Originally Posted by jdcolombo
you will see that WCIA's authorized 1000 kw is far higher than virtually everyone else - for example, WILL-DT is licensed at 30KW; WAND-DT at 350 kw, etc. Only WICD-DT at 950kw comes close to WCIA. So even at half-power WCIA's signal is still stronger than most of the rest of the DT signals in our area. The half-power signal pegs the meter on my DirecTV receivers; when they go to full power, I might have to ditch the signal amp on my antenna that I've used since the beginning of the digital era (I think it was WAND that went on the air first ?).
1000kW may be the highest power in the area, but power is not always the best. I would rather have 2000ft at 350kW. Height will get you much further. So you really need to look at two numbers to get an idea of coverage.
WICD's 950kW should get further out then WCIA's 1000kW. WICD 15 is over 420ft higher up then WCIA's dtv antenna. There may be some differences in ground elevation, particularly between the transmitter sites. But in Illinois, this is not too great.
WILL's 30kW may seem significantly less power then any of the other stations, but they operate on channel 9 dtv. (and are 100ft higher then WCIA) Giving them much further reach for the same amount of power, verses being on a UHF channel. By getting channel 9 DT for WILL-TV they also get a great savings in power bills. Along with being able to go to a solid state transmitter. (are they? Maybe only 3kW need on ground)
If I were operating WICD 15, I might consider going back to ch.15 DTV. Enabling them to go back to their top mounted antenna, another 70ft higher. But more importantly a better antenna pattern without blockage from the tower. Including lower power bills, and better propagation on a lower UHF channel. However, they did have to spend a significant amount on the antenna and transmitter, maybe even transmission line. That alone may not benefit or save that much over the lifetime of the install cost unfortunately.
Another thing to consider regarding WCIA is that they did have to do reinforcement of their tower. Mostly because the tower was designed for a VHF antenna originally, while 15, 17, 20 etc, all were UHF stations to begin with. Thus their towers were designed with significantly stronger tower members and standards of the time. If I remember correctly, old channel 14 out of Jacksonville had a 14 ton antenna, while most UHF stations have about a 7 ton antenna at the top. Huge at the time, and even huge today.
I think your right that, pre-amps may not be necessary when all the stations are at full power. You may have more problems with one if the signals are so strong, the amp will overload, and you will get non-linear distortions that the DTV tuner can't correct for.