<s>
The	O
20-meter	B-Algorithm
band	I-Algorithm
is	O
widely	O
considered	O
among	O
the	O
best	O
for	O
long-distance	O
communication	O
(	O
DXing	O
)	O
,	O
and	O
is	O
one	O
of	O
the	O
most	O
popular	O
—	O
and	O
crowded	O
—	O
during	O
contests	O
.	O
</s>
<s>
Several	O
factors	O
contribute	O
to	O
this	O
,	O
including	O
the	O
band	O
's	O
large	O
size	O
,	O
the	O
relatively	O
small	O
size	O
of	O
antennas	O
tuned	O
to	O
it	O
(	O
especially	O
as	O
compared	O
to	O
antennas	O
for	O
the	O
40-meter	B-Algorithm
band	I-Algorithm
or	O
the	O
80-meter	B-Algorithm
band	I-Algorithm
)	O
and	O
its	O
good	O
potential	O
for	O
daytime	O
DX	O
operation	O
even	O
in	O
unfavorable	O
propagation	O
conditions	O
.	O
</s>
<s>
The	O
Third	O
National	O
Radio	O
Conference	O
was	O
responsible	O
for	O
opening	O
up	O
the	O
20-meter	B-Algorithm
band	I-Algorithm
to	O
amateur	O
radio	O
operators	O
in	O
the	O
US	O
on	O
October	O
10	O
,	O
1924	O
.	O
</s>
