"Arrangements have just been made by the Tropical Radio Company for the purchase of land and the erection of a powerful radiotelegraph station at Hialeah, near Miami, Florida. Within about 18 months, Mr. G. M. Davis, of the radio company promises the public the use of one of the largest radio stations in this country, the estimated cost of which is approximately $200,000. Later on Hialeah will also be equipped with radiophone apparatus."
On a 90-acre lot in Hialeah they constructed a set of 437-foot towers broadcasting with a GE transmitter outfitted with shiny new Langmuir 200 kW tubes. More here. The station was licensed by the U.S. Navy since this predates even the establishment of the FRC let alone the FCC. It operated at 3 Kilowatts on 488 kHz under the call sign WAX-AM. When Wireless Age magazine covered the news, they made a big deal that they were broadcasting not just Morse code, but voice.
It's intended listeners were in the Caribbean and Central America, notably Radiophone to the United Fruit stations which would relay the signals.This is no shocker since United Fruit owned The Tropical Radio Company. Starting in 1908 they built stations in Nicaragua, Honduras, Guatemala, Panama, Costa Rica, Columbia, Mexico and all the way north north to Louisiana as early as 1914. their motto was "The Voice of the Americas." They were an enormous conglomerate with strong government ties, even selling their station in Mexico to the US Navy. It's no surprise though. There's a strategic Military advantage to communications. With favorable contracts the Navy steered them, Westinghouse, General Electric, American Telegraph, and RCA into greater and greater network expansion to compete with the Marconi network. In 1919 they even held a summit with the Navy patting themselves on the back for their "unassailable" radio dominance. The Foreign relations of the United States Volume IV wrote:
"These essential facilities, in friendly American hands, constitute a strategic interest in time of war which, if lost the United States through withdrawal of this American enterprise, could not be counted on with the same security as in the direct control of American citizens... Increased nationalization of U.S. proper- ties would not only deprive the United States and U.S. nationals of a degree of control of strategic resources, but would be contrary to the policy declared in NSC 144,2 of encouraging Latin American countries to take measures to attract private investment."
That's a direct quote. It was never directly assailed by the Marconi Co., but it crumbled anyway. A large radio network is an expensive thing to maintain against the vagaries of the elements, technological progress, malfeasance, changes in business and political upheaval. Popular Science magazine in 1928 notes the station took some damage and lost 2 aerials in a hurricane but continued to operate and maintain contact with WBF in Boston. Similarly their station in Managua survived an earthquake in 1931 to report on news of the devastation. In 1945 the rise of synthetic rubber chased Ford out of Brazil reducing their customer base. In the 1950s union troubles in Panama and Guatemala with the samfistas— members of the SAMF (Sindicato de Acción y Mejoramiento de los Ferrocarrileros) In the 1950s Latin American nations began nationalizing United Fruit Company properties to the tune of about 5 billion dollars of value.
but way up north, inside the US, a 1965 radio listing placed WAX in Ojus, FL an unincorporated area near Hialeah, possibly indicating some zoning changes but the station still operating. But by then they were just doing relays for hams. They still appeared in amateur directories as late as 1979. There is still a Ham radio club in town but that's all that's left I think.