Specifications

2. Using the FLEXCODE chart, rotate S7 from 12 to 5 and
rotate S8 from 9 to 8.
3. Now the Step that was RF156 is effectively Step 133.
6.3 Audio/Digital Modulation System By-
passing
6.3.1 Analog Input Bypassing
On the Analog Input board, three types of bypassing are possible
without compromising transmitter protection. They are as fol-
lows:
6.3.1.1 Power Control
If it has been determined that the HIGH, MED, and LOW power
level control is not operating properly, a fourth Bypass Power
Level control can be made operational as follows:
a. Apply an RF Mute with S1 on the Controller and turn the
transmitter on HIGH.
b. Move P4 from the Normal position of 2-3 to the Bypass
position of 2-1.
c. Turn R68 Bypass Power Level fully counterclockwise.
d. Remove the RF Mute and adjust R68 to the desired power
level.
NOTE
R68 can adjust the power level from 10 to 100 kW. If the power
level needs to be changed while in the Bypass mode, it must be
done manually by adjusting R68.
CAUTION
DO NOT SWITCH TO THE MEDIUM OR LOW POWER LEVELS -
THE MODULATION MONITOR SAMPLE WILL BE MUCH HIGHER
AND COULD POSSIBLY DAMAGE SOME EQUIPMENT.
6.3.1.2 Fine Power Control
If it has been determined that the Fine Power Control is not
operating properly, it can be bypassed as follows:
a. Turn off the Main Breaker for the Low Voltage Power
Supplies.
b. Move P6 from the Normal position of 2-3 to the Bypass
position of 2-1.
c. Turn on the transmitter at the desired power level.
NOTE
To make fine adjustments to the power level, use R66 for LOW,
R67 for MED, and R65 for HIGH.
6.3.1.3 Correction
If it has been determined that the Correction signal is causing
transmitter problems, it can be bypassed as follows:
a. Turn off the Main Breaker for the Low Voltage Power
Supplies.
b. Move P5 from the Normal position of 2-1 to the Bypass
position of 2-3.
c. Turn on the transmitter at the desired power level.
NOTE
It may be necessary on adjustments to readjust the power level
with the Raise/Lower control.
6.3.2 Modulation Encoder Bypass
If a Modulation Encoder has generated a Supply Fault that has
turned off the transmitter, it is possible to bypass the encoder and
operate at a lower power level. The amount of power reduction
depends upon the failed encoder.
After using the Troubleshooting Section to determine the loca-
tion of the encoder to bypass:
a. Turn off the Main Breaker for the Low Voltage Power
Supplies.
b. Move the jumper plug on the encoder from the Normal
position J13 and place it in the Bypass position J12.
NOTE
To remove the jumper, grasp the ends while pressing on the out-
side tabs and pull the jumper straight out. To reinstall the
jumper, simply align and press straight in until the tabs click
when properly seated.
c. Turn on the Main Breaker again, and operate the transmit-
ter at the reduced power level.
NOTE
Only one Modulation Encoder may be bypassed at any time.
The following is a list of the maximum power level obtainable at
100 % modulation for the following encoders when bypassed:
a. A25 - 90kW
b. A26 - 52kW
c. A27 - 24kW
d. A28 - 5kW
NOTE
If the A29 Encoder has failed, it is still possible to bypass the
board and run full power with a lower level of modulation to
prevent distortion.
6.3.3 Changing Modulation Encoder ROM’S
If one of the A29,28,or A27 encoders has failed, it is possible to
bypass the board and move it’s ROM determining jumpers to the
A26 encoder. This will make the A26 encoder control the steps
of the bypassed encoder and allow the highest level of carrier
power and modulation.
The maximum powerlevel obtainable at 100 % modulation when
the A29, A28, or A27 Modulation Encoder is bypassed is 52kW.
Use the following procedure:
a. Turn off the Main Breaker for the Low Voltage Power
Supplies.
b. Carefully remove JP1, JP2, JP4, and JP5 from the A26
Modulation Encoder. These dip jumper plugs are labeled
ME13, ME14, ME15, and ME16.
NOTE
Use an IC extraction tool or a small screwdriver to carefully pull
the plug straight out of the socket without bending any of the
leads.
6A-2 888-2339-002
WARNING: Disconnect primary power prior to servicing.