PS Engineering
PMA7000M-S Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-070-0006
Page 2-6
Rev. 6, Nov 98
system incorporates a "Soft Mute" system. This will mute the entertainment devices dur-
ing ICS or radio conversation.
Any signal appearing in the unswitched audio inputs will always mute the entertainment
sources, even though the passengers may not hear the audio tone itself.
Entertainment inputs #1 and #2 can be paralleled so a single entertainment source can
serve both the passengers and the crew. It is suggested however, that a switch (DPDT) is
installed between the single entertainment device and entertainment input #1. This will al-
low the pilot and copilot to decide if they hear entertainment while in the Crew mode.
Caution:
Local oscillators and internal signals from some entertainment equipment can
cause undesired interference with other aircraft systems. Before takeoff, operate the en-
tertainment devices to determine if there is any adverse effect within the aircraft systems.
If any unusual operation is noted in flight, immediately switch off the entertainment de-
vices.
All entertainment devices must be switched off for both takeoff and landing.
2.4.10.1.3 Entertainment 2 Mute (Pin V)
The ICS button on the PMA7000M-S controls the muting (“Karaoke mode”) of enter-
tainment source #1.
Connecting J2 pin V to ground through a SPST switch places the entertainment #2 music
source into the Karaoke Mode. In this mode, incoming music and intercom conversation
will not mute the music for the passengers’ intercom net. This allows uninterrupted music
during casual conversation and at times when radio communications are of lessor impor-
tance.
2.4.11 Com 3 Audio
As installed in the standard configuration, the PMA7000M-S Com 3 audio is placed in the
audio when the mic selector switch is in the Com 3 position (fully CCW). Pushing the re-
ceiver selector buttons can monitor Com 1 and Com 2 audio. If monitoring of Com 3 is
desired in the Com 1 or Com 2, connect Com 3 audio in parallel to the AUX input (J1, pin
11).
2.4.12 PA Mute (J1, Pin 18)
Pin 18 of J1 is a TTL logic output that is pulled low during PTT operation. This serves as
an input to external public address system to prevent feedback during transmissions.
2.4.13 VOX Override (J2, Pin U)
Connecting pin U of the PMA7000M-S of J2 to ground will force the
IntelliVox
™ open.
This can be hooked up as a hot mic switch which will place all microphones on the inter-
com. This can also be connected through a momentary switch to serve as a VOX test
switch, if desired. Because the
IntelliVox
™ will close in the presence of a steady tone, this
pin is used in testing to defeat the
IntelliVox
™ software.