How to decode Yaesu serial numbers and know exactly when your Yaesu radio was manufactured
serial number of 9J271567
Position 1 = year made
Position 2 = month made
C = January
D = February
E = March
F = April
G = May
H = June
I = July
J = August
K = September
L = October
M = November
N = December
Position 3 and 4 = lot number(s)
Position 5 to 8 sequence in that lot
Position 1: last digit of the year in which the radio was produced
Position 2: Determine the position of the letter in the alphabet (C=3,D=4,E=5, etc)
then subtract 2.
The result gives the month in which the radio was manufactured.
Note that the letters will range from C (January) through N (December).
Thus, my FT-817 radio with a serial number of 9J271567 would have been manufactured in 2009 (9), during the month of August (J, August is the 8th month), was part of lot 27, and was the 1567th radio in that lot.