PS Engineering
PMA450B Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0600
Page 3-1
Rev. 5, August 2020
Section III OPERATION
SCOPE
This section provides detailed operating instructions for the PS Engineering PMA450B, Audio Selector
Panel/Marker Beacon Receiver/Intercom Systems. Please read it carefully before using the equipment so that
you can take full advantage of its capabilities.
This section is divided into sections covering the basic operating areas of the PMA450B systems. They are
Communications Transceiver Selection, Audio Selector, Intercom, Marker Beacon Receiver and special
functions, including the Bluetooth® functionality in the PMA450B.
1
2
3
4
5
6
8
9
7
10
1. Volume on/off
2. Transmit Selection
3. Receiver Selection
4. Navaid Selection
5. Line Select buttons
6. OLED Display
7. Speaker Selection
8. Intercom Mode
9. Marker
10. USB Power Port
Figure 3-1 PMA450B Operating Controls
Power and Fail Safe (1)
The PMA450B will automatically power up when avionics bus voltage is applied. Unit power can also be
turned off and on by pushing the volume knob (1). There is a built-in delay to prevent accidental shut off
while adjusting the intercom volume in turbulent conditions. In the
OFF
or "
EMG
" position, the pilot headset
is connected directly to Com 1 as well as unswitched input #1. This allows communication capability regard-
less of unit condition. Any time power is removed or turned
OFF
, the audio selector 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 stereo mode.
The power switch controls all audio selector panel functions, intercom and marker beacon receiver. All trans-
ceiver and receiver selections will be remembered and return to the last state when turned on.
Display Menu Selection (6)
The PMA450B uses an Organic Light Emitting Diode (OLED) Display and three line-select buttons to access
advanced functionality in a very logical manner. Press the line select key to select a specific item on each