<s>
Medium	B-Algorithm
wave	I-Algorithm
(	O
MW	O
)	O
is	O
the	O
part	O
of	O
the	O
medium	B-Algorithm
frequency	I-Algorithm
(	O
MF	O
)	O
radio	B-Algorithm
band	I-Algorithm
used	O
mainly	O
for	O
AM	O
radio	O
broadcasting	O
.	O
</s>
<s>
The	O
spectrum	O
provides	O
about	O
120	O
channels	O
with	O
more	O
limited	O
sound	O
quality	O
than	O
FM	O
stations	O
on	O
the	O
FM	B-Algorithm
broadcast	I-Algorithm
band	I-Algorithm
.	O
</s>
<s>
In	O
addition	O
,	O
amplitude	B-Device
modulation	I-Device
(	O
AM	O
)	O
is	O
often	O
more	O
prone	O
to	O
interference	O
by	O
various	O
electronic	O
devices	O
,	O
especially	O
power	O
supplies	O
and	O
computers	O
.	O
</s>
<s>
Strong	O
transmitters	O
cover	O
larger	O
areas	O
than	O
on	O
the	O
FM	B-Algorithm
broadcast	I-Algorithm
band	I-Algorithm
but	O
require	O
more	O
energy	O
and	O
longer	O
antennas	O
.	O
</s>
<s>
MW	O
was	O
the	O
main	O
radio	B-Algorithm
band	I-Algorithm
for	O
broadcasting	O
from	O
the	O
beginnings	O
in	O
the	O
1920s	O
into	O
the	O
1950s	O
until	O
FM	O
with	O
a	O
better	O
sound	O
quality	O
took	O
over	O
.	O
</s>
<s>
In	O
Europe	O
,	O
digital	O
radio	O
is	O
gaining	O
popularity	O
and	O
offers	O
AM	O
stations	O
the	O
chance	O
to	O
switch	O
over	O
if	O
no	O
frequency	O
in	O
the	O
FM	B-Algorithm
band	I-Algorithm
is	O
available	O
,	O
(	O
however	O
digital	O
radio	O
still	O
has	O
coverage	O
issues	O
in	O
many	O
parts	O
of	O
Europe	O
)	O
.	O
</s>
<s>
The	O
term	O
is	O
a	O
historic	O
one	O
,	O
dating	O
from	O
the	O
early	O
20th	O
century	O
,	O
when	O
the	O
radio	B-Algorithm
spectrum	I-Algorithm
was	O
divided	O
on	O
the	O
basis	O
of	O
the	O
wavelength	O
of	O
the	O
waves	O
into	O
long	B-Algorithm
wave	I-Algorithm
(	O
LW	O
)	O
,	O
medium	B-Algorithm
wave	I-Algorithm
,	O
and	O
short	O
wave	O
(	O
SW	O
)	O
radio	B-Algorithm
bands	I-Algorithm
.	O
</s>
<s>
Australia	O
uses	O
an	O
expanded	B-Algorithm
band	I-Algorithm
up	O
to	O
1701kHz	O
.	O
</s>
<s>
The	O
9/10kHz	O
channel	O
stepping	O
on	O
MW	O
requires	O
limiting	O
the	O
audio	O
bandwidth	O
to	O
4.5/5kHz	O
because	O
the	O
audio	O
spectrum	O
is	O
transmitted	O
twice	O
on	O
each	O
side	B-Device
band	I-Device
.	O
</s>
<s>
The	O
groundwave	O
reaches	O
further	O
on	O
lower	O
medium	B-Algorithm
wave	I-Algorithm
frequencies	O
.	O
</s>
<s>
Medium	B-Algorithm
waves	I-Algorithm
can	O
also	O
reflect	O
off	O
charged	O
particle	O
layers	O
in	O
the	O
ionosphere	O
and	O
return	O
to	O
Earth	O
at	O
much	O
greater	O
distances	O
;	O
this	O
is	O
called	O
the	O
skywave	O
.	O
</s>
<s>
In	O
the	O
US	O
and	O
Canada	O
the	O
maximum	O
transmitter	O
power	O
is	O
restricted	O
to	O
50kilowatts	O
,	O
while	O
in	O
Europe	O
there	O
are	O
medium	B-Algorithm
