[GreenKeys] FCC substitutes bandwidth limit for baud rate limit on HF

[Harold Hallikainen]

They are substituting a bandwidth limit of 2.8 kHz for the previous baud
rate limit of 300 baud.

https://docs.fcc.gov/public/attachments/FCC-23-93A1.pdf

Looking at the new 97.307...

§ 97.307 Emission standards.
* * * * *
(f) * * *
(3) Only a RTTY or data emission using a specified digital code listed in
§ 97.309(a) may be transmitted. The authorized bandwidth is 2.8 kHz except
in the 2200 m band and 630 m band. In the 2200 m band and the 630 m band
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.

It looks like the 1 kHz shift limit is ONLY for the 2200 meter and 630
meter bands. So, can we run 2 kHz shift to get around selective fading?

Further, the wording of that section appears to limit baud rate or shift,
but not both for those bands. Since those bands are quite narrow (135.7 to
137.8 kHz and 472 kHz to 479 kHz), it's difficult to run very wide shift
or  high baud rate.

Harold
https://w6iwi.org