> 1000 Hz shift and 300 baud symbol rate (old rules) will occupy no
> less than about 1300 Hz bandwidth. You realize that, don't you?
Yes, I realize that but 1300 Hz is still only about 60% of the
bandwidth claimed for PACTOR III and less than the bandwidth of
WINMOR 1600.
> So, 500 Hz definitely does not mesh with the current rules.
500 Hz does not mesh with the maximums *implied by* the current
rules. However, *it does* confirm with the Commission's stated
intent when they established the current rules and the explicit
rule which applies to automatically controlled digital transmissions.
If the ARRL state that their petition *makes no change* to the rules
concerning automatically controlled stations transmitting data emissions
(footnote 11, page 7), it seems entirely proper that the rules should
be codified in such a way as to confirm with both the Commission's
implied intent in Second Report and Order, Docket 20777 on August 11,
1978, Further Notice of Inquiry and Further Notice of Proposed Rule
Making as well as the *clear standard* in 97.211. That would be a
blanket 500 Hz limit on those frequencies below 30 MHz where F1 is
currently permitted.
Even ARRL makes the case of a 500 Hz limit in footnote 11 where they
state, "The bandwidth limitation, and the subband limitation for
automatically controlled stations at HF are both necessary in order to
preclude a plethora of automatically controlled stations usurping the
limited spectrum available." That argument can easily be expanded to
substitute "wide band stations" for "automatically controlled stations"
as the impact of a "plethora of wide band stations" would be identical
to a "plethora of automatically controlled stations."
73,
... Joe, W4TV
On 11/24/2013 10:02 PM, Kok Chen wrote:
On Nov 24, 2013, at 6:28 PM, Joe Subich, W4TV wrote:
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.
1000 Hz shift and 300 baud symbol rate (old rules) will occupy no less than
about 1300 Hz bandwidth. You realize that, don't you?
By judicious waveshaping, we can probably get down to 1200 Hz bandwidth, but
there is no way to get it an FSK bandwidth to be below the shift itself --
1000 Hz.
So, 500 Hz definitely does not mesh with the current rules.
73
Chen, W7AY
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