8 BELL SYSTEM TECHNICAL JOURNAL 



system was made weatherproof, which was accomplished by making the 

 line system pressure-tight and filling it with dry gas. The gas-line system 

 was extended to include the radiating elements by covering the latter with 

 pyrex test tubes sealed to the support with a packing gland as shown in 

 Fig. 4. A device was included in each dipole assembly for supplying the 

 two half-wavelength radiating elements with balanced voltages from the 

 unbalanced line, while a coaxile line harness including impedance matching 



m 



Fig. 4— CX.\S— Dipoles 



transformers was used to connect the several dipole assemblies and provide 

 a matched load to the single transmitter-receiver line. A schematic dia- 

 gram of this arrangement is shown in Fig. 5. The contemplated use of 

 this radar was for surface targets or low-flying planes and rotation was 

 provided only in azimuth. A gas-tight rotary joint was developed to carry 

 the I" coaxial line through the azimuth axis (Fig. 6). 



The operator's cathode ray oscillograph indicator and all of the essential 



