Section III
Operators Guide
3.1
Introduction
This section contains information on day-to-day operation for
the non-technical operator.
3.2
Operating Procedures
These procedures describe normal daily operation of the DX-
25U AM TRANSMITTER, including:
a. Daily pre-operational checkout
b. Transmitter turn-on procedure.
c. Transmitter turn-off procedure.
d. Transmitter operations.
It is important that the operator be aware of normal transmitter
operation and performance, and note any changes or fault indi-
cations. Changes in operation may indicate a need for mainte-
nance or corrective action before more serious problems develop.
WARNING
ALL SERVICE SHOULD ONLY BE PERFORMED BY QUALIFIED
PERSONNEL. DANGEROUS VOLTAGES OR CURRENTS MAY BE
PRESENT INSIDE WHEN DOORS ARE OPEN.
Normal operation and monitoring of the transmitter is accom-
plished through front panel controls, meters, and indicator (see
SECTION IIIA: Controls and Indicators).
NOTE
If remote/extended control of the transmitter is used, the station
chief engineer or qualified technical staff member should provide
instructions for operator use.
3.3
Daily Preoperational Checkout
The following paragraphs describe checks to be made before
normal daily turn-on.
a. Check the transmitter maintenance log to make sure that
maintenance performed on the transmitter, or other abnor-
mal conditions, do not place any restrictions on transmitter
operation. An example is a requirement to operate at re-
duced power.
b. Ensure that the transmitter RF output is properly termi-
nated into the antenna. This may include determining that
antenna pattern switching is correct.
c. Check the ColorStat™ panel on the center front of the
transmitter. If the transmitter is ready for operation, all the
status, interlock, and overload LEDs will be green. If any
LEDs are red, note which indicators are red so that infor-
mation may be entered into the station maintenance log,
then press the RESET button. All indicators should change
to green when the RESET button is pushed and released.
If any indicators are still red after operating the RESET, do
not attempt to turn on the transmitter and contact qualified
maintenance personnel.
3.4
Transmitter Turn-On Procedure
When the Preoperational Checkout has been completed and no
problems are present, the transmitter is ready to turn on.
a. Set the selector switch below the POWER meter on the
meter panel to FORWARD, if it is not already in that
position.
b. Depress the LOW, the MEDIUM, or the HIGH button,
depending on power level desired. Each of these buttons
will turn the transmitter on at the power level which has
been preset.
c. The button operated should illuminate green, and power
will come up to the preset level. (You should also hear three
‘clicks’ as contactors operate, then the blowers should
start, then power will come up.)
NOTE
During the Step Start sequence, you should see the power meter
go to 1/2 of the power selected, then reach the desired power
level.
d. Should FORWARD POWER not be correct, verify that
you have selected the correct power level (LOW, ME-
DIUM, or HIGH). If not, press the proper power level
button, and check forward power again.
e. When the correct power level has been selected, but an
adjustment in power is still needed, press the RAISE
button to INCREASE power, or the LOWER button to
DECREASE power. When you press the button and watch
the FORWARD POWER indication, the power will change
slowly. Hold the button in until the power is correct.
NOTE
RAISE and LOWER buttons will only change power level if the
transmitter is operating in the HIGH, MEDIUM, or LOW func-
tion. This new power level will become the preset power until it
is changed again. The Raise and Lower buttons will adjust power
from zero to 30 kW on each selected power level.
f. Check transmitter panel meter readings for normal values.
If an abnormal meter reading is obtained, qualified main-
tenance personnel should be contacted.
3.5
Transmitter Turn-Off Procedure
a. To turn off (de-energize) the transmitter, depress the OFF
button.
b. The HIGH, MEDIUM or LOW lamp will go out, you
should hear the contactor as it de-energizes, and the blow-
ers will stop.
888-2297-002
3-1
WARNING: Disconnect primary power prior to servicing.