wave	I-Algorithm
stations	O
with	O
transmitter	O
power	O
up	O
to	O
2megawatts	O
daytime	O
.	O
</s>
<s>
Similar	O
regulations	O
are	O
in	O
force	O
for	O
Canadian	O
stations	O
,	O
administered	O
by	O
Industry	O
Canada	O
;	O
however	O
,	O
daytimers	O
no	O
longer	O
exist	O
in	O
Canada	O
,	O
the	O
last	O
station	O
having	O
signed	O
off	O
in	O
2013	O
,	O
after	O
migrating	O
to	O
the	O
FM	B-Algorithm
band	I-Algorithm
.	O
</s>
<s>
International	O
medium	B-Algorithm
wave	I-Algorithm
broadcasting	O
in	O
Europe	O
has	O
decreased	O
markedly	O
with	O
the	O
end	O
of	O
the	O
Cold	B-Application
War	I-Application
and	O
the	O
increased	O
availability	O
of	O
satellite	O
and	O
Internet	O
TV	O
and	O
radio	O
,	O
although	O
the	O
cross-border	O
reception	O
of	O
neighbouring	O
countries	O
 '	O
broadcasts	O
by	O
expatriates	O
and	O
other	O
interested	O
listeners	O
still	O
takes	O
place	O
.	O
</s>
<s>
In	O
the	O
late	O
20th	O
century	O
,	O
overcrowding	O
on	O
the	O
Medium	B-Algorithm
wave	I-Algorithm
band	O
was	O
a	O
serious	O
problem	O
in	O
parts	O
of	O
Europe	O
contributing	O
to	O
the	O
early	O
adoption	O
of	O
VHF	B-Algorithm
FM	O
broadcasting	O
by	O
many	O
stations	O
(	O
particularly	O
in	O
Germany	O
)	O
.	O
</s>
<s>
As	O
of	O
March	O
of	O
2021	O
,	O
broadcaster	O
NHK	O
still	O
broadcasts	O
in	O
regional	O
Indonesia	O
,	O
Myanmar	O
and	O
Tajikistan	O
using	O
Medium	B-Algorithm
Wave	I-Algorithm
transmission	O
.	O
</s>
<s>
It	O
is	O
also	O
possible	O
to	O
realize	O
directional	O
aerials	O
for	O
mediumwave	B-Algorithm
with	O
cage	O
aerials	O
where	O
some	O
parts	O
of	O
the	O
cage	O
are	O
fed	O
with	O
a	O
certain	O
phase	O
difference	O
.	O
</s>
<s>
For	O
medium-wave	B-Algorithm
(	O
AM	O
)	O
broadcasting	O
,	O
quarter-wave	O
masts	O
are	O
between	O
and	O
high	O
,	O
depending	O
on	O
the	O
frequency	O
.	O
</s>
<s>
The	O
medium-wave	B-Algorithm
transmitter	O
at	O
Berlin-Britz	O
for	O
transmitting	O
RIAS	O
used	O
a	O
cross	O
dipole	O
mounted	O
on	O
five	O
30.5-metre-high	O
guyed	O
masts	O
to	O
transmit	O
the	O
skywave	O
to	O
the	O
ionosphere	O
at	O
nighttime	O
.	O
</s>
<s>
For	O
reception	O
at	O
frequencies	O
below	O
1.6MHz	O
,	O
which	O
includes	O
long	O
and	O
medium	B-Algorithm
waves	I-Algorithm
,	O
loop	B-Architecture
antennas	I-Architecture
are	O
popular	O
because	O
of	O
their	O
ability	O
to	O
reject	O
locally	O
generated	O
noise	O
.	O
</s>
<s>
Examples	O
of	O
such	O
medium	B-Algorithm
wave	I-Algorithm
antennas	O
include	O
broadband	O
untuned	O
loops	O
,	O
elongated	O
terminated	O
loops	O
,	O
wave	O
antennas	O
(	O
e.g.	O
</s>
<s>
the	O
Beverage	O
antenna	O
)	O
and	O
the	O
ferrite	O
sleeve	O
loop	B-Architecture
antenna	I-Architecture
.	O
</s>
