PS Engineering PMA8000MP3 Pilot’s Guide - Manual (Page 7)

Page 7 Oct. 2010 PMA8000B MP3
the original level after communications have been completed.
C
REW : Pilot and copilot are connected on one intercom channel and
have exclusive access to the aircraft radios. Again, the music that the
crew and passengers will hear is determined by the Smart Function
Keys.
Marker Beacon Operation (10)
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 cou-
pled 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 Re-
ceiver can be heard by
selecting the "MKR"
push-button switch. To
adjust the volume level,
there is a service adjustment located on the top of the unit.
A pushbutton is used to set the receiver sensitivity and to test the indi-
cator lamps mute the marker audio.
Use "HI" sensitivity initially. This allows you to hear the outer
marker beacon about a mile out. Then touch the smaller MKR button
to switch into Low Sensitivity mode. “LO” sensitivity gives you a
more accurate location of the Outer Marker. Holding the MKR button
for one second activates marker test indicator, labeled "T/M" and illu-
minates all three lamps simultaneously to assure the lamps (internal
and external) are in working order. Test mode does not activate MM
autopilot sense output. Releasing the button returns to the last sensi-
tivity.
Pressing the marker mode select (“T/M”) for one second will also