46 



THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1956 



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10 



TE,° IN 3" DIAM GALVANIZED IRON GUIDE (250 FT LONG) 



Fig. 9 ■ — Multiple reflections from a dominant (TEn) mode waveguide with a 

 rough inside surface. The two trace photos are for polarizations differing by 90 I 

 degrees. 



joints are shown here. In addition, a study was being made of the re- 

 turn loss of the transition piece at the throat of the antenna which • 

 connected the 3" waveguide to the square section of the horn. The I 

 waveguide sections are about 10 feet long. The overloaded pulse at the 

 left on the traces is the leakage through the directional coupler. The 



Fig. 10 — Rough inside surface of a galvanized iron waveguide which produced 

 the reflections shown on Fig. 9. 



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