Ionospheric propagation in VHF television band 1

In order to study the effect of sporadic-E interference on VHF television broadcasting, the European Broadcasting Union conducted an extensive series of measurements, which were continued for 11 years in order to cover a complete sunspot cycle. Measurements were made over 26 paths whose lengths varied between 900 and 2500 km, using frequencies between 40 and 60 MHz. The measurements, their analysis, and the results obtained are described. The final results were used to construct propagation curves for Europe and to derive a field-strength prediction method which may be used for the planning of future V.H.F. broadcasting services.