[RTTY] [MMTTY] Re: Wideband Digital (was: BoD votes LoTW initiatives)

Wed Jul 24 14:26:28 EDT 2013

> So, today, the current rules already permit digital signals as wide
> as (1.2*300 + 1000) = 1360 Hz. (It works out to 2400 Hz in the 10 m
> band today).

your constant of 1.2 is not accurate for all modulations/protocols but
it is useful for discussion.

In any case, 1360 Hz is *already* too wide for reasonable sharing with
modes like traditional RTTY, PSK31, JT65, JT9, and even the narrow
versions of MFSK, OLIVIA, etc. - particularly when that 1360 Hz "mask"
is employed by an automatically controlled station answering a locally
controlled station.  Just a single 1360 KHz "noise" will wipe out the
entire JT9 activity center, 65% of the JT65 activity, 65% of the
PSK31/63 activity, etc. and wipe out an entire RTTY pile-up.

Not only will an automatic responder wipe out a significant amount of
other activity, it will persist in doing so until it "gets *its*
message through or it times out sine there is no "listen before
transmitting" protocol and no intelligent monitoring.  This makes
2.8 KHz wide "data" exponentially more damaging than any *reasonable*
bandwidth data mode.

If 2.8 KHz wide data is to be permitted, it should be placed with
other wide band modes (e.g. the "phone" bands) or restricted to
narrow segments of the spectrum (e.g., 7110-7125, 14,125-14,150,
21,150-21,175 and 28,200-28,300) where the wide band data mask will
not cause harmful interference to users of narrow band modes and
emissions.   2.8 KHz data certainly has *no place* on 80, 30, 17
and 12 meters where spectrum for narrow band modes is already
"fully utilized" - perhaps over utilized.

Activities like WinLink and other wideband, semiautomatic modes can
be accommodated without the right to run roughshod over narrow band
users.

73,

    ... Joe, W4TV

On 7/24/2013 1:59 PM, Kai wrote:
> Joe
> I agree that the 2800 Hz BW now on the table is way too much, except for
> the
> 60 m band channels for which that specific 2800 Hz  rule was written.
>
> The current FCC rules for below 10m  band  (except 60m) already allow
> modulations with as much as 1360 Hz bandwidth, but they restrict those
> digital formats to very specific baud rates (up to 300 baud) and
> specific shifts
> (up to 1 kHz), and specific code formats.  So, today, the current rules
> already
> permit digital signals as wide as (1.2*300 + 1000) = 1360 Hz. (It works
> out to
> 2400 Hz in the 10 m band today).
>
> I think that getting rid of the baud rate restriction is a good idea,
> but allowing
> up to 2.8 kHz bandwidth is not so good (except for the channelized 60 m
> band
> as is currently permitted).
>
> In summary, getting rid of the baud rate restrictions is a good idea, but
> in my opinion permitting BW to extend beyond what is currently permitted
> (around 1360 Hz or so) is not a good idea.
>
> We have at least two opportunities to supply inputs:
> (1) let the ARRL know now how you feel and why, and
> (2) comment to the FCC on any NPRM which might result from this.
>
> 73
> Kai, KE4PT
>
>
>
> On 7/24/2013 12:50 PM, Joe Subich, W4TV wrote:
>>
>> "Compatible with CW" was for emphasis - I strongly urge all users of
>> RTTY, JT65/JT9, PSK31/63/125, etc. to write their Directors and demand
>> that any proposal to the FCC (1) specify a bandwidth less than 300 Hz
>> and (2) prohibit unattended operation *of all types* unless *both*
>> stations contain hardware/software to inhibit transmission if there is
>> *any other signal* in the passband of the transmission plus a guard
>> band equal to 25% of the bandwidth of the signal to be transmitted.
>>
>> 73,
>>
>>    ... Joe, W4TV
>>
>>
>> On 7/24/2013 10:00 AM, Kai wrote:
>>> Why would you want to ban 45.45 baud 170 Hz shift RTTY by suggesting
>>> a "100 Hz
>>> or less" bandwidth rule??
>>> The occupied bandwidth [ITU-R and FCC definitions] of RTTY is 250 Hz,
>>> greater
>>> than that of JT65. Even CW at  more than 30 wpm occupies more than
>>> 100 Hz.
>>> 73,
>>> Kai, KE4PT
>>>
>>> On 7/23/2013 10:50 PM, Joe Subich, W4TV wrote:
>>>>> Symbol Rate Rule Modernization
>>>>>
>>>>> On the motion of ARRL West Gulf Division Director Dr David
>>>>> Woolweaver, K5RAV, on behalf of the Ad Hoc Symbol Rate Rule
>>>>> Modernization Committee,
>>>> the Board directed ARRL General Counsel Chris Imlay, W3KD, to prepare a
>>>> Petition for Rule Making with the FCC seeking to modify Â§97.307(f) to
>>>> delete all references to symbol rate. The Petition would ask the
>>>> FCC Â“to
>>>> apply to all amateur data emissions below 29.7 MHz the existing
>>>> bandwidth limit, per Â§97.303(h), of 2.8 kHz.Â”
>>>>> The committee determined that the current symbol rate restrictions
>>>>> in
>>>> Â§97.307(f) Â“no longer reflect the state of the art of digital
>>>> telecommunications technology,Â” and that the proposed rule change
>>>> would
>>>> Â“encourage both flexibility and efficiency in the employment of
>>>> digital
>>>> emissions by amateur stations.Â” The Ad Hoc Symbol Rate Rule
>>>> Modernization Committee was dissolved with the thanks of the Board.
>>>>
>>>> Save us from a Board of Directors that would not know Digital Operation
>>>> if it bit them on the ass.  All we need is a bunch of 2.8 KHz wide
>>>> chunks of "white noise" across the entire "non-voice" spectrum.  If
>>>> they want to remove the symbol rate, the bandwidth better be compatible
>>>> with that of CW (100 Hz or less) in the majority of the shared
>>>> non-voice
>>>> spectrum.
>>>>
>>>> As usual, the ARRL BOD has proven how little they know about amateur
>>>> operation!
>>>>
>>>> 73,
>>>>
>>>>        ... Joe, W4TV
>>>>
>>>>
>>>> On 7/23/2013 4:06 PM, Radio K0HB wrote:
>>>>> http://www.arrl.org/news/arrl-board-names-award-winners-okays-lotw-initiatives
>>>>>
>>>>>
>>>>> 73, de Hans, K0HB
>>>>> --
>>>>> "Just a boy and his radio"
>>>>> --
>>>>> Proud Member of:
>>>>> A1 Operators - http://www.arrl.org/a-1-op
>>>>> Minnesota Wireless contesters - http://www.W0AA.org
>>>>> Arizona Outlaws contesters - http://www.arizonaoutlaws.net
>>>>> Twin City DX Assn - http://www.tcdxa.org
>>>>> Lake Vermilion DX Assn - http://www.lvdxa.org
>>>>> SOC - http://www.qsl.net/soc
>>>>> --
>>>>> Superstition trails -->  http://oldslowhans.com/
>>>>> Sea stories here --->  http://k0hb.wordpress.com/
>>>>> Request QSL at --->  http://www.clublog.org/logsearch/K0HB
>>>>> All valid QSL requests honored with old fashioned paper QSL!
>>>>> LoTW participant
>>>>>
>>>>
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>>>
>>>
>>> [Non-text portions of this message have been removed]
>>>
>>>
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>