<s>
Very	B-Algorithm
high	I-Algorithm
frequency	I-Algorithm
(	O
VHF	B-Algorithm
)	O
is	O
the	O
ITU	O
designation	O
for	O
the	O
range	O
of	O
radio	O
frequency	O
electromagnetic	O
waves	O
(	O
radio	O
waves	O
)	O
from	O
30	O
to	O
300	O
megahertz	O
(	O
MHz	O
)	O
,	O
with	O
corresponding	O
wavelengths	O
of	O
ten	O
meters	O
to	O
one	O
meter	O
.	O
</s>
<s>
Frequencies	O
immediately	O
below	O
VHF	B-Algorithm
are	O
denoted	O
high	B-Algorithm
frequency	I-Algorithm
(	O
HF	B-Algorithm
)	O
,	O
and	O
the	O
next	O
higher	O
frequencies	O
are	O
known	O
as	O
ultra	O
high	B-Algorithm
frequency	I-Algorithm
(	O
UHF	O
)	O
.	O
</s>
<s>
VHF	B-Algorithm
radio	O
waves	O
propagate	O
mainly	O
by	O
line-of-sight	O
,	O
so	O
they	O
are	O
blocked	O
by	O
hills	O
and	O
mountains	O
,	O
although	O
due	O
to	O
refraction	O
they	O
can	O
travel	O
somewhat	O
beyond	O
the	O
visual	O
horizon	O
out	O
to	O
about	O
160km	O
(	O
100	O
miles	O
)	O
.	O
</s>
<s>
Common	O
uses	O
for	O
radio	O
waves	O
in	O
the	O
VHF	B-Algorithm
band	I-Algorithm
are	O
Digital	O
Audio	O
Broadcasting	O
(	O
DAB	O
)	O
and	O
FM	B-Application
radio	O
broadcasting	O
,	O
television	O
broadcasting	O
,	O
two-way	O
land	O
mobile	O
radio	O
systems	O
(	O
emergency	O
,	O
business	O
,	O
private	O
use	O
and	O
military	O
)	O
,	O
long	O
range	O
data	O
communication	O
up	O
to	O
several	O
tens	O
of	O
kilometers	O
with	O
radio	B-General_Concept
modems	I-General_Concept
,	O
amateur	O
radio	O
,	O
and	O
marine	O
communications	O
.	O
</s>
<s>
Air	B-Application
traffic	I-Application
control	I-Application
communications	O
and	O
air	O
navigation	O
systems	O
(	O
e.g.	O
</s>
<s>
VOR	B-Device
and	O
ILS	O
)	O
work	O
at	O
distances	O
of	O
or	O
more	O
to	O
aircraft	O
at	O
cruising	O
altitude	O
.	O
</s>
<s>
In	O
the	O
Americas	O
and	O
many	O
other	O
parts	O
of	O
the	O
world	O
,	O
VHF	B-Algorithm
Band	I-Algorithm
I	O
was	O
used	O
for	O
the	O
transmission	O
of	O
analog	O
television	O
.	O
</s>
<s>
As	O
part	O
of	O
the	O
worldwide	O
transition	O
to	O
digital	O
terrestrial	O
television	O
most	O
countries	O
require	O
broadcasters	O
to	O
air	O
television	O
in	O
the	O
VHF	B-Algorithm
range	O
using	O
digital	O
,	O
rather	O
than	O
analog	O
encoding	O
.	O
</s>
<s>
Radio	O
waves	O
in	O
the	O
VHF	B-Algorithm
band	I-Algorithm
propagate	O
mainly	O
by	O
line-of-sight	O
and	O
ground-bounce	O
paths	O
;	O
unlike	O
in	O
the	O
HF	B-Algorithm
band	O
there	O
is	O
only	O
some	O
reflection	O
at	O
lower	O
frequencies	O
from	O
the	O
ionosphere	O
(	O
skywave	O
propagation	O
)	O
.	O
</s>
<s>
The	O
VHF	B-Algorithm
band	I-Algorithm
is	I-Algorithm
the	O
first	O
band	O
at	O
which	O
efficient	O
transmitting	O
antennas	O
are	O
small	O
enough	O
that	O
they	O
can	O
be	O
mounted	O
on	O
vehicles	O
and	O
portable	O
devices	O
,	O
so	O
the	O
band	B-Algorithm
is	I-Algorithm
used	O
for	O
two-way	O
land	O
mobile	O
radio	O
systems	O
,	O
such	O
as	O
walkie-talkies	B-Application
,	O
and	O
