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The question of the dependence of sporadic E on the sunspot cycle has largely been unresolved, with many investigators obtaining conflicting answers.In this report results are given covering daily-hourly values of fEs for eleven years at three ionosphere sounding stations. College, Washington, and Huancayo, chosen as representative of the three main sporadic-£ zones. These stations experienced a minimum of equipment changes and changes of location during this period. Scaling procedures were monitored over the eleven years by a data quality-control group at the National Bureau of Standards. The period included the highest average sunspot number for over 200 years.Correlation coefficients for yearly count of fEs > 5 Mc vs. yearly average sunspot number were found to be: College, -0.68 (daytime only, -0.63); Washington, -0.52 (night only, -0.52); Huancayo, -0.42 (night only, -0.66).Various hourly and monthly correlations were obtained.Of the 153 correlation coefficients listed in the paper, 147 are negative.Certain correlations of fEs with magnetic index Ap are presented. The remarkably consistent results obtained by use of the Phillips formula logioP = a + bf, are given.(P=probability of occurrence of fEs> T; f=frequency(Mc); a, b are adjustable constants).An incidental outcome is the confirming of diurnal and seasonal trends at stations in the auroral, north temperate,and equatorial zones, making use of many more data than hitherto available.

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