[Hallicrafters] Final word on 5 char. CW

[Jim Brannigan]

In fact the Enigma
> machine was first patented in 1919 and adapted by the German Army and Navy 
> in the late 1920s.  It used 5 letter groups and initially was used by 
> businesses.

The Enigma machine encoded/decoded one character at a time.  It was a manual 
operation, so the word groups could be any length.
Word groups were all the same length to make it marginally more difficult to 
decrypt by a third party.
Why five letters?  I don't know.

Jim