Harris DX 25U, Техническое руководство

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5.5.2
Controller A38
Once a new Controller is installed the low voltage circuit break-
ers CB1 and CB2 can be turned on. Check to see that regulator
fault indicator DS1 is not illuminated. A dc voltmeter can be used
to ensure that the regulators are operational. Check the following
test points for the indicated voltage.
TP2 ....... +5VDC
TP3 ....... +15VDC
TP7 ....... -15VDC
NOTE
Do not install battery backup BT1 through BT3 until the Control-
ler has been installed and power has been applied for at least 1
minute. This will allow time for C44, backup supply capacitor, to
fully charge.
Once the regulator voltages have been measured, ensure that the
PA turn off switch S2 is in the ON position (down). The trans-
mitter can now be turned ON by depressing the LOW, MEDIUM
OR HIGH button. The power output on all three power levels
will be zero. Reset the transmitter output to the desired power by
pressing the RAISE button. Refer to the Operation Section of the
manual for further information.
5.5.3
Binary Combiner/Motherboard, Main Com-
biner/Motherboards (A5-A8).
The Binary Combiner/Motherboard contains jumpers J30
through J33 to select the proper amplitude of Binary Steps B-7
through B-10. Set these jumpers to the same configuration as the
board to be replaced or refer to the Factory Test Data sheet. Also,
ensure that JP1-JP8 and J30-J33 are configured properly for the
board to be replaced. Check and set the taps on efficiency coils
L1 through L16 on every motherboard to be replaced.
5.5.3.1 Combiner Motherboard Removal
WARNING
ENSURE ALL PRIMARY AC VOLTAGE HAS BEEN REMOVED
FROM TRANSMITTER AND A GROUNDING STICK IS USED TO
GROUND ALL POINTS WHERE AC OR RF POWER HAS BEEN
APPLIED BEFORE PROCEEDING WITH THE FOLLOWING PRO-
CEDURE.
All combiner motherboards are of similar construction and there-
fore will require the same basic procedure.
a. Remove all 16 RF amplifiers from the front.
b. Disconnect all wiring and cables from the motherboard
being replaced.
c. Remove only as much of the combiner cover as necessary.
CAUTION
LOCATE AND REMOVE ANY HARDWARE THAT IS DROPPED. IF
LOST HARDWARE IS REPLACED, MAKE SURE NONE OF IT HAS
LODGED ON ANY RF AMPLIFIER MODULE.
d. Depending on which board is being removed do one of the
following two steps.
1. On the Main and Binary motherboards, remove the two
end screws from the combiner secondary rod.
2. On the Driver/Combiner motherboard, the secondary
rod will have to be removed through the top of the
transmitter. If top removal is not possible because of an
overhead clearance problem, remove the RF Drive
Splitter and lower the rod down to where it will rest on
T1. Continue with the rest of the motherboard removal.
Tilt the motherboard back and continue to slide the rod
down and forward across the top of T1.
e. Remove the motherboard fastening hardware beginning
with the two 4-40 screws in the front center card guide
support. The 4-40 screws to be removed can be identified
by the six inch (15cm) aluminum rods attached to the card
guide support bar.
f. Carefully remove the motherboard from the rear of the
transmitter.
5.5.3.2
Combiner Motherboard Installation
Replacement of the Main Combiner/Motherboards is essentially
the reverse of the removal procedure.
a. During installation of a motherboard, it may not appear to
fit in as easily as it came out. This is due to the blue card
guides not fitting back in their slots at the same time.
1. Install the board, using only a few of the screws to
mount the board to the supports.
2. From the front of the RF Amp Compartment, place the
card guides into their respective slots.
b. Once the motherboard has been fully mounted, insert the
allen screws that bolt the Combiner rods together but do
not fully tighten.
c. Loosen the two set screws in the fiberglass supports on the
motherboard that hold the rod in place. Now tighten the
Allen screws on the copper rod to 150 inch/lbs.
d. Re-tighten the set screws on the motherboard. Replace the
Combiner cover, RF amplifiers, and the interconnection
plugs.
NOTE
Replace all combiner cover screws. The majority of combiner RF
ground current flows through the combiner covers.
5.5.4
Driver Combiner/Motherboard A14
The Driver Combiner/Motherboard has no adjustments. There
are taps on efficiency coils L2-L15 that need to be placed in their
proper frequency determined location. Set these coil taps to the
same configuration as the board to be replaced or refer to the
Factory Test Data sheet.
5.6
Printed Circuit Boards Which Re-
quire Adjustments
The remaining boards in the transmitter have adjustments which
must be checked and possibly preset before applying high volt-
age. Some controls may need further adjustment after applying
high voltage. The following paragraphs describe these boards
and adjustments.
Section V - Maintenance
Rev. Z1: 06-02-00 Additional info to ECN 46105 888-2297-002 5-5
WARNING: Disconnect primary power prior to servicing.