ARLB022 ARRL rebuts late-filed power industry arguments in LF

Paul L. Rinaldo
Thu, 01 Apr 1999 08:09:16 -0700

>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.''