Clandestine data - was: media what died a'bornin'

[John Lawson]

  It is little known (but documented) that, during WWII, radio station KHJ 
in Los Angeles ( and undoubtedly many others ) sent radio-teletype signals 
by shifitng the carrier a miniscule amount - I think about 10 htz, and 
using a very slow baud rate.  This would not be noticed by the average 
equipment of the day, and would take very specialized gear to recover, 
store and print

  But it allowed messages to be sent large distances by powerful 
transmitters - completely 'in the blind'.

   Cheers

John