From: Cavell, Mertz & Associates, Inc.
What: Optimizing RF Coverage for Radio and Television
When: August 8, 2017 6:30 PM
Our August 2017 meeting was a command performance from the NAB Convention in Las Vegas, where NAB Radio Engineering Achievement Award recipient John Kean of Cavell, Mertz & Associates, Inc. discussed the use of specially equipped drones for making field strength measurements to establish and document the "real world" performance of broadcast antennas. The presentation to SBE Chapter 37 was even better because:
- Also speaking was Gary Cavell, a broadcast engineering consultant, licensed aircraft pilot, and principal of Cavell Mertz, who played a significant role in the development of this project.
- John and Gary will bring the drone.
- We'll learn about how the project has progressed since April.
Using UAV’s to make these measurements is a lot faster and dramatically more economical than other methods. Previously, the most popular method was using a helicopter to fly a series of orbits around a tower, with expensive equipment, and to then tabulate that data, and produce a report. Traditional measurements from the ground are slow and tedius since roads seldom outline a circular path around a tower site. Also, ground based measurements tend to be affected by terrain shadowing and local clutter, which are difficult to remove, making determination of transmitting antenna radiation performance quite abstract.
Before joining Cavell Mertz, John was Senior Technologist for National Public Radio from 2004 until 2015, where he developed projects, procedures, and standards and supervised all technical projects of NPR Labs, the only not-for-profit broadcast engineering laboratory in the United States. At NPR Labs, he completed a thorough study of the compatibility of AM Modulation-Dependent Carrier Level with HD Radio®, for the National Radio Systems Committee. Also for the NRSC, he conducted a study of the performance of Single-Sideband FM Stereo and its compatibility with present-day FM receivers.
Gary Cavell is the President of Cavell, Mertz & Associates, Inc. and has worked in management and technology positions in communications and broadcast systems for over 40 years. At Cavell Mertz, in addition to being the general RF and regulatory knowledge resource, his strength is in RF systems, with a particular love for AM antenna arrays. As such, he has designed, built and certified countless station RF systems over the years.
Gary was a cofounder of Cavell Mertz and its predecessor firms in 1989, after having worked with the engineering firm of Lohnes & Culver for nine years. Before coming to the Washington, DC area, he worked in New Orleans for several years in the radio and television industry in the areas of general and engineering management, facility design and construction, program production, and station systems development. He attended the University of New Orleans and has an EIT certification. Gary has also been a radio station manager in his home town of New Orleans, and has experience as a successful small market radio station owner/operator in central Pennsylvania.
Sandwiches, kindly provided by our friends at Cavell Mertz were served about 6:30 PM. We briefly discussed SBE business about 7:00 PM and began our presentation shortly thereafter. Our cordial hosts at WJLA-TV, in addition to allowing our use of their conference facility, provided a facility tour following the meeting. We greatly appreciate their hospitality!