a. Single phase ON, three phase ON, CB1 and CB2 ON, PA
Off switch S2 OFF.
b. Depress the LOW power button and hold a piece of paper
against one of the air filters at the rear of the Output
Network Cabinet. Correct fan rotation will pull air in and
hold the paper in place.
c. If there is incorrect air flow, the transmitter may turn off
again after 20 seconds, and the AIR INTERLOCK indica-
tor on the ColorStat™ panel will indicate RED.
d. Depress the OFF button.
e. Remove the left upper air filter on the back of the Output
Network Cabinet and observe the rotation of the coasting
fans. (The fans are located at the left side of the Output
Network Compartment as viewed from the back of the
transmitter). All four fans should be rotating CCW (coun-
terclockwise).
f. If the rotation is correct, reinstall the air filter.
g. IF ROTATION IS NOT CORRECT:
WARNING
DISCONNECT SINGLE PHASE AND 3 PHASE PRIMARY POWER
AT THE MAIN DISCONNECT BEFORE REMOVING ANY REAR
PANEL.
1. Remove the left rear access panel from the Output
Network Compartment.
2. Disconnect and interchange ANY TWO of the three
wires 1, 2 or 3 connecting the fans to 2TB1. (Inter-
changing any two of three wires to a three phase motor
will reverse its direction of rotation).
3. Reinstall the access panel on the Output Network Com-
partment. Reapply single phase and three phase primary
AC power to the transmitter.
h. Ensure that all rear panels are in place. Turn the transmitter
ON by depressing the LOW power button.
i. When the transmitter is turned ON, the AIR interlock LED
on the ColorStat™ panel will extinguish. It will then come
back on after 20 seconds, as follows:
1. GREEN: Air pressure is okay.
2. AMBER: Air pressure reduced.
3. RED: Air pressure FAULT. The fault will also turn the
transmitter OFF.
An Air Pressure Fault indicates insufficient air. Likely causes
include a back panel not installed or fastened at all points,
incorrect blower tap connections on the primary of T1 or incor-
rectly adjusted circuit on the Driver Encoder/Temp Sense Board.
Correct taps for blower wires 123, 124 and 125 are listed on Table
2-2. The adjustment procedure for the airflow switch is in SEC-
TION V, Maintenance.
2.15.5
Driver Operation Check
If a stereo generator, frequency synthesizer, or other external RF
source equipment is used, it must already be installed and opera-
tional.
a. Remove the clip lead between TP8 and GND on the LED
Board if used in checking out the PA Power Supply.
b. The PA OFF switch S2 on the Controller should be OFF
(up).
c. Apply single phase and three phase primary power at the
main disconnect.
d. Low voltage circuit breakers CB1 and CB2 in the trans-
mitter should be ON.
e. Depress the LOW power button.
f. Rotate the front panel Multimeter switch to the RELA-
TIVE RF DRIVE position and compare the reading with
the Factory Test Data.
g. Using the RF MULTIMETER on the inside of the Driver
Compartment door, compare all readings with the Factory
Test Data. Voltage readings D8A and D8B may differ from
Factory Test Data, depending on the AC line voltage. If the
D8A reading is low, check to see if the AUTO circuit on
the Driver Encoder/Temp Sense Board has turned on
Driver Module D7. This will be indicated by the AUTO
LED on the Driver Encoder/Temp Sense Board in the
Driver Compartment. This is a normal function of this
circuit and does not affect transmitter operation adversely.
If the Underdrive or Overdrive circuits on the transmitter
do not turn the transmitter OFF, the drive level is correct.
NO TUNING OF THE DRIVER STAGE SHOULD BE
NECESSARY.
2.15.6
Raise/Lower Function Check
The normal time interval for running the power level from zero
to 30 kW is approximately 25 seconds. With the +230 VDC PA
Power Supply energized, lower the power level to zero on all 3
positions, LOW, MED, and HIGH, by holding the LOWER push
button for 10 seconds in each position, while simultaneously
depressing S1 on the Controller. Switch S1 speeds up the
RAISE/LOWER command by more than 5:1. After all three
positions have been LOWERED, turn the transmitter OFF by
pressing the OFF button.
2.15.7
Power Amplifier stage Turn On Check
If a 50 Ohm resistive dummy load is used for initial check of the
Power Amplifier stage, only minimum adjustment of the TUN-
ING and LOADING controls will be necessary. When the trans-
mitter is then connected to the antenna or if the antenna is used
for the initial Power Amplifier stage check, additional adjust-
ments to the DETECTOR NULL (ANTENNA) circuitry may be
required.
WARNING
DISCONNECT SINGLE PHASE AND THREE PHASE PRIMARY
POWER AT THE MAIN DISCONNECT BEFORE REMOVING ANY
REAR PANEL.
a. Remove the rear access panels from the RF Amp Compart-
ment and replace fuse F20 on T1 and all fuses removed
from the A24 and A25 Fuse Boards.
Section II - Installation
Rev. AA: 8/9/2000
888-2297-002
2-9
WARNING: Disconnect primary power prior to servicing.
