Harris Platinum HT EL 2000HS, Техническое руководство

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Additional filters may be ordered from HARRIS to assist in
maintenance. Harris filter part number is 448-0974-000. This
filter is a standard filter size 14in. x30in. x1in. The filter media
is a coated fiberglass mat.
The power supply filter Harris part number is 943-5285-126.
5.3.2
MOV’S
Periodically visually inspect all MOV’s to ensure proper tran-
sient protection. In addition to regular inspection, check after
thunder storms. Replace any suspect units exhibiting physical
damage.
5.3.3
Semiconductors
Routine checking of semiconductors used in the Transmitter is
not required.
The best check of semiconductor performance is actual operation
in the transmitter. When semiconductors are replaced, check
circuitry operation which may be affected. Replacement semi-
conductors should be of the original type or a recommended
direct replacement. Preventive maintenance of transistors is ac-
complished by performing the following steps:
a. Inspect the semiconductors and surrounding area as accu-
mulations of dirt or dust could form leakage paths. Dirt on
heat sink surfaces can reduce air flow and be a thermal
barrier.
b. Examine all semiconductors for loose connections or cor-
rosion. RF and other power transistors have specific fas-
tener torque requirements that must be followed.
5.3.3.1 Capacitors
Preventive maintenance of capacitors is accomplished as fol-
lows:
a. Examine all capacitor terminals for loose connections or
corrosion.
b. Ensure that component mountings are tight.
c. Examine the body of each capacitor for swelling, discol-
oration, or other evidence of breakdown.
d. Inspect electrolytic capacitors for leakage signs.
e. Use standard practices to repair poor solder connections
with proper soldering tools.
5.3.3.2 Fixed Resistors
Preventive maintenance of fixed resistors is accomplished by the
following steps:
a. When inspecting a chassis, printed-circuit board, or dis-
crete component assembly, examine resistors for dirt or
signs of overheating. Discolored, cracked, or chipped com-
ponents indicate a possible overload.
b. When replacing a resistor ensure the replacement value
corresponds to the component designated by the schematic
diagram.
c. Clean dirty resistors with a small brush.
5.3.3.3
Transformers
Preventative maintenance of transformers is accomplished by
performing the following:
a. Feel each transformer soon after power removal for signs
of overheating.
b. Inspect each transformer for dirt, loose mounting brackets
and rivets, loose terminal connections, and insecure con-
necting lugs. Dust, dirt, or moisture between terminals may
cause flashovers.
c. Tighten loose mounting lugs, terminals, or rivets.
d. Clean with a dry lint-free cloth. Use an approved cleaning
solvent if required.
e. Clean corroded contacts or connections with crocus cloth.
f. Replace defective transformers.
5.3.3.4 Relays
Replace hermetically sealed relays if defective. Check other
relays for:
a. The relay is mounted securely.
b. Connecting leads are not frayed and the insulation is not
damaged.
c. Terminal connections are tight and clean.
d. Moving parts travel freely.
e. Spring tension is correct.
f. Contacts are clean, adjusted properly and make good con-
tact.
g. The coil shows no signs of overheating.
h. Clean any dirty or corroded terminal connection.
5.4
Performance Checks
Performance checks of multiburst response, linearity and ICPM
will indicate if adjustments are needed. Checks of control circuit
operation and metering calibration are recommended annually.
5.5
Adjustments
The following are adjustment and alignment procedures. It is
strongly suggested that each procedure be read completely be-
fore attempting any adjustments. The abbreviation CW is clock-
wise and CCW is counter-clockwise.
5.6
RF Power Measurements
5.6.1
Through-Line Meters
Through-line wattmeters of known accuracy are acceptable for
power measurements. However, once factory calibrated as a set,
the line section, sampling element and meter must be used
together. The metering will be more accurate if the measurement
is in the upper third of the meter scale .
Platinum™ Series
5-2 888-2457-001
WARNING: Disconnect primary power prior to servicing.