jgorman01 wrote: > I didn't say it was "J" and you didn't answer the questions. What > frequency would it be tuned to, i.e. the main carrier and is it > considered SSB? It could be SSB, DSB, FM, etc. > > Jim WA0LYK
OK, I did not mean you said it is Jxx, and I am glad you did not. > --- In [email protected], "Jose A. Amador" <[EMAIL PROTECTED]> > wrote: > > > jgorman01 wrote: > > > >> Need to know some more info. > >> > >> Is it SSB? No, it is not SSB. It is the baseband modulation, a spectrum chunk, frequency shifted. Where is the main carrier located (suppressed or not)? There is no main carrier in such multitone modulations. You might define a certain heterodyne frequency, like in satellite transponders, which you should tune in your radio to shift the RF spectrum into your demodulator input band. There is not (or should not be) any emission detectable at all in that frequency. Does anyone remember the old telephone long distance FDM multiplex equipment principles and how groups and supergroups were formed and channels recovered? The same applies here. > >> Jim WA0LYK > >> > >> --- In [email protected], Mark Miller <markm@> wrote: > >> > >>> Lets look into the future. What would be the emissions > >>> designator for MT63 or PACTOR III if the DSP and D/A converter > >>> that I was using output something in the 20 meter frequency > >>> range, no SSB transmitter at all? > >> > >>>> Given that all of the power in an OFDM signal is in the data > > subcarriers > > >>>> (and in one sideband) with the RF carrier is suppressed, it > >>>> sure > > > > sounds like > > > >>>> J2 to me. My understanding is that Jxx should only apply to ANALOG signals, i.e., audio. Otherwise, the J designator obscures the designation, because it does not truly reflect what you run into in the RF spectrum. A SSB transmitter is a frequency shifter, a transponder that does not modify the signal it is fed, (excepting the unavoidable distortion that real devices introduce) other than doing a frequency translation, like an audio to RF transponder. And since it does not modify the spectrum chunk it is fed, the baseband modulation designator, whatever it may be, still applies. Jose, CO2JA __________________________________________ XIII Convención Científica de Ingeniería y Arquitectura 28/noviembre al 1/diciembre de 2006 Cujae, Ciudad de la Habana, Cuba http://www.cujae.edu.cu/eventos/convencion
