{HEAD ~ The positions} of the tracers is determined by {TAIL ~ differential transformers} having cores fixed for radial movement with respective tracers 
{ HEAD ~ The positions } of the tracers is determined by { TAIL ~ differential transformers } having cores fixed for radial movement with respective tracers
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH