[RTTY] Hints and tips on how to file comments on RM-11708

[Dave AA6YQ]

A stronger argument is that no increase in bandwidth should be permitted until the issue of  QRM from automatic stations has been
resolved. Though WinMor servers include busy frequency detectors, WinLink servers still do not include busy frequency detectors, and
are now ignoring 97.221's sub-band requirements. Enabling WinLink servers to use wider bandwidth modes outside the 97.221 sub-bands
would result in large increases in QRM to ongoing QSOS. 

        73,

                Dave, AA6YQ

-----Original Message-----
From: RTTY [mailto:rtty-bounces at contesting.com] On Behalf Of Kai
Sent: Sunday, November 24, 2013 10:27 PM
To: rtty at contesting.com
Subject: Re: [RTTY] Hints and tips on how to file comments on RM-11708

Joe
Let's be careful about associating PACTOR with "inefficient modes".
My VERY PRELIMIARY assessment is that PACTOR-III  in its lowest
data rate of about 76 user bps  may outperform "Steam-RTTY" by as
much as 7 dB, while the highest data rate may be 6 dB worse than
Steam-RTTY,  but delivers 2722 bps compared with roughly 30 user
bps for RTTY.

I don't think we'll win by making "inefficient mode" arguments.
I also think we'll eventually lose with no BW cap.

Our best hope is to cap BW at 2200 Hz.

73
Kai, KE4PT


On 11/24/2013 9:28 PM, Joe Subich, W4TV wrote:
>
> If it is 2.4 KHz wide, it can not be legal ... how can one square
> 2.4 KHz occupied bandwidth with a rule that states a combined
> criteria of 1000 Hz and 300 baud which works our to 1500 Hz?
>
> This is *exactly* the reason that comments need to stress a 500 Hz
> bandwidth limit for all "RTTY, data" emissions in the spectrum
> covered by 97.307(f)(3) and 97.307(f)(4) to be consistent with
> "traditional radiotelepinter bandwidths" as the Commission held
> in "Further Notice of Proposed Rule Making, 43 Fed. Reg 36984".
>
> The Commission believed that a 1000 Hz shift and 300 baud symbol
> rate would assure emissions consistent with "traditional radio-
> teleprinter bandwidths" would provide for bandwidths consistent
> with then standard operating practice.  Unfortunately, there was
> at that time no use of composite FSK/PSK systems, multi-tone
> systems, etc. and their use has exploited a regulatory loophole
> *that needs to be closed* lest these wide bandwidth and inefficient
> modes cause irreparable harm to traditional narrow bandwidth modes
> which are limited to frequencies where F1 emissions are authorized.
>
>
> 73,
>
>    ... Joe, W4TV
>
>
> On 11/24/2013 9:01 PM, Kok Chen wrote:
>>
>> On Nov 24, 2013, at 5:02 PM, Joe Subich, W4TV wrote:
>>
>>> PACTOR III is *NOT* currently permitted under the rules.  Its use has
>>> been *overlooked* by enforcement organizations as it *absolutely* can
>>> not be justified under the *dual standard* in 97.307(f)(3) which has
>>> both 300 baud and 1000 Hz shift limits.
>>
>> That is not true Joe... please don't make that mistake in your FCC filing.
>>
>> At all SL levels, Pactor III's symbol rate is fixed at 100 baud (yes, not 
>> even close to 300 baud).  (Don't confuse Symbol Rate (baud rate) with data 
>> rate (bit rate)).
>>
>> Pactor III is not 2 tone FSK, so the FSK shift rule does not even apply 
>> (makes no technical sense since there is no frequency shift happening).
>>
>> Pactor 3 SL1 (the slowest rate) consists of two synchronous PSK signals (not 
>> FSK), that are separated by 840 Hz.  840 Hz is the maximum tone separation 
>> for Pactor 3 (if you want to apply the term "shift" to the signal).  As more 
>> tones are added (SL2, SL3, etc), the tone separations become narrow, and at 
>> the narrowest, there are 18 tones, separated by 120 Hz from one another.
>>
>> Pactor 3 SL1, 2 and 3 uses binary PSK, and Pactor 3 SL4, 5, 6 uses Quadrature 
>> PSK.
>>
>> It is much clearer if you go take a look with a panadapter or a waterfall, or 
>> if you can, in I/Q phase space.
>>
>> Pactor 3 SL1 looks like two broad indistinct tones that are 840 Hz from one 
>> another, with a distinctive gap in between them.  It is quite unmistakable 
>> once you see it on the waterfall.
>>
>> 73
>> Chen, W7AY
>>
>>
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