ETRP

Earth Terminal Refurbishment

Under the Earth Terminal Refurbishment Project (ETRP), NPR Distribution upgraded outdated satellite antennas, coaxial cable, and downconverters throughout the entire Public Radio Satellite System (PRSS), as required. While the title of the project sounds complicated, the process is quite simple. With the help of the station, the project team evaluated current satellite equipment. In order to be considered up-to-date, a station had to of met several criteria:

• Be able to receive an L-band signal into the equipment rack via satellite.
• Possesses an existing antenna that meets the FCC antenna performance standard specified in FCC Rules 25.209(a). Fiberglass reflectors older than ten years as of the ETRP 2000 Survey are eligible for replacement under the project.
• Be able to access the public radio back-up satellites in case the current Public Radio satellite, Galaxy 16, should fail.

L-band Upgrade

Station's were upgraded from the current C-band system to an L-band system a crucial step in the Earth Terminal Refurbishment Project. Leading up to ETRP the system was full of aging equipment that the PRSS Depot would someday be unable to support. Unfortunately, any stations not willing to participate in an L-band upgrade would be hard pressed to find replacement parts, should one of the old C-band components break.

A station's L-band status is easiliy determined by the type of downconverters present in the station control room rack. If a station had the Satellite System Corporation (SSC) Model 4421 downconverters, then it is already receiving an L-band signal and has no need for new downconverters or an LNB (Low Noise Block Converter). If a station was operating with downconverters such as the Scientific Atlanta, Rockwell/Collins, Microdyne, or Microphase models, these needed to be replaced with the newer SSC model. Most stations had the necessary coaxial cable already in place. However, some cable needed to replaced if it has been damaged or was incapable of carrying an adequate signal.

In preparation for the next step in the evolution of PRSS technology, stations ensured that the new L-band downconverters were collocated with the existing ABR-700 demodulators. It will be necessary for the L-band signal to travel directly to the next phase of demodulators.

Satellite Antenna System Upgrade

In addition to replacing outdated downconverters, some station's found their satellite antennas in need of replacement. Some older dishes may experience an audible "chirp" in the signal. Mark Murphy, NPR satellite facilities engineer, describes a chirp as, "a momentary loss of digital synchronization in the digital decoder caused by a short burst of adjacent satellite inference." As a satellite antenna ages, it is prone to damage from exposure to the sun and wind, causing it to lose its parabolic shape. Once this happens, the antenna can no longer prevent outside interference. Station's with antenna's older than ten years, qualified for replacements. An antenna smaller than the recommended 3.7 or 3.8 meter size, or one that is below commercial grade quality was also a candidate for replacement, as well.

The antenna mounting structure and associated hardware was also examined. If the antenna's mount was rusted and immovable, a station will not be able to access the backup satellites. In these cases, the project team often recommended replacing the mount or its defective components. Rusted feed spars and bolts on the face of the antenna were also replaced as required.

Finally, a station's current antenna location was evaluated. If the antenna could not point to 95°, 99°, and 127° orbital locations without hitting an obstruction, the station needed to find a new location or modify the existing location, so the antenna was able to see all back-up satellites. In some cases, a station received a new antenna with mount and coaxial cable to accommodate the emergency back-up provisions. Station's choosing to decline a relocation may be left without programming should the current satellite, Galaxy 16, experience a failure.

Participation

To have participated in this project the station had to be interconnected as of 01/01/01.