two	O
way	O
radio	O
communication	O
with	O
aircraft	O
(	O
Airband	B-Algorithm
)	O
and	O
ships	O
(	O
marine	O
radio	O
)	O
.	O
</s>
<s>
Occasionally	O
,	O
when	O
conditions	O
are	O
right	O
,	O
VHF	B-Algorithm
waves	O
can	O
travel	O
long	O
distances	O
by	O
tropospheric	O
ducting	O
due	O
to	O
refraction	O
by	O
temperature	O
gradients	O
in	O
the	O
atmosphere	O
.	O
</s>
<s>
VHF	B-Algorithm
transmission	O
range	O
is	O
a	O
function	O
of	O
transmitter	O
power	O
,	O
receiver	O
sensitivity	O
,	O
and	O
distance	O
to	O
the	O
horizon	O
,	O
since	O
VHF	B-Algorithm
signals	O
propagate	O
under	O
normal	O
conditions	O
as	O
a	O
near	O
line-of-sight	O
phenomenon	O
.	O
</s>
<s>
VHF	B-Algorithm
is	I-Algorithm
the	O
first	O
band	O
at	O
which	O
wavelengths	O
are	O
small	O
enough	O
that	O
efficient	O
transmitting	O
antennas	O
are	O
short	O
enough	O
to	O
mount	O
on	O
vehicles	O
and	O
handheld	O
devices	O
,	O
a	O
quarter	O
wave	O
whip	O
antenna	O
at	O
VHF	B-Algorithm
frequencies	O
is	O
25cm	O
to	O
2.5	O
meter	O
(	O
10	O
inches	O
to	O
8	O
feet	O
)	O
long	O
.	O
</s>
<s>
So	O
the	O
VHF	B-Algorithm
and	O
UHF	O
wavelengths	O
are	O
used	O
for	O
two-way	O
radios	O
in	O
vehicles	O
,	O
aircraft	O
,	O
and	O
handheld	O
transceivers	O
and	O
walkie-talkies	B-Application
.	O
</s>
<s>
For	O
even	O
higher	O
gain	O
,	O
multiple	O
Yagis	O
or	O
helicals	O
can	O
be	O
mounted	O
together	O
to	O
make	O
array	B-Algorithm
antennas	I-Algorithm
.	O
</s>
<s>
Television	O
and	O
FM	B-Application
broadcasting	O
stations	O
use	O
collinear	O
arrays	O
of	O
specialized	O
dipole	O
antennas	O
such	O
as	O
batwing	O
antennas	O
.	O
</s>
<s>
Certain	O
subparts	O
of	O
the	O
VHF	B-Algorithm
band	I-Algorithm
have	O
the	O
same	O
use	O
around	O
the	O
world	O
.	O
</s>
<s>
5054MHz	O
:	O
Amateur	O
Radio	O
6-meter	B-Algorithm
band	I-Algorithm
.	O
</s>
<s>
108118MHz	O
:	O
Air	O
navigation	O
beacons	O
VOR	B-Device
and	O
Instrument	O
Landing	O
System	O
localizer	O
.	O
</s>
<s>
144146MHz	O
:	O
Amateur	O
Radio	O
2-meter	B-Algorithm
band	I-Algorithm
(	O
Extends	O
up	O
to	O
148MHz	O
in	O
some	O
Regions	O
)	O
.	O
</s>
<s>
156174MHz	O
:	O
VHF	B-Algorithm
maritime	O
mobile	O
band	O
for	O
maritime	O
two-way	O
radio	O
on	O
ships	O
.	O
</s>
<s>
The	O
VHF	B-Algorithm
TV	O
band	O
in	O
Australia	O
was	O
originally	O
allocated	O
channels	O
1	O
to	O
10-with	O
channels2	O
,	O
7	O
and	O
9	O
assigned	O
for	O
the	O
initial	O
services	O
in	O
Sydney	O
and	O
Melbourne	O
,	O
and	O
later	O
the	O
same	O
channels	O
were	O
assigned	O
in	O
Brisbane	O
,	O
Adelaide	O
and	O
Perth	O
.	O
</s>
<s>
Several	O
TV	O
stations	O
were	O
allocated	O
to	O
VHF	B-Algorithm
channels3	O
,	O
4	O
and	O
5	O
,	O
which	O
were	O
within	O
the	O
FM	B-Application
radio	O
bands	O
although	O
not	O
yet	O
used	O
for	O
that	O
purpose	O
.	O
</s>
<s>
While	O
some	O
Channel5	O
stations	O
were	O
moved	O
to	O
5A	O
in	O
the	O
1970s	O
and	O
80s	O
,	O
beginning	O
in	O
the	O
1990s	O
