From Bill Continelli's History Of Amateur Radio

http://ham-shack.com/history.html

Sez 1946 "The military leaves our HF bands in
stages, hams gradually get their frequencies back, all except for 160
meters,
which will be used for the LORAN Radio navigation system. The FCC creates
the Tenth Call District (using the numeral -0-), and realigns the District
boundaries."

Anyone have info as to the date -- month and day??

Reply here please
thanks
Lamont