Height trumps power virtually every time.ZenithCKLW wrote: ↑Tue Apr 25, 2023 6:33 pmAre there advantages or disadvantages between height and lower power vs. lower height and higher power?
By having more antenna height, you create a larger area of line of sight, and that is, for the most part, what determines coverage. Free space path attenuation (the resultant decrease in signal strength as an RF signal passes through air) is increased by distance, but is almost negligible at broadcast FM frequencies compared to the shadowing from objects on the ground that prevent line of sight.
Other than the pure ability to SEE your intended reception area from the perspective of an antenna on a tower, one can theoretically examine the height vs. power question very easily by imagining your having an extremely powerful "flashlight" with you on the tower. You could play the beam all over the place, and up to the edge of the curvature of the earth, and you would be able to shine your theoretic infinitely powerful flashlight on anything that your elevation allowed you to look over obstructions and see. Those are the areas your radio signal would be received at. However, turning up the power on your flashlight would not allow you drill through mountains, hills, buildings, or other obstructions and light up new areas. Only height can make that happen.
Back to reality, more power gives you less whip flutter as you are driving around such obstructions, will tend to fill 'dead' areas with reflections from other obstructions (and maybe cause new problems doing so), and gives you better close-in building penetration to table radios, portable radios, and the like. But, the advantage is often not worth the power bill.
The 50kw/500' standard was put into place when the FCC thought and ruled like engineers, and not like today where they instead often choose to serve special interests and political ideals. It is a pretty good balance of height and power.
It would be a blast to own a grandfathered 'flamethrower' like WJMZ with 100kW at 1000', or even closer to home, WOMC, but in reality, you just don't talk much further than the horizon line from your antenna location, and a whole lot of power just raises your power bill and your FCC consultant's income sometimes without any real advantage.