Register Account

Login Help

ARRL General Bulletin ARLB034 (2013)

ARLB034 Deadline to Comment on ARRL's "Symbol Rate" Petition Looms

QST de W1AW  
ARRL Bulletin 34  ARLB034
From ARRL Headquarters  
Newington CT  December 11, 2013
To all radio amateurs 

ARLB034 Deadline to Comment on ARRL's "Symbol Rate" Petition Looms

The deadline is December 21 to file comments on the ARRL's "Symbol
Rate" Petition for Rule Making (PRM). The ARRL filed the Petition
last month, and the FCC has put it on public notice for comment as
RM-11708. The League subsequently filed an Erratum to correct an
incorrect appendix included within the Petition. The Petition
already has attracted more than 70 comments.  The Petition can be
found on the web at,

The ARRL has asked the FCC to delete the symbol rate limit in
§97.307(f) of its Amateur Service rules and to replace it with a
maximum data emission bandwidth of 2.8 kHz on frequencies below 29.7
MHz. The ARRL contends that the changes it proposes would "relieve
the Amateur Service of outdated, 1980s-era restrictions that
presently hamper or preclude Amateur Radio experimentation with
modern high frequency (HF) and other data transmission protocols"
and "permit greater flexibility in the choice of data emissions."
Symbol rate represents the number of times per second that a change
of state occurs, not to be confused with data (or bit) rate.

Current FCC rules limit digital data emissions below 28 MHz to 300
baud, and between 28.0 and 28.3 MHz to 1200 baud. The League's
petition points out that other radio services use transmission
protocols in which the symbol rate exceeds the present limitations
set forth in §97.307(f), while staying within the bandwidth of a
typical HF single sideband channel (3 kHz).

"The symbol rate restrictions were created to suit digital modes
that are no longer in favor," the ARRL noted in its petition. "If
the symbol rate is allowed to increase as technology develops and
the Amateur Service utilizes new data emission types, the efficiency
of amateur data communications will increase."


Instragram     Facebook     Twitter     YouTube     LinkedIn