"K4KYV wrote:
I can see the rationale of reserving some space for narrow-band modes like
CW and PSK-31, to protect against interference from wideband sources such as
analog voice. But if there is to be a segment defined at 3 kHz, what is the
point of creating two segments, one to exclude voice and another to exclude
RTTY-like digital modes? Interference-wise isn't a 3-khz wide signal a
3-khz wide signal regardless? Would digital radiotelephony be considered
voice or non-voice? Isn't this adding unnecessary complication to a subband
structure that is already more complex than what exists anywhere else in the
world, especially after licence class segmentation is factored in?"
The consideration is to remember that the proposed subbands are to include
digital modes UP TO 3 KHz. These subbands would include modes that typically
use
500 Hz and 2.7KHz. The 200 Hz limit would be reserved for the CW mode and some
data modes like PSK31.
Separation of digital from traditional analog modes as the separation from
narrow/wide
band modes, which has been in place for decades, is its own example and
precedent.
As described, in part, from the petition:
ARRL was guided by advice from an Ad Hoc Digital Committee formed to advise
on issues that arise from the development of new high-frequency digital data
modes of operation. In summary, the recommendations of that Committee were to
delete the symbol rate limitations in Sections 97.307(f)(3) and (4); to segment
the bands below 28.0 MHz by nominal bandwidths of 200, 500 and 2700 Hz as upper
limits; and to require that digital data protocols be published, to facilitate
monitoring. The Committee was aware of the bandwidths and frequency segments
under consideration by Region 1 of the International Amateur Radio Union. The
bandwidth of 200 Hz was chosen to accommodate Morse telegraphy and the
narrowest RTTY/data emissions. A bandwidth of 500 Hz would permit the foregoing
modes and a wide range of RTTY/data modes and some image modes yet to be
designed. IARU Region 1 studies chose a bandwidth of 2700 Hz for SSB telephony
and to accommodate digital voice and higher speed data. The Rules already
specify a bandwidth of 2800 Hz for SSB voice in the 60-meter band. As the issue
is a maximum regulatory bandwidth, not practice, which varies from (say) 2400
to 2800 Hz, a bandwidth of 3000 Hz is recommended.
"K4KYV wrote:
I am concerned about possible unintended consequences of this proposal. For
example, the status of AM phone is supposed to be specifically protected,
but if the League proposal is adopted, instead of being expressly permitted
by language embedded in the rules, AM would be protected by nothing more
than a footnote."
I am also concerned about the unintended consequences, Don. Yes, issues like
license class
segmentation and the AM mode all need to be part of the consideration. The
point is that this
needs to be discussed and commented on by the community so that the ARRL has
the most
intelligent and informed input possible. How they may use that input may be
another matter!
"K4KYV wrote:
I suggest that everyone interested in the future of amateur radio read the
text of the proposal carefully, and try to come up with an informed opinion
and transmit it to the website as requested."
Absolutely!
The idea here is to commence discussion, generate comments and follow the
path of
this petition through the FCC process. It is in everyone's best interest to
participate whether
they support this idea in whole, part or not at all.
But, doing NOTHING is the wrong way to go and I don't think you are
suggesting that. Digital
modes are the future of communications and ham radio. Change is certainly
difficult.
And, I remember back in the late 1950's when SSB started to appear in the AM
bands
and the wars that resulted from that.
73, Jim, K1PX
K1PX@msn.com<mailto:K1PX@msn.com>
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