,	O
the	O
Australian	O
Broadcasting	O
Authority	O
began	O
a	O
process	O
to	O
move	O
these	O
stations	O
to	O
UHF	O
bands	O
to	O
free	O
up	O
valuable	O
VHF	B-Algorithm
spectrum	O
for	O
its	O
original	O
purpose	O
of	O
FM	B-Application
radio	O
.	O
</s>
<s>
Two	O
new	O
VHF	B-Algorithm
channels	O
,	O
9A	O
and	O
12	O
,	O
have	O
since	O
been	O
made	O
available	O
and	O
are	O
being	O
used	O
primarily	O
for	O
digital	O
services	O
(	O
e.g.	O
</s>
<s>
VHF	B-Algorithm
radio	O
is	O
also	O
used	O
for	O
marine	O
Radio	O
as	O
per	O
its	O
long-distance	O
reachability	O
comparing	O
UHF	O
frequencies	O
.	O
</s>
<s>
Example	O
allocation	O
of	O
VHF	B-Algorithm
–	O
UHF	O
frequencies	O
:	O
</s>
<s>
Until	O
2013	O
,	O
the	O
four	O
main	O
free-to-air	O
TV	O
stations	O
in	O
New	O
Zealand	O
used	O
the	O
VHF	B-Algorithm
television	O
bands	O
(	O
Band	B-Algorithm
I	I-Algorithm
and	O
Band	B-Algorithm
III	I-Algorithm
)	O
to	O
transmit	O
to	O
New	O
Zealand	O
households	O
.	O
</s>
<s>
Other	O
stations	O
,	O
including	O
a	O
variety	O
of	O
pay	O
and	O
regional	O
free-to-air	O
stations	O
,	O
were	O
forced	O
to	O
broadcast	O
in	O
the	O
UHF	O
band	O
,	O
since	O
the	O
VHF	B-Algorithm
band	I-Algorithm
had	O
been	O
very	O
overloaded	O
with	O
four	O
stations	O
sharing	O
a	O
very	O
small	O
frequency	O
band	O
,	O
which	O
was	O
so	O
overcrowded	O
that	O
one	O
or	O
more	O
channels	O
would	O
not	O
be	O
available	O
in	O
some	O
smaller	O
towns	O
.	O
</s>
<s>
However	O
,	O
at	O
the	O
end	O
of	O
2013	O
,	O
all	O
television	O
channels	O
stopped	O
broadcasting	O
on	O
the	O
VHF	B-Algorithm
bands	I-Algorithm
,	O
as	O
New	O
Zealand	O
moved	O
to	O
digital	O
television	O
broadcasting	O
,	O
requiring	O
all	O
stations	O
to	O
either	O
broadcast	O
on	O
UHF	O
or	O
satellite	O
(	O
where	O
UHF	O
was	O
unavailable	O
)	O
utilising	O
the	O
Freeview	O
service	O
.	O
</s>
<s>
British	O
television	O
originally	O
used	O
VHF	B-Algorithm
band	I-Algorithm
I	O
and	O
band	B-Algorithm
III	I-Algorithm
.	O
</s>
<s>
Television	O
on	O
VHF	B-Algorithm
was	O
in	O
black	O
and	O
white	O
with	O
405-line	O
format	O
(	O
although	O
there	O
were	O
experiments	O
with	O
all	O
three	O
colour	O
systems-NTSC	O
,	O
PAL	B-Language
,	O
and	O
SECAM-adapted	O
for	O
the	O
405-line	O
system	O
in	O
the	O
late	O
1950s	O
and	O
early	O
60s	O
)	O
.	O
</s>
<s>
From	O
then	O
on	O
,	O
TV	O
was	O
broadcast	O
on	O
both	O
VHF	B-Algorithm
and	O
UHF	O
(	O
VHF	B-Algorithm
being	O
a	O
monochromatic	O
downconversion	O
from	O
the	O
625-line	O
colour	O
signal	O
)	O
,	O
with	O
the	O
exception	O
of	O
BBC2	O
(	O
which	O
had	O
always	O
broadcast	O
solely	O
on	O
UHF	O
)	O
.	O
</s>
<s>
The	O
last	O
British	O
VHF	B-Algorithm
TV	O
transmitters	O
closed	O
down	O
on	O
January	O
3	O
,	O
1985	O
.	O
</s>
<s>
VHF	B-Algorithm
band	I-Algorithm
III	O
is	O
now	O
used	O
in	O
the	O
UK	O
for	O
digital	O
audio	O
broadcasting	O
,	O
and	O
VHF	B-Algorithm
band	I-Algorithm
II	O
is	O
