Modern Electrics, April, 1909, page 17:

NIGHT  AIR  FULL  OF  WIRELESS

    A. L. Deitz, a young electrical engineer, says the air above Manhattan at night is filled with wireless messages. Mr. Deitz's apparatus is on top of the apartment building, No. 100 West Eighty-sixth street, in which he lives.
    "I pick up messages from all sorts of places," he says. "There must be hundreds of experimental stations in New York, and the messages are going through the air all night long. My apparatus has a radius of seventy-five miles."