212 



BELL SYSTEM TECHNICAL JOURNAL 



of dielectric constant 10 and resistivity 10,000 ohms per cm. cube, and 

 to have a plane reflecting surface inclined to the horizontal at an angle 

 of 5.9 degrees, reception curves for an antenna raised and lowered over 



a -3 



20 30 40 



ANTENNA HEIGHT IN FEET 



Fig. 11 — Local reflection at McCatharn Hill, 

 polarization X = 4.39 meters. 



Horizontal 



it have been calculated and are compared with the experimental results. 

 These measurements, being relative only, have been adjusted to best 

 coincidence by adding the necessary decibels. The resulting fit is 

 fairly good. A quantitative comparison between theory and experi- 

 ment is later given. 



the owner, some trees below the hill were cut down to clear the radiation path. 

 The antenna structure was a 40-foot lattice mast with a boom carrying the antenna 

 itself and extending fifteen feet above the mast top. The transmission line was 

 incandescent lamp cord (a twisted pair of rubber and cotton insulated conductors) 

 and was tied to boom and mast so as not to swing. It had a measured loss (erected 

 and measured at Holmdel) of 0.1 decibel per foot. The boom swung in an arc in a 

 plane perpendicular to the line of transmission. No evidence of a rotation of the 

 plane of polarization was observed. 



