In facsimile, a frequency modulationsystem where one frequency represents picture black and another frequency represents picture white[?]. Frequencies between these two limits may represent shades of gray
An intentional frequency change used for modulation purposes
... north and north-east with numerous rapids and shallows, and enters the Sea of Okhotsk. The Poronai flows south-south-east to the Gulf of Patience or Shichiro Bay, on the ...