To prevent communications failure, the Hagerstown Regional Airport managers invested in amplifier redundancy using an Automatic Failure Detector and Substitutor (AFDS2), and a pair of Gold Seal Series Public Address Amplifiers (GS250). One GS250 operates as a primary amplifier and the other serves as a backup in case the first one fails.
The Ceiling Speaker Assemblies provide the required intelligibility through a range of sound levels to help passengers hear announcements clearly. Other system components include 1 Gold Seal Series Public Address Amplifier (GS150), 1 Mixer/Pre-Amplifier (CAM2) and 2 Ambient Noise Sensor Systems (ANS501).
To connect these components, the Commlink installers wired the Automatic Failure Detector and Substitutor (AFDS2) between two GS250 amplifiers. The AFDS2 also connects with a panel monitor and an Ambient Noise Sensor (ANS501). The Mixer/Pre-Amplifier (CAM2) connects with four microphones as well as with both GS250 amplifiers. The panel monitor is wired to a third Gold Seal Series Public Address Amplifier (GS150) located in the hold room. The primary and backup GS250 amplifiers and GS150 as well as the panel monitor connect with the Ambient Noise Sensors (ANS501) — one of which is in the terminal and one is in the hold room. These ANS501 sensors, in turn, connect with existing speakers in the terminal and new Ceiling Speaker Assemblies in the hold room.
There are two new microphones in the hold room connected to the GS150 and four existing microphones in the terminal connected to both GS250 amplifiers, permitting airport personnel to move quickly to a nearby location to make an announcement.