This is a report on a series of tests and simulated as well as actual CATV system operation with the application of additional TV channels in the 120 to 175 MHz frequency spectrum. This region is generally referred to as the "mid-band". Standard production unmodified Phoenician Series trunk line amplifiers (KAISER Model Nos. KGAA and KGMA) were used with normal 22 dB spacing.
In assigning the frequencies for the various mid-band channels, it was considered practical to use 6 MHz separation between each of the video carriers with the lowest mid-band channel (Channel "A") at 121.25 MHz. No attempt was made to use mid-band frequencies above 157.25 MHz (Channel "G") in order to avoid interference with the 166.5 MHz pilot carrier used in the KAISER equipment. The lower frequency limitation of 121.25 MHz was selected in order to avoid any possibility of interference with aircraft navigational radio devices.