third detector means electrically coupled to said second coil means for amplitude detecting changes in {HEAD ~ RF signals} generated across {TAIL ~ an up sensor segment} of said second coil means, and for generating an up output pulse 
third detector means electrically coupled to said second coil means for amplitude detecting changes in { HEAD ~ RF signals } generated across { TAIL ~ an up sensor segment } of said second coil means , and for generating an up output pulse
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH