Harris ZX10, Техническое руководство

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5-22 888-2595-001 12/20/11
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WARNING: Disconnect primary power prior to servicing.
Section 5 Maintenance and Alignments
ZX Series
STEP 5
Locate POWER LIMIT potentiometer for current operating mode on
transmitter controller board. Each mode has its own power set
potentiometer (POWER LIMIT - FM, FMHD, HD).
STEP 6
Dial POWER LIMIT potentiometer for current mode fully clockwise.
Transmitter APC power controls rises to its maximum boost setting and
a FORWARD POWER LOW alarm is reported, indicating transmitter
does not have enough gain to achieve current power set level (i.e. APC
is out of range). Transmitter power does not actually rise due to exciter
limit adjustment performed previously.
STEP 7
Slowly raise or lower FlexStar exciter limit setting to achieve 103%-
105% of desired transmitter power level.
!
CAUTION:
NEVER RAISE THE FLEXSTAR EXCITER LIMIT SETTING MORE THAN 100 UNITS AT
A TIME. FAILURE TO OBSERVE THIS PRECAUTION COULD RESULT IN DAMAGE
TO THE PA MODULE FROM A SUDDEN DRIVE SPIKE AS THE NEW LIMIT SETTING
TAKES EFFECT.
STEP 8
Adjust POWER LIMIT potentiometer for current operating mode
counter-clockwise until power level drops to 100% of desired power
level.
STEP 9
Verify FORWARD POWER LOW alarm LED has extinguished.
STEP 10
Increase FlexStar limit setting an additional 100 units to provide some
system gain margin.
STEP 11
Actuate controller board POWER RAISE and LOWER pushbuttons to
verify it is possible to adjust power over a <10% to 100% range.
STEP 12
Note exciter power level and limit settings for future reference.
STEP 13
Repeat procedure for other operating modes as necessary.
STEP 14
Remove one PA module and adjust APC IDLE potentiometer to return
individual currents of remaining PA modules to pre-fault levels, as
measured with front panel meter PA AMPS position and PA MODULE
CURRENTS pushbuttons.
NOTE:
This adjustment is typically performed at the highest gain channel (only) for fre-
quency-agile N+1 applications.