Transmission loss at high frequencies on 3260 km temperate-latitude path

Measurements of the pulse modal patterns and received-signal strengths were made at frequencies of 9.9, 17.5 and 23.0 MHz over a 3260 km path from Akrotiri, Cyprus to Slough, England for 12 months during 1968¿69 at sunspot maximum. The principal modes of propagation involved one and two reflections from the F2 layer. The oblique-path ionospheric absorptions are estimated from the signal-strength data by allowing for all other transmission-loss factors. The absorptions so deduced are compared with those given by various published formulas.