<s>
The	O
70-centimeter	O
or	O
440	B-Algorithm
MHz	I-Algorithm
band	I-Algorithm
is	O
a	O
portion	O
of	O
the	O
UHF	O
radio	O
spectrum	O
internationally	O
allocated	O
to	O
amateur	O
radio	O
and	O
amateur	O
satellite	O
use	O
.	O
</s>
<s>
Depending	O
on	O
the	O
country	O
the	O
band	O
is	O
shared	O
with	O
other	O
radio	O
services	O
(	O
in	O
United	O
States	O
with	O
government	O
radar	B-Application
systems	I-Application
such	O
as	O
PAVE	O
PAWS	O
)	O
.	O
</s>
<s>
70	B-Algorithm
centimeters	I-Algorithm
is	O
a	O
popular	O
ham	O
band	O
due	O
to	O
the	O
ready	O
availability	O
of	O
equipment	O
in	O
both	O
new	O
and	O
used	O
markets	O
.	O
</s>
<s>
Most	O
amateurs	O
operating	O
on	O
70	B-Algorithm
cm	I-Algorithm
use	O
either	O
equipment	O
purpose-built	O
for	O
ham	O
radio	O
,	O
or	O
commercial	O
equipment	O
designed	O
for	O
nearby	O
land	O
mobile	O
frequencies	O
.	O
</s>
<s>
Amateurs	O
predominately	O
use	O
the	O
band	O
for	O
FM	B-Application
or	O
digital	O
voice	O
communications	O
through	O
repeaters	O
(	O
useful	O
for	O
emergency	O
communications	O
)	O
,	O
as	O
well	O
narrow	O
band	O
modes	O
(	O
analog	O
and	O
digital	O
)	O
for	O
long-distance	O
communications	O
(	O
called	O
"	O
DX	O
"	O
,	O
including	O
Moonbounce	O
)	O
.	O
</s>
<s>
Due	O
to	O
its	O
size	B-Algorithm
,	O
it	O
's	O
the	O
lowest	O
frequency	O
ham	O
band	O
which	O
can	O
support	O
amateur	O
television	O
transmissions	O
.	O
</s>
<s>
One	O
practical	O
concern	O
when	O
comparing	O
the	O
70-centimeter	B-Algorithm
band	I-Algorithm
to	O
the	O
2-meter	O
band	O
is	O
that	O
a	O
quarter-wavelength	O
antenna	O
is	O
much	O
less	O
unwieldy	O
at	O
70	B-Algorithm
centimeters	I-Algorithm
than	O
it	O
is	O
at	O
2	O
meters	O
.	O
</s>
<s>
Portable	O
antennas	O
for	O
2	O
meters	O
are	O
generally	O
continuously	O
loaded	O
coil	O
spring	O
or	O
"	O
rubber	O
duck	O
"	O
types	O
,	O
while	O
on	O
70	B-Algorithm
centimeters	I-Algorithm
they	O
can	O
be	O
a	O
full	O
quarter	O
wavelength	O
.	O
</s>
<s>
The	O
primary	O
advantage	O
of	O
70	B-Algorithm
centimeters	I-Algorithm
is	O
that	O
base	O
station	O
antennas	O
of	O
very	O
significant	O
gain	O
(	O
up	O
to	O
11dB	O
or	O
so	O
)	O
are	O
practical	O
while	O
6dB	O
is	O
about	O
the	O
practical	O
limit	O
on	O
2m	O
.	O
</s>
<s>
The	O
reflective	O
properties	O
of	O
the	O
70-centimeter	B-Algorithm
band	I-Algorithm
allow	O
signals	O
to	O
be	O
reflected	O
by	O
dense	O
and	O
solid	O
material	O
such	O
as	O
cement	O
or	O
rock	O
.	O
</s>
<s>
The	O
problem	O
is	O
much	O
less	O
severe	O
with	O
modern	O
FM	B-Application
systems	O
because	O
the	O
receiver	O
's	O
limiter	O
circuitry	O
compensates	O
for	O
variations	O
in	O
received	O
signal	O
strength	O
over	O
a	O
very	O
wide	O
amplitude	O
range	O
.	O
</s>
<s>
70	B-Algorithm
centimeters	I-Algorithm
is	O
very	O
close	O
to	O
the	O
third	O
harmonic	O
of	O
2	O
meters	O
,	O
which	O
allows	O
sufficiently	O
broadband	O
2meter	O
antennas	O
to	O
be	O
used	O
for	O
70	B-Algorithm
centimeters	I-Algorithm
.	O
</s>
<s>
Also	O
,	O
2	O
meters	O
is	O
far	O
enough	O
away	O
from	O
70	B-Algorithm
centimeters	I-Algorithm
to	O
make	O
diplexers	O
small	O
and	O
simple	O
,	O
making	O
it	O
easy	O
to	O
cross-band	O
repeat	O
signals	O
between	O
the	O
two	O
bands	O
with	O
a	O
single	O
dual-band	O
radio	O
.	O
</s>
<s>
In	O
some	O
countries	O
,	O
particularly	O
Germany	O
(	O
until	O
the	O
end	O
of	O
2008	O
)	O
and	O
Switzerland	B-Protocol
,	O
a	O
portion	O
of	O
the	O
70cm	B-Algorithm
band	I-Algorithm
overlaps	O
with	O
a	O
secondary	O
frequency	O
allocation	O
for	O
the	O
operation	O
of	O
Radio	O
control	O
models	O
.	O
</s>
<s>
In	O
Germany	O
,	O
33	O
frequencies	O
were	O
available	O
for	O
RC	O
use	O
,	O
and	O
in	O
Switzerland	B-Protocol
,	O
ten	O
frequencies	O
are	O
available	O
.	O
</s>
<s>
These	O
frequencies	O
fall	O
within	O
the	O
LPD433	B-Algorithm
band	O
used	O
by	O
short	O
range	O
devices	O
in	O
Europe	O
.	O
</s>
<s>
In	O
North	O
America	O
,	O
licensed	O
amateurs	O
may	O
conduct	O
RC	O
operations	O
in	O
the	O
70cm	B-Algorithm
band	I-Algorithm
,	O
but	O
unlike	O
similar	O
operations	O
in	O
the	O
6-meter	O
band	O
,	O
no	O
specific	O
frequencies	O
have	O
been	O
set	O
aside	O
for	O
RC	O
use	O
.	O
</s>
