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BELL SYSTEM TECHNICAL JOURNAL 



detection sets with 100 decibels or more gain at the intermediate 

 frequency and the spring operated recording mechanism recorded the 

 set gain as the operator varied it manually, to hold the set output 

 constant. 



At Sea Bright two transmitters were installed in separate rooms on 

 the top floor of the house and the high-frequency power was fed to the 

 antennas by transmission lines. These antennas were center-driven 

 vertical half-wave units mounted on wood beams which were erected 

 in the gables of the house and extended above the roof. The antenna 

 centers were about 8 feet above the roof peak and some 60 feet above 

 mean sea level. Both sets were simple " push-pull " oscillators, the 

 4.6 meter one using two UX852 tubes and generating something like 

 80 watts, the 1.58 meter set using two 149Y tubes and generating 12 

 watts. Meters were arranged so as to maintain a check on the 

 constancy of the antenna currents. Modulating equipment and a 

 3-5 megacycle receiver were provided so that contact with the plane 



Q 40 



ui 20 



y 15 



30 



40 50 60 



MILES FROM 



70 80 



TRANSMITTER 



Fig. 2- 



-Flight toward transmitter. Wave-length — 4.6 meters; Altitude— 8000 feet; 

 September 27, 1933; 11:30 a.m. to 1:00 p.m. 



