Original vintage advertising media trade magazine ad for WGN,  a Clear Channel Radio Station of Chicago, IL.   Service.  WGN has More Facts About Chicago Radio Programs than Any Other Station.    Combined information of the Nielsen Radio Index, Supplementary and Regular Hopper reports and the Broadcast Measurement Bureau enable WGN to offer a superior and continuing service to present and potential advertisers.   Old 1947 magazine advertising industry advertisement, would display beautifully matted and framed. Signed by FH.