Standard Horizon HX-471S - Manual (Page 12)

HX471S Page 10
3.3 ABOUT RECEIVE ONLY CHANNELS and FREQUENCIES
AM/FM Broadcast Bands
The AM/FM bands contained within the HX471S are the same channels you
use every day to listen to music, news and commentary with your car or
home stereo.
The AM broadcast band currently extends from 530
to 1700 kHz. Channels are spaced in even 10 kHz
increments; i.e.: 530, 540, 550, ... , 1600 kHz in the
United States and Canada. Elsewhere, channels are
spaced in 9 kHz increments, i.e.: 531, 540, 549, etc.
The FM broadcast band in the United States extends
from 88 to 108 MHz. Channels are assigned at 200
kHz increments; i.e.: 88.1, 88.3, 88.5, ... , 107.9. The
channels from 88.1 to 91.9 are reserved for non-
commercial educational stations. Outside the United States and Canada,
the boundaries and channel spacing vary. In Japan, the band starts at 76
MHz. In Western Europe, the band generally runs from 88-108 MHz, but
channels can be irregularly spaced, i.e.: 101.25 MHz.
AIR (Aircraft) Bands
The AM VHF aeronautical communications band lies
between 108.000 MHz and 136.975 MHz. This fre-
quency spectrum can be divided into a lower and
upper range. The lower range between 108.000 MHz
and 118.000 MHz is primarily used for navigational aids such as the ILS -
Instrument Landing Systems, DME - Distance Measuring Equipment, and
VOR’s - Very High Frequency Omni Range. The lower range offers very little
in the way of voice communications, it does however provide someone with
a working knowledge of Morse code the opportunity to identify various bea-
cons. The upper range of the aeronautical band 118.000 MHz to 136.975
MHz is where the majority of voice communications can be monitored. Com-
munications in the VHF band are transmitted in AM mode and most if not all
compatible receivers automatically default to this mode. Frequencies within
the aeronautical range are spaced in increments of 25 kHz, as such you will
find transmissions at 118.000, 118.025, 118.050 MHz etc.
The frequency(s) you monitor will determine the nature of traffic you will
hear. As previously mentioned frequencies in the lower range of the aero-