Originally Posted by nwiser
What kind of power output do analog stations have now? is it the same level as what their digital counterparts have or is it higher? If the digital signal is much lower, what would be the problem in sending out their digital signal at the same power as their analog, other than it wouldnt save stations money?
Well, power levels aren't measured the same in analog and in digital. Analog power is measured by peak power, since a black picture requires more power than a white picture (or the other way around, I forget). So even if a UHF station is licensed for 5000 kW, that's assuming a solid black/white (whichever) picture is being transmitted. At the opposite end, you'll be much, much lower. I honestly don't remember what the average number is, but I want to say it could be in the 2000 kW range.
On top of that, audio is generally carried at 1/10 the power of the video, so that 5000 kW UHF has a 500 kW audio signal.
Digital power is measured as an average, rather than a peak. So 1000 kW is only 3 dB down from 2000 kW (assuming I'm right, which I may not be). And that's without the consideration that much less signal is needed for a digital. On top of that, boosting signal makes multipath interference worse, so you need to take that under consideration.
The problem is that a lot of stations were low-VHF analogs and on UHF they don't cover the same area. No amount of power on UHF is going to make the signals bend around the curvature of the Earth better. Translators or DTS will have to be the solution, assuming stations even consider it to be worthwhile.
And moving them back to low-VHF is no good because low-VHF digitals break up all the time over the tiniest things. That noise that didn't bother you too much on low-VHF analog destroys the digital.