PS Engineering
PAC24 Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-240-0010
Page 2-12
Rev. 29, Sept. 2021
2.4.13 Entertainment Input (J3 Pin 7)
If music or entertainment is desired, a monaural input can be applied to Pin 7 of J3.
N O T E
: U s e t h e l o w l e v e l o u t p u t o f a n y e n t e r t a i n m e n t d e v i c e t o c o n n e c t t o t h e a u d i o
p a n e l . M a x i m u m s i g n a l l e v e l i s
2 V A C
p - p .
D O N O T
u s e a s p e a k e r - l e v e l o u t p u t , t h i s w i l l c a u s e i n t e r n a l d a m a g e i n t h e a u d i o p a n -
e l .
All entertainment devices must be switched
off
for both takeoff and landing.
2.4.13.1 Entertainment distribution
The entertainment source provides music for all intercom positions. In ISO, it is removed from the pilot.
The PAC24-system incorporates a "Soft Mute" system. This will mute the entertainment devices during
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.
Caution:
Local oscillators and internal signals from some entertainment equipment can cause undesired
interference with other aircraft systems. Before takeoff, operate the entertainment devices to determine if
there is any adverse effect within the aircraft systems. If any unusual operation is noted in flight, immedi-
ately switch off the entertainment devices.
All entertainment devices must be switched off for both takeoff and landing.
2.4.13.2 Entertainment inhibit
The music input to the PAC24 uses the existing Speaker Power input from the KMA24-71. This pin should
be removed even if music is not desired. However, if avionics power remains on Pin 7, there is the possibil-
ity of power ripple entering the system. The Music input can be deactivated from the front panel by press-
ing the NAV 1 and AUX (ADF in –0500) buttons for at least 3 seconds. The audio panel will then ignore
any signal on this input, until the Music Off mode is toggled again.
2.4.14 Intercom expansion (P/N 11606 or 11606R)
The PAC24 contains a five-place intercom (pilot, copilot and up to three passengers). The passengers hear
the same audio output as the copilot.
If a true “crew” mode is desired, or in applications where more intercom positions are needed, PS Engi-
neering can provide intercom expansion units, such as the IntelliPAX, part number 11606 or 11606R (re-
mote). These can add up to six additional stereo intercom stations, plus independent stereo music inputs.
DIP switches in the PAC24
must
be configured to use the expansion. See § 2.2.4.
Note: Observer versions (-0400) are wired differently than others. Please use correct wiring diagram to
avoid damaging the unit.
NOTE
: The radio audio to the expansion unit is provided only by the audio panel connected. For example,
the expansion unit connected to the copilot audio panel will
ONLY
receive audio selected by the copilot.
The expansion unit connected to the pilot audio panel will
ONLY
receive audio selected by the pilot. Do
not use the expansion Mono input for radio. (11606 Pin 22).
When a panel mounted IntelliPax (11606) expansion unit is used, only the expansion volume controls are
active. The knob on the 11606, or the trimmer pots on the 11606R control passenger intercom volume.
NOTE: In installations where an expansion unit is NOT used, the passenger and copilot audio output is
paralleled (J1, pin b). Therefore, unswitched audio will
be heard by the passenger(s).
Use an expansion
unit, P/N 11606, or 11606R (remote) to isolate passenger audio from unswitched alert audio.