Field Strengths Recorded on Adjacent FM Channels at 93 MC over Distances from 40 to 150 Miles

Field strengths of KE2XCC (93.1 mc, Alpine, N.J.) and WBZ-FM (92.9 mc, Boston, Mass.) have been recorded for more than a year at two locations (Hauppauge and Riverhead) on Long Island. Statistical analysis of data for the eveninghours reveals a broad seasonal trend toward higher intensities in the summer, with larger over-all variation on the longer transmission paths. Based on analysis of one summer month, refraction effects appeared to vary independently in the two directions. During periods of rapid and violent fading, hourly median field strengths of WBZ-FM varied over a range of 32 db at Riverhead and 25 db at Hauppauge. Furthermore, for the above-mentioned fading conditions, it was observed that on the 150-mile path, the hourly curves of field-strength distribution with time approached a log-normal distribution when the median field was less than 10 db above 1 ¿v per meter, and a Rayleigh distribution when the median field was greater than 15 db above 1 ¿v per meter.