Channel Eye Online - Watch Live Cricket Match - Sri LankaCATV has channels with frequencies below channel 2. They are designated T-7 (tee seven or tee dash seven) through T-14 and are usually used for transmission in the reverse direction. If your local city council meeting is broadcast live, the camera is being modulated onto one of those T channels and sent back up to the cable system headend whereupon it is broadcast outbound on the community cable access channel. In the list I have some channels with the designation A-1 (A minus one, not A dash one) through A-8. They are so designated because their frequencies immediately precede that of the CATV channel known as A. In the CATV listing, the column labeled Common gives the common industry parlance for that channel. The next column labeled EIA gives the new EIA standardized designation. Column STD shows the standard CATV frequency which usually matches IRC. IRC stands for Incrementally Related Carrier and means that the lower edge of the channel space is on the nice, round-numbered boundary such as 54 MHz, 60 MHz, 66 MHz etc. HRC stands for Harmonically Related Carrier, and as you can see means that it is the video carrier that is assigned the nice round number (6 MHz harmonics, hence). Some cable systems use IRC, some use HRC. The number of channels on a given cable system varies. Very old systems might only go up to 300 or 350 MHz. Most common in the past ten years or so is 450 MHz. Newer systems may be 550 MHz. The latest and greatest with any meaningful installed base is 800 or 860 MHz (somebody correct me), but it is rare and pricey. The list herein only goes up to 550 MHz.
