Why don't loading coils use all alphabet letters for spacing designations?

[jayryap]

Why not all letters of the alphabet are used in loading coil distance?
and why there is no pattern followed in the spacing designation?thank you very much...

 

[berkeman]

Why not all letters of the alphabet are used in loading coil distance?
and why there is no pattern followed in the spacing designation?thank you very much...

Could you please clarify your question? Do you mean this kind of loading coil?

http://en.wikipedia.org/wiki/Loading_coil

.

 

[jayryap]

sir, loading coils in telephone lines,A=700 ft
B=3000 ft
C=929 ft
D=4500 ft
E=5575 ft
F=2787 ft
H=6000 ft
X=680 ft
Y=2130 ft

thank you very much...

 

[berkeman]

sir, loading coils in telephone lines,


A=700 ft
B=3000 ft
C=929 ft
D=4500 ft
E=5575 ft
F=2787 ft
H=6000 ft
X=680 ft
Y=2130 ft

thank you very much...

Those distances sound kind of short for load coils (the H looks to be more typical). Where did you get them?

http://www.charlesindustries.com/main/te_coils.html

.