Thanks, Bonnie.
According to the formulae presented in table 2 on page 49 of the document you
cite below, binary (2-tone) FSK with a maximum shift of 1 kHz and a maximum
symbol rate of 300 baud would require a maximum bandwidth of 2011 hz. for any
practical modulation index (i.e. less than 20).
§97.307(f)(3) says "Only a RTTY or data emission using a specified digital code
listed in §97.309(a) of this Part may be transmitted. The symbol rate must not
exceed 300 bauds, or for frequency-shift keying, the frequency shift between
mark and space must not exceed 1 kHz."
While §97.307(f)(3) does not directly specify a maximum bandwidth, a maximum
bandwidth for 2-tone FSK can be computed from the parameters that §97.307(f)(3)
does specify: specifically, 2011 hz.
Thus the statement "There is unquestionably a bandwidth restriction on HF for
frequency-shift keying, though there could be debate about what mark and space
mean for FSK modes with more than 2 tones" is in fact correct.
It would be logical to assume that for n-tone FSK, "mark" and "space" refer to
the highest and lowest tones of the ensemble respectively, meaning that that
maximum bandwidth for n-tone FSK with a maximum shift of 1 kHz and a maximum
symbol rate of 300 baud would also be 2011 hz -- but this is speculative until
ruled upon.
73,
Dave, AA6YQ
--- In digitalradio@yahoogroups.com, "expeditionradio" <expeditionra...@...>
wrote:
>
> > Dave AA6YQ wrote:
> > Please identify the significant factors...
>
> Hi Dave,
>
> Some of the answers you seek are in a previous
> message:
> http://groups.yahoo.com/group/digitalradio/message/30581
>
> I will leave the rest up to you to determine.
>
> 73 Bonnie KQ6XA
>
