PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800
Page 1-1
July 2022
Section I – GENERAL INFORMATION
1.1
INTRODUCTION
The PMA450C represents a revolutionary step in cockpit audio control and intercommunications utility. In-
telliAudio®, using the USAF patented technology, provides True Dimensional Sound, which helps pilots to
easily discern simultaneous radio receptions. Our patented
IntelliVox®
design, front panel USB power jack,
and pilot programmable configurations, marks this panel as the next level of audio control. The unit is de-
signed for outstanding ergonomics and visually defined mode annunciation and selection.
Before installing and/or using this product, please read this manual completely. This will ensure that you will
take full advantage of all the advanced features in the PMA450C.
1.2
SCOPE
This manual provides detailed installation and operation instructions for the PS Engineering PMA450C-
series of Audio Selector Panel/Intercom Systems. This includes the following units:
Model
Part Number
Marker Receiver
PMA450C
050-450-0801
YES
PMA450C
050-450-0901
NO
1.3
EQUIPMENT DESCRIPTION
The PMA450C is a state-of-the-art audio isolation amplifier and audio selector that contains an automatic
voice activated (VOX) intercom system and integral marker beacon receiver. It can switch two transceivers
(Com 1, Com 2) and six receivers (Nav 1, Nav 2, MKR, and three additional inputs that can be individually
labeled, for use with ADF, DME AUX, etc.).
Warning
: Use of non-aviation approved cellular telephone equipment may be prohibited by FCC regulation.
PS Engineering is not responsible for unauthorized airborne use of cellular telephones.
For airborne use, the PMA450C must be interfaced with an approved system.
There are four unswitched inputs, available for traffic or EGPWS, autopilot disconnect, and/or radar altimeter
warning.
Pushbuttons select the receiver audio source provided to the headphones. A SPR button allows the user to
listen to the receiver(s) selected on the cabin speaker. Except for the unswitched inputs, all speaker audio is
muted during transmit. Unswitched inputs 1& 2 are always presented to the aircraft speaker. Unswitched
input 3 & 4 will be presented to the speaker when the front panel SPR push button has been selected.
Pushbutton switches select one of the communication transceivers for the pilot and copilot position, and allow
radio transmission. In "Split Mode”, the PMA450C has the ability to allow the pilot to transmit on Com 1
while the copilot can transmit on Com 2. A fail-safe mode connects the pilot headphone and microphone to
COM 1 if power is removed for any reason, or if the power switch is placed in the Off (Fail-safe) position.
Unswitched input #1 is also provided to the pilot headphone (left side headset ear cup) in fail-safe
A six-station voice activated (VOX) intercom is included in the PMA450C. This system has PS Engineering’s
patented
IntelliVox®
circuitry that eliminates manual adjustments. The intercom system incorporates pilot
isolate, all and crew modes, two independent stereo music inputs with "SoftMute™". Intercom volume con-
trol is through two concentric front panel knobs and a pushbutton intercom mode switch. The small volume
knob controls the intercom level for the pilot and copilot, while the large knob controls the passenger inter-
com volume. Intercom squelch is automatic.
PMA450C part number 050-450-0801 contains a 75 MHz Marker Beacon receiver and 3-light indicator. This
provides the necessary Marker Beacon lights and audio indications necessary for that portion of an Instrument
