John,
Given sufficient carrier suppression, any tone inputed to the microphone
makes the transmitter output a pure RF carrier at a frequency of the
suppressed carrier frequency plus the tone frequency for USB, or minus
the tone frequency for LSB. Whatever you do with the tones determines
what RF carriers come out. You can key the tones, or shift the tone
frequencies, etc., and the RF output will follow. The ARRL Handbook
usually has an explanation of this.
Hope that answers the question.
73 - Skip KH6TY
John wrote:
So as to not continue growing the ROS legality discussion even
further, I would like to ask a fairly simple question.
How will the modulation be determined from any SSB transmitter when
the source of the modulation is via the microphone audio input of that
transmitter?
Simply stated, how would any digital mode create anything other than
some form of FSK simply by inputting a tone at the microphone input?
Regardless of the software being used to generate the tone(s), at any
given time there is nothing more than the absence or presence of a
tone at the audio input of the transmitter. This is true of HRD's
DM780, MixW modes, MMSSTV, or many other sound card driven software
packages. They all have one thing in common, they generate a sequence
of tones which is then processed by the very same transmitter in the
very same way. The maximum output bandwidth is supposed to be somewhat
limited in the bandpass of the transmitter circuitry (which is NOT
being altered). Again, NO transmitter circuitry is being altered in
any way that I am aware of.
With this discussion, how do we arbitrarily change the transmitter
output definitions? I am truly asking because that is a concept beyond
my feeble mind. I really do not know. To me, regardless of the
"source" of the modulation itself, the modulation still remains an
offset of the carrier frequency by the frequency of the input tone.
To me, the discussion of particular FCC designators for any of these
modes is rather moot, unless there is some method to tie the two
together. To simply start an argument about a particular FCC rule,
without showing the correlation to the subject is somewhat like
arguing the color of orange peels in an apple pie instruction sheet.
They simply don't necessarily relate. Both may have valid points about
their own arguments, but the tow simply do not go together.
Am I missing something besides a few marbles now? My head is spinning
from all these rules being bandied about, that may have no application
here at all.
John
KE5HAM
