[dewdude]

Here's how I remember the NTSC days....back when I still had a working antenna on the roof, living here 40 miles or so from DC.

"Local" channels 4 and 5 came in ok. 7 and 9 were always the easiest and clearest. The UHF performance was horrible. The only analog uhf channel I got was. 53...only because I lived 5 miles from the transmitter. In fact, at night, I can see its blinking red light just over the tree tops.

Baltimore channels were iffy. They were all fuzzy, but 2 came in better than 11 or 13, Baltimore UHFs were impossible.

Mind you, I live amongst trees, in a slight valley, without a very good antenna or rotor.

When things went ATSC, well..back when I had an OTA tuner, everything was UHF, and I couldn't get anything. I had better luck getting one or two locals in digital with an indoor antenna.

Lower frequencies travel "farther" due to the fact they follow the curve of the earth slightly...higher frequencies are more line of sight. Higher frequencies are less sensitive to interference as lower frequencies. In TV, this simply means a VHF signal is going to travel farther than UHF. UHF will have less interference than VHF...but more noise. UHF transmitters usually used quite a bit more power because of that.

The official switch to all digital....I honestly don't know why many stations stayed UHF. The virtual channels are simply because they can, and its what we all grew up with. Its like I'm used to refferring to WTTG as channel 5...not 35,36, whatever its on these days. I'm sure they mostly wanted to avoid confusion to people who, for the most part, grew up with those channel numbers.