CHHA-1610 Toronto has proposed a novel (for broadcasters) new directional antenna.
The station has been operating at 10,000 watts daytime/1,000 watts nighttime, non-directonal, using a 22.5m Valcom loaded whip antenna in downtown Toronto. Due to unexpectedly good DX conditions (excessive skywave..) CJWI Montreal, on the same frequency, has suffered interference. Industry Canada asked the station to temporarily reduce nighttime power to 250 watts - which addressed the interference but left CHHA unable to reach much of their northwest Toronto audience.
CHHA proposes a directional antenna, with a null protecting CJWI. They'll operate at a power of 6,250 watts day and night, using the directional antenna at all hours with the same pattern. At a traditional AM station, this would be accomplished by erecting two towers.
CHHA proposes to do it with only one tower -- and a "Hot Guy Wire".
The single tower will be roughly 50m high. The guy wire facing due east will be insulated from the tower, at the top, by an insulator similar to that used on high-voltage AC power lines. Another insulator will "break up" the guy wire, electrically, about 25% down from the top of the guy wire. A third insulator, an 8-inch ceramic "egg", will be used at the base of the wire. A 4.1uH inductor will be installed between the bottom of the guy wire and an earth ground.
The "floating" guy wire will serve as a second, reflecting element to the antenna system. It will "deflect" much of the power that would otherwise be radiated towards Montreal, and direct it instead to the north and south. (right into the Toronto neighborhood the station wishes to reach)