User's Manual

ROCKWELL COLLINS
COMPONENT MAINTENANCE MA NUAL with IPL
TDR-94, PART NO 622-9352
equal in amplitude to that of the peak side lobe. Therefore, the P2 pulse detected
by airplane B will be at least as great in amplitude as the P1/P3 pulses. The
transponder in airplane B will detect this relationship in pulses and discard the
interrogation as invalid, because the P2 pulse is not substantially less than the
P1/P3 pulses. As a further safeguard against replies to late-arriving echoes to
this invalid interrogation, the transponder suppresses replies to all interrogations
for an additional 25 to 45 μs. In addition, the receiver is desensitized for reception
of P1/P3 pulses. The rationale here is that if the side l obes are detectable, then
the main lobe must be much greater.
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May 18/06