AG17
QST de W1AW  
ARRL Bulletin 17  ARLB017
>From ARRL Headquarters  
Newington CT  August 3, 2023
To all radio amateurs 

SB QST ARL ARLB017
ARLB017 ARRL Files Comments Against 'Seriously Flawed' HF Rules
Petition

ARRL, as part of its mission to protect Amateur Radio, has filed
comments against a proposal that would introduce high-power digital
communications to the shortwave spectrum that in many instances is
immediately adjacent to the Amateur HF bands.

The 'Shortwave Modernization Coalition' (SMC), which represents
certain high-frequency stock trading interests, filed the petition
with the Federal Communications Commission (FCC). ARRL responded on
behalf of its members and the 760,000 licensees of the Amateur Radio
Service in the US.

The petition can be found online at,
https://www.fcc.gov/ecfs/document/1042840187330/1  .

The ARRL Laboratory performed a detailed technical analysis over
several months to determine if the proposed rules would affect
operations on the bands allocated to Radio Amateurs that are
inter-mixed with the Part 90 bands in the spectrum in question.

ARRL's analysis determined that, if the proposed rules are adopted,
the new operations inevitably will cause significant harmful
interference to many users of adjacent and nearby spectrum,
including Amateur Radio licensees. Ed Hare, W1RFI, a 37-year veteran
of the ARRL Lab and internationally recognized expert on radio
frequency interference, was the principal investigator on the study.
Hare concluded the petition should not be granted. 'This petition
seeks to put 50 kHz wide, 20,000-watt signals immediately next to
seven different amateur bands with weaker protections against
interference than required in other services,' said Hare.

In its formal opposition, ARRL stated, 'That destructive
interference would result if operations commenced using anything
close to the proposed maximum levels.'

ARRL's filed comments highlight flawed analysis and incomplete data
submitted by the petitioners. It noted the petitioners
'...significantly understate the harmful interference that is not
just likely, but certain, if the rules proposed by SMC are adopted
as proposed. It is noteworthy that SMC's proposed rules would
provide less protection than the much-lower power amateur radio
transmitters are required to provide Part 90 receivers.' ARRL's
opposition also noted that there was no reported tests conducted
with Amateur or other affected stations, but referenced a spectrum
capture in the Comments filed with the Dayton Group that showed
actual interference into the Amateur 20-meter band from one of the
High Frequency Trading experimental stations.

Part 90 HF rules currently authorize a maximum signal bandwidth
equal to a voice communications channel, at up to 1000 W peak
envelope power (PEP). The petition seeks multiplication of signal
width, greater transmitted power, and weaker rules that protect
users of adjacent spectrum. ARRL's comments expose the likely
fallout:

'Incredibly, notwithstanding the significant increase in potential
interference that would result from using digital schemes with 50
kHz bandwidths and 20,000 watts of power, SMC also proposes to
substantially lessen the protections required to protect adjacent
and neighboring licensees. SMC proposes [out-of-band emissions]
limits that offer less protection than the existing Part 90 limits
and would actually permit no attenuation (0 dB) at the edge of
adjacent allocations, many of which are bands allocated to and
heavily used in the Amateur Radio Service. Consistent with lessening
protections while increasing the potential for harmful interference,
SMC also proposes a lower limit for spurious emissions. SMC would
reduce the existing protection of -73 dB for the applicable
1000-watt power limit to just -50 dB protection for their proposed
20,000-watt limit. Due to the much wider 50 kHz proposed bandwidth,
the resulting interference would penetrate deep into the adjacent
Amateur bands.'

The proposal has been assigned FCC Docket No. RM-11953. While the
period for commenting on the petition has now closed, replies to
comments in the record may now be submitted.

Hundreds of licensed Radio Amateurs filed comments in the Docket,
expressing overwhelming opposition to the proposal. Those interested
may read ARRL's full comments and the results of the technical
analysis, which are included in the filing. 'If granted as written,
this would be devastating to Amateur operation for many tens of kHz
into our bands,' said Hare.

ARRL will continue to advocate for its members and the Amateur Radio
Service in this proceeding.