Currently, and applying broadly to the FCC term "RTTY", 97.307(f) - "The
symbol rate must not exceed 300 bauds, or for frequency-shift keying, the
frequency shift between mark and space must not exceed 1 kHz. "
That means two-tone FSK RTTY at up to 300 baud and up to 1000 Hz shift is
permitted, and has a bandwidth of 1500 Hz* (not 500 Hz). Digital emissions that
do are not subject to the "or for frequency-shift keying, the frequency shift
between mark and space must not exceed 1 kHz" restriction of 97.307(f) are
subject ONLY to the 300 baud restriction (there are several ham digital
non-voice modulations in use with up to about 2400 Hz BW today: G-TOR, PacTor,
Clover are specifically listed by the FCC; there are more). If one choses to,
and has a good reason to, one could legally occupy, as I stated, in the 100's of
kHz.
So many of us see and understand that the technology has outpaced the out dated
97.307(f), since it restricts the bandwidth of two-tone FSK RTTY ONLY, and not
any other digital modulation. But the 300 baud limit can render many other
digital modulations very spectrum inefficient (but not illegal) without limiting
their bandwidth.
RM 11708 seeks to replace that 97.307(f) phrase with "The authorized bandwidth
is 2.8 kHz."
*See US CFR 2.202 for bandwidth calculation of two tone FSK RTTY: BW =
BaudRate + 1.2Shift = 300+1.2(1000) = 1500 Hz.
-Kai, KE4PT
On 2/27/2014 11:25 AM, Joe Subich, W4TV wrote:
Were we to see some lid or lids fire up with 300 KHz wide signals on
10 meters - or 200 KHz wide signals on 160 meters - ARRL and the FCC
would quickly scramble to impose a bandwidth limit. 2.8 KHz in the
spectrum traditionally reserved for bandwidths 500 Hz and less is just
as bad as 200 or 300 KHz- as the punch line of the old joke goes:
"Young Lady, we have already determined what you are - now we're only
haggling over price."
And before you try to argue again that 500 Hz is not the de facto
standard, read *the Commission's *own words* at footnote 89, page 12 of
http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-06-149A1.pdf in
which they forcefully *rejected* ARRL's request that *image* modes not
be restricted to 500 Hz bandwidth in the "data" allocations. Note:
even *analog* image modes are permitted in the "data" allocations as
long as their bandwidth is less that 500 Hz.
As far back as 2006 the Commission made it absolutely clear to ARRL
what they would accept and what they would not accept. ARRL's Board of
Directors, CEO and Counsel are quite simply incompetent and dishonest
in their handling of this matter. Had they simply requested that RTTY
and Data modes as defined in 97.3(c)(7) and 97.3(c)(2) be added to the
emission types where voice and image emission re already permitted and
the 500 Hz limit currently in 97.3(2)(2) be extended to all data modes
below 30 MHz where voice and image are *not* currently permitted, this
matter would be completely non-controversial. The rules currently limit
non-voice modes to 2.8 KHz (single channel) or 6 KHz (multiplexed) in
the "voice/image" segments - there would be no need to impose a special
limitation.
The Commission would have gladly made the *minor* changes - which would
prevent the doomsday scenario both you and the ARRL are using to panic
amateurs to support a *bad* proposal which will ultimately destroy narrow band
modes. If you don't believe that allowing 2.8 KHz data will
destroy the narrow band modes, just wait and see how quickly ALE, STANAG
and other 2.8 KHz "data" modes carrying primarily digital voice start to
pour into the "data allocations" once wideband modes are "blessed" by
this proposal - their advocates are salivating on the sidelines right
now.
73,
... Joe, W4TV
On 2/27/2014 10:53 AM, Kai wrote:
Ron,
Answer:
Wide bandwidths are not prohibited under today's rules. Bandwidths of up
to 200 kHz depending on the MF-HF ham band (300 kHz at 10m band) are
*permitted* today in the digital sections of our bands. Under RM-11708
there would be a limit of 2.8 kHz, a massive DECREASE in the allowed BW
for Data/Digital modes.
Band plans like we have already, and courteous operation (like most of
the RTTY community) are very good ideas.
73
Kai, KE4PT
On 2/27/2014 1:53 AM, Ron Kolarik wrote:
Yup, trust us. This is what one question/answer should look like
Q. Did ARRL evaluate the potential for interference to RTTY, CW and
narrow bandwidth data modes that could result from an increase in
wider-bandwidth data stations? A. Yes. we asked K5RAV and the rest of
the ad hoc digital committee and they thought it was
okey dokey fine. We'll put a bandplan in after we get enough
complaints, we want a bandplan not regulation, it's easier to ignore a
bandplan if no one can identify a station or content and
no pesky regulations that carry the weight of law.
The rest isn't much better and the cynic in me says I should provide
new answers
to all the questions and send them to Sumner but he has a history of
ignoring input.
Ron K0IDT
----- Original Message ----- From: "Mark" <n2qt@yahoo.com>
To: "Ron Kolarik" <rkolarik@neb.rr.com>
Cc: "RTTY" <rtty@contesting.com>
Sent: Wednesday, February 26, 2014 10:53 AM
Subject: Re: [RTTY] RM-11708 FAQ posted
Basically, a "trust us". And if it goes all wrong, well something can
be done eventually...
Mark. N2QT
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