10/06/2021

ARESLAX, an arm of the ARRL Los Angeles Section, has used a $23,600 grant from
Amateur Radio Digital Communications (ARDC[1]) to purchase equipment that will
help Amateur Radio Emergency Service¿ (ARES¿) team members to locate and
eliminate sources of radio frequency interference (RFI) that could hinder their
operations.

"ARESLAX is a 501(c)3 nonprofit organization supporting emergency communication
initiatives of the Los Angeles Section's ARES program," ARRL Los Angeles
Section Manager Diana Feinberg, AI6DF, explained. "Earthquakes and wildfires
are the primary disaster threats this region faces. Because these incidents
occur without any advance warning, disaster communication groups in the Los
Angeles Section must maintain a high degree of readiness."

Thanks to the grant, Feinberg said, last spring ARESLAX purchased a Fluke ii910
Precision Acoustic Imager, which combines ultrasonic detection with visual
techniques to pinpoint an interference source, such as power line noise, and
produce photographic evidence. At the same time, ARESLAX used its own funds to
purchase a Radar Engineers 243 RFI Locator and spent the summer familiarizing
itself with the sophisticated equipment.

"By combining these two purchases with our preexisting equipment, ARRL Los
Angeles Section Technical Specialist Chris Parker, AF6PX, believes the Los
Angeles Section now has EMI/RFI locating capabilities exceeding those of area
utility companies and their contractors," Feinberg said. ARESLAX would like to
eliminate all RFI sources in Los Angeles County.

The equipment will be used across the ARRL Los Angeles Section, the only ARRL
Section consisting of a single county - Los Angeles County with 10 million
residents and the most populous US county. Terrain ranges from sea level to
just over 10,000 feet, including an extensive mountain range. "Using NVIS
[near-vertical incidence skywave] on 80, 60, and 40 meters is essential for
communicating between all these areas and neighboring counties during major
disasters," Feinberg said.

"For an increasing number of Los Angeles Section hams, EMI or RFI issues have
made the HF bands difficult or impossible to use for DXing, contesting,
emergency communication, or casual operating," Feinberg said. She pointed out
that the network of overhead power lines that expanded with the county from
1940 through 2010 has now deteriorated, resulting in arcing. "Additionally, our
urban noise floor is rising from the millions of electrical devices used by
consumers and businesses, including solar charging controllers and grow
lights," Feinberg said. "Unfortunately, the major electric utility companies
eliminated their long-standing EMI investigative departments in recent years
following personnel retirements and business restructurings. The utility
companies now hire outside contractors for locating specific EMI issues, but
this approach hasn't sufficiently solved many problems for hams."

RFI complaints can go unresolved for years, and tracking down interference
sources has been the focus of a corps of technical volunteers. The new
equipment makes that job far less time-consuming and more successful, ARESLAX
said.

In 2019, ARDC announced the sale of some 4 million consecutive unused
AMPRNet[2] internet addresses, with the proceeds to establish a program of
grants and scholarships in support of communications and networking research
with a strong emphasis on Amateur Radio. ARDC, which manages AMPRNet, said it
planned to provide monetary grants to organizations, groups, projects, and
scholarships that have significant potential to advance the state of the art of
amateur radio and of digital communications.

[1] https://www.ampr.org/
[2] http://www.ampr.org/amprnet/

---
■ Synchronet ■ Whiskey Lover's Amateur Radio BBS