A New Technique for Wide-Band Video Recording
W. Frost, C. T. Masters · IBM Journal of Research and Development · 1968
An efficient means for distributing the information contained in a wide-band analog signal over two limited bandwidth channels is provided by using frequency modulation and “zero-crossing counting.” The new technique should accommodate at least twice the bandwidth that can be recorded or transmitted by the usual FM methods. Experimental results with a two-channel magnetic tape system confirm this expectation.