used	O
for	O
FM	B-Application
radio	O
,	O
as	O
it	O
is	O
in	O
most	O
of	O
the	O
world	O
.	O
</s>
<s>
Unusually	O
,	O
the	O
UK	O
has	O
an	O
amateur	O
radio	O
allocation	O
at	O
4	B-Algorithm
metres	I-Algorithm
,	O
70	O
–	O
70.5MHz	O
.	O
</s>
<s>
Frequency	O
assignments	O
between	O
US	O
and	O
Canadian	O
users	O
are	O
closely	O
coordinated	O
since	O
much	O
of	O
the	O
Canadian	O
population	O
is	O
within	O
VHF	B-Algorithm
radio	O
range	O
of	O
the	O
US	O
border	O
.	O
</s>
<s>
The	O
general	O
services	O
in	O
the	O
VHF	B-Algorithm
band	I-Algorithm
are	O
:	O
</s>
<s>
4350MHz	O
:	O
Cordless	O
telephones	O
,	O
49MHz	O
FM	B-Application
walkie-talkies	B-Application
and	O
radio	O
controlled	O
toys	O
,	O
and	O
mixed	O
2-way	O
mobile	O
communication	O
.	O
</s>
<s>
The	O
FM	B-Algorithm
broadcast	I-Algorithm
band	I-Algorithm
originally	O
operated	O
here	O
(	O
4250MHz	O
)	O
before	O
it	O
was	O
moved	O
to	O
88108MHz	O
.	O
</s>
<s>
159.81160.2	O
are	O
railroads	B-Application
in	O
Canada	O
only	O
and	O
is	O
used	O
by	O
trucking	O
companies	O
in	O
the	O
U.S.	O
</s>
<s>
Cable	O
television	O
,	O
though	O
not	O
transmitted	O
aerially	O
,	O
uses	O
a	O
spectrum	O
of	O
frequencies	O
overlapping	O
VHF	B-Algorithm
.	O
</s>
<s>
87.587.9MHz	O
is	O
a	O
radio	O
frequency	O
which	O
,	O
in	O
most	O
of	O
the	O
world	O
,	O
is	O
used	O
for	O
FM	B-Application
broadcasting	O
.	O
</s>
<s>
In	O
North	O
America	O
,	O
however	O
,	O
this	O
bandwidth	O
is	O
allocated	O
to	O
VHF	B-Algorithm
television	O
channel6	O
(	O
8288MHz	O
)	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
FM	B-Application
radio	O
receivers	O
such	O
as	O
those	O
found	O
in	O
automobiles	O
which	O
are	O
designed	O
to	O
tune	O
into	O
this	O
frequency	O
range	O
could	O
receive	O
the	O
audio	O
for	O
analog-mode	O
programming	O
on	O
the	O
local	O
TV	O
channel	O
6	O
while	O
in	O
North	O
America	O
.	O
</s>
<s>
The	O
FM	B-Application
broadcast	O
channel	O
at	O
87.9MHz	B-Algorithm
is	O
normally	O
off-limits	O
for	O
FM	B-Application
audio	O
broadcasting	O
;	O
it	O
is	O
reserved	O
for	O
displaced	O
classD	O
stations	O
which	O
have	O
no	O
other	O
frequencies	O
in	O
the	O
normal	O
88.1107.9MHz	O
subband	O
to	O
move	O
to	O
.	O
</s>
<s>
So	O
far	O
,	O
only	O
two	O
stations	O
have	O
qualified	O
to	O
operate	O
on	O
87.9MHz	B-Algorithm
:	O
10watt	O
KSFH	O
in	O
Mountain	O
View	O
,	O
California	O
and	O
34watt	O
translator	O
K200AA	O
in	O
Sun	O
Valley	O
,	O
Nevada	O
.	O
</s>
<s>
In	O
some	O
countries	O
,	O
particularly	O
the	O
United	O
States	O
and	O
Canada	O
,	O
limited	O
low-power	O
license-free	O
operation	O
is	O
available	O
in	O
the	O
FM	B-Algorithm
broadcast	I-Algorithm
band	I-Algorithm
for	O
purposes	O
such	O
as	O
micro-broadcasting	O
and	O
sending	O
output	O
from	O
CD	O
or	O
digital	O
media	O
players	O
to	O
radios	O
without	O
auxiliary-in	O
jacks	O
,	O
though	O
this	O
is	O
illegal	O
in	O
some	O
other	O
countries	O
.	O
</s>
