rotate 180° and again indicate the magnetic bearing to station.
Distance range (ADF) - Check as follows:
(1) Mode selector switch ADF.
(2) Tune control - Tune stations to determine operating range of direction finder. End of effective
operating range may be considered to be reached when the RMI bearing needle fails to return
to within three degrees of starting bearing when loop is slewed first clockwise and then
*9. Marker beacon/glideslope receiver - Check as follows:
Marker beacon volume control (pedestal extension) - Rotate rotate full clockwise.
NAV A control (pilot's audio control panel) - Push on and turn clockwise to adjust volume. Clear
audio signals should be available.
Marker beacon sensitivity switch (pedestal extension) - As required.
Frequency selectors (VOR control panel) - Select localizer frequency.