Power And Fail Safe; Communications Transmit (Xmt) Selection; Com Audio Selector - PS Engineering PAC45L Pilot's Manual And Operation Manual

Power and Fail Safe

Unit power is controlled by the transmitter
(XMT) selector knob. In the "EMG" or off
(fully clockwise) position, the pilot headset is
connected directly to COM 1 as well as alerts
and unswitched input #1. This allows commu-
nication capability regardless of unit condition.
NAV1 audio is also provided to the pilot in the
other ear of a stereo headset.
In Fail Safe (EMG) on the Copilot panel, that position will hear COM 2. The
copilot can place the control panel in EMG without affecting pilot operation.
Any time power is removed or turned off, the audio selectors will revert to fail
-safe mode. If fail-safe audio is present in both ears of a stereo headset, or
completely absent, verify that a stereo headset is used and is selected for ste-
reo mode.
The power controls all audio selector panel functions and intercom.

Communications Transmit (XMT) Selection

The PAC45L has a rotary control knob to select communications transceiver
functions. To select a transceiver for transmit; turn the knob to select the de-
sired radio.
The radio is automatically selected to receive in-
coming radio calls when the XMT is selected.
With a PAC45L, you will never transmit on a
radio that you are not receiving. The selected au-
dio is indicated by both knob position and the
green text. The pilot and copilot controllers can
select any of the installed transceivers. In the case
where both have selected the same radio for trans-
mission, the pilot will have priority when he uses the radio push to talk.
OXY Selector
The OXY button Activates the Oxygen Mask microphone inputs
if configured.

COM Audio Selector

The communications receiver
audio sources are controlled by
a combination pull on-push-off
switch/volume control. Com-
munication audio from another
radio, not selected for transmit,
can be heard by pulling out the
PAC45L Pilot Guide 202-045-3000 Page 3