More precisely, each transformer 28 serves to transmit signals from the surface installation 16 to {HEAD ~ the active portion} 14 of {TAIL ~ the corresponding tool} 
of
More precisely , each transformer 28 serves to transmit signals from the surface installation 16 to { HEAD ~ the active portion } 14 of { TAIL ~ the corresponding tool }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL