GENERAL AEROSPACE
Boeing 737-300
MAINTENANCE MANUAL
EFFECTIVITY
PW245
34-53-00GA
DRAWING # GA-BC17-ATC-MM
Page 510
Use and disclosure shall be in accordance with the proprietary legend located on the cover of this document
AUG 15/10
(a)
Make sure the test set shows PASS.
(20)
For test set without the TAP 125 option, do the Mode S Diversity Channel Isolation (Mode-S
transponder Only) Test as follows:
(a)
Disconnect the antenna cable at connector D9628P.
(b)
Install the wattmeter between the antenna cable and the connector D9628P.
NOTE
: Make sure the correct element is installed into the sample port of the wattmeter.
(c)
Turn the element to the stop to select the direction of the power toward the antenna.
(d)
Make a note of the maximum power output and the minimum power output measured by the RF
through-line wattmeter during the mode S squitter transmission period.
1)
Make sure the minimum power output is 100 times or 20 db lower than the maximum power
output.
(e)
Disconnect the RF through-line wattmeter.
(f)
Connect the antenna cable to connector D9628P.
(21)
Remove the antenna coupler from the lower ATC antenna and insert it to the top ATC antenna.
NOTE
: Make sure the orientation of antenna coupler setup is correct.
(22)
Do the system test again for the ATC system No 2, and use the No 1 air data source.
NOTE:
Use BOT antenna.
Transponder 2 is mode C, skips Mode S steps for check of Transponder 2.
G.
Put the Airplane Back to its Usual Condition
(1)
Remove the antenna coupler and the test set.
(2)
Close this circuit breaker.
(a)
P6 Circuit Breaker Panel:
1)
AIR/GND and LTS
(3)
Remove electrical power if it is not necessary (Ref 24-22-00/201).