I noticed in the gym I work out in, which is located in a basment or rather underground level, I cannot get any radio or TV. Neither AM or FM or TV comes in on my radio. But every one there uses a cellphone quite well.
I heard that one of the reasons for the switch to digital TV is so they can free up TV channels for cell phone use. But how can the cell phone work if the radio and TV don’t pick up? I thought they all used the same airwaves.
It’s a line-of-sight issue, mostly. Cell towers are much closer together than either TV or radio broadcast antennas, and chances are there’s one or more that are close enough to “see” down into the basement.
Soil is a good conductor of electrical energy. The signal won’t pass through the soil. This is why it’s a line of site issue as was stated. Ignore the house structure, because if the cell phone works you know signals can get through the house structure. Not exactly right, but I’ll explain later. We will count the house structure as not being there. Now climb the fifty foot tall tree that’s fifteen feet from the basement. The interior of the basement is visable. This counts as a relatively close cell tower. Get a telescope and climb the tv tower of the channel you want to watch. Look where your basement is with your telescope. You can’t see the basement because there is something like 30 linear miles of dirt in the way. Soil isn’t going to instantly absorb all the signal at it’s point of intercept. The cell tower signal likely passes through some soil, but not anything like the amount of soil the tv signal would have to pass through to be recieved. Radio waves also bounce off structures and clouds acting as a wave guide in some cases and as a disperser in others, so this may also be a factor of why the cell signal is received and not the tv signal. This is also why you get ghost images. The signal gets bounced around and is recieved a bit later than the stronger non deflected part of the signal.