Originally Posted by mobilelawyer
Why did most of the stations switch to a uhf frequency for the digital transition?
For marketing purposes, I can certainly see why a station which was on a certain analog channel would keep the same digital channel, but, apparantly, few did.
And I noticed that WALA, while not keeping the channel 10 frequency, switched to channel 9. Not sure what their rationale was.
Like in the old days, would a digitial transmission on a VHF frequency carry a greater distance, using less power, or is the frequency difference less relevant? I assume the latter, becuase otherwise, the airwaves would be filled with VHF assignments, and that does not seem to be the case.
It's actually pretty complicated and I don't understand all the ins and outs of the transition, but I'll do the best I can.
The UHF channels work better with the digital signal. Impulse noise and other factors that make VHF low and even VHF high less than ideal for digital transmissions aren't as much of factor, if at all, on UHF. That's one reason many former VHF stations migrated to UHF permanently after the transition.
I think the main reason stations migrated to their same VHF channel or one nearby is one of cost savings. By staying with or near the same VHF channel, they can reuse parts of the transmission system including the antenna. That stuff is very expensive, and converting from a VHF to UHF operation means replacing pretty much everything at the transmitter site.
The impression I get from LIN, who owns WALA, is they are cheap operators, hence the desire to reuse the existing analog 10 antenna for digital operations on 9.
All things being equal, I believe even with digital transmissions, VHF broadcasts travel further with less power. But as PBSengineer noted, the noise factor prevents it from working well in the real world.