, 2005, John Champa, K8OCL,ARRL Chairman, High
Speed
> > > Multimedia Networks Working Group, issued the Technology Task
Force
> > > report to the ARRL Board of Directors, which includes the
following:
> > >
> > > "At a minimum, 20 kHz wide emissions should be allowed in the
> > > following segments:
> > >
> > > 3.58 - 3.725 MHz
> > > 7.035 - 7.125 MHz
> > > 14.065 - 14.15 MHz
> > > 21.08 - 21.2 MHz
> > > 29 - 29.7 MHz"
> > >
> > > Obviously, a *single* HSMM transmission, 20 KHz wide, could
> > > totally wipe out all PSK31, MFSK16, RTTY, and many CW and DX
> > > operations on 80m, 40m, and 20m, where they are now used
> > > worldwide. Dozens of CW QSOS could be obliterated within
> > > one 20 kHz swath. NOT a good idea at all!
> > >
> > > We have never seen such a lack of concern and compassion for the
> > > majority of radio amateur activities as evidenced by the ARRL
> > > Committee on HSMM and ARRL support for Winlink's attempted
> > > domination of the HF frequencies, in both cases, to sacrifice
the
> > > hobby on HF for everyone else in order to favor a very small
special
> > > interest group.
> > >
> > > I can only hope that they really are coming to their senses at
the
> > > top level of leadership, but this is cause for alarm. JIm Haynie
> > > says that they are going to have a new band plan by July. I
hope it
> > > is a workable one that averyone can live with. The
Winlink/Pactor
> > > mess will hopefully get reined in by this.
> > >
> > > OK back to some fun CW contacts now, and a little less
grumbling!
> > >
> > > 73 de AF4K
> > >
> > >
> > >
> > >
> > > << Try MT63 on 80m - great fun!>>
> > >
> > > - The MT63 Reflector -
> > > MT63@egroups.com
> > >
> > > (To unsubscribe. send email to
> > > MT63-unsubscribe@onelist.com)
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
> >
> >
> >
> >
> >
> > ------------------------ Yahoo! Groups Sponsor
> > --------------------~--> Over 1 billion served! The most music
videos
> > on the web. Click to Watch now!
> > http://us.click.yahoo.com/xmKGzA/IARHAA/kkyPAA/CPMolB/TM
> > ------------------------------------------------------------------
--~-
> > >
> >
> > << Try MT63 on 80m - great fun!>>
> >
> > - The MT63 Reflector -
> > MT63@egroups.com
> >
> > (To unsubscribe. send email to
> > MT63-unsubscribe@onelist.com)
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
------------------------ Yahoo! Groups Sponsor --------------------~-->
Listen to Internet Radio! Access to your favorite Artists!
Click to listen to LAUNCHcast now!
http://us.click.yahoo.com/_mKGzA/GARHAA/kkyPAA/CPMolB/TM
--------------------------------------------------------------------~->
<< Try MT63 on 80m - great fun!>>
- The MT63 Reflector -
MT63@egroups.com
(To unsubscribe. send email to
MT63-unsubscribe@onelist.com)
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/MT63/
<*> To unsubscribe from this group, send an email to:
MT63-unsubscribe@yahoogroups.com
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
Read previous mail | Read next mail
| |
