BendixKing KXP 756 - Manual (Page 41)

40
Marker Beacon
marker the pilot hears a medium
pitched tone in a series of dots and
dashes and the amber light flashes
synchronously with the tones.
The inner marker is located close
to the end of the runway. The beacon
transmitter and antenna project a
vertical cone shaped pattern of radio
frequency energy. The radio
frequency output of the transmitter is
modulated with an audio tone of
3000Hz. An aircraft equipped with the
KMR 675 will receiver a 3000Hz tone
in headphone or speaker and the
white lamp will be on while over the
station. The inner marker is used to
indicate a point approximately 1500
feet from the runway and if on proper
glide path the altitude above the
runway should be approximately 100
feet. The inner marker is used for Cat.
II ILS approaches.
The optional Hi-Lo Switch in the
KMR 675 provides sensitivity
switching control. Many marker
receivers provide only a “low
sensitivity” position. The effect of the
high sensitivity position is to greatly
enlarge the size of the cone shaped
“area of indication” above the station.
An aircraft flying at high altitude or
slightly off course may fail to receive
the signal when in the low sensitivity
position. It is suggested that the KMR
675 marker sensitivity switch first be
placed in high sensitivity position until
aural and/or lamp indication is
received. The control switch may be
turned to low sensitivity to reduce the
duration of the indication and to obtain
a more accurate reading of passage
since the signal appears to build and
KA 35 When Used With the
KMR 675
Marker beacon receivers are
used to provide accurate fixes by
informing the pilot of his passage over
beacon stations located on airways
and ILS approach courses. Three
types of beacons are used. They are
the inner marker, the outer marker and
the middle marker.
The outer, middle and inner
markers are used in conjunction with
the radio instrument landing systems.
The outer marker is normally
positioned on the front localizer course
near the point where the glideslope
approach path intersects the minimum
inbound altitude after the procedure
turn. Distance from the airport will
vary from 4 to 7 miles. Radio
frequency from the marker is projected
vertically in an elliptical cone shaped
pattern. The marker signal is
modulated at 400Hz and is keyed to
emit dashes at a rate of two per
second.
When passing the outer marker
the blue light will falsh “on/off” at a two
per second rate and the pilot will hear
a series of low tone dashes.
The middle marker is normally
located on the front localizer course
about 3200 feet from the approach
end of the ILS runway. The radiated
pattern is similar in shape and power
to the outer marker. The middle
marker signal is modulated with
1300Hz and the modulation is keyed
to identify by alternate dots and
dashes. When the KMR 675
equipped aircraft passes the middle