Honeywell Bendix/King Silver Crown Plus Pilot's Manual page 48

Silver Crown Plus Pilot's Guide
pressing the FRQ button, then
transferred to active use by pressing
the FRQ button again.
While FLT or ET is displayed the
"in use" frequency on the left side of
the window may be changed, by using
the frequency select knobs, without
any effect on the stored standby
frequency or the other modes. This
feature is especially useful when
searching for stations with unknown
frequencies.
Erroneous ADF Bearings
Due to Radio Frequency
Phenomena
Station Overlap
In the U.S., the FCC, which
assigns AM radio frequencies,
occasionally will assign the same
frequency to more than one station in
an area. Certain conditions, such as
Night Effect, may cause signals from
such stations to overlap. This should
be taken into consideration when
using AM broadcast stations for
navigation.
Sunspots and atmospheric
phenomena may occasionally distort
reception so that signals from two
stations on the same frequency will
overlap. For this reason it is always
wise to make positive identification of
the station being tuned, by switching
44
the function selector to ANT and
listening for station call letters.
Electrical Storms
In the vicinity of electrical storms,
an ADF Indicator pointer tends to
swing from the station tuned toward
the electrical discharges. Location of
the storm can be useful information,
but the erratic behavior of the pointer
should be taken into account.
Night Effect
This is a disturbance particularly
strong just after sunset and just after
dawn. An ADF indicator pointer may
swing erratically at these times. If
possible, tune to the most powerful
station at the lowest frequency. If this
is not possible, take the average of
pointer oscillations to determine
relative station bearing.
Mountain Effect
Radio waves reflecting from the
surface of mountains may cause the
pointer to fluctuate or show an
erroneous bearing. This should be
taken into account when taking
bearings over mountainous terrain.
Coastal Refraction
Radio waves may be refracted
when passing from land to sea or
when moving parallel to the coastline.
This should be taken into account
when operating near coastal areas.