The error signal from summer 82 affects the constant speed drive 66 of {HEAD ~ each channel} in {TAIL ~ an identical manner} 
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The error signal from summer 82 affects the constant speed drive 66 of { HEAD ~ each channel } in { TAIL ~ an identical manner }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL