Sirius Satellite Radio PMA8000-SR Existing GMA340 Installation, Power, Audio Panel interface

PS Engineering

PMA8000-SR Series Audio Selector Panel and Intercom System

Installation and Operator’s Manual

Radiated signals can be a factor when low level microphone signals are "bundled" with current carrying power wires. Keep these cables physically separated. It is very important that you use insulated washers to isolate the ground return path from the airframe to all headphone and microphone jacks.

NOTE:

Adding a high-performance audio control system, particularly in conjunction with high-performance active noise canceling headsets, cannot improve on older avionics that were designed for cabin-speaker use. PS Engineering makes no claim that the audio panel will provide a noise-free audio quality under all installa- tion conditions, particularly with older avionics.

2.4.2Existing GMA340 Installation

In order to replace the GMA340 with a PMA8000SR, the unit tray must be removed and replaced with the new PMA8000 tray. The connectors can be reused. You will have to replace the back plate (430-880-0050) and connect the Satellite Radio antenna to the RF connector (425-880-3003).

2.4.2.1 J2, Pin 30 GMA340

Some GMA340 installations may have a ground strap on J2, Pin 30, Com TX mute.” THIS

CONNECTION MUST BE REMOVED.

If the PMA8000 installation is routing the SIRIUS Satellite Radio audio externally, this pin is reused as Satellite Radio Audio Right channel. If the Satellite Radio remains internal, this pin must be disconnected.

2.4.3Power

The PMA8000-SR-Series are compatible with both 14 and 28 Volt DC systems. A five (5) Amp circuit breaker is required for all installations. Power and ground wires must be a twisted #22 AWG pair con- nected to J2 Pins 8 and 9. Connect airframe ground to J2 Pin 10 and 11 only. No dropping resistors are required.

2.4.4Communications Push-to-Talk

An important part of the installation is the PTT (Push-To-Talk) switches that allow the use of your aircraft communications radio for transmissions. There are three typical configurations that can be used. Select the case that best fits the installation. Only the person who presses their PTT switch will be heard over the ra- dio. If the pilot and copilot both use the PTT, the only pilot position has access to the radio. The pilot posi- tion will have PTT control regardless of the mic selector switch or copilot PTT when the PMA8000-SR is in the OFF/EMG mode.

CASE I: PTT is built into both pilot and copilot yokes.

CASE II: PTT is in pilot yoke only. This configuration requires a modified external PTT switch plugged into the copilot's microphone jack. (See Appendix A). When the copilot's PTT is pressed, the intercom switches the microphone audio from pilot to copilot mic.

CASE III: No built in PTT. This requires two built in PTTs to be installed, or modified external PTT switches to be used. Modify external PTT as required. See Appendix A.

2.4.5Audio Panel interface

The PMA8000-SR is designed to interface with standard aircraft avionics, and presents a 500Ω receiver impedance. For best results, a twisted-shielded cable is recommended from the avionics audio source to the audio panel, with the shield grounded at the audio panel end.

Some avionics do not provide a separate audio low, and may introduce additional electrical noise into the system. For best results, connect the audio low from the audio panel to the radio ground, using one conduc- tor of the twisted-shielded cable.

2.4.5.1 Speaker Load

The PMA8000-SR contains one speaker amplifier. Some units with internal speaker amplifiers, such as the King Radio KX170-series, require a resistive load to prevent damage if their speaker amplifier is not used.

200-880-0000 Page 2-3 Rev. 13, July 2006