Just for the records,
If you won't follow the arguments of those 'experts' - you are also welcome to
file a comment that you are perfectly fine with the proposal from our league.
There're always naysayers but SSB was not the end of ham radio - the Internet
was not the end of ham radio - 2.8kHz bandwidth will not be the end of RTTY.
It will just open the door to experiment and develop new modes - this is ham
radio.
And the co-existance has been proven in the rest of the ham world where this
is allowed since many years.
Stan
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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