white-to-black frequency swing

white-to-black frequency swing

[¦wīt tə ¦blak ′frē·kwən·sē ‚swiŋ]
(communications)
In a facsimile system employing frequency modulation, the numerical difference between the signal frequencies corresponding to picture white and picture black at any point in the system.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.