PS Engineering PMA450 Installation Manual - Manual (Page 25)

PS Engineering
PMA450 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0000 Page 3-5 Rev. 3, November 2014
When PA mode is active, all microphones except for the Pilot will be disabled for complete and uninter-
rupted announcements.
The pilot microphone will be heard on the speaker and headsets when the pilot PTT is used.
The copilot can continue to use the selected com radio while the pilot will be heard over the speaker.
To exit PA mode, push and hold the middle line-select button again until PUBLIC ADDRESS is off or
cycle power on the audio panel.
3.7 Marker Beacon Operation (9) (unit part number 050-450-0100, only)
The Marker Beacon Receiver uses visual and audio indicators to alert you when the aircraft passes over a
75 MHz transmitter.
The audio from the Marker Beacon Receiver can be heard by pushing the "MKR" button. AUD will light
up green.
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 air-
craft 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 combi-
nations 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.
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. TST does not
activate MM autopilot sense output. Releasing the button returns to the last sensitivity.
Pressing the marker mode select (“T/M”)
for one second, while beacon audio is ac-
tive, will also cause the marker audio to
mute for that beacon. The next beacon re-
ceived will re-activate the audio.
The marker beacon receiver audio volume
can be adjusted from the menu.
Press RADIO → VOLUMES →