Each transformer 28, in association with the link 18, thus serves to transmit {HEAD ~ signals} between {TAIL ~ the surface installation} 16 and the tool in question 
between
Each transformer 28 , in association with the link 18 , thus serves to transmit { HEAD ~ signals } between { TAIL ~ the surface installation } 16 and the tool in question
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH