I have recently come across quite a few more arrays very similar to this one in the area. I've never seen them anywhere else. Any ideas why?
I have recently come across quite a few more arrays very similar to this one in the area. I've never seen them anywhere else. Any ideas why?
Because of the nature of how AM is broadcast.
Unlike an FM transmitter, which can be located within the area that it is targeting, AM radio transmitters must be located away from the target area (in this case, Toronto) due to propagation.
As well, mediumwave transmitters are normally mast radiators (the antenna mast itself is the radiating element, instead of merely supporting the element) and are also rather tall (usually a quarter wavelength, which can be pretty high in the lower frequencies)... you can't put a 100 meter-tall antenna on top of a 80 storey high-rise. As well, the surrounding area must be clear in order to not interfere with the radiation pattern.
Also.. since mast radiators can have a pretty high voltage against ground, they need to be well fenced in case some idiot decides to go for a climb.
There are other factors too (Ground wave propigation, mush zone, etc.) that other more learned members of the board can add to my very layman explaination.
That's why you see AM radio antenna farms in Grimsby, Oakville, etc. instead of on the top of First Canadian Place, the CN Tower, etc.