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BELL SYSTEM TECHNICAL JOURNAL 



3.17 meters above ground, generator antenna horizontal and 2.55 

 meters above ground, horizontal separation between ring plane and 

 transmitting antenna 7.2 meters. The results were: 



Ring Shaped 250 cm. Rod with Gap 



GAP ANGLE 



Curve IV 



These values are plotted in Curve IV and do not check Macdonald's 

 conclusion earlier referred to. In fact the first part of the curve is 

 most simply explained by viewing the rod as a resonant inductance 

 whose tuning capacity is decreased as the rod gap opens. The 

 existence of a minimum resonant wave length is less easy to explain 

 in this manner. 



It was early observed that the current amplitude and sharpness of 

 resonance of a rectilinear rod were greatly increased by the proximity 

 of a second rod. Curves were therefore run with two parallel rods 

 arranged both in horizontal and vertical planes, the spacing being 

 changed while current magnitude and resonance wave length were 

 observed. In each case the rods were symmetrically mounted about 

 a central point held at the height of the generator antenna above 

 ground (2.55 meters) and the short knife edge support, mentioned in 

 connection with the rings, was used. All the antennas were horizontal 

 and as accurately parallel as it was possible to set them. Fig. 4 

 shows one mounting and Curve V the current versus spacing relation, 

 while Curve VI gives the resonance wave length versus spacing. 



