User's Manual

Digital UHF Transmitter Chapter 3, Installation and Setup Procedures
DT835A, Rev. 1 3-8
for the system and needs to be checked
and corrected. A center bullet missing
from the 1-5/8" or 3-1/8" rigid coax lines
or loose bolts on the connections can
cause this problem. Return the
Operate/Standby switch to Standby.
Observe the % Exciter Power reading of
the meter on the exciter; it should be the
same as on the Test Data Sheet for the
transmitter, typically 70%. Move the
Operate/Standby switch on the exciter to
Standby.
The gain and phase controls on the front
panels of the individual UHF amplifier
trays were adjusted at the factory to
attain 100% output of the transmitter
and should not need to be readjusted.
The forward meter readings for side A
and side B may not be the same, but
should be the same as the values written
on the Test Data Sheet. Side A and side
B are combined to give the total output,
which is 100% in the combined output
power position.
The readings on each of the individual
UHF amplifier trays may not be the
same. Refer to the Test Data Sheet and
compare the final readings from the
factory with the readings on each of the
trays after the setup. They should be
very similar. If a reading is way off, refer
to the phasing and power adjustment
procedures for the UHF amplifier trays in
Chapter 5, Detailed Alignment
Procedures, of this manual before trying
to make any adjustments.
If a dummy load is connected to the
transmitter, switch the transmitter to
Standby and switch off the main AC
circuit breakers found on the AC
distribution panels in each cabinet.
Remove the dummy load and make all of
the connections needed to connect the
transmitter to the antenna. Switch the
main AC circuit breakers on and the
Operate/Standby switch to Operate.
Adjust the exciter power adjust pot to
attain 100% combined visual output.
If the transmitter is already connected to
the antenna, check that the combined
power output is 100%. If necessary,
adjust the power adjust pot located on
the UHF exciter for 100%.
3.6.1 DM8-R Modulator Setup
Procedures
NOTE: The modulator was setup at the
factory to meet specifications for digital
mask and corrections and should not
need adjusted.