PS Engineering PMA8000D Installation Manual - Manual (Page 28)

PS Engineering
PMA8000D Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-890-0304 Page 3-4 Rev. 6, Oct. 2014
heard over the speaker. During Public Address, the Mute and SPR buttons will flash. To exit PA mode,
push Mute and SPR again. This feature is reset at power cycles.
3.6 Marker Beacon Operation (9)
The Marker Beacon Receiver uses visual and audio indicators to alert you when the aircraft passes over a
75 MHz transmitter.
The Blue lamp, labeled “O”, is the Outer Marker lamp and has an associated 400-Hertz 'dash' tone. The
lamp and tone will be keyed at a rate of two tones/flashes per second when the
aircraft is in the range of the Outer Marker Beacon.
The Amber lamp, labeled “M”, is the Middle Marker lamp and is coupled with a
1300 Hertz tone. It is keyed alternately with short 'dot' and long 'dash' bursts at 95
combinations per minute.
The White lamp, labeled “I”, is the Inner marker and has a 3000 Hertz 'dot' tone. The lamp and tone will be
keyed at a rate of six times per second.
The audio from the Marker Beacon Receiver can be heard by pushing the "MKR" push-button switch mo-
mentarily.
A marker AUD LED will indicate the marker beacon audio has been selected.
To adjust the volume level, there is a service adjustment located on the top of the unit.
The Marker Sensitivity is controlled by an external switch, labeled MKR HI sense. When switched to
ground, the marker receiver is in high sensitivity, otherwise, the marker is in LOW sense by default, and the
“LOW” indicator on the audio panel is illuminated.
Holding the MKR button for one second activates marker test lamp, labeled "T/M" and illuminates all three
lamps simultaneously to assure the lamps (internal and external) are in working order. T/M does not acti-
vate MM autopilot sense output.
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 sam-
pled. 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, preferably 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.