first detector means electrically coupled to said first coil means for amplitude detecting {HEAD ~ changes} in {TAIL ~ RF signals} generated across a left sensor segment of said first coil means, and for generating a left output pulse 
first detector means electrically coupled to said first coil means for amplitude detecting { HEAD ~ changes } in { TAIL ~ RF signals } generated across a left sensor segment of said first coil means , and for generating a left output pulse
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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH