Thanks for the further info, Oak...that's very interesting. As for the combining of towers, it depends a lot on the service provided, but more so it depends on politics.
There are considerations regarding wind loads, maximum physical load, etc., etc. that all have to be dealt with. Then there's technical issues like co-channel interference, intermodulation, receive antenna desensing, maximum legal RF emission levels....There's some combined TV towers going up now due to HDTV...but they are massive sumbitches that cost a huge amount of money.
Then you get into politics...whose antennas get to go on top (better gain)? Who's responsible for tower maintenance, or how does the charge get divided up? If there's a problem, whose fault is it? All kinds of arbitration issues to straighten out. All of that, of course, can be worked out, but it would be a can of worms to force something like that in the thousands of tower locations across the US. I doubt you'd find many politicians that'd touch it with a 10-foot pole.
In our case, the current tower has been in place since the 60's...the station has been there for 50 years. We own our property, and the station & tower were built when there was nothing around it but corn fields. So the first thing, I'm sure, out of the owner's mouth would be "why should WE move?"
Mooooving back to the windmills... <BLOCKQUOTE>quote:</font><HR>But the wind-farm industry report puts the bird deaths into perspective, contending more birds get killed every year in collisions with vehicles (60 million) and window panes (98 million) than windmills.<HR></BLOCKQUOTE>I think that says a lot.