Thanks Skip, Unfortunately, this really does not get to the crux of my question(s). I understand how an SSB transmitter works, but that is not really what I am after.
What I am driving at is if like this. If I use DM780 to run some version of digital mode via an SSB transceiver, it uses a tone or series of tone modulation/shifting to create the output of the transmitter, and not one single mode is called "spread spectrum" output, but is called FSK or PSK, etc. Now, we get into the aforementioned discussion regarding ROS, and suddenly, still via the microphone input of the same transmitter, those shifted frequencies are now called "spread spectrum" instead. I am having a great deal of difficulty understanding, other than the author happened to call his scheme "spread spectrum" in his technical documentation. Thanks .... John KE5HAM --- In digitalradio@yahoogroups.com, KH6TY <kh...@...> wrote: > > 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 > > > > >
