The predecessor to today's IARU HF Championship, this midsummer contest originally ran for a full 48 hours with a 36-hour operating time limit. It also allowed VHF contacts on 6- and 2-meters along with the usual HF bands of 160- through 10-meters. In 1986, the contest period dropped to 24 hours with no off-time requirement, eliminated the VHF bands, and added the IARU HQ multipliers.