AUSTIN: RESISTANCE OF ANTENNAS 



11 



the results and at least for the longer wave lengths may be per- 

 fectly well omitted. Si and *S 2 are switches for connecting either 

 the antenna and ground or C 2 to the rest of the circuit. R is a 

 resistance introduced in the circuit C 2 to bring down the thermo- 

 element deflection to the same value as that observed when the 

 antenna and ground are in circuit. The high frequency resist- 

 ance consists of separate units of fine constantan wire inserted in 

 mercury cups. The measurement circuit is excited by a buzzer- 

 driven wave meter W of the ordinary type. 



Fig. 2 shows the curves obtained on the Dolphin, at the Wash- 



800 



7600 



2400 



3200 



4000 



Fig. 2. Diagram showing resistance curves 



ington Navy Yard and at the Bureau of Standards. It is seen 

 that beginning with the short wave lengths, the resistance falls 

 rapidly in accordance with the Herzian radiation theory until a 

 point is reached which is not far from twice the fundamental 

 wave length of the antennas. 



