P139-HD Audio System User Manual
GA063-3 Rev G 08/25/2015
Page 5 of 35
1. Introduction
1.1. Description
This document describes the general operation of the Eagle Copters P139-HD Digital Audio System.
As the P139-HD is highly customizable, this document describes features common to all audio systems.
Customer-specific information may be found in the configuration documentation that came with the Audio
System.
1.2. Definition of Terms
Throughout this document, the term “Radio” applies to any audio device that may be connected to this
audio system, even though that device may not be an actual radio.
A “Listen-Only” device may be a radio receiver or any type of device that generates an audio signal, such
as NAV radios, and warning tone generators.
A “Transmit-Only” device, such as a Public Address System, does not provide any receive audio. The
unused receive input on a transmit-only channel may be used for an unrelated listen-only device.
“Gnet” is the Eagle Copters proprietary network used to communicate with control heads and other Eagle
Copters equipment. Each Gnet Bus consists of a two-wire serial data connection, 28V power and Ground.
Up to 15 devices may be connected to each bus in a parallel or daisy-chain fashion. Devices are
identified by jumpering specific ID pins in the device connector.
