The associated circuitry within the transponder does the actual testing and includes an oscillator, {TAIL ~ a transmit frequency circuit}, {HEAD ~ a self test interrogation circuit}, and forward power detectors 
The associated circuitry within the transponder does the actual testing and includes an oscillator , { TAIL ~ a transmit frequency circuit } , { HEAD ~ a self test interrogation circuit } , and forward power detectors
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH