--- In digitalradio@yahoogroups.com, "Dave AA6YQ" <aa...@...> wrote: > > Thanks. > > To repeat my first question, "What's the bandwidth of an FSK signal whose > shift is 1 kHz and whose symbol rate is limited to a maximum of 300 baud? > Feel free to parametize as necessary." > Using the approximation I just posted, treat it as a pair of on-off keyed carriers 1 KHz apart. For 300 baud the dot-cycle frequency is 150 Hz, the frequency of a square wave made up of 1010101010... So you're going to have the first pair of sidebands at 150 Hz each side of the carrier, or a total width of 1300 Hz, with a big hole in the middle. Then depending on signal shaping you'll have the higher-order sidebands in there, the third harmonic at 450 Hz each side of the carrier for a total width of 1900 Hz. With random signals rather than the square wave the general shape of the spectrum will be filled in under the shape of the square wave signal.
Or you can answer the question experimentally by generating such a signal with your radio and looking at the waterfall or spectrum display. Jim W6JVE
