Each fall, I send and copy many thousands of CQ zone numbers in my participation in the fall CQ World Wide DX Contests. The 40 CQ zones are also used as multipliers in scoring the CQWW DX Contests. Less major contests using the CQ zones in their exchange include DX stations in the CQ 160 Meter CW and SSB contests, the GACW WWSA CW DX contest, non-Japanese stations in the JIDX SSB and CW contests, the JT DX contest, and the World Wide Iron Ham contest.
In his article, “A Brief History of the CQWW Contest”, Bob Cox, W3EST, traces the origins of a 40-zone DX map to an R/9 magazine award in 1934 (the precursor of today’s CQ Worked), which was later revised in 1936 by magazine to boundaries very similar to today’s CQ Zone map. In the February 1936 magazine article, “DX Zones of the World: A new DX Yardstick,” he finds a note that the zones were drawn with “no consideration to the number of amateurs which may be located within a particular zone, as this is a factor of no permanence.” You can read more about K3EST’s research into the evolution of the 40-zone map at the start of <>.