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11. Set the scope delay to approximately 119.5usec and adjust as necessary to observe the last
pulse of the TX pulse train. Check the pulse Width. It should be 520nsec +/- 10nsec.
Make minor adjustments to R4 then R30 if necessary. Verify that the pulse Rise and Fall
times are within the specifications listed above. If not, make minor adjustments to the TX
board tuning caps as necessary.
12. Check the TX Pulse Spectrum on the spectrum analyzer. With a Span of 1GHz, verify there
are no spurs on either side of the 1090Mhz TX pulse.
13. Measure the close-in TX Pulse Spectrum with the analyzer Span set to 50MHz and the RES
BW set to 300Khz. The spectrum observed should meet the TX Pulse Spectrum requirements
shown below on both the lower and upper side frequencies down from the 1090Mhz peak:
MHz difference from 1090mHz
>1.3 to <7 Mhz
>7 to <23 Mhz
Increase span to 200Mhz. Set RES BW to 3Mhz.
>23 to <78 Mhz
Increase span to 500Mhz.
>78Mhz
14. Make slight adjustments if necessary to C26, C27, and C44 on the TX Final board to bring the
side lobes within specifications.
15. Set the IFR back to ATCRBS.
16. Set the Spectrum analyzer Span to 1Ghz and the RES BW back to 3Mhz.
17. Repeat all TX Pulse Spectrum tests as listed above on both sides of the 1090Mhz peak. Verify
the spectrum measurements are within specifications. Make minor TX tuning
adjustments only if necessary. Note: When testing spectrums >78Mhz in ATCRBS
reduce the RES BW to 1Mhz.
18. Repeat the pulse Width measurements on the first and last TX pulse. The pulse Width should
now be 450 +/- 100 ns. If not, make minor adjustments to R4 and R30 on the Driver board.
Check the pulse Rise and Fall times for the first and last TX pulse. Verify they are within
specifications (Ref step 6). Make only miner adjustments as necessary.
Honeywell International Inc.
KXP2290 Diversity Mode S Transponder
Alignment Procedure
HONEYWELL CONFIDENTIAL
dB down from 1090Mhz peak
3dB or more
20dB or more
40dB or more
60dB or more
001-05117-0010
Revision -
9 of 11
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