<s>
In	O
Europe	O
,	O
75m	O
is	O
a	O
shortwave	B-Algorithm
broadcast	I-Algorithm
band	I-Algorithm
,	O
with	O
a	O
number	O
of	O
national	O
radio	O
services	O
operating	O
between	O
3.9	O
and	O
4.0MHz	O
.	O
</s>
<s>
Because	O
of	O
high	O
D	O
layer	O
absorption	O
that	O
persists	O
until	O
sunset	O
,	O
80	B-Algorithm
meters	I-Algorithm
is	O
usually	O
only	O
good	O
for	O
local	O
communications	O
during	O
the	O
day	O
,	O
and	O
hardly	O
ever	O
good	O
for	O
communications	O
over	O
intercontinental	O
distances	O
during	O
the	O
day	O
.	O
</s>
<s>
The	O
80-meter	B-Algorithm
band	I-Algorithm
is	O
favoured	O
for	O
ragchews	O
between	O
amateurs	O
within	O
a	O
range	O
of	O
500	O
miles/800km	O
.	O
</s>
<s>
Amateurs	O
interested	O
in	O
regional	O
communication	O
can	O
use	O
low	O
wire	O
antennas	O
,	O
such	O
as	O
horizontal	O
dipoles	O
,	O
inverted	O
vee	O
dipole	O
antennas	O
or	O
loop	B-Architecture
antennas	I-Architecture
on	O
this	O
band	O
.	O
</s>
<s>
The	O
80-meter	B-Algorithm
band	I-Algorithm
was	O
made	O
available	O
to	O
amateurs	O
in	O
the	O
United	O
States	O
by	O
the	O
Third	O
National	O
Radio	O
Conference	O
on	O
October	O
10	O
,	O
1924	O
.	O
</s>
<s>
The	O
lower	O
edge	O
of	O
80	B-Algorithm
meters	I-Algorithm
is	O
predominated	O
by	O
CW	O
emissions	O
,	O
with	O
the	O
lower	O
10kHz	O
(	O
3.5	O
–	O
3.51MHz	O
)	O
primarily	O
used	O
for	O
long-distance	O
communications	O
.	O
</s>
<s>
It	O
is	O
common	O
for	O
illegal	O
marine	O
operations	O
,	O
generally	O
using	O
USB	O
voice	O
,	O
to	O
occupy	O
frequencies	O
on	O
the	O
low	O
end	O
of	O
80	B-Algorithm
meters	I-Algorithm
.	O
</s>
<s>
Amateurs	O
with	O
perfect	O
transmitters	O
,	O
the	O
highest	O
usable	O
frequency	O
in	O
the	O
80m	B-Algorithm
band	I-Algorithm
for	O
lower	B-Device
side	I-Device
band	I-Device
phone	O
is	O
3.999MHz	O
.	O
</s>
<s>
The	O
European	O
75m	O
broadcast	O
band	O
overlaps	O
the	O
North	O
American	O
80m	B-Algorithm
ham	O
band	O
allocation	O
.	O
</s>
