Intercom operation, Intellivox® vox-squelch, Intercom volume control (7) – PS Engineering PMA8000B Installation Manual User Manual
Page 25: Ntercom, Peration, Ntelli, Vox-s, Quelch, Olume, Ontrol

PS Engineering
PMA8000B Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-890-0101
Page 3-4
Rev. 4, April 2012
ternal) are in working order. TST does not activate MM autopilot sense output. Releasing the button re-
turns to the last sensitivity. 
Pressing the marker mode select (“T/M”) for one second will also cause the marker audio to mute for that 
beacon. The next beacon received will re-activate the audio. 
3.7 Intercom Operation
3.7.1
IntelliVox® VOX-Squelch
No adjustment of the IntelliVox® squelch control is necessary. There is no field adjustment. Through 
three individual signal processors, the ambient noise appearing in all six 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 consistent performance, any headset microphone must be placed within ¼-inch of your lips, prefera-
bly against them. (ref: RTCA/DO-214, 1.3.1.1 (a)). 
NOTE
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. 
The IntelliVox® is designed to work with normal aircraft cabin noise levels (70 dB and above). It loves 
airplane noise! Therefore, it may not recognize speech and clip syllables in a quiet cabin, such as in the 
hangar, or without the engine running. This is normal. 
For optimum microphone performance, PS Engineering 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. 
 
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
All
90015
Peltor
7003 
7004 
90010 
90015 
Pilot
11-20 & 11-90
90015
Sennheiser
90015
Telex
Airman 750, Echelon 
AIR3000 
90015 
90010 
Table 3-1 Mic Muff ™ Part Numbers
3.7.2
Intercom Volume Control (7)
The inner volume control knob adjusts the loudness of the intercom for the pilot and copilot. It has no 
effect on selected radio levels, music input levels or passengers' volume level. 
The outer volume control knob controls intercom volume for the passengers. It has no effect on radio or 
music levels. 
Adjust the radios and intercom volume for a comfortable listening level. Most general aviation headsets 
today have built-in volume controls; therefore, volume also can be further adjusted at the individual head-
set. 
