Digital TV Power

[Jim]

I'm trying to find out the maximum broadcast power for digital stations, I have search the FCC site but I haven't been able to find anything so I'm sure I have searched for the wrong thing.

It appears that UHF is limited to 1000kw but what is the VHF-L and VHF-H limited to?

Thanks
Jim

 

[MW_FM_DT_DXer]

Channels 2-6: 45 kW
Channels 7-13: 160 kW

This information is located here, in Section 73.622: http://a257.g.akamaitech.net/7/257/2422/13nov20061500/edocket.access.gpo.gov/cfr_2006/octqtr/47cfr73.622.htm

 

[azumanga]

The thing though is why digital signals have lower maximum power than analog? On analog, 2 to 6 has a maximum power of 100kw; 7 to 13 is 316kw (325kw in Canada); and UHF channels are 5000kw. Is there any rationale as to why digital signals are lower-powered?

 

[fybush]

The thing though is why digital signals have lower maximum power than analog? On analog, 2 to 6 has a maximum power of 100kw; 7 to 13 is 316kw (325kw in Canada); and UHF channels are 5000kw. Is there any rationale as to why digital signals are lower-powered?

There is - you're comparing apples to oranges. To simplify as much as possible: the analog power level specified by the FCC is actually a peak power; the digital power level is an average power.

If the FCC's engineering is correct, most stations that maximize their digital power levels will end up "replicating" (the key word here) between 98-100% of their analog coverage from their final digital facility. A handful of stations that chose not to maximize their DTV powers by the deadline (which varied by affiliation and market, but generally passed for most stations last year) face the possibility that they won't get to replicate their full analog coverage area.