RADIO BROADCASTING TRANSMITTERS 



135 



distortion in the audio tube. With so powerful an equipment, the 

 suppression of radio-frequency harmonics to a satisfactory degree 

 becomes a difficult problem. The push-pull circuits, capacity coup- 



Fig. 10 — -Panel assembly for Western Electric 5-C (5-k;w.) radio transmitter. 



ling, three tuned circuits in cascade, shielding of all coils, and the 

 two tuned shunts adjusted to the second harmonic which are con- 

 nected between each side of the transmission line and ground all 



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Fig. 11 — Rear view of panels in 5-C radio transmitter. 



contribute to superior performance in this respect. The amplitude of 

 the harmonics radiated, as determined by field strength measure- 

 ments, is less than 0.03 per cent. 



A 5-kw. equipment of similar general design is shown in Figs. 10 



