PS Engineering PMA9000EX Installation Manual - Manual (Page 13)

PS Engineering
PMA9000EX Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-920-0000 Page 2-6 Rev. 9, Jan. 2011
NOTE
Inputs 1, 2 and 4 are fixed (1:1), and any audio level adjustments must be made at the input source. Unswitched #3
has a variable adjustment control located on the bottom side of the unit. This control allows you to control the volume
level of that unswitched input from 50% to 200% of the input level. Refer to Adjustments section.
The front panel jack can be configured to act as a fifth unswitched input. When configured through the
front panel function switches (see operational section), the audio input to this jack will be presented to the
pilot and copilot headset, and not muted.
NOTE
The front-mounted utility jack is intended for portable equipment that is advisory in nature. It is NOT
INTENDED for use as a primary warning channel. Audio of importance MUST ALWAYS be hard-wired
into the unswitched inputs of the audio panel.
2.4.11 Public Address Mode
Using the ECAPS data control, the PMA9000EX can be placed into Public Address (PA) mode. In this
mode, the pilot will be talking over the cockpit speaker when he presses his PTT switch. Copilot will still
continue on the selected COM radio.
When the Public Address is active, C1 and C2 indicators flash to indicate that th e pilot’s microphone is
tied to the PA.
2.4.11.1 PA Control Output (J2, Pin 19)
When PA Control Output is enabled, J2 Pin 19 will go low when in PA mode, providing a logic level that
can be used to incorporate a speaker-switching scheme. This 50 mA circuit (10Ω Z) can control a switch-
ing means such as a relay that would transfer the speaker output amplifier from the coc kpit speaker to
drive another cabin speaker. If the PA mode is used with a microphone in proximity to an active cockpit
speaker, feedback might result.
To enable the PA discrete Output located at the rear connector, the internal configuration jumper, J4,
MUST be placed across both pins in the header. This jumper is shipped as open from the factory. Contact
PS Engineering for details on changing this configuration jumper.
2.4.12 PA Mute (J2, Pin 12)
Pin 12 of J2 is a TTL logic output that is pulled low during radio PTT operation. This serves as an input
to external public address system to prevent feedback during transmissions.
2.4.13 Miscellaneous Logic Output (J2, Pin 18)
Pin 18 of the J2 connector is pulled to ground whenever the AUX mode is activated. This serves as a con-
trol line for external devices, such as an entertainment system that the pilot wishes to control.
This pin can also be used to control passenger Karaoke Mode, by connecting to pin 13 of the J2, or as a
PA cockpit/cabin speaker relay control.
2.5 Intercom wiring
See Appendix C and D for intercom connection configurations. It is critical to the proper operation of this
system to have this connector wiring made in accordance with these diagrams. Use 2 - and 3-conductor,
MIL-spec cable as shown. Connect the shields at the audio panel end only, and tie to th e audio low inputs
as shown.
NOTE
The intercom harness can be custom made by PS Engineering, Inc. Simply call the factory or www.ps-
engineering.com to obtain a wire harness work sheet. The harness will be made to your specifications and
fully functionally tested. Harness can be ordered with jack, or without the intercom jacks installed, for
easier wire routing through the aircraft.