Published: TV Technology Magazine

Issue:  December 4, 1997





FCC Issues New RFR Compliance Regulations       

by Joe Fedele



WASHINGTON, D.C.--On August 25th, the FCC’s Office of Engineering and Technology (OET) 

issued an advisory bulletin, OET-65 Edition 97-01, that contained information aimed at providing 

assistance for determining whether FCC-regulated transmitting facilities, operations or devices 

comply with acceptable limits of radio frequency radiation (RFR) for human exposure. 

        With the issuance of Edition 97-01, broadcasters, tower management firms and 

telecommunications companies around the country now have an updated set of guidelines for 

complying with FCC rules.

        Lodestar Towers, Inc., a tower management firm based in Tequesta, Florida, has been in the 

multi-purpose communications site business since 1984.  It owns and manages over 300 sites 

across the U.S. that must adhere to these guidelines. Ron Gibbs, President of Lodestar, noted 

that they, and every other transmission licensee, must "effectively manage RF for the benefit of 

[their] clients and for public safety."   

        In an effort to show compliance with the RFR guidelines, Lodestar plans to implement an 

RFR measurement campaign at every one of its sites and "provide details to individual clients 

within six months."

        In addition, Lodestar will begin testing its clients' equipment via the use of RF monitoring 

software and detailed databases that include the exact specifications of all equipment operating 

on each site.

 

        But, in order for licensees to comply with the standards, a good understanding of what they 

entail must first be established. Gibbs said that engineers must be capable of  "distinguishing 

[between] controlled vs. uncontrolled environments, and the related challenges inherent in rooftop 

facilities and those located on mountain tops where broadcast antennas are located very close to 

ground level."

        To address this need, Lodestar is implementing programs to educate its employees, 

government officials and the public on RF issues. "In light of the new compliance standards, 

understanding the difference between controlled and uncontrolled environments is crucial when 

addressing effective management of RF levels," he stated. "Can RF be dangerous? Yes it can if 

not properly managed. Can RF be managed? Absolutely."

        Joe Davis, a partner in the broadcast engineering and consulting firm of Cavell, Mertz and 

Perryman, agrees and points to his company's experience working at a broadcast transmitter 

location atop a volcano in Hawaii.  The tower itself was only 100 feet tall and its five full powered 

TV stations, two LPTVs and one FM antenna gave cause for concern.   "While the calculations we 

performed indicated that there may be some compliance issues, our measurements showed that 

all public accessible areas were in full compliance with RFR regulations."  

        Davis explained that licensees are confronted with a complex set of guidelines where 

multipurpose sites are concerned.  He noted that several "trigger levels" of calculated and/or 

measured RFR will determine the extent to which stations must study the matter in order to show 

compliance with safety standards.

        If, for example, your antenna contributes less than 5 percent of the overall energy emanating 

from all the radiators on the tower, then your station remains in full compliance and no further 

studies must be performed. 

        But, "It starts to get complicated when the calculations show levels higher than 5 percent," 

Davis stated. "Then you have to do measurements to determine if the actual RF levels match your 

calculations."

        "Calculations are generally very conservative," he said, "and do not consider such things as 

true (versus theoretical) antenna patterns and wave propagation.  In many cases the measured 

power levels, when taken near ground level, reveal a different story."

        Because different radiation limits are in effect for frequencies across the spectrum, narrow 

band measurements are sometimes also used to determine if a licensee or a transmission site is 

in compliance.

        Davis also stressed the importance that RFR studies play in the maintenance of transmission 

towers and antennas.  "Measurements are very useful in determining how far up a tower 

maintenance crews can climb before they encounter a danger zone. These measurements will 

also tell you if and when stations need to either reduce power levels or cease operations during 

maintenance periods.”

        Peter Stark,  director of Broadcast Tower Development for Houston, Texas-based American 

Tower System (owners of nearly one thousand multi-use transmission sites), stated that 

"broadcaster have a large responsibility and a financial investment in insuring RFR compliance."         

Stark mentioned that his company plans to have all of its facilities "mapped-out" to insure 

compliance now and in the future.  "We are the third largest tower site owner behind AT&T and 

Motorola and have a lot to loose if RFR problems are not managed properly," Stark said.

        Although engineers should always remain current in their understanding of RFR matters, 

Lodestar's Gibb stated that, much like what his company is doing, "site owners and managers 

must begin programs intended to educate everyone."  

        He added that even members of an organization's sales and marketing staff should become 

aware of RFR matters because the issue of RF emission has become a hot subject with the 

public and local governments. In fact, numerous transmission licensees across the country have 

met stiff resistance from local zoning boards (see zoning story in the September 25th issue of TV 

Technology), so reliable RF monitoring and public education programs have become crucial.