In international aviation, SELCAL or SelCal is a selective-calling radio system that can alert an aircraft's crew that a ground radio station wishes to communicate with the aircraft.
SELCAL Alphabet-audio frequency equivalents
A 312.6 Hz
B 346.7 Hz
C 384.6 Hz
D 426.6 Hz
E 473.2 Hz
F 524.8 Hz
G 582.1 Hz
H 645.7 Hz
J 716.1 Hz
K 794.3 Hz
L 881.0 Hz
M 977.2 Hz
P 1083.2 Hz
Q 1202.3 Hz
R 1333.5 Hz
S 1479.1 Hz
A 312.6 Hz
B 346.7 Hz
C 384.6 Hz
D 426.6 Hz
E 473.2 Hz
F 524.8 Hz
G 582.1 Hz
H 645.7 Hz
J 716.1 Hz
K 794.3 Hz
L 881.0 Hz
M 977.2 Hz
P 1083.2 Hz
Q 1202.3 Hz
R 1333.5 Hz
S 1479.1 Hz
by Rosenbaa29 February 26, 2011