PS Engineering PMA8000B Installation Manual - Manual (Page 11)

PS Engineering
PMA8000B Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-890-0101 Page 2-4 Rev. 4, April 2012
2.4.5 Audio Panel interface
The PMA8000B 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 con-
ductor of the twisted-shielded cable.
2.4.5.1 Speaker Load
The PMA8000B contains one speaker amplifier. Some units with internal speaker amplifiers, such as the
King Radio KX170-series, require a resistive load to prevent damage if their speaker amplifier is not used.
Connect the speaker output from the unit to the COM 2 Speaker load input on the PMA8000B (J1 27
WRT 28). The speaker load is 16 , 3W.
2.4.6 TEL (Duplex) Function for Cell Phones
This mode is designed to operate with telecommunications systems, such as the AirCell Guardian 1000.
Audio streams selected by the intercom mode are provided to the Tel output, and audio from Tel is pre-
sented to the headset. This allows a telephone-like audio interface.
The TEL mode in the PMA8000B is also compatible with many cellular telephones with hands-free head-
set 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
PMA8000B 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
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
Figure 2-1 Cellular telephone interface for rear connector, if an additional jack is desired
2.4.6.1 Cell phone Sidetone
As shipped from PS Engineering, the PMA8000B does NOT provide cellular telephone sidetone (the
user’s voice fed back to the headset). Some cell phones do not provide sidetone. In PMA8000B audio pan-
els above serial number W04748, Telephone sidetone can be enabled by pressing the TEL and ADF but-
tons for more than one second. For units with serial number W04747 and below, an internal modification
can be made that will allow the PMA8000B to provide sidetone. Contact PS Engineering for more infor-
mation.
NOTE
Unauthorized use of unapproved cellular telephone devices in aircraft is subject to FCC enforcement ac-
tion, which may include a $10,000 fine per incident. PS Engineering, Inc. does not endorse using unap-
proved cellular telephone equipment in flight, and takes no responsibility for the user’s action.