PS Engineering PMA4000 Installation Manual - Manual (Page 15)

PS Engineering
PMA4000 Series Audio Selector Panel and IntelliVox™ Intercom System
Installation Manual
200-041-0002 Page 3-3 Rev 5, March 2007
noise appearing in all four microphones is constantly being sampled. Non-voice signals
are blocked. When someone speaks, only their microphone circuit opens, placing their
voice on the intercom.
The system is designed to block continuous tones, therefore people humming or whistling
in monotone may be blocked after a few moments.
For best performance, the headset microphone must be placed within ¼ inch of your lips,
preferably against them. It is also a good idea to keep the microphone out of a direct wind
path. Moving your head through a vent air stream may cause the IntelliVox™ to open
momentarily. This is normal.
For optimum microphone performance, PS Engineering, Inc. recommends installation of
a Microphone Muff Kit from Oregon Aero (1-800-888-6910). This will not only optimize
VOX performance, but will improve the overall clarity of all your communications.
Table 3-1 Mic Muff ™ Part Numbers
Manufacturer Model Mic Muff™ Part
Number
Bose Dynamic
Electret
M87 Dynamic
90010
90015
90020
David Clark H10-30
H10-20, H10-40
H10-13.4 90010
90015
90015
Lightspeed 15K & 20K 90015
Peltor 7003
7004
90010
90015
Pilot 11-20 & 11-90 90015
Sennheiser 90015
Telex Airman 750
AIR3000
90015
90010
3.3.3 Intercom Modes
The audio selector panel has provisions for an entertainment input device.
While in the ISO (Isolate) mode, only the copilot and the four passengers will hear enter-
tainment device. In normal operation, whenever a person speaks or if the aircraft radio
becomes active, the music will automatically mute and then will gradually return to the
original listening level when the radio or intercom activity ceases.
If a stereo entertainment device is used, the left and right channels can be combined in
the plug to provide full sound.