On the other hand, it takes 50 kw to cover well a metro today with all the new man-made noise from lighting, wall warts, computers, LEDs and the like. Remember, power vs. coverage is not linear: 10 kw does not cover twice as much as 5 kw... it takes 20 kw to double the coverage.Which is why I say the two Audacy signals in Chicago are so vulnerable.
The only place "double" works in Chicago is with Doublemint gum.