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