Conversely, each transformer 28 also serves to transmit {HEAD ~ signals} from the corresponding tool 12 1 to 12 4 to {TAIL ~ the surface installation} 16 
Conversely , each transformer 28 also serves to transmit { HEAD ~ signals } from the corresponding tool 12 1 to 12 4 to { TAIL ~ the surface installation } 16
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH