10 



AUSTIN: RESISTANCE OF ANTENNAS 



to the wave length, and he appears to believe that this increased 

 resistance is due to radiation. 



Systematic measurements on the resistance of the Bureau of 

 Standards antenna were begun as soon as Dr. Fischer's article 

 appeared. Observations have also been taken on the antenna 

 of the U. S. S. Dolphin lying at the Washington Navy Yard 

 and on the antenna of the Navy Yard station. 



»-, — )$— — {TotSSFI 1 



J 



Fig. 1. Diagram of apparatus for measuring antenna resistance 



The arrangement of apparatus is shown in Fig. 1. Here A is 

 the antenna, E the ground, L x the tuning inductance, C\ an air 

 condenser for tuning to very short wave lengths, Th a thermoele- 

 ment, 1 G a galvanometer and C 2 a variable air condenser set at 

 the capacity of the antenna to be measured. A small inductance 

 L 2 was sometimes inserted in circuit with the condenser C 2 to 

 represent the antenna inductance. This has little influence on 



1 A zincite rectifier with galvanometer very loosely coupled to the circuit may be 

 used instead of the thermoelement. 



