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ARRL General Bulletin ARLB022 (1999)

ARLB022 ARRL rebuts late-filed power industry arguments in LF

QST de W1AW  
ARRL Bulletin 22  ARLB022
From ARRL Headquarters  
Newington CT  March 31, 1999
To all radio amateurs 

ARLB022 ARRL rebuts late-filed power industry arguments in LF

The ARRL has rebutted assertions that amateur LF allocations at 136
and 160 kHz could lead to interference with utility-operated power
line carrier (PLC) systems.  The unallocated and unlicensed Part 15
PLC systems are used by electric utilities to send control signals,
data and voice.  At the same time, the League urged the FCC to issue
a Notice of Proposed Rulemaking to open the LF bands up to amateurs.

Last October, the League petitioned the FCC to create low-frequency
Amateur Radio allocations at 135.7 to 137.8 kHz and 160 to 190 kHz.
The ARRL proposed permitting CW, SSB, RTTY/data, and image emissions
at a maximum power level of 2 W effective isotropic radiated power.
The utilities' PLCs operate between 10 and 490 kHz.

The comments in question--from four parties including Commonwealth
Edison and Mark Simon--arrived at the FCC well beyond the December
23, 1998, comment and the January 7, 1999 reply comment deadlines.
They also appear to be the only comments filed on behalf of the
power industry.

The League has requested that the FCC strike the late comments from
the record, but it also rebutted their substance in case the FCC
decides to accept them anyway.

The League debunked Simon's suggestion that ham interference could
lead to dire consequences to unlicensed PLC systems.  The League
said Simon fails to explain why a marginal-level amateur signal
would cause problems ''where loud static crashes in the same bands do

The League said PLC systems already have been shown to operate
effectively ''in an environment of extremely high power government
stations using thousands of watts of EIRP.''

The League also took ComEd to task for suggesting that hams be
obliged to protect PLC systems against interference.  The ARRL
pointed out that PLCs have ''no incumbent allocation status'' and are
not entitled to protection from licensed systems.  The ARRL
acknowledged existence of the PLC systems in its October petition
and provided a technical analysis indicating that amateur
interference to PLCs was unlikely.

The League suggested that the utilities make available an industry
database of PLC operating parameters that hams could consult as a
guide to avoid interference.  It concluded that the FCC should not
make allocations decisions ''based in whole or in part on the
presence or absence of Part 15 devices in a particular band segment''
since the devices have no inherent allocation status.

The League said it remains willing to address any interference cases
that might arise and urged the FCC to issue a Notice of Proposed
Rulemaking on the ARRL's request ''without further delay.''


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