CHST-FM is a Canadian radio station in London, Ontario. The station uses the on-air brand and format Jack 102.3. CHST broadcasts from the CFPL-TV tower in Southwest London. Due to CHST's low ERP relative to some London area radio stations, its broadcast signal covers only Middlesex, Elgin, and Oxford counties. The station's coverage to the west is impeded by co-channel WGRT in Port Huron, Michigan.