1, Operation of monitor amplifier and loud-speaker to obtain 

 a noise check on each channel,, 



2, Adjustment of sensitivity control on automatic switching unit,, 



3o Operation of graphic level recorders to check writing response 

 and time indexing on both manual and automatic motor switch 

 positions, 



4o Operation of each magnetic tape recorder on record, playback, 

 and time indexing, 



5, Operation of break circuit chronometer to check time indexing 

 and operation of code switch, 



6, Check of headphone monitor position in Rack 1 



7, During dual channel operation, monitoring check at each 

 graphic level recorder, using crystal headphones, 



B, Weekly 



1, Over-all gain check on each channel, (Paragraph 17) 



2, Cleaning of slider arm on graphic level recorder potentio- 

 meters with carbon tetrachloride, (Paragraph 54) 



1, Response test of the magnetic tape recorders „ (Paragraphs 

 91 and 92) 



2, Replenishment of oil supply in magnetic tape recorder oil 

 reservoir, 



120, Each test should be logged when performed for subsequent comparison 

 and reference. The performances of the tests should follow the procedure 

 for each component as outlined in the manual. 



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