Simultaneous recording of atmospherics on four different frequency bands in the low-frequency region

Abstract

With a view to studying the variations in the intensity and the number of atmospherics received in the low-frequency region, four narrow band t.r.f. receivers were designed and constructed. The bands are 85 kc/s, 125 kc/s, 175 kc/s and 455 kc/s respectively. The output of the receivers were given to the X-deflecting plates of four identical cathode ray tubes. A moving plate camera with an  2.5 coated lens recorded simultaneously the deflections of all the c.r.t. spots. Records of l min duration were taken at two fixed hours (2000 and 2200 hours) during the night. In all over seventy plates were obtained during the period March–June 1956. The plates were measured to give intensities and number of atmospherics on the four bands. The results were analysed statistically and summarized in tables and presented in the form of histograms and curves. It is found that: 1. (a) atmospherics with relatively large field strengths are less frequent than those with smaller field strengths on each band; 2. (b) the field strength of atmospherics received on 125 kc/s band has maximum values as compared with those on the other bands and in fact is the seat of maximum activity of atmospherics with both large field strengths and number.