Out of curiosity, where is this information coming from? The fact that it is all quoted seems to indicate it is pulled from some other source, and much of it is wrong.
- Degradation due to length is pretty negligible. You certainly don't want a big spool of cable at one end of a run, but if a couple extra feet is going to make the difference in reception, scrap the whole run and install a Silcondust HDhomerun right next to the antenna. Ethernet is effectively lossless for the distances you're going to see in a home installation.
- You should use the correct type of cable, and CAT-5 is not. Short runs will use twin-lead 300-ohm wire. Longer runs will use 75-ohm coaxial RG-6.
- Television tuners operate by extracting a 6MHz chunk of spectrum from the 100MHz-1000MHz frequency band. If they couldn't filter out a 60Hz signal, then they wouldn't be doing a very good job. The AC issues exist for baseband signals, things like speaker cable or s-video. If nearby AC power is causing sufficiently high line levels that it is causing problems, either the cable shielding is damaged, or you have a bad crimp.
- New antennas are not designed for the new digital signals. A signal is a signal is a signal, and they're all analog until they hit the demodulator. Digital TV uses the same exact frequency bands as old analog broadcasts. Any antenna claiming otherwise is false advertising to the gullible.
- The information is from my experience installing hundreds of home theater systems.
- The "quotes" are due to my inexperience formatting text in wiki. The content is 100% original. Please feel free to improve the look of the page.
- The difference in signal strength between 100' of cable and 50' cable will almost always effect the number of stations your tuner can pick up. I don't consider that negligible.
- RG-6 coaxial cable is the best choice. The reference to CAT was a typo and has been corrected. Flat, twin lead wire will work but my experience has been that it is not the best option.
- RE: electrical wires. I agree the potential problem is greater with speaker cable and s-video wiring. I mention it only because I prefer to avoid problems, especially when it is so easy to accomplish.
- Poor choice of words on my part describing antennas. I was using language I hoped would be easily understood by beginners untrained in electrical engineering. It is correct that the signal received by the antenna is not digital. In fact, I am personally using an antenna that is about 20 years old, predating the digital TV systems. I have found the newer antennas can do a better job of receiving the analog signals transmitted by the broadcast towers.
Please feel free to make any changes, corrections or additions to the post. I submitted the post because there was, previously, no information in this wiki at all regarding RF amplifiers. The primary message I mean to convey is that they are useful when needed but often unnecessary.