AG35
QST de W1AW  
ARRL Bulletin 35  ARLB035
>From ARRL Headquarters  
Newington CT  December 11, 2023
To all radio amateurs 

SB QST ARL ARLB035
ARLB035 Bandwidth Limits Replace Symbol Rates on the HF Bands, Other
Bands Open for Comment

The Federal Communications Commission (FCC) published new rules
adopted last month that replace the symbol rate restrictions on the
HF bands with a bandwidth limit of 2.8 kHz. The new rules go into
effect January 8, 2024.

Please see
https://www.federalregister.gov/documents/2023/12/07/2023-26770/amateur-radio-service-rules-to-permit-greater-flexibility-in-data-communications
for further details.

The bands and band segments affected by the rules change are those
authorized for data transmission between 160 and 10 meters,
exclusive of 60 meters (where no change was made).

In adopting a bandwidth limit in place of the baud rate limit the
FCC agreed with ARRL that some limitation is necessary because
'without a baud rate or bandwidth limit, data stations using a large
amount of spectrum for a single emission could do so to the
detriment of simultaneous use by other stations using narrowband
emission modes.'

ARRL has advocated for this change for a long time. The move opens
amateur data communications to faster and more modern modes and
restores the incentive for amateurs to experiment with and develop
faster and more efficient data methods. Previously, ARRL obtained
waivers to the symbol rate rules on a case-by-case basis to
facilitate communications during situations like hurricane
responses. These delays will now be removed, permitting drills to be
conducted with the faster modes and more timely responses when
needed.

The FCC also requested comment on removing similar symbol rate
restrictions in the rules governing 135.7 - 137.8 kHz (2200-meter
band), 472 - 479 kHz (630-meter band), and the very high-frequency
(VHF) and ultra-high frequency (UHF) bands.

The VHF bands with baud rates are the 6-meter band, 2-meter band,
and the 1.25-meter band. The single UHF band with a baud rate is the
70-centimeter band (420 - 450 MHz). The Further Notice of Proposed
Rule Making (FNPRM) proposes to maintain the existing bandwidth
limits in the Commission's rules for these VHF and UHF bands but
seeks comment on whether they should be kept, and if so, whether the
bandwidths should be changed. The Commission also sought comment on
whether bandwidth limits should be adopted for application to the
2200 and 630-meter bands, and if so, what an appropriate bandwidth
limit would be.

Public comments on these additional issues are sought in the FNPRM.
The comment period is open until January 8, 2024. Replies to
comments are due no later than January 22, 2024. If changes are
later adopted, the rules will go into effect in the same manner as
they did for the other bands -- after notice and publication in the
Federal Register.