Mike Sheridan said:
I'm not a big fan of directional AM's. They can end up being very complicated and it seems like most of them have coverage holes. That was the problem with a lot of South Florida AM's as the population moved West.
Any number of directionals have been designed to improve coverage. Originally, WOR was set up to cover NY and Philadelphia, and its advertising in the 30's and 40's all pointed that out. Similarly, there are a number of intentional directionals like WBZ and WWL that don't need to be directional, but prefer to push more power over the market.
My favorite is 710 in Buenos Aires. It is licensed at 100 kw, and the site is on the NW outskirts of the metro (17 million). Seeing that the 50 kw non-directionals had terrible signals in the dense central areas of the city, they directionalized to push about 150 kw over downtown, thus making it the only listenable signal in many areas. The directional was not critical, and never needed any adjustment.
If WQAM could find a nice tower site that was close to the Dade/Browad line the could probably serve the market very well. The old site behind the Herald building worked well until the signal was hemmed in by the development of the tall buildings in the area. I remember hearing WQAM as we were moving to Florida. They had a great signal with just 1,000 watts since it was at night.
WQAM died the death of a thousand knives. First, in 1981 the SFBA voted to have Arbitron add Broward to the metro, thus killing a dozen AMs in the process. Then, gradually, Broward grew in population (Can you say "WFTL" boys and girls?). Dade became less and less non-Hispanic white, so the balance for English stations swung some more. Then, over the last 30 years devices like computers, computer controlled devices, CFLs and dimmers have raised the noise level significantly making a 5 kw signal cover usefully what 1 kw covered in the 60's. Finally, the PPM showed most English language talkers to be generating too little cume to create share, and that pretty much was the end...
At the same time, the metro grew. In the 60's I recall Jerry Starr complaining about the growth outside the WFUN pattern when the QAM-FUN battle was going on... and FUN was down at 72nd near the Turnpike. The same thing happened to WQBA, in that same general area. Even WWOK, way out at 137th and 8th next to Rinker shot over the city nicely for a while... until the growth south of Kendall and in the Miami Springs area where even in Dade they missed the population.
And that is without discussing programming, Mr. Rogers, etc.