PS Engineering
PMA5000EX Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-550-0100
Page 2-3
Rev. 3, Dec. 2015
NOTE
Adding a high-performance audio control system, particularly in conjunction with high-performance active
noise canceling headsets, cannot improve on older avionics that were designed for cabin-speaker use. PS
Engineering makes no claim that the audio panel will provide a noise-free audio quality under all installa-
tion conditions, particularly with older avionics.
2.4.2
Power
The PMA5000EX is compatible with both 14 and 28 Volt DC systems. A five (5) Amp circuit breaker is
required for all installations. Power and ground wires should be #22 connected to J2 Pins 8 and 9. Connect
airframe ground to J2 Pin 10 and 11 only. No dropping resistors are required.
2.4.3
Communications Push-to-Talk
An important part of the installation is the PTT (Push-To-Talk) switches that allow the use of your aircraft
communications radio for transmissions. There are three typical configurations that can be used. Select the
case that best fits the installation. Only the person who presses their PTT switch will be heard over the ra-
dio. If the pilot and copilot both use the PTT, the only pilot position has access to the radio. The pilot posi-
tion will have PTT control regardless of the mic selector switch or copilot PTT when the PMA5000EX is in
the
OFF
/E
MG
mode.
CASE I
: PTT is built into both pilot and copilot yokes.
CASE II:
PTT is in pilot yoke only. This configuration requires a modified external PTT switch plugged
into the copilot's microphone jack. (See Appendix A). When the copilot's PTT is pressed, the intercom
switches the microphone audio from pilot to copilot mic.
CASE III
: No built in PTT. This requires two built in PTTs to be installed, or modified external PTT
switches to be used. Modify external PTT as required. See Appendix A.
2.4.4
Audio Panel interface
The PMA5000EX is designed to interface with standard aircraft avionics, and presents a 510
receiver
impedance. For best results, a twisted-shielded cable is recommended from the avionics audio source to the
audio panel, with the shield grounded at the audio panel end.
Some avionics do not provide a separate audio low, and may introduce additional electrical noise into the
system. For best results, connect the audio low from the audio panel to the radio ground, using one conduc-
tor of the twisted-shielded cable.
2.4.5
TEL (Duplex) Function for Cell Phones
The TEL mode in the PMA5000EX is compatible with many cellular telephones with hands-free headset
interfaces. The front panel 3/32” utility jack can be used as the interface to the Cell Phone, or a 3/32” jack
can be installed somewhere on the aircraft panel. The wired interface jack is connected with the
PMA5000EX as shown: A patch cord (3/32” to 3/32”) is available from PS Engineering under P/N 425-
006-7026.
3/32" Cellular Jack
COM 3 Mic Input
Com 3 Audio
Audio Lo
3
5
4
PMA5000EX
J1
Cellular Plug (typical)
Tip= Microphone out
Ring= Speaker audio
Base=Ground
This is a typical interconnect
PS Engineering does not guarantee
compatability in all cases.
Cellular Phone
Interconnect