The reduced bay-spacing antenna design and two-station combiner will accommodate a second station while providing Educational Media Foundation’s WJKL-FM with a robust FM signal.
Dielectric’s global business continues to expand through key customer wins, with the CALA region representing an especially strong region of activity for FM radio business. Educational Media Foundation (EMF) has added to Dielectric’s CALA business momentum with the installation of a listener-funded Dielectric DCR-M for WJKL-FM, a non-commercial station serving the island of Puerto Rico.
EMF worked closely with Dielectric on a broadband antenna design to support both WJKL on 105.7 FM and a second station (104.7 FM) in the future. The center-fed DCR-M accommodates both frequencies (with 1 MHz separation) through a special reduced bay-spacing design that eliminates the need for future field tuning. EMF also added a new, specially designed two-station branch combiner to serve both transmission frequencies, and prevent intermodulation issues from signal mixing inside the transmitters.
Side-mounted to a mountaintop tower with a center of radiation at 118 feet above ground level (1787 feet above sea level), the DCR-M was specified to withstand the often stormy weather elements of Puerto Rico, which are amplified during hurricane season. The project was in fact delayed due to several harsh storms including Hurricane Maria in 2017, which caused widespread devastation to the island. The project was revived once power was returned to the remote site and the general infrastructure was restored.
“Dielectric’s robust antenna design meets the weight and wind-load specifications of our tower while building in the appropriate protections for continued operation in our harshest weather conditions,” said Kim Allison, director of site development, EMF/WJKL-FM. “This was of high importance considering the remote tower location. We were also very pleased at Dielectric’s collaborative approach with our other partners, which ultimately delivered the antenna system required to accommodate a second FM station.”
Dielectric worked closely with Sabre to develop a custom mounting system that could support the unique bay-spacing design. This included a standoff pole for the tapered tower architecture, and a bracket design that eliminated complex anti-rotation elements for the antenna bays. Dielectric also added its “funky elbow” design to reduce ground radiation from the DCR-M, through a robust inter-bay feed system that optimizes signal coverage without directing radiation downward from the tower.
Dielectric Vice President and General Manager Keith Pelletier notes that Dielectric worked closely with EMF, Sabre, and local contractors in Puerto Rico to ensure that timelines were met and logistics were well-coordinated. Everything was shipped in a single container to reduce costs, with Sabre designing the stand-off pole in short, modular sections to fit cleanly alongside Dielectric’s antenna.
“This project was a labor of love for Dielectric considering the unforeseen delays and challenges that EMF faced on the road to installation,” said Pelletier. “We are grateful for the opportunity to support EMF and its mission to bring Christian radio programming to the audiences throughout Puerto Rico.”
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