<s>
Because	O
it	O
is	O
local	O
and	O
reliable	O
,	O
and	O
because	O
the	O
licensing	O
requirements	O
to	O
transmit	O
on	O
the	O
2-meter	B-Algorithm
band	I-Algorithm
are	O
easy	O
to	O
meet	O
in	O
many	O
parts	O
of	O
the	O
world	O
,	O
this	O
band	O
is	O
one	O
of	O
the	O
most	O
popular	O
non-HF	O
ham	O
bands	O
.	O
</s>
<s>
Much	O
of	O
2-meter	O
FM	B-Application
operation	O
uses	O
a	O
radio	O
repeater	O
,	O
a	O
radio	O
receiver	O
and	O
transmitter	O
that	O
instantly	O
retransmits	O
a	O
received	O
signal	O
on	O
a	O
separate	O
frequency	O
.	O
</s>
<s>
On	O
VHF	B-Algorithm
frequencies	O
such	O
as	O
2-meters	O
,	O
antenna	O
height	O
greatly	O
influences	O
how	O
far	O
one	O
can	O
talk	O
.	O
</s>
<s>
The	O
typical	O
hand	O
held	O
two	O
meter	O
FM	B-Application
transceiver	O
produces	O
about	O
5	O
watts	O
of	O
transmit	O
power	O
.	O
</s>
<s>
Even	O
without	O
repeaters	O
available	O
,	O
however	O
,	O
the	O
2-meter	B-Algorithm
band	I-Algorithm
provides	O
reliable	O
crosstown	O
communications	O
throughout	O
smaller	O
towns	O
,	O
making	O
it	O
ideal	O
for	O
emergency	O
communications	O
.	O
</s>
<s>
Simple	O
radios	O
for	O
FM	B-Application
repeater	O
operation	O
have	O
become	O
plentiful	O
and	O
inexpensive	O
in	O
recent	O
years	O
.	O
</s>
<s>
While	O
the	O
2meter	O
band	O
is	O
best	O
known	O
as	O
a	O
local	O
band	O
using	O
the	O
FM	B-Application
mode	O
,	O
there	O
are	O
many	O
opportunities	O
for	O
long	O
distance	O
(	O
DX	O
)	O
communications	O
using	O
other	O
modes	O
.	O
</s>
<s>
The	O
typical	O
2meter	O
station	O
using	O
CW	O
(	O
Morse	O
code	O
)	O
or	O
SSB	B-Device
(	O
single	B-Device
side	I-Device
band	I-Device
)	O
modes	O
consists	O
of	O
a	O
radio	O
driving	O
a	O
power	O
amplifier	O
generating	O
about	O
200	O
–	O
500Watts	O
of	O
RF	O
power	O
.	O
</s>
<s>
These	O
and	O
other	O
well-known	O
forms	O
of	O
VHF	B-Algorithm
signal	O
enhancement	O
that	O
allow	O
trans-oceanic	O
and	O
trans-continental	O
contacts	O
on	O
2meters	O
are	O
described	O
in	O
the	O
subsections	O
that	O
follow	O
within	O
this	O
section	O
.	O
</s>
<s>
When	O
a	O
well-equipped	O
station	O
with	O
its	O
antenna	O
well-located	O
“	O
high	O
and	O
in	O
the	O
clear	O
”	O
is	O
operating	O
during	O
a	O
signal	O
enhancement	O
,	O
astonishing	O
distances	O
can	O
be	O
bridged	O
,	O
momentarily	O
approaching	O
what	O
is	O
regularly	O
possible	O
on	O
shortwave	O
and	O
mediumwave	B-Algorithm
.	O
</s>
<s>
These	O
so-called	O
"	O
Openings	O
"	O
are	O
generally	O
first	O
spotted	O
by	O
amateurs	O
operating	O
SSB	B-Device
(	O
Single	B-Device
Side	I-Device
Band	I-Device
)	O
and	O
CW	O
(	O
Continuous	O
Wave	O
)	O
modes	O
since	O
amateurs	O
using	O
these	O
modes	O
typically	O
are	O
attempting	O
distance	O
contacts	O
(	O
DX	O
)	O
and	O
alert	O
for	O
signal	O
enhancement	O
events	O
.	O
</s>
<s>
Long	O
distance	O
ducting	O
contacts	O
do	O
occur	O
using	O
FM	B-Application
modes	O
as	O
well	O
but	O
for	O
the	O
most	O
part	O
go	O
unnoticed	O
by	O
many	O
FM	B-Application
operators	O
.	O
</s>
<s>
Another	O
form	O
of	O
VHF	B-Algorithm
propagation	O
is	O
called	O
Sporadic	O
E	O
propagation	O
.	O
</s>
<s>
The	O
2meter	O
band	O
is	O
also	O
used	O
in	O
conjunction	O
with	O
the	O
70-centimeter	B-Algorithm
band	I-Algorithm
,	O
or	O
the	O
10-meter	B-Algorithm
band	I-Algorithm
and	O
various	O
microwave	O
bands	O
via	O
orbiting	O
amateur	O
radio	O
satellites	O
.	O
</s>
<s>
In	O
this	O
example	O
,	O
V/U	O
means	O
VHF/UHF	O
or	O
VHF	B-Algorithm
uplink	O
with	O
UHF	O
downlink	O
.	O
</s>
<s>
Depending	O
on	O
the	O
intensity	O
of	O
the	O
ionized	O
meteor	O
trail	O
,	O
multiple	O
contacts	O
from	O
multiple	O
stations	O
can	O
be	O
made	O
off	O
the	O
same	O
trail	O
until	O
it	O
dissipates	O
and	O
can	O
no	O
longer	O
reflect	O
VHF	B-Algorithm
signals	O
with	O
sufficient	O
strength	O
.	O
</s>
<s>
Another	O
phenomenon	O
that	O
produces	O
upper	O
atmosphere	O
ionization	O
suitable	O
for	O
2-meter	O
DXing	O
are	O
the	O
auroras	B-Protocol
.	O
</s>
<s>
In	O
most	O
instances	O
using	O
auroral	O
reflections	O
on	O
2meters	O
,	O
audio	O
or	O
voice	O
is	O
totally	O
unintelligible	O
and	O
ham	O
operators	O
wishing	O
to	O
make	O
contacts	O
via	O
aurora	B-Protocol
,	O
must	O
resort	O
to	O
CW	O
(	O
Morse	O
code	O
)	O
.	O
</s>
<s>
In	O
many	O
instances	O
6meter	O
voice	O
modes	O
are	O
readable	O
but	O
with	O
varying	O
degrees	O
of	O
difficulty	O
when	O
reflected	O
off	O
an	O
aurora	B-Protocol
.	O
</s>
<s>
VHF	B-Algorithm
signals	O
normally	O
escape	O
the	O
Earth	O
's	O
atmosphere	O
,	O
so	O
using	O
the	O
moon	O
as	O
a	O
target	O
is	O
quite	O
practical	O
.	O
</s>
