> Our best hope is to cap BW at 2200 Hz.
I still believe our best hope is to show the Commission that
PACTOR III and WINMOR 1600 are not consistent with the clear
intent of the Commission to maintain "traditional radioteleprinter
bandwidth" in 1978 and are certainly contrary to the explicit
requirements of 97.221 *even though a substantial number of*
*automatically controlled stations are using those modes*.
The Commission should not and must not reward the lawbreakers
by now making those modes "legal" under the guise of "not taking
away current privileges."
There is no objective study that would prove the additional data
throughput is necessary for either routine or emergency amateur
communications. In fact after action reports of large scale
disaster responses regularly show that such HF capability was not
used - the short range large scale transfers were conducted at VHF
while the long range transfers were conducted via the internet.
The additional *HF* throughput only benefits those who would abuse
amateur allocations for large scale file transfers consistent with
the transfer of commercial scale data in lieu of using commercial
networks/data providers.
73,
... Joe, W4TV
On 11/24/2013 10:26 PM, Kai wrote:
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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