PS Engineering
PAC45 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-045-0100
Page 2-5
January 2020
2.4.3.1 Navaid wiring and selection
The PAC45D has NAV 1, NAV 2, and three additional auxiliary navaid inputs for ADF, etc. The
three auxiliary audio inputs on P452 pins 9, 10 and 11 will be presented with the audio control
on the bottom row is selected.
2.4.3.2 Additional transmit position or passenger 6 (P451-6, 23, 40)
The PAC45D system can support six passenger intercom stations, in addition to the pilot and co-
pilot. The input to the PAC45D P451 6, 23, 40 can be used as an additional transmit position, or
a hand microphone, or as passenger 6, with transmit capability on the selected radio.
This microphone transmitter follows the last control head selection as follows:
Configuration
Microphone connected to
Single Control Head
Selected radio
Two Control Heads
Copilot selected radio
Three Control Heads Observer selected radio
Passenger 2 (Observer 2) can use this hand mic as a transmit seat.
2.4.3.3 Passenger 5 and 6
Passenger 6 is an intercom station input on P454-16 wrt 25.
The headphone outputs for passenger 5 and 6 are paralleled from passenger 1 and passenger 2.
NOTE: Do not parallel headphones to passenger 3 or 4.
2.4.3.4 Installation with Monaural Headsets
Not recommended, because the benefit of MultiTalker is lost. However, if desired, the PAC45D
can be installed monaurally by using the LEFT audio connections only (left side contains Fail-Safe
audio). Do NOT short left and right headphone outputs together.
NOTE: Mono headsets that short the tip and ring (i.e. older models) may introduce audio dis-
tortion when used. Modern, stereo headsets are recommended in all positions.
2.4.4 Transmit Interlock
Some communications transceivers use a transmit-interlock system. To fully utilize the multi-
user, transmit capability, this function must be disabled. Consult the radio manufacturer's in-
stallation manual.
2.4.5 Backlighting
Control of the unit backlighting is through the aircraft avionics dimmer Connect P452 Pins 19 to
the aircraft dimmer bus. All control heads dimming is control by the HUB. The audio controller
can be configured for either 5VDC or 28V dimmer installations. The default setting is 28V from
the factory. The ratio of white to green indicator intensity is adjustable, see
Units with configuration status
BBGAA
and above:
The green/white pot has been changed, and now works as follows:
PRELIMINARY
