P/N 11934-S01
9 of 10
Cirrus Design
Section 9
SR20
Supplements
Marker beacon audio is selected by pressing the MKR push-button. If
no marker beacon signal is being received, pressing the MKR push-
button a second time deselects marker beacon audio. However, if
marker beacon is being received, pressing the MKR push-button a
second time will mute the audio but the light will continue to flash.
Pressing the MKR push-button a third time (while marker beacon
audio is muted) deselects marker beacon audio. Marker beacon audio
muting automatically disables when the current signal is no longer
received.
• Note •
The marker beacon lamps (O, M, A) operate independently of
the audio and cannot be disabled.
Marker beacon light and audio keying for ILS approach are
summarized below:
Marker Beacon Sensitivity
The SENS push-button on the left side of the panel is used to set the
marker beacon receiver sensitivity. The selected sensitivity level is
indicated by illumination of the HIGH or LOW LED. When HIGH
sensitivity is selected, the outer marker beacon tone will sound farther
out. Selecting LOW sensitivity at this point allows more accurate
location of the Outer Marker. Typically, HIGH sensitivity is selected
until the outer marker tone is heard, and then LOW sensitivity is
selected for more accurate outer marker location.
O (Blue)
Outer Marker light and associated 400 Hertz tone. The
light and tone are keyed at a rate of two tones/flashes per
second.
M (Amber)
Middle Marker light and associated 1300 Hertz tone. The
light and tone are keyed alternately with short and long
bursts.
A (White)
Airway/Inner Marker light and associated 3000 Hertz
tone. The light and tone are keyed at a rate of six times
per second.
Revision 1: 07-18-05
