TheCodeBreakers
will sound lower than norm, The result will be an alternation of
squeaks and grow-sounding exactly as if a phonograph record were
alternately raced and almost stopped.
Most of the basic scrambler systems were invented during the 1920s
and 1930s by engineers for the growing radio and telephone companies.
A need for them first became apparent when the radio hams began
listening in to the conversations of erring husbands and their wives and
on stockbrokers giving tips on the first public radiotelephone service,
offered after World War I by the Pacific Telephone Company between Los
Angeles and nearby Catalina Island. The American Telephone &
Telegraph Company installed an inverter. While it prevented casual
eavesdropping, it would not keep a determined amateur from inverting
the inversion. And several did just that on the East Coast in the latter
1920s when the telephone company was setting up its radiotelephone
link to Europe
annaabi.ee 
