638 BELL SYSTEM TECHNICAL JOURNAL 



Such an antenna as used at Netcong, New Jersey, for reception is 

 shown in Fig. 18. 



In the course of time further improvements in directive antennas 

 have been made. One improvement is indicated in Fig. 19 and is 

 known as the "rhombic antenna" ^ because it consists of a wire or 

 wires supported by four poles in the shape of a rhombus elevated some 

 distance above the ground and parallel to the ground. As usually 

 used two contiguous sides of the rhombus form one branch of the 

 antenna and the other two sides form the other branch. At one end 

 is connected the receiver (or transmitter). At the end opposite the 

 connection to the receiver are connected resistances of suitable value. 



Fig. 18 — Bruce receiving antenna at Netcong, New Jersey, used for transoceanic 

 communication. This type of antenna has been superseded by the rhombic type 

 at Netcong. 



This antenna differs radically from the previous ones and most other 

 directive antennas in one respect and that is it does not usually operate 

 with a standing wave thereon. The purpose of the resistors is to 

 absorb all the energy reaching such resistors. This antenna when 

 arranged as in Fig. 19 receives from the right. The energy strikes the 

 wires and is thence transmitted to the receivers. Energy coming 

 from the left-hand side travels away from the receivers and when it 

 strikes the resistors is absorbed. If the resistors are not used and the 

 two terminals are either connected together or kept insulated, energy 

 reaching this end will be reflected, in which case this antenna will 

 operate with a standing wave thereon and will receive or transmit 

 from either the right or the left. Inasmuch as this antenna as 

 preferably used is unidirectional and does not operate with a standing 



