One question for you, how do you tell if a P2-4 station(s) operating
outside the auto sub bands
is P2P, from a non-domestic source or yet another illegal mailbox? The
reason you don't see
a lot of the MTxx modes could be because the masses don't see them as a
useful conversational
mode even though they have advantages.
Ron K0IDT
On 8/17/2016 9:01 AM, Michael Adams wrote:
I think that part of the discrepancy of opinion when it comes to the pros and
cons of the NPRM is a difference in outlooks.
Setting aside the not-insignificant problem of Winlink operators carelessly
keying without listening for non-Winmor/Pactor signals and how that muddies up
the question of the efficacy of LBT logic on the automated stations' side, I
see the problem of having neither symbol rate nor bandwidth limitations as
primarily a long-term one.
Today, most of the demand for wideband text transmissions (remember that images
are restricted to the phone/image subbands) is in automated usage. It doesn't
make sense to go wider today given that non-automated signals are primarily
keyboard-to-keyboard communications. If there were demand for a lot of
non-automated text file transmissions today, we'd see a lot more MT63-1000 and
-2000 on the bands; they're legal all the way down to the bottom of the bands,
and I don't recall seeing complaints suggesting that there is a problem with
such transmissions.
My predictions follow. Please read through before shooting me. :)
Assume the NPRM is incorporated into Part 97 as-is. I believe that in the
short term, the problem of Pactor vs RTTY interference will be reduced.
Winlinkians start using P4, and the total on-air time of their traffic will
decline, assuming no additional traffic.
However, it's probably unreasonable to assume that traffic levels will remain
the same. In the mid-term, there's a decent chance that the increased
capabilities introduced by the legalization of P4 in the US will increase
demand for that system, potentially returning us to the current status quo or a
little worse if/when traffic increases. Worse than the status quo would be
extremely unfortunate on 30m and 80m in particular.
Note, however, that all these changes are occurring within the automated
subbands. In the short-to-mid term, it's hard for me to imagine that there will
suddenly materialize some demand for a lot of non-automated wideband data
transmissions (keeping in mind, again, that image is not allowed in the CW/data
sides of the band). RM-11708 will not yield immediate Armageddon.
Armageddon is a potential long-term outcome. Today most text transmissions on
the band consist of either keyboard-to-keyboard communications (and I'm
including the JT modes in that category, for simplicity) or automated
communications like Winlink...I don't know what the future holds. Given that
part of the FCC's thinking is to facilitate experimentation and allow for
future developments, it seems not unreasonable to wonder if there will be some
future development that gives amateurs a reason to make non-automated wideband
text transmissions. I don't know what that development will be...but a lot can
happen over 1, 2, 3 or more decades.
If there is ever such a development, there will likely be a problem for
narrowband users outside the automated subbands....and I think that possibility
is enough to justify to the FCC that a bandwidth limit be imposed on part of
the CW/data dubbands. In my comments to the FCC, I suggested 500Hz below the
automated frequencies...but your mileage may vary.
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