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