Not really. With the huge power in NTSC analog signals around the visual and aural carriers, as well as the color subcarrier, stations had to be geographically far apart to be able to share channels. Even odd channel pairings such as the "taboo" relationships whereby stations could not operate close together if they were on pairs differing by 8 channels (8 x 6 MHz = 48 MHz which falls in the receivers' IF passbands) could not be used. The high powers concentrated at the visual carriers even required adjacent stations to shift their frequencies by 10 KHz. Digital transmitters operate with generally lower power and that power is noise-like, spead evenly across each 6 MHz channel. With the inherent error checking and correction power built into the ATSC digital television system, digital-into-digital interference is much less of a problem than analog-into-analog interference was. Therefore, it is possible to cram all 1600 broadcast stations into less spectrum with digital. It could not have been done with analog.
Digital reception is amazing. At WRLK in Columbia, SC, we are running 650 kilowatts ERP on analog on channel 35, and simultaneously from the same antenna, 65 kilowatts of digital on channel 32. The digital station can be received perfectly at locations where the analog station is unwatchable in the snow. Once the analog transmitters can be turned off, broadcasters' electric bills will be MUCH less than they are today. My eleven station network pays over a half million $$$ in electrical costs per year. We expect it to be cut to about one third of that after next year. Hap Griffin WZ4O ----- Original Message ----- From: MCH To: Repeater-Builder@yahoogroups.com Sent: Monday, January 07, 2008 6:04 PM Subject: Re: [Repeater-Builder] Re: Off Topic (but with on topic questions): NTIA propaganda But, how is that related to the transition to digital? The same could have happened with simple channel reassignment. Joe M. Hap Griffin wrote: > > Actually, there will be a huge amount of spectrum freed up. Currently, the > television allocation is from channel 2 through channel 69. After February > 2009, all analog operation will cease and all of the digital stations will > be occulying only the channels 2 through 51. Thus, eighteen 6-MHz channels > will be freed up, or a total of 108 MHz. > > Hap Griffin > WZ4O
