RADAR ANTENNAS 



297 



14.6 Allien lias for Early Fire Control Radars^^ 



The first radars to be produced in quantity for fire coiitrol on naval ves- 

 sels were the Mark 1, Mark 3 and Mark 4 (originally designated FA, FC 

 and FD). These radars were used to obtain the position of the target with 

 sufficient accuracy to permit computation of the firing data required by the 

 guns. The first two (Mark 1 and Mark 3) were used against enemy surface 

 targets while the Mark 4 Radar was a dual purpose system for use against 

 both surface and aircraft targets. These radars were described in detail 

 in an earlier issue. ^'^ However, photographs of the antennas and per- 

 tinent information on the antenna characteristics are repeated herein for 

 the sake of completeness. (See Table B and Figures 48, 49 and 50.) 



Table B 



An antenna quite similar to the Mark 3, 6 ft. x 6 ft. antenna, was also 

 used on Radio Set SCR-296 for the Army. This equipment was similar to 

 the Mark 3 in operating characteristics but was designed mechanically for 

 fixed installations at shore points for the direction of coast artillery gun 

 fire. For these installations the antenna was mounted on an amplidyne 

 controlled turntable located on a high steel tower. The entire antenna and 

 turntable was housed within a cylindrical wooden structure resembling a 

 water tower. Equipments of this type were used as a part of the coastal 

 defense system of the United States, Hawaiian Islands, Aleutian Islands 

 and Panama. 



" Written by W. H. C. Higgins. 



""Early Fire Control Radars for Naval Vessels," W. C. Tinus and W. H. C. Higgins, 

 B. S. T. J. 



